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// SPDX-License-Identifier: GPL-2.0-or-later
/* Validate the trust chain of a PKCS#7 message.
 *
 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#define pr_fmt(fmt) "PKCS7: "fmt
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/asn1.h>
#include <linux/key.h>
#include <keys/asymmetric-type.h>
#include <crypto/public_key.h>
#include "pkcs7_parser.h"

/*
 * Check the trust on one PKCS#7 SignedInfo block.
 */
static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
                                    struct pkcs7_signed_info *sinfo,
                                    struct key *trust_keyring)
{
        struct public_key_signature *sig = sinfo->sig;
        struct x509_certificate *x509, *last = NULL, *p;
        struct key *key;
        int ret;

        kenter(",%u,", sinfo->index);

        if (sinfo->unsupported_crypto) {
                kleave(" = -ENOPKG [cached]");
                return -ENOPKG;
        }

        for (x509 = sinfo->signer; x509; x509 = x509->signer) {
                if (x509->seen) {
                        if (x509->verified)
                                goto verified;
                        kleave(" = -ENOKEY [cached]");
                        return -ENOKEY;
                }
                x509->seen = true;

                /* Look to see if this certificate is present in the trusted
                 * keys.
                 */
                key = find_asymmetric_key(trust_keyring,
                                          x509->id, x509->skid, NULL, false);
                if (!IS_ERR(key)) {
                        /* One of the X.509 certificates in the PKCS#7 message
                         * is apparently the same as one we already trust.
                         * Verify that the trusted variant can also validate
                         * the signature on the descendant.
                         */
                        pr_devel("sinfo %u: Cert %u as key %x\n",
                                 sinfo->index, x509->index, key_serial(key));
                        goto matched;
                }
                if (key == ERR_PTR(-ENOMEM))
                        return -ENOMEM;

                 /* Self-signed certificates form roots of their own, and if we
                  * don't know them, then we can't accept them.
                  */
                if (x509->signer == x509) {
                        kleave(" = -ENOKEY [unknown self-signed]");
                        return -ENOKEY;
                }

                might_sleep();
                last = x509;
                sig = last->sig;
        }

        /* No match - see if the root certificate has a signer amongst the
         * trusted keys.
         */
        if (last && (last->sig->auth_ids[0] || last->sig->auth_ids[1])) {
                key = find_asymmetric_key(trust_keyring,
                                          last->sig->auth_ids[0],
                                          last->sig->auth_ids[1],
                                          NULL, false);
                if (!IS_ERR(key)) {
                        x509 = last;
                        pr_devel("sinfo %u: Root cert %u signer is key %x\n",
                                 sinfo->index, x509->index, key_serial(key));
                        goto matched;
                }
                if (PTR_ERR(key) != -ENOKEY)
                        return PTR_ERR(key);
        }

        /* As a last resort, see if we have a trusted public key that matches
         * the signed info directly.
         */
        key = find_asymmetric_key(trust_keyring,
                                  sinfo->sig->auth_ids[0], NULL, NULL, false);
        if (!IS_ERR(key)) {
                pr_devel("sinfo %u: Direct signer is key %x\n",
                         sinfo->index, key_serial(key));
                x509 = NULL;
                sig = sinfo->sig;
                goto matched;
        }
        if (PTR_ERR(key) != -ENOKEY)
                return PTR_ERR(key);

        kleave(" = -ENOKEY [no backref]");
        return -ENOKEY;

matched:
        ret = verify_signature(key, sig);
        key_put(key);
        if (ret < 0) {
                if (ret == -ENOMEM)
                        return ret;
                kleave(" = -EKEYREJECTED [verify %d]", ret);
                return -EKEYREJECTED;
        }

verified:
        if (x509) {
                x509->verified = true;
                for (p = sinfo->signer; p != x509; p = p->signer)
                        p->verified = true;
        }
        kleave(" = 0");
        return 0;
}

/**
 * pkcs7_validate_trust - Validate PKCS#7 trust chain
 * @pkcs7: The PKCS#7 certificate to validate
 * @trust_keyring: Signing certificates to use as starting points
 *
 * Validate that the certificate chain inside the PKCS#7 message intersects
 * keys we already know and trust.
 *
 * Returns, in order of descending priority:
 *
 *  (*) -EKEYREJECTED if a signature failed to match for which we have a valid
 *        key, or:
 *
 *  (*) 0 if at least one signature chain intersects with the keys in the trust
 *        keyring, or:
 *
 *  (*) -ENOPKG if a suitable crypto module couldn't be found for a check on a
 *        chain.
 *
 *  (*) -ENOKEY if we couldn't find a match for any of the signature chains in
 *        the message.
 *
 * May also return -ENOMEM.
 */
int pkcs7_validate_trust(struct pkcs7_message *pkcs7,
                         struct key *trust_keyring)
{
        struct pkcs7_signed_info *sinfo;
        struct x509_certificate *p;
        int cached_ret = -ENOKEY;
        int ret;

        for (p = pkcs7->certs; p; p = p->next)
                p->seen = false;

        for (sinfo = pkcs7->signed_infos; sinfo; sinfo = sinfo->next) {
                ret = pkcs7_validate_trust_one(pkcs7, sinfo, trust_keyring);
                switch (ret) {
                case -ENOKEY:
                        continue;
                case -ENOPKG:
                        if (cached_ret == -ENOKEY)
                                cached_ret = -ENOPKG;
                        continue;
                case 0:
                        cached_ret = 0;
                        continue;
                default:
                        return ret;
                }
        }

        return cached_ret;
}
EXPORT_SYMBOL_GPL(pkcs7_validate_trust);




























































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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kvm_host.h>
#include <linux/debugfs.h>
#include "lapic.h"
#include "mmu.h"
#include "mmu/mmu_internal.h"

static int vcpu_get_timer_advance_ns(void *data, u64 *val)
{
        struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
        *val = vcpu->arch.apic->lapic_timer.timer_advance_ns;
        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");

static int vcpu_get_guest_mode(void *data, u64 *val)
{
        struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
        *val = vcpu->stat.guest_mode;
        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vcpu_guest_mode_fops, vcpu_get_guest_mode, NULL, "%lld\n");

static int vcpu_get_tsc_offset(void *data, u64 *val)
{
        struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
        *val = vcpu->arch.tsc_offset;
        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL, "%lld\n");

static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
{
        struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
        *val = vcpu->arch.tsc_scaling_ratio;
        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio, NULL, "%llu\n");

static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
{
        *val = kvm_caps.tsc_scaling_ratio_frac_bits;
        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");

void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
{
        debugfs_create_file("guest_mode", 0444, debugfs_dentry, vcpu,
                            &vcpu_guest_mode_fops);
        debugfs_create_file("tsc-offset", 0444, debugfs_dentry, vcpu,
                            &vcpu_tsc_offset_fops);

        if (lapic_in_kernel(vcpu))
                debugfs_create_file("lapic_timer_advance_ns", 0444,
                                    debugfs_dentry, vcpu,
                                    &vcpu_timer_advance_ns_fops);

        if (kvm_caps.has_tsc_control) {
                debugfs_create_file("tsc-scaling-ratio", 0444,
                                    debugfs_dentry, vcpu,
                                    &vcpu_tsc_scaling_fops);
                debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
                                    debugfs_dentry, vcpu,
                                    &vcpu_tsc_scaling_frac_fops);
        }
}

/*
 * This covers statistics <1024 (11=log(1024)+1), which should be enough to
 * cover RMAP_RECYCLE_THRESHOLD.
 */
#define  RMAP_LOG_SIZE  11

static const char *kvm_lpage_str[KVM_NR_PAGE_SIZES] = { "4K", "2M", "1G" };

static int kvm_mmu_rmaps_stat_show(struct seq_file *m, void *v)
{
        struct kvm_rmap_head *rmap;
        struct kvm *kvm = m->private;
        struct kvm_memory_slot *slot;
        struct kvm_memslots *slots;
        unsigned int lpage_size, index;
        /* Still small enough to be on the stack */
        unsigned int *log[KVM_NR_PAGE_SIZES], *cur;
        int i, j, k, l, ret;

        if (!kvm_memslots_have_rmaps(kvm))
                return 0;

        ret = -ENOMEM;
        memset(log, 0, sizeof(log));
        for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
                log[i] = kcalloc(RMAP_LOG_SIZE, sizeof(unsigned int), GFP_KERNEL);
                if (!log[i])
                        goto out;
        }

        mutex_lock(&kvm->slots_lock);
        write_lock(&kvm->mmu_lock);

        for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
                int bkt;

                slots = __kvm_memslots(kvm, i);
                kvm_for_each_memslot(slot, bkt, slots)
                        for (k = 0; k < KVM_NR_PAGE_SIZES; k++) {
                                rmap = slot->arch.rmap[k];
                                lpage_size = kvm_mmu_slot_lpages(slot, k + 1);
                                cur = log[k];
                                for (l = 0; l < lpage_size; l++) {
                                        index = ffs(pte_list_count(&rmap[l]));
                                        if (WARN_ON_ONCE(index >= RMAP_LOG_SIZE))
                                                index = RMAP_LOG_SIZE - 1;
                                        cur[index]++;
                                }
                        }
        }

        write_unlock(&kvm->mmu_lock);
        mutex_unlock(&kvm->slots_lock);

        /* index=0 counts no rmap; index=1 counts 1 rmap */
        seq_printf(m, "Rmap_Count:\t0\t1\t");
        for (i = 2; i < RMAP_LOG_SIZE; i++) {
                j = 1 << (i - 1);
                k = (1 << i) - 1;
                seq_printf(m, "%d-%d\t", j, k);
        }
        seq_printf(m, "\n");

        for (i = 0; i < KVM_NR_PAGE_SIZES; i++) {
                seq_printf(m, "Level=%s:\t", kvm_lpage_str[i]);
                cur = log[i];
                for (j = 0; j < RMAP_LOG_SIZE; j++)
                        seq_printf(m, "%d\t", cur[j]);
                seq_printf(m, "\n");
        }

        ret = 0;
out:
        for (i = 0; i < KVM_NR_PAGE_SIZES; i++)
                kfree(log[i]);

        return ret;
}

static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file)
{
        struct kvm *kvm = inode->i_private;
        int r;

        if (!kvm_get_kvm_safe(kvm))
                return -ENOENT;

        r = single_open(file, kvm_mmu_rmaps_stat_show, kvm);
        if (r < 0)
                kvm_put_kvm(kvm);

        return r;
}

static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file)
{
        struct kvm *kvm = inode->i_private;

        kvm_put_kvm(kvm);

        return single_release(inode, file);
}

static const struct file_operations mmu_rmaps_stat_fops = {
        .owner                = THIS_MODULE,
        .open                = kvm_mmu_rmaps_stat_open,
        .read                = seq_read,
        .llseek                = seq_lseek,
        .release        = kvm_mmu_rmaps_stat_release,
};

void kvm_arch_create_vm_debugfs(struct kvm *kvm)
{
        debugfs_create_file("mmu_rmaps_stat", 0644, kvm->debugfs_dentry, kvm,
                            &mmu_rmaps_stat_fops);
}






























































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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * VLAN                An implementation of 802.1Q VLAN tagging.
 *
 * Authors:        Ben Greear <greearb@candelatech.com>
 */
#ifndef _LINUX_IF_VLAN_H_
#define _LINUX_IF_VLAN_H_

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/bug.h>
#include <uapi/linux/if_vlan.h>

#define VLAN_HLEN        4                /* The additional bytes required by VLAN
                                         * (in addition to the Ethernet header)
                                         */
#define VLAN_ETH_HLEN        18                /* Total octets in header.         */
#define VLAN_ETH_ZLEN        64                /* Min. octets in frame sans FCS */

/*
 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
 */
#define VLAN_ETH_DATA_LEN        1500        /* Max. octets in payload         */
#define VLAN_ETH_FRAME_LEN        1518        /* Max. octets in frame sans FCS */

#define VLAN_MAX_DEPTH        8                /* Max. number of nested VLAN tags parsed */

/*
 *         struct vlan_hdr - vlan header
 *         @h_vlan_TCI: priority and VLAN ID
 *        @h_vlan_encapsulated_proto: packet type ID or len
 */
struct vlan_hdr {
        __be16        h_vlan_TCI;
        __be16        h_vlan_encapsulated_proto;
};

/**
 *        struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
 *        @h_dest: destination ethernet address
 *        @h_source: source ethernet address
 *        @h_vlan_proto: ethernet protocol
 *        @h_vlan_TCI: priority and VLAN ID
 *        @h_vlan_encapsulated_proto: packet type ID or len
 */
struct vlan_ethhdr {
        struct_group(addrs,
                unsigned char        h_dest[ETH_ALEN];
                unsigned char        h_source[ETH_ALEN];
        );
        __be16                h_vlan_proto;
        __be16                h_vlan_TCI;
        __be16                h_vlan_encapsulated_proto;
};

#include <linux/skbuff.h>

static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
{
        return (struct vlan_ethhdr *)skb_mac_header(skb);
}

/* Prefer this version in TX path, instead of
 * skb_reset_mac_header() + vlan_eth_hdr()
 */
static inline struct vlan_ethhdr *skb_vlan_eth_hdr(const struct sk_buff *skb)
{
        return (struct vlan_ethhdr *)skb->data;
}

#define VLAN_PRIO_MASK                0xe000 /* Priority Code Point */
#define VLAN_PRIO_SHIFT                13
#define VLAN_CFI_MASK                0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */
#define VLAN_VID_MASK                0x0fff /* VLAN Identifier */
#define VLAN_N_VID                4096

/* found in socket.c */
extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));

#define skb_vlan_tag_present(__skb)        (!!(__skb)->vlan_all)
#define skb_vlan_tag_get(__skb)                ((__skb)->vlan_tci)
#define skb_vlan_tag_get_id(__skb)        ((__skb)->vlan_tci & VLAN_VID_MASK)
#define skb_vlan_tag_get_cfi(__skb)        (!!((__skb)->vlan_tci & VLAN_CFI_MASK))
#define skb_vlan_tag_get_prio(__skb)        (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT)

static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
{
        ASSERT_RTNL();
        return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
}

static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
{
        ASSERT_RTNL();
        call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev);
}

static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
{
        ASSERT_RTNL();
        return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
}

static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
{
        ASSERT_RTNL();
        call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev);
}

/**
 *        struct vlan_pcpu_stats - VLAN percpu rx/tx stats
 *        @rx_packets: number of received packets
 *        @rx_bytes: number of received bytes
 *        @rx_multicast: number of received multicast packets
 *        @tx_packets: number of transmitted packets
 *        @tx_bytes: number of transmitted bytes
 *        @syncp: synchronization point for 64bit counters
 *        @rx_errors: number of rx errors
 *        @tx_dropped: number of tx drops
 */
struct vlan_pcpu_stats {
        u64_stats_t                rx_packets;
        u64_stats_t                rx_bytes;
        u64_stats_t                rx_multicast;
        u64_stats_t                tx_packets;
        u64_stats_t                tx_bytes;
        struct u64_stats_sync        syncp;
        u32                        rx_errors;
        u32                        tx_dropped;
};

#if IS_ENABLED(CONFIG_VLAN_8021Q)

extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
                                               __be16 vlan_proto, u16 vlan_id);
extern int vlan_for_each(struct net_device *dev,
                         int (*action)(struct net_device *dev, int vid,
                                       void *arg), void *arg);
extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
extern u16 vlan_dev_vlan_id(const struct net_device *dev);
extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);

/**
 *        struct vlan_priority_tci_mapping - vlan egress priority mappings
 *        @priority: skb priority
 *        @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
 *        @next: pointer to next struct
 */
struct vlan_priority_tci_mapping {
        u32                                        priority;
        u16                                        vlan_qos;
        struct vlan_priority_tci_mapping        *next;
};

struct proc_dir_entry;
struct netpoll;

/**
 *        struct vlan_dev_priv - VLAN private device data
 *        @nr_ingress_mappings: number of ingress priority mappings
 *        @ingress_priority_map: ingress priority mappings
 *        @nr_egress_mappings: number of egress priority mappings
 *        @egress_priority_map: hash of egress priority mappings
 *        @vlan_proto: VLAN encapsulation protocol
 *        @vlan_id: VLAN identifier
 *        @flags: device flags
 *        @real_dev: underlying netdevice
 *        @dev_tracker: refcount tracker for @real_dev reference
 *        @real_dev_addr: address of underlying netdevice
 *        @dent: proc dir entry
 *        @vlan_pcpu_stats: ptr to percpu rx stats
 *        @netpoll: netpoll instance "propagated" down to @real_dev
 */
struct vlan_dev_priv {
        unsigned int                                nr_ingress_mappings;
        u32                                        ingress_priority_map[8];
        unsigned int                                nr_egress_mappings;
        struct vlan_priority_tci_mapping        *egress_priority_map[16];

        __be16                                        vlan_proto;
        u16                                        vlan_id;
        u16                                        flags;

        struct net_device                        *real_dev;
        netdevice_tracker                        dev_tracker;

        unsigned char                                real_dev_addr[ETH_ALEN];

        struct proc_dir_entry                        *dent;
        struct vlan_pcpu_stats __percpu                *vlan_pcpu_stats;
#ifdef CONFIG_NET_POLL_CONTROLLER
        struct netpoll                                *netpoll;
#endif
};

static inline bool is_vlan_dev(const struct net_device *dev)
{
        return dev->priv_flags & IFF_802_1Q_VLAN;
}

static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
{
        return netdev_priv(dev);
}

static inline u16
vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
{
        struct vlan_priority_tci_mapping *mp;

        smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */

        mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
        while (mp) {
                if (mp->priority == skprio) {
                        return mp->vlan_qos; /* This should already be shifted
                                              * to mask correctly with the
                                              * VLAN's TCI */
                }
                mp = mp->next;
        }
        return 0;
}

extern bool vlan_do_receive(struct sk_buff **skb);

extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);

extern int vlan_vids_add_by_dev(struct net_device *dev,
                                const struct net_device *by_dev);
extern void vlan_vids_del_by_dev(struct net_device *dev,
                                 const struct net_device *by_dev);

extern bool vlan_uses_dev(const struct net_device *dev);

#else
static inline bool is_vlan_dev(const struct net_device *dev)
{
        return false;
}

static inline struct net_device *
__vlan_find_dev_deep_rcu(struct net_device *real_dev,
                     __be16 vlan_proto, u16 vlan_id)
{
        return NULL;
}

static inline int
vlan_for_each(struct net_device *dev,
              int (*action)(struct net_device *dev, int vid, void *arg),
              void *arg)
{
        return 0;
}

static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{
        WARN_ON_ONCE(1);
        return NULL;
}

static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
{
        WARN_ON_ONCE(1);
        return 0;
}

static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
{
        WARN_ON_ONCE(1);
        return 0;
}

static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
                                               u32 skprio)
{
        return 0;
}

static inline bool vlan_do_receive(struct sk_buff **skb)
{
        return false;
}

static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
{
        return 0;
}

static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
{
}

static inline int vlan_vids_add_by_dev(struct net_device *dev,
                                       const struct net_device *by_dev)
{
        return 0;
}

static inline void vlan_vids_del_by_dev(struct net_device *dev,
                                        const struct net_device *by_dev)
{
}

static inline bool vlan_uses_dev(const struct net_device *dev)
{
        return false;
}
#endif

/**
 * eth_type_vlan - check for valid vlan ether type.
 * @ethertype: ether type to check
 *
 * Returns: true if the ether type is a vlan ether type.
 */
static inline bool eth_type_vlan(__be16 ethertype)
{
        switch (ethertype) {
        case htons(ETH_P_8021Q):
        case htons(ETH_P_8021AD):
                return true;
        default:
                return false;
        }
}

static inline bool vlan_hw_offload_capable(netdev_features_t features,
                                           __be16 proto)
{
        if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
                return true;
        if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
                return true;
        return false;
}

/**
 * __vlan_insert_inner_tag - inner VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 * @mac_len: MAC header length including outer vlan headers
 *
 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
 * Does not change skb->protocol so this function can be used during receive.
 *
 * Returns: error if skb_cow_head fails.
 */
static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
                                          __be16 vlan_proto, u16 vlan_tci,
                                          unsigned int mac_len)
{
        struct vlan_ethhdr *veth;

        if (skb_cow_head(skb, VLAN_HLEN) < 0)
                return -ENOMEM;

        skb_push(skb, VLAN_HLEN);

        /* Move the mac header sans proto to the beginning of the new header. */
        if (likely(mac_len > ETH_TLEN))
                memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
        if (skb_mac_header_was_set(skb))
                skb->mac_header -= VLAN_HLEN;

        veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);

        /* first, the ethernet type */
        if (likely(mac_len >= ETH_TLEN)) {
                /* h_vlan_encapsulated_proto should already be populated, and
                 * skb->data has space for h_vlan_proto
                 */
                veth->h_vlan_proto = vlan_proto;
        } else {
                /* h_vlan_encapsulated_proto should not be populated, and
                 * skb->data has no space for h_vlan_proto
                 */
                veth->h_vlan_encapsulated_proto = skb->protocol;
        }

        /* now, the TCI */
        veth->h_vlan_TCI = htons(vlan_tci);

        return 0;
}

/**
 * __vlan_insert_tag - regular VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 *
 * Inserts the VLAN tag into @skb as part of the payload
 * Does not change skb->protocol so this function can be used during receive.
 *
 * Returns: error if skb_cow_head fails.
 */
static inline int __vlan_insert_tag(struct sk_buff *skb,
                                    __be16 vlan_proto, u16 vlan_tci)
{
        return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
}

/**
 * vlan_insert_inner_tag - inner VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 * @mac_len: MAC header length including outer vlan headers
 *
 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
 * Returns a VLAN tagged skb. This might change skb->head.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 *
 * Does not change skb->protocol so this function can be used during receive.
 *
 * Return: modified @skb on success, NULL on error (@skb is freed).
 */
static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb,
                                                    __be16 vlan_proto,
                                                    u16 vlan_tci,
                                                    unsigned int mac_len)
{
        int err;

        err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len);
        if (err) {
                dev_kfree_skb_any(skb);
                return NULL;
        }
        return skb;
}

/**
 * vlan_insert_tag - regular VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 *
 * Inserts the VLAN tag into @skb as part of the payload
 * Returns a VLAN tagged skb. This might change skb->head.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 *
 * Does not change skb->protocol so this function can be used during receive.
 *
 * Return: modified @skb on success, NULL on error (@skb is freed).
 */
static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
                                              __be16 vlan_proto, u16 vlan_tci)
{
        return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
}

/**
 * vlan_insert_tag_set_proto - regular VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 *
 * Inserts the VLAN tag into @skb as part of the payload
 * Returns a VLAN tagged skb. This might change skb->head.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 *
 * Return: modified @skb on success, NULL on error (@skb is freed).
 */
static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
                                                        __be16 vlan_proto,
                                                        u16 vlan_tci)
{
        skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
        if (skb)
                skb->protocol = vlan_proto;
        return skb;
}

/**
 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info
 * @skb: skbuff to clear
 *
 * Clears the VLAN information from @skb
 */
static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
{
        skb->vlan_all = 0;
}

/**
 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb
 * @dst: skbuff to copy to
 * @src: skbuff to copy from
 *
 * Copies VLAN information from @src to @dst (for branchless code)
 */
static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
{
        dst->vlan_all = src->vlan_all;
}

/*
 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
 * @skb: skbuff to tag
 *
 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 */
static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
{
        skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
                                        skb_vlan_tag_get(skb));
        if (likely(skb))
                __vlan_hwaccel_clear_tag(skb);
        return skb;
}

/**
 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 *
 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 */
static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
                                          __be16 vlan_proto, u16 vlan_tci)
{
        skb->vlan_proto = vlan_proto;
        skb->vlan_tci = vlan_tci;
}

/**
 * __vlan_get_tag - get the VLAN ID that is part of the payload
 * @skb: skbuff to query
 * @vlan_tci: buffer to store value
 *
 * Returns: error if the skb is not of VLAN type
 */
static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
{
        struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);

        if (!eth_type_vlan(veth->h_vlan_proto))
                return -ENODATA;

        *vlan_tci = ntohs(veth->h_vlan_TCI);
        return 0;
}

/**
 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 * @skb: skbuff to query
 * @vlan_tci: buffer to store value
 *
 * Returns: error if @skb->vlan_tci is not set correctly
 */
static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
                                         u16 *vlan_tci)
{
        if (skb_vlan_tag_present(skb)) {
                *vlan_tci = skb_vlan_tag_get(skb);
                return 0;
        } else {
                *vlan_tci = 0;
                return -ENODATA;
        }
}

/**
 * vlan_get_tag - get the VLAN ID from the skb
 * @skb: skbuff to query
 * @vlan_tci: buffer to store value
 *
 * Returns: error if the skb is not VLAN tagged
 */
static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
{
        if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
                return __vlan_hwaccel_get_tag(skb, vlan_tci);
        } else {
                return __vlan_get_tag(skb, vlan_tci);
        }
}

/**
 * __vlan_get_protocol_offset() - get protocol EtherType.
 * @skb: skbuff to query
 * @type: first vlan protocol
 * @mac_offset: MAC offset
 * @depth: buffer to store length of eth and vlan tags in bytes
 *
 * Returns: the EtherType of the packet, regardless of whether it is
 * vlan encapsulated (normal or hardware accelerated) or not.
 */
static inline __be16 __vlan_get_protocol_offset(const struct sk_buff *skb,
                                                __be16 type,
                                                int mac_offset,
                                                int *depth)
{
        unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;

        /* if type is 802.1Q/AD then the header should already be
         * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
         * ETH_HLEN otherwise
         */
        if (eth_type_vlan(type)) {
                if (vlan_depth) {
                        if (WARN_ON(vlan_depth < VLAN_HLEN))
                                return 0;
                        vlan_depth -= VLAN_HLEN;
                } else {
                        vlan_depth = ETH_HLEN;
                }
                do {
                        struct vlan_hdr vhdr, *vh;

                        vh = skb_header_pointer(skb, mac_offset + vlan_depth,
                                                sizeof(vhdr), &vhdr);
                        if (unlikely(!vh || !--parse_depth))
                                return 0;

                        type = vh->h_vlan_encapsulated_proto;
                        vlan_depth += VLAN_HLEN;
                } while (eth_type_vlan(type));
        }

        if (depth)
                *depth = vlan_depth;

        return type;
}

static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type,
                                         int *depth)
{
        return __vlan_get_protocol_offset(skb, type, 0, depth);
}

/**
 * vlan_get_protocol - get protocol EtherType.
 * @skb: skbuff to query
 *
 * Returns: the EtherType of the packet, regardless of whether it is
 * vlan encapsulated (normal or hardware accelerated) or not.
 */
static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
{
        return __vlan_get_protocol(skb, skb->protocol, NULL);
}

/* This version of __vlan_get_protocol() also pulls mac header in skb->head */
static inline __be16 vlan_get_protocol_and_depth(struct sk_buff *skb,
                                                 __be16 type, int *depth)
{
        int maclen;

        type = __vlan_get_protocol(skb, type, &maclen);

        if (type) {
                if (!pskb_may_pull(skb, maclen))
                        type = 0;
                else if (depth)
                        *depth = maclen;
        }
        return type;
}

/* A getter for the SKB protocol field which will handle VLAN tags consistently
 * whether VLAN acceleration is enabled or not.
 */
static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan)
{
        if (!skip_vlan)
                /* VLAN acceleration strips the VLAN header from the skb and
                 * moves it to skb->vlan_proto
                 */
                return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol;

        return vlan_get_protocol(skb);
}

static inline void vlan_set_encap_proto(struct sk_buff *skb,
                                        struct vlan_hdr *vhdr)
{
        __be16 proto;
        unsigned short *rawp;

        /*
         * Was a VLAN packet, grab the encapsulated protocol, which the layer
         * three protocols care about.
         */

        proto = vhdr->h_vlan_encapsulated_proto;
        if (eth_proto_is_802_3(proto)) {
                skb->protocol = proto;
                return;
        }

        rawp = (unsigned short *)(vhdr + 1);
        if (*rawp == 0xFFFF)
                /*
                 * This is a magic hack to spot IPX packets. Older Novell
                 * breaks the protocol design and runs IPX over 802.3 without
                 * an 802.2 LLC layer. We look for FFFF which isn't a used
                 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
                 * but does for the rest.
                 */
                skb->protocol = htons(ETH_P_802_3);
        else
                /*
                 * Real 802.2 LLC
                 */
                skb->protocol = htons(ETH_P_802_2);
}

/**
 * vlan_remove_tag - remove outer VLAN tag from payload
 * @skb: skbuff to remove tag from
 * @vlan_tci: buffer to store value
 *
 * Expects the skb to contain a VLAN tag in the payload, and to have skb->data
 * pointing at the MAC header.
 *
 * Returns: a new pointer to skb->data, or NULL on failure to pull.
 */
static inline void *vlan_remove_tag(struct sk_buff *skb, u16 *vlan_tci)
{
        struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);

        *vlan_tci = ntohs(vhdr->h_vlan_TCI);

        memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
        vlan_set_encap_proto(skb, vhdr);
        return __skb_pull(skb, VLAN_HLEN);
}

/**
 * skb_vlan_tagged - check if skb is vlan tagged.
 * @skb: skbuff to query
 *
 * Returns: true if the skb is tagged, regardless of whether it is hardware
 * accelerated or not.
 */
static inline bool skb_vlan_tagged(const struct sk_buff *skb)
{
        if (!skb_vlan_tag_present(skb) &&
            likely(!eth_type_vlan(skb->protocol)))
                return false;

        return true;
}

/**
 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
 * @skb: skbuff to query
 *
 * Returns: true if the skb is tagged with multiple vlan headers, regardless
 * of whether it is hardware accelerated or not.
 */
static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
{
        __be16 protocol = skb->protocol;

        if (!skb_vlan_tag_present(skb)) {
                struct vlan_ethhdr *veh;

                if (likely(!eth_type_vlan(protocol)))
                        return false;

                if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
                        return false;

                veh = skb_vlan_eth_hdr(skb);
                protocol = veh->h_vlan_encapsulated_proto;
        }

        if (!eth_type_vlan(protocol))
                return false;

        return true;
}

/**
 * vlan_features_check - drop unsafe features for skb with multiple tags.
 * @skb: skbuff to query
 * @features: features to be checked
 *
 * Returns: features without unsafe ones if the skb has multiple tags.
 */
static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
                                                    netdev_features_t features)
{
        if (skb_vlan_tagged_multi(skb)) {
                /* In the case of multi-tagged packets, use a direct mask
                 * instead of using netdev_interesect_features(), to make
                 * sure that only devices supporting NETIF_F_HW_CSUM will
                 * have checksum offloading support.
                 */
                features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
                            NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
                            NETIF_F_HW_VLAN_STAG_TX;
        }

        return features;
}

/**
 * compare_vlan_header - Compare two vlan headers
 * @h1: Pointer to vlan header
 * @h2: Pointer to vlan header
 *
 * Compare two vlan headers.
 *
 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
 *
 * Return: 0 if equal, arbitrary non-zero value if not equal.
 */
static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
                                                const struct vlan_hdr *h2)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
        return *(u32 *)h1 ^ *(u32 *)h2;
#else
        return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
               ((__force u32)h1->h_vlan_encapsulated_proto ^
                (__force u32)h2->h_vlan_encapsulated_proto);
#endif
}
#endif /* !(_LINUX_IF_VLAN_H_) */

































































































































































































































































































































































































































































































































































































































































































































































































































































































































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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/usb.h>
#include <linux/i2c.h>
#include <asm/byteorder.h>
#include <media/i2c/saa7115.h>
#include <media/tuner.h>
#include <media/i2c/uda1342.h>

#include "go7007-priv.h"

static unsigned int assume_endura;
module_param(assume_endura, int, 0644);
MODULE_PARM_DESC(assume_endura,
                        "when probing fails, hardware is a Pelco Endura");

/* #define GO7007_I2C_DEBUG */ /* for debugging the EZ-USB I2C adapter */

#define        HPI_STATUS_ADDR        0xFFF4
#define        INT_PARAM_ADDR        0xFFF6
#define        INT_INDEX_ADDR        0xFFF8

/*
 * Pipes on EZ-USB interface:
 *        0 snd - Control
 *        0 rcv - Control
 *        2 snd - Download firmware (control)
 *        4 rcv - Read Interrupt (interrupt)
 *        6 rcv - Read Video (bulk)
 *        8 rcv - Read Audio (bulk)
 */

#define GO7007_USB_EZUSB                (1<<0)
#define GO7007_USB_EZUSB_I2C                (1<<1)

struct go7007_usb_board {
        unsigned int flags;
        struct go7007_board_info main_info;
};

struct go7007_usb {
        const struct go7007_usb_board *board;
        struct mutex i2c_lock;
        struct usb_device *usbdev;
        struct urb *video_urbs[8];
        struct urb *audio_urbs[8];
        struct urb *intr_urb;
};

/*********************** Product specification data ***********************/

static const struct go7007_usb_board board_matrix_ii = {
        .flags                = GO7007_USB_EZUSB,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO |
                                        GO7007_BOARD_USE_ONBOARD_I2C,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_VALID_ENABLE |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_SAA7115 |
                                        GO7007_SENSOR_VBI |
                                        GO7007_SENSOR_SCALING,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "saa7115",
                                .addr        = 0x20,
                                .is_video = 1,
                        },
                },
                .num_inputs         = 2,
                .inputs                 = {
                        {
                                .video_input        = 0,
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 9,
                                .name                = "S-Video",
                        },
                },
                .video_config        = SAA7115_IDQ_IS_DEFAULT,
        },
};

static const struct go7007_usb_board board_matrix_reload = {
        .flags                = GO7007_USB_EZUSB,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO |
                                        GO7007_BOARD_USE_ONBOARD_I2C,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_TV,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "saa7113",
                                .addr        = 0x25,
                                .is_video = 1,
                        },
                },
                .num_inputs         = 2,
                .inputs                 = {
                        {
                                .video_input        = 0,
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 9,
                                .name                = "S-Video",
                        },
                },
                .video_config        = SAA7115_IDQ_IS_DEFAULT,
        },
};

static const struct go7007_usb_board board_star_trek = {
        .flags                = GO7007_USB_EZUSB | GO7007_USB_EZUSB_I2C,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO, /* |
                                        GO7007_BOARD_HAS_TUNER, */
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_VALID_ENABLE |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_SAA7115 |
                                        GO7007_SENSOR_VBI |
                                        GO7007_SENSOR_SCALING,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_WORD_16,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "saa7115",
                                .addr        = 0x20,
                                .is_video = 1,
                        },
                },
                .num_inputs         = 2,
                .inputs                 = {
                /*        {
                 *                .video_input        = 3,
                 *                .audio_index        = AUDIO_TUNER,
                 *                .name                = "Tuner",
                 *        },
                 */
                        {
                                .video_input        = 1,
                        /*        .audio_index        = AUDIO_EXTERN, */
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 8,
                        /*        .audio_index        = AUDIO_EXTERN, */
                                .name                = "S-Video",
                        },
                },
                .video_config        = SAA7115_IDQ_IS_DEFAULT,
        },
};

static const struct go7007_usb_board board_px_tv402u = {
        .flags                = GO7007_USB_EZUSB | GO7007_USB_EZUSB_I2C,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO |
                                        GO7007_BOARD_HAS_TUNER,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_VALID_ENABLE |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_SAA7115 |
                                        GO7007_SENSOR_VBI |
                                        GO7007_SENSOR_SCALING,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_WORD_16,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .num_i2c_devs         = 5,
                .i2c_devs         = {
                        {
                                .type        = "saa7115",
                                .addr        = 0x20,
                                .is_video = 1,
                        },
                        {
                                .type        = "uda1342",
                                .addr        = 0x1a,
                                .is_audio = 1,
                        },
                        {
                                .type        = "tuner",
                                .addr        = 0x60,
                        },
                        {
                                .type        = "tuner",
                                .addr        = 0x43,
                        },
                        {
                                .type        = "sony-btf-mpx",
                                .addr        = 0x44,
                        },
                },
                .num_inputs         = 3,
                .inputs                 = {
                        {
                                .video_input        = 3,
                                .audio_index        = 0,
                                .name                = "Tuner",
                        },
                        {
                                .video_input        = 1,
                                .audio_index        = 1,
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 8,
                                .audio_index        = 1,
                                .name                = "S-Video",
                        },
                },
                .video_config        = SAA7115_IDQ_IS_DEFAULT,
                .num_aud_inputs         = 2,
                .aud_inputs         = {
                        {
                                .audio_input        = UDA1342_IN2,
                                .name                = "Tuner",
                        },
                        {
                                .audio_input        = UDA1342_IN1,
                                .name                = "Line In",
                        },
                },
        },
};

static const struct go7007_usb_board board_xmen = {
        .flags                = 0,
        .main_info        = {
                .flags                  = GO7007_BOARD_USE_ONBOARD_I2C,
                .hpi_buffer_cap   = 0,
                .sensor_flags          = GO7007_SENSOR_VREF_POLAR,
                .sensor_width          = 320,
                .sensor_height          = 240,
                .sensor_framerate = 30030,
                .audio_flags          = GO7007_AUDIO_ONE_CHANNEL |
                                        GO7007_AUDIO_I2S_MODE_3 |
                                        GO7007_AUDIO_WORD_14 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_BCLK_POLAR |
                                        GO7007_AUDIO_OKI_MODE,
                .audio_rate          = 8000,
                .audio_bclk_div          = 48,
                .audio_main_div          = 1,
                .num_i2c_devs          = 1,
                .i2c_devs          = {
                        {
                                .type        = "ov7640",
                                .addr        = 0x21,
                        },
                },
                .num_inputs          = 1,
                .inputs                  = {
                        {
                                .name                = "Camera",
                        },
                },
        },
};

static const struct go7007_usb_board board_matrix_revolution = {
        .flags                = GO7007_USB_EZUSB,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO |
                                        GO7007_BOARD_USE_ONBOARD_I2C,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_VBI,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "tw9903",
                                .is_video = 1,
                                .addr        = 0x44,
                        },
                },
                .num_inputs         = 2,
                .inputs                 = {
                        {
                                .video_input        = 2,
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 8,
                                .name                = "S-Video",
                        },
                },
        },
};

#if 0
static const struct go7007_usb_board board_lifeview_lr192 = {
        .flags                = GO7007_USB_EZUSB,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO |
                                        GO7007_BOARD_USE_ONBOARD_I2C,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_VALID_ENABLE |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_VBI |
                                        GO7007_SENSOR_SCALING,
                .num_i2c_devs         = 0,
                .num_inputs         = 1,
                .inputs                 = {
                        {
                                .video_input        = 0,
                                .name                = "Composite",
                        },
                },
        },
};
#endif

static const struct go7007_usb_board board_endura = {
        .flags                = 0,
        .main_info        = {
                .flags                 = 0,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 8000,
                .audio_bclk_div         = 48,
                .audio_main_div         = 8,
                .hpi_buffer_cap  = 0,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_TV,
                .sensor_h_offset = 8,
                .num_i2c_devs         = 0,
                .num_inputs         = 1,
                .inputs                 = {
                        {
                                .name                = "Camera",
                        },
                },
        },
};

static const struct go7007_usb_board board_adlink_mpg24 = {
        .flags                = 0,
        .main_info        = {
                .flags                 = GO7007_BOARD_USE_ONBOARD_I2C,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 0,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_VBI,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "tw2804",
                                .addr        = 0x00, /* yes, really */
                                .flags  = I2C_CLIENT_TEN,
                                .is_video = 1,
                        },
                },
                .num_inputs         = 1,
                .inputs                 = {
                        {
                                .name                = "Composite",
                        },
                },
        },
};

static const struct go7007_usb_board board_sensoray_2250 = {
        .flags                = GO7007_USB_EZUSB | GO7007_USB_EZUSB_I2C,
        .main_info        = {
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_WORD_16,
                .flags                 = GO7007_BOARD_HAS_AUDIO,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_TV,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "s2250",
                                .addr        = 0x43,
                                .is_video = 1,
                                .is_audio = 1,
                        },
                },
                .num_inputs         = 2,
                .inputs                 = {
                        {
                                .video_input        = 0,
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 1,
                                .name                = "S-Video",
                        },
                },
                .num_aud_inputs         = 3,
                .aud_inputs         = {
                        {
                                .audio_input        = 0,
                                .name                = "Line In",
                        },
                        {
                                .audio_input        = 1,
                                .name                = "Mic",
                        },
                        {
                                .audio_input        = 2,
                                .name                = "Mic Boost",
                        },
                },
        },
};

static const struct go7007_usb_board board_ads_usbav_709 = {
        .flags                = GO7007_USB_EZUSB,
        .main_info        = {
                .flags                 = GO7007_BOARD_HAS_AUDIO |
                                        GO7007_BOARD_USE_ONBOARD_I2C,
                .audio_flags         = GO7007_AUDIO_I2S_MODE_1 |
                                        GO7007_AUDIO_I2S_MASTER |
                                        GO7007_AUDIO_WORD_16,
                .audio_rate         = 48000,
                .audio_bclk_div         = 8,
                .audio_main_div         = 2,
                .hpi_buffer_cap  = 7,
                .sensor_flags         = GO7007_SENSOR_656 |
                                        GO7007_SENSOR_TV |
                                        GO7007_SENSOR_VBI,
                .num_i2c_devs         = 1,
                .i2c_devs         = {
                        {
                                .type        = "tw9906",
                                .is_video = 1,
                                .addr        = 0x44,
                        },
                },
                .num_inputs         = 2,
                .inputs                 = {
                        {
                                .video_input        = 0,
                                .name                = "Composite",
                        },
                        {
                                .video_input        = 10,
                                .name                = "S-Video",
                        },
                },
        },
};

static const struct usb_device_id go7007_usb_id_table[] = {
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION |
                                        USB_DEVICE_ID_MATCH_INT_INFO,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x200,   /* Revision number of XMen */
                .bcdDevice_hi        = 0x200,
                .bInterfaceClass        = 255,
                .bInterfaceSubClass        = 0,
                .bInterfaceProtocol        = 255,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_XMEN,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x202,   /* Revision number of Matrix II */
                .bcdDevice_hi        = 0x202,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_MATRIX_II,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x204,   /* Revision number of Matrix */
                .bcdDevice_hi        = 0x204,   /*     Reloaded */
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_MATRIX_RELOAD,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION |
                                        USB_DEVICE_ID_MATCH_INT_INFO,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x205,   /* Revision number of XMen-II */
                .bcdDevice_hi        = 0x205,
                .bInterfaceClass        = 255,
                .bInterfaceSubClass        = 0,
                .bInterfaceProtocol        = 255,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_XMEN_II,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x208,   /* Revision number of Star Trek */
                .bcdDevice_hi        = 0x208,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_STAR_TREK,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION |
                                        USB_DEVICE_ID_MATCH_INT_INFO,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x209,   /* Revision number of XMen-III */
                .bcdDevice_hi        = 0x209,
                .bInterfaceClass        = 255,
                .bInterfaceSubClass        = 0,
                .bInterfaceProtocol        = 255,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_XMEN_III,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x0eb1,  /* Vendor ID of WIS Technologies */
                .idProduct        = 0x7007,  /* Product ID of GO7007SB chip */
                .bcdDevice_lo        = 0x210,   /* Revision number of Matrix */
                .bcdDevice_hi        = 0x210,   /*     Revolution */
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_MATRIX_REV,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x093b,  /* Vendor ID of Plextor */
                .idProduct        = 0xa102,  /* Product ID of M402U */
                .bcdDevice_lo        = 0x1,           /* revision number of Blueberry */
                .bcdDevice_hi        = 0x1,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_PX_M402U,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x093b,  /* Vendor ID of Plextor */
                .idProduct        = 0xa104,  /* Product ID of TV402U */
                .bcdDevice_lo        = 0x1,
                .bcdDevice_hi        = 0x1,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_PX_TV402U,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x10fd,  /* Vendor ID of Anubis Electronics */
                .idProduct        = 0xde00,  /* Product ID of Lifeview LR192 */
                .bcdDevice_lo        = 0x1,
                .bcdDevice_hi        = 0x1,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_LIFEVIEW_LR192,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x1943,  /* Vendor ID Sensoray */
                .idProduct        = 0x2250,  /* Product ID of 2250/2251 */
                .bcdDevice_lo        = 0x1,
                .bcdDevice_hi        = 0x1,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_SENSORAY_2250,
        },
        {
                .match_flags        = USB_DEVICE_ID_MATCH_DEVICE_AND_VERSION,
                .idVendor        = 0x06e1,  /* Vendor ID of ADS Technologies */
                .idProduct        = 0x0709,  /* Product ID of DVD Xpress DX2 */
                .bcdDevice_lo        = 0x204,
                .bcdDevice_hi        = 0x204,
                .driver_info        = (kernel_ulong_t)GO7007_BOARDID_ADS_USBAV_709,
        },
        { }                                        /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, go7007_usb_id_table);

/********************* Driver for EZ-USB HPI interface *********************/

static int go7007_usb_vendor_request(struct go7007 *go, int request,
                int value, int index, void *transfer_buffer, int length, int in)
{
        struct go7007_usb *usb = go->hpi_context;
        int timeout = 5000;

        if (in) {
                return usb_control_msg(usb->usbdev,
                                usb_rcvctrlpipe(usb->usbdev, 0), request,
                                USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                                value, index, transfer_buffer, length, timeout);
        } else {
                return usb_control_msg(usb->usbdev,
                                usb_sndctrlpipe(usb->usbdev, 0), request,
                                USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                value, index, transfer_buffer, length, timeout);
        }
}

static int go7007_usb_interface_reset(struct go7007 *go)
{
        struct go7007_usb *usb = go->hpi_context;
        u16 intr_val, intr_data;

        if (go->status == STATUS_SHUTDOWN)
                return -1;
        /* Reset encoder */
        if (go7007_write_interrupt(go, 0x0001, 0x0001) < 0)
                return -1;
        msleep(100);

        if (usb->board->flags & GO7007_USB_EZUSB) {
                /* Reset buffer in EZ-USB */
                pr_debug("resetting EZ-USB buffers\n");
                if (go7007_usb_vendor_request(go, 0x10, 0, 0, NULL, 0, 0) < 0 ||
                    go7007_usb_vendor_request(go, 0x10, 0, 0, NULL, 0, 0) < 0)
                        return -1;

                /* Reset encoder again */
                if (go7007_write_interrupt(go, 0x0001, 0x0001) < 0)
                        return -1;
                msleep(100);
        }

        /* Wait for an interrupt to indicate successful hardware reset */
        if (go7007_read_interrupt(go, &intr_val, &intr_data) < 0 ||
                        (intr_val & ~0x1) != 0x55aa) {
                dev_err(go->dev, "unable to reset the USB interface\n");
                return -1;
        }
        return 0;
}

static int go7007_usb_ezusb_write_interrupt(struct go7007 *go,
                                                int addr, int data)
{
        struct go7007_usb *usb = go->hpi_context;
        int i, r;
        u16 status_reg = 0;
        int timeout = 500;

        pr_debug("WriteInterrupt: %04x %04x\n", addr, data);

        for (i = 0; i < 100; ++i) {
                r = usb_control_msg(usb->usbdev,
                                usb_rcvctrlpipe(usb->usbdev, 0), 0x14,
                                USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
                                0, HPI_STATUS_ADDR, go->usb_buf,
                                sizeof(status_reg), timeout);
                if (r < 0)
                        break;
                status_reg = le16_to_cpu(*((__le16 *)go->usb_buf));
                if (!(status_reg & 0x0010))
                        break;
                msleep(10);
        }
        if (r < 0)
                goto write_int_error;
        if (i == 100) {
                dev_err(go->dev, "device is hung, status reg = 0x%04x\n", status_reg);
                return -1;
        }
        r = usb_control_msg(usb->usbdev, usb_sndctrlpipe(usb->usbdev, 0), 0x12,
                        USB_TYPE_VENDOR | USB_RECIP_DEVICE, data,
                        INT_PARAM_ADDR, NULL, 0, timeout);
        if (r < 0)
                goto write_int_error;
        r = usb_control_msg(usb->usbdev, usb_sndctrlpipe(usb->usbdev, 0),
                        0x12, USB_TYPE_VENDOR | USB_RECIP_DEVICE, addr,
                        INT_INDEX_ADDR, NULL, 0, timeout);
        if (r < 0)
                goto write_int_error;
        return 0;

write_int_error:
        dev_err(go->dev, "error in WriteInterrupt: %d\n", r);
        return r;
}

static int go7007_usb_onboard_write_interrupt(struct go7007 *go,
                                                int addr, int data)
{
        struct go7007_usb *usb = go->hpi_context;
        int r;
        int timeout = 500;

        pr_debug("WriteInterrupt: %04x %04x\n", addr, data);

        go->usb_buf[0] = data & 0xff;
        go->usb_buf[1] = data >> 8;
        go->usb_buf[2] = addr & 0xff;
        go->usb_buf[3] = addr >> 8;
        go->usb_buf[4] = go->usb_buf[5] = go->usb_buf[6] = go->usb_buf[7] = 0;
        r = usb_control_msg(usb->usbdev, usb_sndctrlpipe(usb->usbdev, 2), 0x00,
                        USB_TYPE_VENDOR | USB_RECIP_ENDPOINT, 0x55aa,
                        0xf0f0, go->usb_buf, 8, timeout);
        if (r < 0) {
                dev_err(go->dev, "error in WriteInterrupt: %d\n", r);
                return r;
        }
        return 0;
}

static void go7007_usb_readinterrupt_complete(struct urb *urb)
{
        struct go7007 *go = (struct go7007 *)urb->context;
        __le16 *regs = (__le16 *)urb->transfer_buffer;
        int status = urb->status;

        if (status) {
                if (status != -ESHUTDOWN &&
                                go->status != STATUS_SHUTDOWN) {
                        dev_err(go->dev, "error in read interrupt: %d\n", urb->status);
                } else {
                        wake_up(&go->interrupt_waitq);
                        return;
                }
        } else if (urb->actual_length != urb->transfer_buffer_length) {
                dev_err(go->dev, "short read in interrupt pipe!\n");
        } else {
                go->interrupt_available = 1;
                go->interrupt_data = __le16_to_cpu(regs[0]);
                go->interrupt_value = __le16_to_cpu(regs[1]);
                pr_debug("ReadInterrupt: %04x %04x\n",
                                go->interrupt_value, go->interrupt_data);
        }

        wake_up(&go->interrupt_waitq);
}

static int go7007_usb_read_interrupt(struct go7007 *go)
{
        struct go7007_usb *usb = go->hpi_context;
        int r;

        r = usb_submit_urb(usb->intr_urb, GFP_KERNEL);
        if (r < 0) {
                dev_err(go->dev, "unable to submit interrupt urb: %d\n", r);
                return r;
        }
        return 0;
}

static void go7007_usb_read_video_pipe_complete(struct urb *urb)
{
        struct go7007 *go = (struct go7007 *)urb->context;
        int r, status = urb->status;

        if (!vb2_is_streaming(&go->vidq)) {
                wake_up_interruptible(&go->frame_waitq);
                return;
        }
        if (status) {
                dev_err(go->dev, "error in video pipe: %d\n", status);
                return;
        }
        if (urb->actual_length != urb->transfer_buffer_length) {
                dev_err(go->dev, "short read in video pipe!\n");
                return;
        }
        go7007_parse_video_stream(go, urb->transfer_buffer, urb->actual_length);
        r = usb_submit_urb(urb, GFP_ATOMIC);
        if (r < 0)
                dev_err(go->dev, "error in video pipe: %d\n", r);
}

static void go7007_usb_read_audio_pipe_complete(struct urb *urb)
{
        struct go7007 *go = (struct go7007 *)urb->context;
        int r, status = urb->status;

        if (!vb2_is_streaming(&go->vidq))
                return;
        if (status) {
                dev_err(go->dev, "error in audio pipe: %d\n",
                        status);
                return;
        }
        if (urb->actual_length != urb->transfer_buffer_length) {
                dev_err(go->dev, "short read in audio pipe!\n");
                return;
        }
        if (go->audio_deliver != NULL)
                go->audio_deliver(go, urb->transfer_buffer, urb->actual_length);
        r = usb_submit_urb(urb, GFP_ATOMIC);
        if (r < 0)
                dev_err(go->dev, "error in audio pipe: %d\n", r);
}

static int go7007_usb_stream_start(struct go7007 *go)
{
        struct go7007_usb *usb = go->hpi_context;
        int i, r;

        for (i = 0; i < 8; ++i) {
                r = usb_submit_urb(usb->video_urbs[i], GFP_KERNEL);
                if (r < 0) {
                        dev_err(go->dev, "error submitting video urb %d: %d\n", i, r);
                        goto video_submit_failed;
                }
        }
        if (!go->audio_enabled)
                return 0;

        for (i = 0; i < 8; ++i) {
                r = usb_submit_urb(usb->audio_urbs[i], GFP_KERNEL);
                if (r < 0) {
                        dev_err(go->dev, "error submitting audio urb %d: %d\n", i, r);
                        goto audio_submit_failed;
                }
        }
        return 0;

audio_submit_failed:
        for (i = 0; i < 7; ++i)
                usb_kill_urb(usb->audio_urbs[i]);
video_submit_failed:
        for (i = 0; i < 8; ++i)
                usb_kill_urb(usb->video_urbs[i]);
        return -1;
}

static int go7007_usb_stream_stop(struct go7007 *go)
{
        struct go7007_usb *usb = go->hpi_context;
        int i;

        if (go->status == STATUS_SHUTDOWN)
                return 0;
        for (i = 0; i < 8; ++i)
                usb_kill_urb(usb->video_urbs[i]);
        if (go->audio_enabled)
                for (i = 0; i < 8; ++i)
                        usb_kill_urb(usb->audio_urbs[i]);
        return 0;
}

static int go7007_usb_send_firmware(struct go7007 *go, u8 *data, int len)
{
        struct go7007_usb *usb = go->hpi_context;
        int transferred, pipe;
        int timeout = 500;

        pr_debug("DownloadBuffer sending %d bytes\n", len);

        if (usb->board->flags & GO7007_USB_EZUSB)
                pipe = usb_sndbulkpipe(usb->usbdev, 2);
        else
                pipe = usb_sndbulkpipe(usb->usbdev, 3);

        return usb_bulk_msg(usb->usbdev, pipe, data, len,
                                        &transferred, timeout);
}

static void go7007_usb_release(struct go7007 *go)
{
        struct go7007_usb *usb = go->hpi_context;
        struct urb *vurb, *aurb;
        int i;

        if (usb->intr_urb) {
                usb_kill_urb(usb->intr_urb);
                kfree(usb->intr_urb->transfer_buffer);
                usb_free_urb(usb->intr_urb);
        }

        /* Free USB-related structs */
        for (i = 0; i < 8; ++i) {
                vurb = usb->video_urbs[i];
                if (vurb) {
                        usb_kill_urb(vurb);
                        kfree(vurb->transfer_buffer);
                        usb_free_urb(vurb);
                }
                aurb = usb->audio_urbs[i];
                if (aurb) {
                        usb_kill_urb(aurb);
                        kfree(aurb->transfer_buffer);
                        usb_free_urb(aurb);
                }
        }

        kfree(go->hpi_context);
}

static const struct go7007_hpi_ops go7007_usb_ezusb_hpi_ops = {
        .interface_reset        = go7007_usb_interface_reset,
        .write_interrupt        = go7007_usb_ezusb_write_interrupt,
        .read_interrupt                = go7007_usb_read_interrupt,
        .stream_start                = go7007_usb_stream_start,
        .stream_stop                = go7007_usb_stream_stop,
        .send_firmware                = go7007_usb_send_firmware,
        .release                = go7007_usb_release,
};

static const struct go7007_hpi_ops go7007_usb_onboard_hpi_ops = {
        .interface_reset        = go7007_usb_interface_reset,
        .write_interrupt        = go7007_usb_onboard_write_interrupt,
        .read_interrupt                = go7007_usb_read_interrupt,
        .stream_start                = go7007_usb_stream_start,
        .stream_stop                = go7007_usb_stream_stop,
        .send_firmware                = go7007_usb_send_firmware,
        .release                = go7007_usb_release,
};

/********************* Driver for EZ-USB I2C adapter *********************/

static int go7007_usb_i2c_master_xfer(struct i2c_adapter *adapter,
                                        struct i2c_msg msgs[], int num)
{
        struct go7007 *go = i2c_get_adapdata(adapter);
        struct go7007_usb *usb = go->hpi_context;
        u8 *buf = go->usb_buf;
        int buf_len, i;
        int ret = -EIO;

        if (go->status == STATUS_SHUTDOWN)
                return -ENODEV;

        mutex_lock(&usb->i2c_lock);

        for (i = 0; i < num; ++i) {
                /* The hardware command is "write some bytes then read some
                 * bytes", so we try to coalesce a write followed by a read
                 * into a single USB transaction */
                if (i + 1 < num && msgs[i].addr == msgs[i + 1].addr &&
                                !(msgs[i].flags & I2C_M_RD) &&
                                (msgs[i + 1].flags & I2C_M_RD)) {
#ifdef GO7007_I2C_DEBUG
                        pr_debug("i2c write/read %d/%d bytes on %02x\n",
                                msgs[i].len, msgs[i + 1].len, msgs[i].addr);
#endif
                        buf[0] = 0x01;
                        buf[1] = msgs[i].len + 1;
                        buf[2] = msgs[i].addr << 1;
                        memcpy(&buf[3], msgs[i].buf, msgs[i].len);
                        buf_len = msgs[i].len + 3;
                        buf[buf_len++] = msgs[++i].len;
                } else if (msgs[i].flags & I2C_M_RD) {
#ifdef GO7007_I2C_DEBUG
                        pr_debug("i2c read %d bytes on %02x\n",
                                        msgs[i].len, msgs[i].addr);
#endif
                        buf[0] = 0x01;
                        buf[1] = 1;
                        buf[2] = msgs[i].addr << 1;
                        buf[3] = msgs[i].len;
                        buf_len = 4;
                } else {
#ifdef GO7007_I2C_DEBUG
                        pr_debug("i2c write %d bytes on %02x\n",
                                        msgs[i].len, msgs[i].addr);
#endif
                        buf[0] = 0x00;
                        buf[1] = msgs[i].len + 1;
                        buf[2] = msgs[i].addr << 1;
                        memcpy(&buf[3], msgs[i].buf, msgs[i].len);
                        buf_len = msgs[i].len + 3;
                        buf[buf_len++] = 0;
                }
                if (go7007_usb_vendor_request(go, 0x24, 0, 0,
                                                buf, buf_len, 0) < 0)
                        goto i2c_done;
                if (msgs[i].flags & I2C_M_RD) {
                        memset(buf, 0, msgs[i].len + 1);
                        if (go7007_usb_vendor_request(go, 0x25, 0, 0, buf,
                                                msgs[i].len + 1, 1) < 0)
                                goto i2c_done;
                        memcpy(msgs[i].buf, buf + 1, msgs[i].len);
                }
        }
        ret = num;

i2c_done:
        mutex_unlock(&usb->i2c_lock);
        return ret;
}

static u32 go7007_usb_functionality(struct i2c_adapter *adapter)
{
        /* No errors are reported by the hardware, so we don't bother
         * supporting quick writes to avoid confusing probing */
        return (I2C_FUNC_SMBUS_EMUL) & ~I2C_FUNC_SMBUS_QUICK;
}

static const struct i2c_algorithm go7007_usb_algo = {
        .master_xfer        = go7007_usb_i2c_master_xfer,
        .functionality        = go7007_usb_functionality,
};

static struct i2c_adapter go7007_usb_adap_templ = {
        .owner                        = THIS_MODULE,
        .name                        = "WIS GO7007SB EZ-USB",
        .algo                        = &go7007_usb_algo,
};

/********************* USB add/remove functions *********************/

static int go7007_usb_probe(struct usb_interface *intf,
                const struct usb_device_id *id)
{
        struct go7007 *go;
        struct go7007_usb *usb;
        const struct go7007_usb_board *board;
        struct usb_device *usbdev = interface_to_usbdev(intf);
        struct usb_host_endpoint *ep;
        unsigned num_i2c_devs;
        char *name;
        int video_pipe, i, v_urb_len;

        pr_debug("probing new GO7007 USB board\n");

        switch (id->driver_info) {
        case GO7007_BOARDID_MATRIX_II:
                name = "WIS Matrix II or compatible";
                board = &board_matrix_ii;
                break;
        case GO7007_BOARDID_MATRIX_RELOAD:
                name = "WIS Matrix Reloaded or compatible";
                board = &board_matrix_reload;
                break;
        case GO7007_BOARDID_MATRIX_REV:
                name = "WIS Matrix Revolution or compatible";
                board = &board_matrix_revolution;
                break;
        case GO7007_BOARDID_STAR_TREK:
                name = "WIS Star Trek or compatible";
                board = &board_star_trek;
                break;
        case GO7007_BOARDID_XMEN:
                name = "WIS XMen or compatible";
                board = &board_xmen;
                break;
        case GO7007_BOARDID_XMEN_II:
                name = "WIS XMen II or compatible";
                board = &board_xmen;
                break;
        case GO7007_BOARDID_XMEN_III:
                name = "WIS XMen III or compatible";
                board = &board_xmen;
                break;
        case GO7007_BOARDID_PX_M402U:
                name = "Plextor PX-M402U";
                board = &board_matrix_ii;
                break;
        case GO7007_BOARDID_PX_TV402U:
                name = "Plextor PX-TV402U (unknown tuner)";
                board = &board_px_tv402u;
                break;
        case GO7007_BOARDID_LIFEVIEW_LR192:
                dev_err(&intf->dev, "The Lifeview TV Walker Ultra is not supported. Sorry!\n");
                return -ENODEV;
#if 0
                name = "Lifeview TV Walker Ultra";
                board = &board_lifeview_lr192;
#endif
                break;
        case GO7007_BOARDID_SENSORAY_2250:
                dev_info(&intf->dev, "Sensoray 2250 found\n");
                name = "Sensoray 2250/2251";
                board = &board_sensoray_2250;
                break;
        case GO7007_BOARDID_ADS_USBAV_709:
                name = "ADS Tech DVD Xpress DX2";
                board = &board_ads_usbav_709;
                break;
        default:
                dev_err(&intf->dev, "unknown board ID %d!\n",
                                (unsigned int)id->driver_info);
                return -ENODEV;
        }

        go = go7007_alloc(&board->main_info, &intf->dev);
        if (go == NULL)
                return -ENOMEM;

        usb = kzalloc(sizeof(struct go7007_usb), GFP_KERNEL);
        if (usb == NULL) {
                kfree(go);
                return -ENOMEM;
        }

        usb->board = board;
        usb->usbdev = usbdev;
        usb_make_path(usbdev, go->bus_info, sizeof(go->bus_info));
        go->board_id = id->driver_info;
        strscpy(go->name, name, sizeof(go->name));
        if (board->flags & GO7007_USB_EZUSB)
                go->hpi_ops = &go7007_usb_ezusb_hpi_ops;
        else
                go->hpi_ops = &go7007_usb_onboard_hpi_ops;
        go->hpi_context = usb;

        ep = usb->usbdev->ep_in[4];
        if (!ep)
                goto allocfail;

        /* Allocate the URB and buffer for receiving incoming interrupts */
        usb->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
        if (usb->intr_urb == NULL)
                goto allocfail;
        usb->intr_urb->transfer_buffer = kmalloc_array(2, sizeof(u16),
                                                       GFP_KERNEL);
        if (usb->intr_urb->transfer_buffer == NULL)
                goto allocfail;

        if (usb_endpoint_type(&ep->desc) == USB_ENDPOINT_XFER_BULK)
                usb_fill_bulk_urb(usb->intr_urb, usb->usbdev,
                        usb_rcvbulkpipe(usb->usbdev, 4),
                        usb->intr_urb->transfer_buffer, 2*sizeof(u16),
                        go7007_usb_readinterrupt_complete, go);
        else
                usb_fill_int_urb(usb->intr_urb, usb->usbdev,
                        usb_rcvintpipe(usb->usbdev, 4),
                        usb->intr_urb->transfer_buffer, 2*sizeof(u16),
                        go7007_usb_readinterrupt_complete, go, 8);
        usb_set_intfdata(intf, &go->v4l2_dev);

        /* Boot the GO7007 */
        if (go7007_boot_encoder(go, go->board_info->flags &
                                        GO7007_BOARD_USE_ONBOARD_I2C) < 0)
                goto allocfail;

        /* Register the EZ-USB I2C adapter, if we're using it */
        if (board->flags & GO7007_USB_EZUSB_I2C) {
                memcpy(&go->i2c_adapter, &go7007_usb_adap_templ,
                                sizeof(go7007_usb_adap_templ));
                mutex_init(&usb->i2c_lock);
                go->i2c_adapter.dev.parent = go->dev;
                i2c_set_adapdata(&go->i2c_adapter, go);
                if (i2c_add_adapter(&go->i2c_adapter) < 0) {
                        dev_err(go->dev, "error: i2c_add_adapter failed\n");
                        goto allocfail;
                }
                go->i2c_adapter_online = 1;
        }

        /* Pelco and Adlink reused the XMen and XMen-III vendor and product
         * IDs for their own incompatible designs.  We can detect XMen boards
         * by probing the sensor, but there is no way to probe the sensors on
         * the Pelco and Adlink designs so we default to the Adlink.  If it
         * is actually a Pelco, the user must set the assume_endura module
         * parameter. */
        if ((go->board_id == GO7007_BOARDID_XMEN ||
                                go->board_id == GO7007_BOARDID_XMEN_III) &&
                        go->i2c_adapter_online) {
                union i2c_smbus_data data;

                /* Check to see if register 0x0A is 0x76 */
                i2c_smbus_xfer(&go->i2c_adapter, 0x21, I2C_CLIENT_SCCB,
                        I2C_SMBUS_READ, 0x0A, I2C_SMBUS_BYTE_DATA, &data);
                if (data.byte != 0x76) {
                        if (assume_endura) {
                                go->board_id = GO7007_BOARDID_ENDURA;
                                usb->board = board = &board_endura;
                                go->board_info = &board->main_info;
                                strscpy(go->name, "Pelco Endura",
                                        sizeof(go->name));
                        } else {
                                u16 channel;

                                /* read channel number from GPIO[1:0] */
                                if (go7007_read_addr(go, 0x3c81, &channel))
                                        goto allocfail;

                                channel &= 0x3;
                                go->board_id = GO7007_BOARDID_ADLINK_MPG24;
                                usb->board = board = &board_adlink_mpg24;
                                go->board_info = &board->main_info;
                                go->channel_number = channel;
                                snprintf(go->name, sizeof(go->name),
                                        "Adlink PCI-MPG24, channel #%d",
                                        channel);
                        }
                        go7007_update_board(go);
                }
        }

        num_i2c_devs = go->board_info->num_i2c_devs;

        /* Probe the tuner model on the TV402U */
        if (go->board_id == GO7007_BOARDID_PX_TV402U) {
                /* Board strapping indicates tuner model */
                if (go7007_usb_vendor_request(go, 0x41, 0, 0, go->usb_buf, 3,
                                        1) < 0) {
                        dev_err(go->dev, "GPIO read failed!\n");
                        goto allocfail;
                }
                switch (go->usb_buf[0] >> 6) {
                case 1:
                        go->tuner_type = TUNER_SONY_BTF_PG472Z;
                        go->std = V4L2_STD_PAL;
                        strscpy(go->name, "Plextor PX-TV402U-EU",
                                sizeof(go->name));
                        break;
                case 2:
                        go->tuner_type = TUNER_SONY_BTF_PK467Z;
                        go->std = V4L2_STD_NTSC_M_JP;
                        num_i2c_devs -= 2;
                        strscpy(go->name, "Plextor PX-TV402U-JP",
                                sizeof(go->name));
                        break;
                case 3:
                        go->tuner_type = TUNER_SONY_BTF_PB463Z;
                        num_i2c_devs -= 2;
                        strscpy(go->name, "Plextor PX-TV402U-NA",
                                sizeof(go->name));
                        break;
                default:
                        pr_debug("unable to detect tuner type!\n");
                        break;
                }
                /* Configure tuner mode selection inputs connected
                 * to the EZ-USB GPIO output pins */
                if (go7007_usb_vendor_request(go, 0x40, 0x7f02, 0,
                                        NULL, 0, 0) < 0) {
                        dev_err(go->dev, "GPIO write failed!\n");
                        goto allocfail;
                }
        }

        /* Print a nasty message if the user attempts to use a USB2.0 device in
         * a USB1.1 port.  There will be silent corruption of the stream. */
        if ((board->flags & GO7007_USB_EZUSB) &&
                        usbdev->speed != USB_SPEED_HIGH)
                dev_err(go->dev, "*** WARNING ***  This device must be connected to a USB 2.0 port! Attempting to capture video through a USB 1.1 port will result in stream corruption, even at low bitrates!\n");

        /* Allocate the URBs and buffers for receiving the video stream */
        if (board->flags & GO7007_USB_EZUSB) {
                if (!usb->usbdev->ep_in[6])
                        goto allocfail;
                v_urb_len = 1024;
                video_pipe = usb_rcvbulkpipe(usb->usbdev, 6);
        } else {
                if (!usb->usbdev->ep_in[1])
                        goto allocfail;
                v_urb_len = 512;
                video_pipe = usb_rcvbulkpipe(usb->usbdev, 1);
        }
        for (i = 0; i < 8; ++i) {
                usb->video_urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
                if (usb->video_urbs[i] == NULL)
                        goto allocfail;
                usb->video_urbs[i]->transfer_buffer =
                                                kmalloc(v_urb_len, GFP_KERNEL);
                if (usb->video_urbs[i]->transfer_buffer == NULL)
                        goto allocfail;
                usb_fill_bulk_urb(usb->video_urbs[i], usb->usbdev, video_pipe,
                                usb->video_urbs[i]->transfer_buffer, v_urb_len,
                                go7007_usb_read_video_pipe_complete, go);
        }

        /* Allocate the URBs and buffers for receiving the audio stream */
        if ((board->flags & GO7007_USB_EZUSB) &&
            (board->main_info.flags & GO7007_BOARD_HAS_AUDIO)) {
                if (!usb->usbdev->ep_in[8])
                        goto allocfail;
                for (i = 0; i < 8; ++i) {
                        usb->audio_urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
                        if (usb->audio_urbs[i] == NULL)
                                goto allocfail;
                        usb->audio_urbs[i]->transfer_buffer = kmalloc(4096,
                                                                GFP_KERNEL);
                        if (usb->audio_urbs[i]->transfer_buffer == NULL)
                                goto allocfail;
                        usb_fill_bulk_urb(usb->audio_urbs[i], usb->usbdev,
                                usb_rcvbulkpipe(usb->usbdev, 8),
                                usb->audio_urbs[i]->transfer_buffer, 4096,
                                go7007_usb_read_audio_pipe_complete, go);
                }
        }

        /* Do any final GO7007 initialization, then register the
         * V4L2 and ALSA interfaces */
        if (go7007_register_encoder(go, num_i2c_devs) < 0)
                goto allocfail;

        go->status = STATUS_ONLINE;
        return 0;

allocfail:
        go7007_usb_release(go);
        kfree(go);
        return -ENOMEM;
}

static void go7007_usb_disconnect(struct usb_interface *intf)
{
        struct go7007 *go = to_go7007(usb_get_intfdata(intf));

        mutex_lock(&go->queue_lock);
        mutex_lock(&go->serialize_lock);

        if (go->audio_enabled)
                go7007_snd_remove(go);

        go->status = STATUS_SHUTDOWN;
        v4l2_device_disconnect(&go->v4l2_dev);
        video_unregister_device(&go->vdev);
        mutex_unlock(&go->serialize_lock);
        mutex_unlock(&go->queue_lock);

        v4l2_device_put(&go->v4l2_dev);
}

static struct usb_driver go7007_usb_driver = {
        .name                = "go7007",
        .probe                = go7007_usb_probe,
        .disconnect        = go7007_usb_disconnect,
        .id_table        = go7007_usb_id_table,
};

module_usb_driver(go7007_usb_driver);
MODULE_DESCRIPTION("WIS GO7007 USB support");
MODULE_LICENSE("GPL v2");
















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// SPDX-License-Identifier: GPL-2.0-only
/* This is a module which is used to mark packets for tracing.
 */
#include <linux/module.h>
#include <linux/skbuff.h>

#include <linux/netfilter/x_tables.h>
#include <net/netfilter/nf_log.h>

MODULE_DESCRIPTION("Xtables: packet flow tracing");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_TRACE");
MODULE_ALIAS("ip6t_TRACE");

static int trace_tg_check(const struct xt_tgchk_param *par)
{
        return nf_logger_find_get(par->family, NF_LOG_TYPE_LOG);
}

static void trace_tg_destroy(const struct xt_tgdtor_param *par)
{
        nf_logger_put(par->family, NF_LOG_TYPE_LOG);
}

static unsigned int
trace_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
        skb->nf_trace = 1;
        return XT_CONTINUE;
}

static struct xt_target trace_tg_reg[] __read_mostly = {
        {
                .name                = "TRACE",
                .revision        = 0,
                .family                = NFPROTO_IPV4,
                .table                = "raw",
                .target                = trace_tg,
                .checkentry        = trace_tg_check,
                .destroy        = trace_tg_destroy,
                .me                = THIS_MODULE,
        },
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
        {
                .name                = "TRACE",
                .revision        = 0,
                .family                = NFPROTO_IPV6,
                .table                = "raw",
                .target                = trace_tg,
                .checkentry        = trace_tg_check,
                .destroy        = trace_tg_destroy,
                .me                = THIS_MODULE,
        },
#endif
};

static int __init trace_tg_init(void)
{
        return xt_register_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
}

static void __exit trace_tg_exit(void)
{
        xt_unregister_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg));
}

module_init(trace_tg_init);
module_exit(trace_tg_exit);
MODULE_SOFTDEP("pre: nf_log_syslog");















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/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM fib

#if !defined(_TRACE_FIB_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_FIB_H

#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <net/flow.h>
#include <net/inet_dscp.h>
#include <net/ip_fib.h>
#include <linux/tracepoint.h>

TRACE_EVENT(fib_table_lookup,

        TP_PROTO(u32 tb_id, const struct flowi4 *flp,
                 const struct fib_nh_common *nhc, int err),

        TP_ARGS(tb_id, flp, nhc, err),

        TP_STRUCT__entry(
                __field(        u32,        tb_id                )
                __field(        int,        err                )
                __field(        int,        oif                )
                __field(        int,        iif                )
                __field(        u8,        proto                )
                __field(        __u8,        tos                )
                __field(        __u8,        scope                )
                __field(        __u8,        flags                )
                __array(        __u8,        src,        4        )
                __array(        __u8,        dst,        4        )
                __array(        __u8,        gw4,        4        )
                __array(        __u8,        gw6,        16        )
                __field(        u16,        sport                )
                __field(        u16,        dport                )
                __array(char,  name,   IFNAMSIZ )
        ),

        TP_fast_assign(
                struct net_device *dev;
                struct in6_addr *in6;
                __be32 *p32;

                __entry->tb_id = tb_id;
                __entry->err = err;
                __entry->oif = flp->flowi4_oif;
                __entry->iif = flp->flowi4_iif;
                __entry->tos = inet_dscp_to_dsfield(flp->flowi4_dscp);
                __entry->scope = flp->flowi4_scope;
                __entry->flags = flp->flowi4_flags;

                p32 = (__be32 *) __entry->src;
                *p32 = flp->saddr;

                p32 = (__be32 *) __entry->dst;
                *p32 = flp->daddr;

                __entry->proto = flp->flowi4_proto;
                if (__entry->proto == IPPROTO_TCP ||
                    __entry->proto == IPPROTO_UDP) {
                        __entry->sport = ntohs(flp->fl4_sport);
                        __entry->dport = ntohs(flp->fl4_dport);
                } else {
                        __entry->sport = 0;
                        __entry->dport = 0;
                }

                dev = nhc ? nhc->nhc_dev : NULL;
                strscpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ);

                if (nhc) {
                        if (nhc->nhc_gw_family == AF_INET) {
                                p32 = (__be32 *) __entry->gw4;
                                *p32 = nhc->nhc_gw.ipv4;

                                in6 = (struct in6_addr *)__entry->gw6;
                                *in6 = in6addr_any;
                        } else if (nhc->nhc_gw_family == AF_INET6) {
                                p32 = (__be32 *) __entry->gw4;
                                *p32 = 0;

                                in6 = (struct in6_addr *)__entry->gw6;
                                *in6 = nhc->nhc_gw.ipv6;
                        }
                } else {
                        p32 = (__be32 *) __entry->gw4;
                        *p32 = 0;

                        in6 = (struct in6_addr *)__entry->gw6;
                        *in6 = in6addr_any;
                }
        ),

        TP_printk("table %u oif %d iif %d proto %u %pI4/%u -> %pI4/%u tos %d scope %d flags %x ==> dev %s gw %pI4/%pI6c err %d",
                  __entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
                  __entry->src, __entry->sport, __entry->dst, __entry->dport,
                  __entry->tos, __entry->scope, __entry->flags,
                  __entry->name, __entry->gw4, __entry->gw6, __entry->err)
);
#endif /* _TRACE_FIB_H */

/* This part must be outside protection */
#include <trace/define_trace.h>






























































































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// SPDX-License-Identifier: GPL-2.0-only
/*
 * VMware VMCI Driver
 *
 * Copyright (C) 2012 VMware, Inc. All rights reserved.
 */

#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>

#include "vmci_driver.h"
#include "vmci_event.h"

static bool vmci_disable_host;
module_param_named(disable_host, vmci_disable_host, bool, 0);
MODULE_PARM_DESC(disable_host,
                 "Disable driver host personality (default=enabled)");

static bool vmci_disable_guest;
module_param_named(disable_guest, vmci_disable_guest, bool, 0);
MODULE_PARM_DESC(disable_guest,
                 "Disable driver guest personality (default=enabled)");

static bool vmci_guest_personality_initialized;
static bool vmci_host_personality_initialized;

static DEFINE_MUTEX(vmci_vsock_mutex); /* protects vmci_vsock_transport_cb */
static vmci_vsock_cb vmci_vsock_transport_cb;
static bool vmci_vsock_cb_host_called;

/*
 * vmci_get_context_id() - Gets the current context ID.
 *
 * Returns the current context ID.  Note that since this is accessed only
 * from code running in the host, this always returns the host context ID.
 */
u32 vmci_get_context_id(void)
{
        if (vmci_guest_code_active())
                return vmci_get_vm_context_id();
        else if (vmci_host_code_active())
                return VMCI_HOST_CONTEXT_ID;

        return VMCI_INVALID_ID;
}
EXPORT_SYMBOL_GPL(vmci_get_context_id);

/*
 * vmci_register_vsock_callback() - Register the VSOCK vmci_transport callback.
 *
 * The callback will be called when the first host or guest becomes active,
 * or if they are already active when this function is called.
 * To unregister the callback, call this function with NULL parameter.
 *
 * Returns 0 on success. -EBUSY if a callback is already registered.
 */
int vmci_register_vsock_callback(vmci_vsock_cb callback)
{
        int err = 0;

        mutex_lock(&vmci_vsock_mutex);

        if (vmci_vsock_transport_cb && callback) {
                err = -EBUSY;
                goto out;
        }

        vmci_vsock_transport_cb = callback;

        if (!vmci_vsock_transport_cb) {
                vmci_vsock_cb_host_called = false;
                goto out;
        }

        if (vmci_guest_code_active())
                vmci_vsock_transport_cb(false);

        if (vmci_host_users() > 0) {
                vmci_vsock_cb_host_called = true;
                vmci_vsock_transport_cb(true);
        }

out:
        mutex_unlock(&vmci_vsock_mutex);
        return err;
}
EXPORT_SYMBOL_GPL(vmci_register_vsock_callback);

void vmci_call_vsock_callback(bool is_host)
{
        mutex_lock(&vmci_vsock_mutex);

        if (!vmci_vsock_transport_cb)
                goto out;

        /* In the host, this function could be called multiple times,
         * but we want to register it only once.
         */
        if (is_host) {
                if (vmci_vsock_cb_host_called)
                        goto out;

                vmci_vsock_cb_host_called = true;
        }

        vmci_vsock_transport_cb(is_host);
out:
        mutex_unlock(&vmci_vsock_mutex);
}

static int __init vmci_drv_init(void)
{
        int vmci_err;
        int error;

        vmci_err = vmci_event_init();
        if (vmci_err < VMCI_SUCCESS) {
                pr_err("Failed to initialize VMCIEvent (result=%d)\n",
                       vmci_err);
                return -EINVAL;
        }

        if (!vmci_disable_guest) {
                error = vmci_guest_init();
                if (error) {
                        pr_warn("Failed to initialize guest personality (err=%d)\n",
                                error);
                } else {
                        vmci_guest_personality_initialized = true;
                        pr_info("Guest personality initialized and is %s\n",
                                vmci_guest_code_active() ?
                                "active" : "inactive");
                }
        }

        if (!vmci_disable_host) {
                error = vmci_host_init();
                if (error) {
                        pr_warn("Unable to initialize host personality (err=%d)\n",
                                error);
                } else {
                        vmci_host_personality_initialized = true;
                        pr_info("Initialized host personality\n");
                }
        }

        if (!vmci_guest_personality_initialized &&
            !vmci_host_personality_initialized) {
                vmci_event_exit();
                return -ENODEV;
        }

        return 0;
}
module_init(vmci_drv_init);

static void __exit vmci_drv_exit(void)
{
        if (vmci_guest_personality_initialized)
                vmci_guest_exit();

        if (vmci_host_personality_initialized)
                vmci_host_exit();

        vmci_event_exit();
}
module_exit(vmci_drv_exit);

MODULE_AUTHOR("VMware, Inc.");
MODULE_DESCRIPTION("VMware Virtual Machine Communication Interface.");
MODULE_VERSION("1.1.6.0-k");
MODULE_LICENSE("GPL v2");







































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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Packet matching code.
 *
 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
 * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/capability.h>
#include <linux/in.h>
#include <linux/skbuff.h>
#include <linux/kmod.h>
#include <linux/vmalloc.h>
#include <linux/netdevice.h>
#include <linux/module.h>
#include <linux/poison.h>
#include <net/ipv6.h>
#include <net/compat.h>
#include <linux/uaccess.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/err.h>
#include <linux/cpumask.h>

#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/netfilter/x_tables.h>
#include <net/netfilter/nf_log.h>
#include "../../netfilter/xt_repldata.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("IPv6 packet filter");

void *ip6t_alloc_initial_table(const struct xt_table *info)
{
        return xt_alloc_initial_table(ip6t, IP6T);
}
EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table);

/* Returns whether matches rule or not. */
/* Performance critical - called for every packet */
static inline bool
ip6_packet_match(const struct sk_buff *skb,
                 const char *indev,
                 const char *outdev,
                 const struct ip6t_ip6 *ip6info,
                 unsigned int *protoff,
                 u16 *fragoff, bool *hotdrop)
{
        unsigned long ret;
        const struct ipv6hdr *ipv6 = ipv6_hdr(skb);

        if (NF_INVF(ip6info, IP6T_INV_SRCIP,
                    ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk,
                                         &ip6info->src)) ||
            NF_INVF(ip6info, IP6T_INV_DSTIP,
                    ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk,
                                         &ip6info->dst)))
                return false;

        ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask);

        if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0))
                return false;

        ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask);

        if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0))
                return false;

/* ... might want to do something with class and flowlabel here ... */

        /* look for the desired protocol header */
        if (ip6info->flags & IP6T_F_PROTO) {
                int protohdr;
                unsigned short _frag_off;

                protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL);
                if (protohdr < 0) {
                        if (_frag_off == 0)
                                *hotdrop = true;
                        return false;
                }
                *fragoff = _frag_off;

                if (ip6info->proto == protohdr) {
                        if (ip6info->invflags & IP6T_INV_PROTO)
                                return false;

                        return true;
                }

                /* We need match for the '-p all', too! */
                if ((ip6info->proto != 0) &&
                        !(ip6info->invflags & IP6T_INV_PROTO))
                        return false;
        }
        return true;
}

/* should be ip6 safe */
static bool
ip6_checkentry(const struct ip6t_ip6 *ipv6)
{
        if (ipv6->flags & ~IP6T_F_MASK)
                return false;
        if (ipv6->invflags & ~IP6T_INV_MASK)
                return false;

        return true;
}

static unsigned int
ip6t_error(struct sk_buff *skb, const struct xt_action_param *par)
{
        net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo);

        return NF_DROP;
}

static inline struct ip6t_entry *
get_entry(const void *base, unsigned int offset)
{
        return (struct ip6t_entry *)(base + offset);
}

/* All zeroes == unconditional rule. */
/* Mildly perf critical (only if packet tracing is on) */
static inline bool unconditional(const struct ip6t_entry *e)
{
        static const struct ip6t_ip6 uncond;

        return e->target_offset == sizeof(struct ip6t_entry) &&
               memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0;
}

static inline const struct xt_entry_target *
ip6t_get_target_c(const struct ip6t_entry *e)
{
        return ip6t_get_target((struct ip6t_entry *)e);
}

#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
/* This cries for unification! */
static const char *const hooknames[] = {
        [NF_INET_PRE_ROUTING]                = "PREROUTING",
        [NF_INET_LOCAL_IN]                = "INPUT",
        [NF_INET_FORWARD]                = "FORWARD",
        [NF_INET_LOCAL_OUT]                = "OUTPUT",
        [NF_INET_POST_ROUTING]                = "POSTROUTING",
};

enum nf_ip_trace_comments {
        NF_IP6_TRACE_COMMENT_RULE,
        NF_IP6_TRACE_COMMENT_RETURN,
        NF_IP6_TRACE_COMMENT_POLICY,
};

static const char *const comments[] = {
        [NF_IP6_TRACE_COMMENT_RULE]        = "rule",
        [NF_IP6_TRACE_COMMENT_RETURN]        = "return",
        [NF_IP6_TRACE_COMMENT_POLICY]        = "policy",
};

static const struct nf_loginfo trace_loginfo = {
        .type = NF_LOG_TYPE_LOG,
        .u = {
                .log = {
                        .level = LOGLEVEL_WARNING,
                        .logflags = NF_LOG_DEFAULT_MASK,
                },
        },
};

/* Mildly perf critical (only if packet tracing is on) */
static inline int
get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e,
                      const char *hookname, const char **chainname,
                      const char **comment, unsigned int *rulenum)
{
        const struct xt_standard_target *t = (void *)ip6t_get_target_c(s);

        if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) {
                /* Head of user chain: ERROR target with chainname */
                *chainname = t->target.data;
                (*rulenum) = 0;
        } else if (s == e) {
                (*rulenum)++;

                if (unconditional(s) &&
                    strcmp(t->target.u.kernel.target->name,
                           XT_STANDARD_TARGET) == 0 &&
                    t->verdict < 0) {
                        /* Tail of chains: STANDARD target (return/policy) */
                        *comment = *chainname == hookname
                                ? comments[NF_IP6_TRACE_COMMENT_POLICY]
                                : comments[NF_IP6_TRACE_COMMENT_RETURN];
                }
                return 1;
        } else
                (*rulenum)++;

        return 0;
}

static void trace_packet(struct net *net,
                         const struct sk_buff *skb,
                         unsigned int hook,
                         const struct net_device *in,
                         const struct net_device *out,
                         const char *tablename,
                         const struct xt_table_info *private,
                         const struct ip6t_entry *e)
{
        const struct ip6t_entry *root;
        const char *hookname, *chainname, *comment;
        const struct ip6t_entry *iter;
        unsigned int rulenum = 0;

        root = get_entry(private->entries, private->hook_entry[hook]);

        hookname = chainname = hooknames[hook];
        comment = comments[NF_IP6_TRACE_COMMENT_RULE];

        xt_entry_foreach(iter, root, private->size - private->hook_entry[hook])
                if (get_chainname_rulenum(iter, e, hookname,
                    &chainname, &comment, &rulenum) != 0)
                        break;

        nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo,
                     "TRACE: %s:%s:%s:%u ",
                     tablename, chainname, comment, rulenum);
}
#endif

static inline struct ip6t_entry *
ip6t_next_entry(const struct ip6t_entry *entry)
{
        return (void *)entry + entry->next_offset;
}

/* Returns one of the generic firewall policies, like NF_ACCEPT. */
unsigned int
ip6t_do_table(void *priv, struct sk_buff *skb,
              const struct nf_hook_state *state)
{
        const struct xt_table *table = priv;
        unsigned int hook = state->hook;
        static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
        /* Initializing verdict to NF_DROP keeps gcc happy. */
        unsigned int verdict = NF_DROP;
        const char *indev, *outdev;
        const void *table_base;
        struct ip6t_entry *e, **jumpstack;
        unsigned int stackidx, cpu;
        const struct xt_table_info *private;
        struct xt_action_param acpar;
        unsigned int addend;

        /* Initialization */
        stackidx = 0;
        indev = state->in ? state->in->name : nulldevname;
        outdev = state->out ? state->out->name : nulldevname;
        /* We handle fragments by dealing with the first fragment as
         * if it was a normal packet.  All other fragments are treated
         * normally, except that they will NEVER match rules that ask
         * things we don't know, ie. tcp syn flag or ports).  If the
         * rule is also a fragment-specific rule, non-fragments won't
         * match it. */
        acpar.fragoff = 0;
        acpar.hotdrop = false;
        acpar.state   = state;

        WARN_ON(!(table->valid_hooks & (1 << hook)));

        local_bh_disable();
        addend = xt_write_recseq_begin();
        private = READ_ONCE(table->private); /* Address dependency. */
        cpu        = smp_processor_id();
        table_base = private->entries;
        jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];

        /* Switch to alternate jumpstack if we're being invoked via TEE.
         * TEE issues XT_CONTINUE verdict on original skb so we must not
         * clobber the jumpstack.
         *
         * For recursion via REJECT or SYNPROXY the stack will be clobbered
         * but it is no problem since absolute verdict is issued by these.
         */
        if (static_key_false(&xt_tee_enabled))
                jumpstack += private->stacksize * current->in_nf_duplicate;

        e = get_entry(table_base, private->hook_entry[hook]);

        do {
                const struct xt_entry_target *t;
                const struct xt_entry_match *ematch;
                struct xt_counters *counter;

                WARN_ON(!e);
                acpar.thoff = 0;
                if (!ip6_packet_match(skb, indev, outdev, &e->ipv6,
                    &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) {
 no_match:
                        e = ip6t_next_entry(e);
                        continue;
                }

                xt_ematch_foreach(ematch, e) {
                        acpar.match     = ematch->u.kernel.match;
                        acpar.matchinfo = ematch->data;
                        if (!acpar.match->match(skb, &acpar))
                                goto no_match;
                }

                counter = xt_get_this_cpu_counter(&e->counters);
                ADD_COUNTER(*counter, skb->len, 1);

                t = ip6t_get_target_c(e);
                WARN_ON(!t->u.kernel.target);

#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
                /* The packet is traced: log it */
                if (unlikely(skb->nf_trace))
                        trace_packet(state->net, skb, hook, state->in,
                                     state->out, table->name, private, e);
#endif
                /* Standard target? */
                if (!t->u.kernel.target->target) {
                        int v;

                        v = ((struct xt_standard_target *)t)->verdict;
                        if (v < 0) {
                                /* Pop from stack? */
                                if (v != XT_RETURN) {
                                        verdict = (unsigned int)(-v) - 1;
                                        break;
                                }
                                if (stackidx == 0)
                                        e = get_entry(table_base,
                                            private->underflow[hook]);
                                else
                                        e = ip6t_next_entry(jumpstack[--stackidx]);
                                continue;
                        }
                        if (table_base + v != ip6t_next_entry(e) &&
                            !(e->ipv6.flags & IP6T_F_GOTO)) {
                                if (unlikely(stackidx >= private->stacksize)) {
                                        verdict = NF_DROP;
                                        break;
                                }
                                jumpstack[stackidx++] = e;
                        }

                        e = get_entry(table_base, v);
                        continue;
                }

                acpar.target   = t->u.kernel.target;
                acpar.targinfo = t->data;

                verdict = t->u.kernel.target->target(skb, &acpar);
                if (verdict == XT_CONTINUE)
                        e = ip6t_next_entry(e);
                else
                        /* Verdict */
                        break;
        } while (!acpar.hotdrop);

        xt_write_recseq_end(addend);
        local_bh_enable();

        if (acpar.hotdrop)
                return NF_DROP;
        else return verdict;
}

/* Figures out from what hook each rule can be called: returns 0 if
   there are loops.  Puts hook bitmask in comefrom. */
static int
mark_source_chains(const struct xt_table_info *newinfo,
                   unsigned int valid_hooks, void *entry0,
                   unsigned int *offsets)
{
        unsigned int hook;

        /* No recursion; use packet counter to save back ptrs (reset
           to 0 as we leave), and comefrom to save source hook bitmask */
        for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
                unsigned int pos = newinfo->hook_entry[hook];
                struct ip6t_entry *e = entry0 + pos;

                if (!(valid_hooks & (1 << hook)))
                        continue;

                /* Set initial back pointer. */
                e->counters.pcnt = pos;

                for (;;) {
                        const struct xt_standard_target *t
                                = (void *)ip6t_get_target_c(e);
                        int visited = e->comefrom & (1 << hook);

                        if (e->comefrom & (1 << NF_INET_NUMHOOKS))
                                return 0;

                        e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));

                        /* Unconditional return/END. */
                        if ((unconditional(e) &&
                             (strcmp(t->target.u.user.name,
                                     XT_STANDARD_TARGET) == 0) &&
                             t->verdict < 0) || visited) {
                                unsigned int oldpos, size;

                                /* Return: backtrack through the last
                                   big jump. */
                                do {
                                        e->comefrom ^= (1<<NF_INET_NUMHOOKS);
                                        oldpos = pos;
                                        pos = e->counters.pcnt;
                                        e->counters.pcnt = 0;

                                        /* We're at the start. */
                                        if (pos == oldpos)
                                                goto next;

                                        e = entry0 + pos;
                                } while (oldpos == pos + e->next_offset);

                                /* Move along one */
                                size = e->next_offset;
                                e = entry0 + pos + size;
                                if (pos + size >= newinfo->size)
                                        return 0;
                                e->counters.pcnt = pos;
                                pos += size;
                        } else {
                                int newpos = t->verdict;

                                if (strcmp(t->target.u.user.name,
                                           XT_STANDARD_TARGET) == 0 &&
                                    newpos >= 0) {
                                        /* This a jump; chase it. */
                                        if (!xt_find_jump_offset(offsets, newpos,
                                                                 newinfo->number))
                                                return 0;
                                } else {
                                        /* ... this is a fallthru */
                                        newpos = pos + e->next_offset;
                                        if (newpos >= newinfo->size)
                                                return 0;
                                }
                                e = entry0 + newpos;
                                e->counters.pcnt = pos;
                                pos = newpos;
                        }
                }
next:                ;
        }
        return 1;
}

static void cleanup_match(struct xt_entry_match *m, struct net *net)
{
        struct xt_mtdtor_param par;

        par.net       = net;
        par.match     = m->u.kernel.match;
        par.matchinfo = m->data;
        par.family    = NFPROTO_IPV6;
        if (par.match->destroy != NULL)
                par.match->destroy(&par);
        module_put(par.match->me);
}

static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
{
        const struct ip6t_ip6 *ipv6 = par->entryinfo;

        par->match     = m->u.kernel.match;
        par->matchinfo = m->data;

        return xt_check_match(par, m->u.match_size - sizeof(*m),
                              ipv6->proto, ipv6->invflags & IP6T_INV_PROTO);
}

static int
find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par)
{
        struct xt_match *match;
        int ret;

        match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
                                      m->u.user.revision);
        if (IS_ERR(match))
                return PTR_ERR(match);

        m->u.kernel.match = match;

        ret = check_match(m, par);
        if (ret)
                goto err;

        return 0;
err:
        module_put(m->u.kernel.match->me);
        return ret;
}

static int check_target(struct ip6t_entry *e, struct net *net, const char *name)
{
        struct xt_entry_target *t = ip6t_get_target(e);
        struct xt_tgchk_param par = {
                .net       = net,
                .table     = name,
                .entryinfo = e,
                .target    = t->u.kernel.target,
                .targinfo  = t->data,
                .hook_mask = e->comefrom,
                .family    = NFPROTO_IPV6,
        };

        return xt_check_target(&par, t->u.target_size - sizeof(*t),
                               e->ipv6.proto,
                               e->ipv6.invflags & IP6T_INV_PROTO);
}

static int
find_check_entry(struct ip6t_entry *e, struct net *net, const char *name,
                 unsigned int size,
                 struct xt_percpu_counter_alloc_state *alloc_state)
{
        struct xt_entry_target *t;
        struct xt_target *target;
        int ret;
        unsigned int j;
        struct xt_mtchk_param mtpar;
        struct xt_entry_match *ematch;

        if (!xt_percpu_counter_alloc(alloc_state, &e->counters))
                return -ENOMEM;

        j = 0;
        memset(&mtpar, 0, sizeof(mtpar));
        mtpar.net        = net;
        mtpar.table     = name;
        mtpar.entryinfo = &e->ipv6;
        mtpar.hook_mask = e->comefrom;
        mtpar.family    = NFPROTO_IPV6;
        xt_ematch_foreach(ematch, e) {
                ret = find_check_match(ematch, &mtpar);
                if (ret != 0)
                        goto cleanup_matches;
                ++j;
        }

        t = ip6t_get_target(e);
        target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
                                        t->u.user.revision);
        if (IS_ERR(target)) {
                ret = PTR_ERR(target);
                goto cleanup_matches;
        }
        t->u.kernel.target = target;

        ret = check_target(e, net, name);
        if (ret)
                goto err;
        return 0;
 err:
        module_put(t->u.kernel.target->me);
 cleanup_matches:
        xt_ematch_foreach(ematch, e) {
                if (j-- == 0)
                        break;
                cleanup_match(ematch, net);
        }

        xt_percpu_counter_free(&e->counters);

        return ret;
}

static bool check_underflow(const struct ip6t_entry *e)
{
        const struct xt_entry_target *t;
        unsigned int verdict;

        if (!unconditional(e))
                return false;
        t = ip6t_get_target_c(e);
        if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
                return false;
        verdict = ((struct xt_standard_target *)t)->verdict;
        verdict = -verdict - 1;
        return verdict == NF_DROP || verdict == NF_ACCEPT;
}

static int
check_entry_size_and_hooks(struct ip6t_entry *e,
                           struct xt_table_info *newinfo,
                           const unsigned char *base,
                           const unsigned char *limit,
                           const unsigned int *hook_entries,
                           const unsigned int *underflows,
                           unsigned int valid_hooks)
{
        unsigned int h;
        int err;

        if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 ||
            (unsigned char *)e + sizeof(struct ip6t_entry) >= limit ||
            (unsigned char *)e + e->next_offset > limit)
                return -EINVAL;

        if (e->next_offset
            < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target))
                return -EINVAL;

        if (!ip6_checkentry(&e->ipv6))
                return -EINVAL;

        err = xt_check_entry_offsets(e, e->elems, e->target_offset,
                                     e->next_offset);
        if (err)
                return err;

        /* Check hooks & underflows */
        for (h = 0; h < NF_INET_NUMHOOKS; h++) {
                if (!(valid_hooks & (1 << h)))
                        continue;
                if ((unsigned char *)e - base == hook_entries[h])
                        newinfo->hook_entry[h] = hook_entries[h];
                if ((unsigned char *)e - base == underflows[h]) {
                        if (!check_underflow(e))
                                return -EINVAL;

                        newinfo->underflow[h] = underflows[h];
                }
        }

        /* Clear counters and comefrom */
        e->counters = ((struct xt_counters) { 0, 0 });
        e->comefrom = 0;
        return 0;
}

static void cleanup_entry(struct ip6t_entry *e, struct net *net)
{
        struct xt_tgdtor_param par;
        struct xt_entry_target *t;
        struct xt_entry_match *ematch;

        /* Cleanup all matches */
        xt_ematch_foreach(ematch, e)
                cleanup_match(ematch, net);
        t = ip6t_get_target(e);

        par.net      = net;
        par.target   = t->u.kernel.target;
        par.targinfo = t->data;
        par.family   = NFPROTO_IPV6;
        if (par.target->destroy != NULL)
                par.target->destroy(&par);
        module_put(par.target->me);
        xt_percpu_counter_free(&e->counters);
}

/* Checks and translates the user-supplied table segment (held in
   newinfo) */
static int
translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0,
                const struct ip6t_replace *repl)
{
        struct xt_percpu_counter_alloc_state alloc_state = { 0 };
        struct ip6t_entry *iter;
        unsigned int *offsets;
        unsigned int i;
        int ret = 0;

        newinfo->size = repl->size;
        newinfo->number = repl->num_entries;

        /* Init all hooks to impossible value. */
        for (i = 0; i < NF_INET_NUMHOOKS; i++) {
                newinfo->hook_entry[i] = 0xFFFFFFFF;
                newinfo->underflow[i] = 0xFFFFFFFF;
        }

        offsets = xt_alloc_entry_offsets(newinfo->number);
        if (!offsets)
                return -ENOMEM;
        i = 0;
        /* Walk through entries, checking offsets. */
        xt_entry_foreach(iter, entry0, newinfo->size) {
                ret = check_entry_size_and_hooks(iter, newinfo, entry0,
                                                 entry0 + repl->size,
                                                 repl->hook_entry,
                                                 repl->underflow,
                                                 repl->valid_hooks);
                if (ret != 0)
                        goto out_free;
                if (i < repl->num_entries)
                        offsets[i] = (void *)iter - entry0;
                ++i;
                if (strcmp(ip6t_get_target(iter)->u.user.name,
                    XT_ERROR_TARGET) == 0)
                        ++newinfo->stacksize;
        }

        ret = -EINVAL;
        if (i != repl->num_entries)
                goto out_free;

        ret = xt_check_table_hooks(newinfo, repl->valid_hooks);
        if (ret)
                goto out_free;

        if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) {
                ret = -ELOOP;
                goto out_free;
        }
        kvfree(offsets);

        /* Finally, each sanity check must pass */
        i = 0;
        xt_entry_foreach(iter, entry0, newinfo->size) {
                ret = find_check_entry(iter, net, repl->name, repl->size,
                                       &alloc_state);
                if (ret != 0)
                        break;
                ++i;
        }

        if (ret != 0) {
                xt_entry_foreach(iter, entry0, newinfo->size) {
                        if (i-- == 0)
                                break;
                        cleanup_entry(iter, net);
                }
                return ret;
        }

        return ret;
 out_free:
        kvfree(offsets);
        return ret;
}

static void
get_counters(const struct xt_table_info *t,
             struct xt_counters counters[])
{
        struct ip6t_entry *iter;
        unsigned int cpu;
        unsigned int i;

        for_each_possible_cpu(cpu) {
                seqcount_t *s = &per_cpu(xt_recseq, cpu);

                i = 0;
                xt_entry_foreach(iter, t->entries, t->size) {
                        struct xt_counters *tmp;
                        u64 bcnt, pcnt;
                        unsigned int start;

                        tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
                        do {
                                start = read_seqcount_begin(s);
                                bcnt = tmp->bcnt;
                                pcnt = tmp->pcnt;
                        } while (read_seqcount_retry(s, start));

                        ADD_COUNTER(counters[i], bcnt, pcnt);
                        ++i;
                        cond_resched();
                }
        }
}

static void get_old_counters(const struct xt_table_info *t,
                             struct xt_counters counters[])
{
        struct ip6t_entry *iter;
        unsigned int cpu, i;

        for_each_possible_cpu(cpu) {
                i = 0;
                xt_entry_foreach(iter, t->entries, t->size) {
                        const struct xt_counters *tmp;

                        tmp = xt_get_per_cpu_counter(&iter->counters, cpu);
                        ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt);
                        ++i;
                }
                cond_resched();
        }
}

static struct xt_counters *alloc_counters(const struct xt_table *table)
{
        unsigned int countersize;
        struct xt_counters *counters;
        const struct xt_table_info *private = table->private;

        /* We need atomic snapshot of counters: rest doesn't change
           (other than comefrom, which userspace doesn't care
           about). */
        countersize = sizeof(struct xt_counters) * private->number;
        counters = vzalloc(countersize);

        if (counters == NULL)
                return ERR_PTR(-ENOMEM);

        get_counters(private, counters);

        return counters;
}

static int
copy_entries_to_user(unsigned int total_size,
                     const struct xt_table *table,
                     void __user *userptr)
{
        unsigned int off, num;
        const struct ip6t_entry *e;
        struct xt_counters *counters;
        const struct xt_table_info *private = table->private;
        int ret = 0;
        const void *loc_cpu_entry;

        counters = alloc_counters(table);
        if (IS_ERR(counters))
                return PTR_ERR(counters);

        loc_cpu_entry = private->entries;

        /* FIXME: use iterator macros --RR */
        /* ... then go back and fix counters and names */
        for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
                unsigned int i;
                const struct xt_entry_match *m;
                const struct xt_entry_target *t;

                e = loc_cpu_entry + off;
                if (copy_to_user(userptr + off, e, sizeof(*e))) {
                        ret = -EFAULT;
                        goto free_counters;
                }
                if (copy_to_user(userptr + off
                                 + offsetof(struct ip6t_entry, counters),
                                 &counters[num],
                                 sizeof(counters[num])) != 0) {
                        ret = -EFAULT;
                        goto free_counters;
                }

                for (i = sizeof(struct ip6t_entry);
                     i < e->target_offset;
                     i += m->u.match_size) {
                        m = (void *)e + i;

                        if (xt_match_to_user(m, userptr + off + i)) {
                                ret = -EFAULT;
                                goto free_counters;
                        }
                }

                t = ip6t_get_target_c(e);
                if (xt_target_to_user(t, userptr + off + e->target_offset)) {
                        ret = -EFAULT;
                        goto free_counters;
                }
        }

 free_counters:
        vfree(counters);
        return ret;
}

#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
static void compat_standard_from_user(void *dst, const void *src)
{
        int v = *(compat_int_t *)src;

        if (v > 0)
                v += xt_compat_calc_jump(AF_INET6, v);
        memcpy(dst, &v, sizeof(v));
}

static int compat_standard_to_user(void __user *dst, const void *src)
{
        compat_int_t cv = *(int *)src;

        if (cv > 0)
                cv -= xt_compat_calc_jump(AF_INET6, cv);
        return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
}

static int compat_calc_entry(const struct ip6t_entry *e,
                             const struct xt_table_info *info,
                             const void *base, struct xt_table_info *newinfo)
{
        const struct xt_entry_match *ematch;
        const struct xt_entry_target *t;
        unsigned int entry_offset;
        int off, i, ret;

        off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
        entry_offset = (void *)e - base;
        xt_ematch_foreach(ematch, e)
                off += xt_compat_match_offset(ematch->u.kernel.match);
        t = ip6t_get_target_c(e);
        off += xt_compat_target_offset(t->u.kernel.target);
        newinfo->size -= off;
        ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
        if (ret)
                return ret;

        for (i = 0; i < NF_INET_NUMHOOKS; i++) {
                if (info->hook_entry[i] &&
                    (e < (struct ip6t_entry *)(base + info->hook_entry[i])))
                        newinfo->hook_entry[i] -= off;
                if (info->underflow[i] &&
                    (e < (struct ip6t_entry *)(base + info->underflow[i])))
                        newinfo->underflow[i] -= off;
        }
        return 0;
}

static int compat_table_info(const struct xt_table_info *info,
                             struct xt_table_info *newinfo)
{
        struct ip6t_entry *iter;
        const void *loc_cpu_entry;
        int ret;

        if (!newinfo || !info)
                return -EINVAL;

        /* we dont care about newinfo->entries */
        memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
        newinfo->initial_entries = 0;
        loc_cpu_entry = info->entries;
        ret = xt_compat_init_offsets(AF_INET6, info->number);
        if (ret)
                return ret;
        xt_entry_foreach(iter, loc_cpu_entry, info->size) {
                ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
                if (ret != 0)
                        return ret;
        }
        return 0;
}
#endif

static int get_info(struct net *net, void __user *user, const int *len)
{
        char name[XT_TABLE_MAXNAMELEN];
        struct xt_table *t;
        int ret;

        if (*len != sizeof(struct ip6t_getinfo))
                return -EINVAL;

        if (copy_from_user(name, user, sizeof(name)) != 0)
                return -EFAULT;

        name[XT_TABLE_MAXNAMELEN-1] = '\0';
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
        if (in_compat_syscall())
                xt_compat_lock(AF_INET6);
#endif
        t = xt_request_find_table_lock(net, AF_INET6, name);
        if (!IS_ERR(t)) {
                struct ip6t_getinfo info;
                const struct xt_table_info *private = t->private;
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
                struct xt_table_info tmp;

                if (in_compat_syscall()) {
                        ret = compat_table_info(private, &tmp);
                        xt_compat_flush_offsets(AF_INET6);
                        private = &tmp;
                }
#endif
                memset(&info, 0, sizeof(info));
                info.valid_hooks = t->valid_hooks;
                memcpy(info.hook_entry, private->hook_entry,
                       sizeof(info.hook_entry));
                memcpy(info.underflow, private->underflow,
                       sizeof(info.underflow));
                info.num_entries = private->number;
                info.size = private->size;
                strcpy(info.name, name);

                if (copy_to_user(user, &info, *len) != 0)
                        ret = -EFAULT;
                else
                        ret = 0;

                xt_table_unlock(t);
                module_put(t->me);
        } else
                ret = PTR_ERR(t);
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
        if (in_compat_syscall())
                xt_compat_unlock(AF_INET6);
#endif
        return ret;
}

static int
get_entries(struct net *net, struct ip6t_get_entries __user *uptr,
            const int *len)
{
        int ret;
        struct ip6t_get_entries get;
        struct xt_table *t;

        if (*len < sizeof(get))
                return -EINVAL;
        if (copy_from_user(&get, uptr, sizeof(get)) != 0)
                return -EFAULT;
        if (*len != sizeof(struct ip6t_get_entries) + get.size)
                return -EINVAL;

        get.name[sizeof(get.name) - 1] = '\0';

        t = xt_find_table_lock(net, AF_INET6, get.name);
        if (!IS_ERR(t)) {
                struct xt_table_info *private = t->private;
                if (get.size == private->size)
                        ret = copy_entries_to_user(private->size,
                                                   t, uptr->entrytable);
                else
                        ret = -EAGAIN;

                module_put(t->me);
                xt_table_unlock(t);
        } else
                ret = PTR_ERR(t);

        return ret;
}

static int
__do_replace(struct net *net, const char *name, unsigned int valid_hooks,
             struct xt_table_info *newinfo, unsigned int num_counters,
             void __user *counters_ptr)
{
        int ret;
        struct xt_table *t;
        struct xt_table_info *oldinfo;
        struct xt_counters *counters;
        struct ip6t_entry *iter;

        counters = xt_counters_alloc(num_counters);
        if (!counters) {
                ret = -ENOMEM;
                goto out;
        }

        t = xt_request_find_table_lock(net, AF_INET6, name);
        if (IS_ERR(t)) {
                ret = PTR_ERR(t);
                goto free_newinfo_counters_untrans;
        }

        /* You lied! */
        if (valid_hooks != t->valid_hooks) {
                ret = -EINVAL;
                goto put_module;
        }

        oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
        if (!oldinfo)
                goto put_module;

        /* Update module usage count based on number of rules */
        if ((oldinfo->number > oldinfo->initial_entries) ||
            (newinfo->number <= oldinfo->initial_entries))
                module_put(t->me);
        if ((oldinfo->number > oldinfo->initial_entries) &&
            (newinfo->number <= oldinfo->initial_entries))
                module_put(t->me);

        xt_table_unlock(t);

        get_old_counters(oldinfo, counters);

        /* Decrease module usage counts and free resource */
        xt_entry_foreach(iter, oldinfo->entries, oldinfo->size)
                cleanup_entry(iter, net);

        xt_free_table_info(oldinfo);
        if (copy_to_user(counters_ptr, counters,
                         sizeof(struct xt_counters) * num_counters) != 0) {
                /* Silent error, can't fail, new table is already in place */
                net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n");
        }
        vfree(counters);
        return 0;

 put_module:
        module_put(t->me);
        xt_table_unlock(t);
 free_newinfo_counters_untrans:
        vfree(counters);
 out:
        return ret;
}

static int
do_replace(struct net *net, sockptr_t arg, unsigned int len)
{
        int ret;
        struct ip6t_replace tmp;
        struct xt_table_info *newinfo;
        void *loc_cpu_entry;
        struct ip6t_entry *iter;

        if (len < sizeof(tmp))
                return -EINVAL;
        if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
                return -EFAULT;

        /* overflow check */
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
        if (tmp.num_counters == 0)
                return -EINVAL;
        if ((u64)len < (u64)tmp.size + sizeof(tmp))
                return -EINVAL;

        tmp.name[sizeof(tmp.name)-1] = 0;

        newinfo = xt_alloc_table_info(tmp.size);
        if (!newinfo)
                return -ENOMEM;

        loc_cpu_entry = newinfo->entries;
        if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
                        tmp.size) != 0) {
                ret = -EFAULT;
                goto free_newinfo;
        }

        ret = translate_table(net, newinfo, loc_cpu_entry, &tmp);
        if (ret != 0)
                goto free_newinfo;

        ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
                           tmp.num_counters, tmp.counters);
        if (ret)
                goto free_newinfo_untrans;
        return 0;

 free_newinfo_untrans:
        xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
                cleanup_entry(iter, net);
 free_newinfo:
        xt_free_table_info(newinfo);
        return ret;
}

static int
do_add_counters(struct net *net, sockptr_t arg, unsigned int len)
{
        unsigned int i;
        struct xt_counters_info tmp;
        struct xt_counters *paddc;
        struct xt_table *t;
        const struct xt_table_info *private;
        int ret = 0;
        struct ip6t_entry *iter;
        unsigned int addend;

        paddc = xt_copy_counters(arg, len, &tmp);
        if (IS_ERR(paddc))
                return PTR_ERR(paddc);
        t = xt_find_table_lock(net, AF_INET6, tmp.name);
        if (IS_ERR(t)) {
                ret = PTR_ERR(t);
                goto free;
        }

        local_bh_disable();
        private = t->private;
        if (private->number != tmp.num_counters) {
                ret = -EINVAL;
                goto unlock_up_free;
        }

        i = 0;
        addend = xt_write_recseq_begin();
        xt_entry_foreach(iter, private->entries, private->size) {
                struct xt_counters *tmp;

                tmp = xt_get_this_cpu_counter(&iter->counters);
                ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt);
                ++i;
        }
        xt_write_recseq_end(addend);
 unlock_up_free:
        local_bh_enable();
        xt_table_unlock(t);
        module_put(t->me);
 free:
        vfree(paddc);

        return ret;
}

#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
struct compat_ip6t_replace {
        char                        name[XT_TABLE_MAXNAMELEN];
        u32                        valid_hooks;
        u32                        num_entries;
        u32                        size;
        u32                        hook_entry[NF_INET_NUMHOOKS];
        u32                        underflow[NF_INET_NUMHOOKS];
        u32                        num_counters;
        compat_uptr_t                counters;        /* struct xt_counters * */
        struct compat_ip6t_entry entries[];
};

static int
compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr,
                          unsigned int *size, struct xt_counters *counters,
                          unsigned int i)
{
        struct xt_entry_target *t;
        struct compat_ip6t_entry __user *ce;
        u_int16_t target_offset, next_offset;
        compat_uint_t origsize;
        const struct xt_entry_match *ematch;
        int ret = 0;

        origsize = *size;
        ce = *dstptr;
        if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 ||
            copy_to_user(&ce->counters, &counters[i],
            sizeof(counters[i])) != 0)
                return -EFAULT;

        *dstptr += sizeof(struct compat_ip6t_entry);
        *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);

        xt_ematch_foreach(ematch, e) {
                ret = xt_compat_match_to_user(ematch, dstptr, size);
                if (ret != 0)
                        return ret;
        }
        target_offset = e->target_offset - (origsize - *size);
        t = ip6t_get_target(e);
        ret = xt_compat_target_to_user(t, dstptr, size);
        if (ret)
                return ret;
        next_offset = e->next_offset - (origsize - *size);
        if (put_user(target_offset, &ce->target_offset) != 0 ||
            put_user(next_offset, &ce->next_offset) != 0)
                return -EFAULT;
        return 0;
}

static int
compat_find_calc_match(struct xt_entry_match *m,
                       const struct ip6t_ip6 *ipv6,
                       int *size)
{
        struct xt_match *match;

        match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name,
                                      m->u.user.revision);
        if (IS_ERR(match))
                return PTR_ERR(match);

        m->u.kernel.match = match;
        *size += xt_compat_match_offset(match);
        return 0;
}

static void compat_release_entry(struct compat_ip6t_entry *e)
{
        struct xt_entry_target *t;
        struct xt_entry_match *ematch;

        /* Cleanup all matches */
        xt_ematch_foreach(ematch, e)
                module_put(ematch->u.kernel.match->me);
        t = compat_ip6t_get_target(e);
        module_put(t->u.kernel.target->me);
}

static int
check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e,
                                  struct xt_table_info *newinfo,
                                  unsigned int *size,
                                  const unsigned char *base,
                                  const unsigned char *limit)
{
        struct xt_entry_match *ematch;
        struct xt_entry_target *t;
        struct xt_target *target;
        unsigned int entry_offset;
        unsigned int j;
        int ret, off;

        if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 ||
            (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit ||
            (unsigned char *)e + e->next_offset > limit)
                return -EINVAL;

        if (e->next_offset < sizeof(struct compat_ip6t_entry) +
                             sizeof(struct compat_xt_entry_target))
                return -EINVAL;

        if (!ip6_checkentry(&e->ipv6))
                return -EINVAL;

        ret = xt_compat_check_entry_offsets(e, e->elems,
                                            e->target_offset, e->next_offset);
        if (ret)
                return ret;

        off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);
        entry_offset = (void *)e - (void *)base;
        j = 0;
        xt_ematch_foreach(ematch, e) {
                ret = compat_find_calc_match(ematch, &e->ipv6, &off);
                if (ret != 0)
                        goto release_matches;
                ++j;
        }

        t = compat_ip6t_get_target(e);
        target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name,
                                        t->u.user.revision);
        if (IS_ERR(target)) {
                ret = PTR_ERR(target);
                goto release_matches;
        }
        t->u.kernel.target = target;

        off += xt_compat_target_offset(target);
        *size += off;
        ret = xt_compat_add_offset(AF_INET6, entry_offset, off);
        if (ret)
                goto out;

        return 0;

out:
        module_put(t->u.kernel.target->me);
release_matches:
        xt_ematch_foreach(ematch, e) {
                if (j-- == 0)
                        break;
                module_put(ematch->u.kernel.match->me);
        }
        return ret;
}

static void
compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr,
                            unsigned int *size,
                            struct xt_table_info *newinfo, unsigned char *base)
{
        struct xt_entry_target *t;
        struct ip6t_entry *de;
        unsigned int origsize;
        int h;
        struct xt_entry_match *ematch;

        origsize = *size;
        de = *dstptr;
        memcpy(de, e, sizeof(struct ip6t_entry));
        memcpy(&de->counters, &e->counters, sizeof(e->counters));

        *dstptr += sizeof(struct ip6t_entry);
        *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry);

        xt_ematch_foreach(ematch, e)
                xt_compat_match_from_user(ematch, dstptr, size);

        de->target_offset = e->target_offset - (origsize - *size);
        t = compat_ip6t_get_target(e);
        xt_compat_target_from_user(t, dstptr, size);

        de->next_offset = e->next_offset - (origsize - *size);
        for (h = 0; h < NF_INET_NUMHOOKS; h++) {
                if ((unsigned char *)de - base < newinfo->hook_entry[h])
                        newinfo->hook_entry[h] -= origsize - *size;
                if ((unsigned char *)de - base < newinfo->underflow[h])
                        newinfo->underflow[h] -= origsize - *size;
        }
}

static int
translate_compat_table(struct net *net,
                       struct xt_table_info **pinfo,
                       void **pentry0,
                       const struct compat_ip6t_replace *compatr)
{
        unsigned int i, j;
        struct xt_table_info *newinfo, *info;
        void *pos, *entry0, *entry1;
        struct compat_ip6t_entry *iter0;
        struct ip6t_replace repl;
        unsigned int size;
        int ret;

        info = *pinfo;
        entry0 = *pentry0;
        size = compatr->size;
        info->number = compatr->num_entries;

        j = 0;
        xt_compat_lock(AF_INET6);
        ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries);
        if (ret)
                goto out_unlock;
        /* Walk through entries, checking offsets. */
        xt_entry_foreach(iter0, entry0, compatr->size) {
                ret = check_compat_entry_size_and_hooks(iter0, info, &size,
                                                        entry0,
                                                        entry0 + compatr->size);
                if (ret != 0)
                        goto out_unlock;
                ++j;
        }

        ret = -EINVAL;
        if (j != compatr->num_entries)
                goto out_unlock;

        ret = -ENOMEM;
        newinfo = xt_alloc_table_info(size);
        if (!newinfo)
                goto out_unlock;

        memset(newinfo->entries, 0, size);

        newinfo->number = compatr->num_entries;
        for (i = 0; i < NF_INET_NUMHOOKS; i++) {
                newinfo->hook_entry[i] = compatr->hook_entry[i];
                newinfo->underflow[i] = compatr->underflow[i];
        }
        entry1 = newinfo->entries;
        pos = entry1;
        size = compatr->size;
        xt_entry_foreach(iter0, entry0, compatr->size)
                compat_copy_entry_from_user(iter0, &pos, &size,
                                            newinfo, entry1);

        /* all module references in entry0 are now gone. */
        xt_compat_flush_offsets(AF_INET6);
        xt_compat_unlock(AF_INET6);

        memcpy(&repl, compatr, sizeof(*compatr));

        for (i = 0; i < NF_INET_NUMHOOKS; i++) {
                repl.hook_entry[i] = newinfo->hook_entry[i];
                repl.underflow[i] = newinfo->underflow[i];
        }

        repl.num_counters = 0;
        repl.counters = NULL;
        repl.size = newinfo->size;
        ret = translate_table(net, newinfo, entry1, &repl);
        if (ret)
                goto free_newinfo;

        *pinfo = newinfo;
        *pentry0 = entry1;
        xt_free_table_info(info);
        return 0;

free_newinfo:
        xt_free_table_info(newinfo);
        return ret;
out_unlock:
        xt_compat_flush_offsets(AF_INET6);
        xt_compat_unlock(AF_INET6);
        xt_entry_foreach(iter0, entry0, compatr->size) {
                if (j-- == 0)
                        break;
                compat_release_entry(iter0);
        }
        return ret;
}

static int
compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
{
        int ret;
        struct compat_ip6t_replace tmp;
        struct xt_table_info *newinfo;
        void *loc_cpu_entry;
        struct ip6t_entry *iter;

        if (len < sizeof(tmp))
                return -EINVAL;
        if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
                return -EFAULT;

        /* overflow check */
        if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
                return -ENOMEM;
        if (tmp.num_counters == 0)
                return -EINVAL;
        if ((u64)len < (u64)tmp.size + sizeof(tmp))
                return -EINVAL;

        tmp.name[sizeof(tmp.name)-1] = 0;

        newinfo = xt_alloc_table_info(tmp.size);
        if (!newinfo)
                return -ENOMEM;

        loc_cpu_entry = newinfo->entries;
        if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp),
                        tmp.size) != 0) {
                ret = -EFAULT;
                goto free_newinfo;
        }

        ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp);
        if (ret != 0)
                goto free_newinfo;

        ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
                           tmp.num_counters, compat_ptr(tmp.counters));
        if (ret)
                goto free_newinfo_untrans;
        return 0;

 free_newinfo_untrans:
        xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
                cleanup_entry(iter, net);
 free_newinfo:
        xt_free_table_info(newinfo);
        return ret;
}

struct compat_ip6t_get_entries {
        char name[XT_TABLE_MAXNAMELEN];
        compat_uint_t size;
        struct compat_ip6t_entry entrytable[];
};

static int
compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
                            void __user *userptr)
{
        struct xt_counters *counters;
        const struct xt_table_info *private = table->private;
        void __user *pos;
        unsigned int size;
        int ret = 0;
        unsigned int i = 0;
        struct ip6t_entry *iter;

        counters = alloc_counters(table);
        if (IS_ERR(counters))
                return PTR_ERR(counters);

        pos = userptr;
        size = total_size;
        xt_entry_foreach(iter, private->entries, total_size) {
                ret = compat_copy_entry_to_user(iter, &pos,
                                                &size, counters, i++);
                if (ret != 0)
                        break;
        }

        vfree(counters);
        return ret;
}

static int
compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
                   int *len)
{
        int ret;
        struct compat_ip6t_get_entries get;
        struct xt_table *t;

        if (*len < sizeof(get))
                return -EINVAL;

        if (copy_from_user(&get, uptr, sizeof(get)) != 0)
                return -EFAULT;

        if (*len != sizeof(struct compat_ip6t_get_entries) + get.size)
                return -EINVAL;

        get.name[sizeof(get.name) - 1] = '\0';

        xt_compat_lock(AF_INET6);
        t = xt_find_table_lock(net, AF_INET6, get.name);
        if (!IS_ERR(t)) {
                const struct xt_table_info *private = t->private;
                struct xt_table_info info;
                ret = compat_table_info(private, &info);
                if (!ret && get.size == info.size)
                        ret = compat_copy_entries_to_user(private->size,
                                                          t, uptr->entrytable);
                else if (!ret)
                        ret = -EAGAIN;

                xt_compat_flush_offsets(AF_INET6);
                module_put(t->me);
                xt_table_unlock(t);
        } else
                ret = PTR_ERR(t);

        xt_compat_unlock(AF_INET6);
        return ret;
}
#endif

static int
do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len)
{
        int ret;

        if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
                return -EPERM;

        switch (cmd) {
        case IP6T_SO_SET_REPLACE:
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
                if (in_compat_syscall())
                        ret = compat_do_replace(sock_net(sk), arg, len);
                else
#endif
                        ret = do_replace(sock_net(sk), arg, len);
                break;

        case IP6T_SO_SET_ADD_COUNTERS:
                ret = do_add_counters(sock_net(sk), arg, len);
                break;

        default:
                ret = -EINVAL;
        }

        return ret;
}

static int
do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
{
        int ret;

        if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
                return -EPERM;

        switch (cmd) {
        case IP6T_SO_GET_INFO:
                ret = get_info(sock_net(sk), user, len);
                break;

        case IP6T_SO_GET_ENTRIES:
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
                if (in_compat_syscall())
                        ret = compat_get_entries(sock_net(sk), user, len);
                else
#endif
                        ret = get_entries(sock_net(sk), user, len);
                break;

        case IP6T_SO_GET_REVISION_MATCH:
        case IP6T_SO_GET_REVISION_TARGET: {
                struct xt_get_revision rev;
                int target;

                if (*len != sizeof(rev)) {
                        ret = -EINVAL;
                        break;
                }
                if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
                        ret = -EFAULT;
                        break;
                }
                rev.name[sizeof(rev.name)-1] = 0;

                if (cmd == IP6T_SO_GET_REVISION_TARGET)
                        target = 1;
                else
                        target = 0;

                try_then_request_module(xt_find_revision(AF_INET6, rev.name,
                                                         rev.revision,
                                                         target, &ret),
                                        "ip6t_%s", rev.name);
                break;
        }

        default:
                ret = -EINVAL;
        }

        return ret;
}

static void __ip6t_unregister_table(struct net *net, struct xt_table *table)
{
        struct xt_table_info *private;
        void *loc_cpu_entry;
        struct module *table_owner = table->me;
        struct ip6t_entry *iter;

        private = xt_unregister_table(table);

        /* Decrease module usage counts and free resources */
        loc_cpu_entry = private->entries;
        xt_entry_foreach(iter, loc_cpu_entry, private->size)
                cleanup_entry(iter, net);
        if (private->number > private->initial_entries)
                module_put(table_owner);
        xt_free_table_info(private);
}

int ip6t_register_table(struct net *net, const struct xt_table *table,
                        const struct ip6t_replace *repl,
                        const struct nf_hook_ops *template_ops)
{
        struct nf_hook_ops *ops;
        unsigned int num_ops;
        int ret, i;
        struct xt_table_info *newinfo;
        struct xt_table_info bootstrap = {0};
        void *loc_cpu_entry;
        struct xt_table *new_table;

        newinfo = xt_alloc_table_info(repl->size);
        if (!newinfo)
                return -ENOMEM;

        loc_cpu_entry = newinfo->entries;
        memcpy(loc_cpu_entry, repl->entries, repl->size);

        ret = translate_table(net, newinfo, loc_cpu_entry, repl);
        if (ret != 0) {
                xt_free_table_info(newinfo);
                return ret;
        }

        new_table = xt_register_table(net, table, &bootstrap, newinfo);
        if (IS_ERR(new_table)) {
                struct ip6t_entry *iter;

                xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
                        cleanup_entry(iter, net);
                xt_free_table_info(newinfo);
                return PTR_ERR(new_table);
        }

        if (!template_ops)
                return 0;

        num_ops = hweight32(table->valid_hooks);
        if (num_ops == 0) {
                ret = -EINVAL;
                goto out_free;
        }

        ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL);
        if (!ops) {
                ret = -ENOMEM;
                goto out_free;
        }

        for (i = 0; i < num_ops; i++)
                ops[i].priv = new_table;

        new_table->ops = ops;

        ret = nf_register_net_hooks(net, ops, num_ops);
        if (ret != 0)
                goto out_free;

        return ret;

out_free:
        __ip6t_unregister_table(net, new_table);
        return ret;
}

void ip6t_unregister_table_pre_exit(struct net *net, const char *name)
{
        struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name);

        if (table)
                nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks));
}

void ip6t_unregister_table_exit(struct net *net, const char *name)
{
        struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name);

        if (table)
                __ip6t_unregister_table(net, table);
}

/* The built-in targets: standard (NULL) and error. */
static struct xt_target ip6t_builtin_tg[] __read_mostly = {
        {
                .name             = XT_STANDARD_TARGET,
                .targetsize       = sizeof(int),
                .family           = NFPROTO_IPV6,
#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
                .compatsize       = sizeof(compat_int_t),
                .compat_from_user = compat_standard_from_user,
                .compat_to_user   = compat_standard_to_user,
#endif
        },
        {
                .name             = XT_ERROR_TARGET,
                .target           = ip6t_error,
                .targetsize       = XT_FUNCTION_MAXNAMELEN,
                .family           = NFPROTO_IPV6,
        },
};

static struct nf_sockopt_ops ip6t_sockopts = {
        .pf                = PF_INET6,
        .set_optmin        = IP6T_BASE_CTL,
        .set_optmax        = IP6T_SO_SET_MAX+1,
        .set                = do_ip6t_set_ctl,
        .get_optmin        = IP6T_BASE_CTL,
        .get_optmax        = IP6T_SO_GET_MAX+1,
        .get                = do_ip6t_get_ctl,
        .owner                = THIS_MODULE,
};

static int __net_init ip6_tables_net_init(struct net *net)
{
        return xt_proto_init(net, NFPROTO_IPV6);
}

static void __net_exit ip6_tables_net_exit(struct net *net)
{
        xt_proto_fini(net, NFPROTO_IPV6);
}

static struct pernet_operations ip6_tables_net_ops = {
        .init = ip6_tables_net_init,
        .exit = ip6_tables_net_exit,
};

static int __init ip6_tables_init(void)
{
        int ret;

        ret = register_pernet_subsys(&ip6_tables_net_ops);
        if (ret < 0)
                goto err1;

        /* No one else will be downing sem now, so we won't sleep */
        ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
        if (ret < 0)
                goto err2;

        /* Register setsockopt */
        ret = nf_register_sockopt(&ip6t_sockopts);
        if (ret < 0)
                goto err4;

        return 0;

err4:
        xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
err2:
        unregister_pernet_subsys(&ip6_tables_net_ops);
err1:
        return ret;
}

static void __exit ip6_tables_fini(void)
{
        nf_unregister_sockopt(&ip6t_sockopts);

        xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg));
        unregister_pernet_subsys(&ip6_tables_net_ops);
}

EXPORT_SYMBOL(ip6t_register_table);
EXPORT_SYMBOL(ip6t_unregister_table_pre_exit);
EXPORT_SYMBOL(ip6t_unregister_table_exit);
EXPORT_SYMBOL(ip6t_do_table);

module_init(ip6_tables_init);
module_exit(ip6_tables_fini);



























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// SPDX-License-Identifier: GPL-2.0-or-later
/* SCTP kernel implementation
 * (C) Copyright Red Hat Inc. 2017
 *
 * This file is part of the SCTP kernel implementation
 *
 * These functions manipulate sctp stream queue/scheduling.
 *
 * Please send any bug reports or fixes you make to the
 * email addresched(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
 */

#include <linux/list.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <net/sctp/stream_sched.h>

/* First Come First Serve (a.k.a. FIFO)
 * RFC DRAFT ndata Section 3.1
 */
static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
                               __u16 value, gfp_t gfp)
{
        return 0;
}

static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
                               __u16 *value)
{
        *value = 0;
        return 0;
}

static int sctp_sched_fcfs_init(struct sctp_stream *stream)
{
        return 0;
}

static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
                                    gfp_t gfp)
{
        return 0;
}

static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid)
{
}

static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
                                    struct sctp_datamsg *msg)
{
}

static struct sctp_chunk *sctp_sched_fcfs_dequeue(struct sctp_outq *q)
{
        struct sctp_stream *stream = &q->asoc->stream;
        struct sctp_chunk *ch = NULL;
        struct list_head *entry;

        if (list_empty(&q->out_chunk_list))
                goto out;

        if (stream->out_curr) {
                ch = list_entry(stream->out_curr->ext->outq.next,
                                struct sctp_chunk, stream_list);
        } else {
                entry = q->out_chunk_list.next;
                ch = list_entry(entry, struct sctp_chunk, list);
        }

        sctp_sched_dequeue_common(q, ch);

out:
        return ch;
}

static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
                                         struct sctp_chunk *chunk)
{
}

static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
{
}

static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
{
}

static struct sctp_sched_ops sctp_sched_fcfs = {
        .set = sctp_sched_fcfs_set,
        .get = sctp_sched_fcfs_get,
        .init = sctp_sched_fcfs_init,
        .init_sid = sctp_sched_fcfs_init_sid,
        .free_sid = sctp_sched_fcfs_free_sid,
        .enqueue = sctp_sched_fcfs_enqueue,
        .dequeue = sctp_sched_fcfs_dequeue,
        .dequeue_done = sctp_sched_fcfs_dequeue_done,
        .sched_all = sctp_sched_fcfs_sched_all,
        .unsched_all = sctp_sched_fcfs_unsched_all,
};

static void sctp_sched_ops_fcfs_init(void)
{
        sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
}

/* API to other parts of the stack */

static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];

void sctp_sched_ops_register(enum sctp_sched_type sched,
                             struct sctp_sched_ops *sched_ops)
{
        sctp_sched_ops[sched] = sched_ops;
}

void sctp_sched_ops_init(void)
{
        sctp_sched_ops_fcfs_init();
        sctp_sched_ops_prio_init();
        sctp_sched_ops_rr_init();
        sctp_sched_ops_fc_init();
        sctp_sched_ops_wfq_init();
}

static void sctp_sched_free_sched(struct sctp_stream *stream)
{
        struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
        struct sctp_stream_out_ext *soute;
        int i;

        sched->unsched_all(stream);
        for (i = 0; i < stream->outcnt; i++) {
                soute = SCTP_SO(stream, i)->ext;
                if (!soute)
                        continue;
                sched->free_sid(stream, i);
                /* Give the next scheduler a clean slate. */
                memset_after(soute, 0, outq);
        }
}

int sctp_sched_set_sched(struct sctp_association *asoc,
                         enum sctp_sched_type sched)
{
        struct sctp_sched_ops *old = asoc->outqueue.sched;
        struct sctp_datamsg *msg = NULL;
        struct sctp_sched_ops *n;
        struct sctp_chunk *ch;
        int i, ret = 0;

        if (sched > SCTP_SS_MAX)
                return -EINVAL;

        n = sctp_sched_ops[sched];
        if (old == n)
                return ret;

        if (old)
                sctp_sched_free_sched(&asoc->stream);

        asoc->outqueue.sched = n;
        n->init(&asoc->stream);
        for (i = 0; i < asoc->stream.outcnt; i++) {
                if (!SCTP_SO(&asoc->stream, i)->ext)
                        continue;

                ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC);
                if (ret)
                        goto err;
        }

        /* We have to requeue all chunks already queued. */
        list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
                if (ch->msg == msg)
                        continue;
                msg = ch->msg;
                n->enqueue(&asoc->outqueue, msg);
        }

        return ret;

err:
        sctp_sched_free_sched(&asoc->stream);
        asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */

        return ret;
}

int sctp_sched_get_sched(struct sctp_association *asoc)
{
        int i;

        for (i = 0; i <= SCTP_SS_MAX; i++)
                if (asoc->outqueue.sched == sctp_sched_ops[i])
                        return i;

        return 0;
}

int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
                         __u16 value, gfp_t gfp)
{
        if (sid >= asoc->stream.outcnt)
                return -EINVAL;

        if (!SCTP_SO(&asoc->stream, sid)->ext) {
                int ret;

                ret = sctp_stream_init_ext(&asoc->stream, sid);
                if (ret)
                        return ret;
        }

        return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
}

int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
                         __u16 *value)
{
        if (sid >= asoc->stream.outcnt)
                return -EINVAL;

        if (!SCTP_SO(&asoc->stream, sid)->ext)
                return 0;

        return asoc->outqueue.sched->get(&asoc->stream, sid, value);
}

void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch)
{
        if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
            !q->asoc->peer.intl_capable) {
                struct sctp_stream_out *sout;
                __u16 sid;

                /* datamsg is not finish, so save it as current one,
                 * in case application switch scheduler or a higher
                 * priority stream comes in.
                 */
                sid = sctp_chunk_stream_no(ch);
                sout = SCTP_SO(&q->asoc->stream, sid);
                q->asoc->stream.out_curr = sout;
                return;
        }

        q->asoc->stream.out_curr = NULL;
        q->sched->dequeue_done(q, ch);
}

/* Auxiliary functions for the schedulers */
void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch)
{
        list_del_init(&ch->list);
        list_del_init(&ch->stream_list);
        q->out_qlen -= ch->skb->len;
}

int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
{
        struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
        struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;

        INIT_LIST_HEAD(&ext->outq);
        return sched->init_sid(stream, sid, gfp);
}

struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream)
{
        struct sctp_association *asoc;

        asoc = container_of(stream, struct sctp_association, stream);

        return asoc->outqueue.sched;
}



































































































































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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2004, 2005 Oracle.  All rights reserved.
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/configfs.h>

#include "tcp.h"
#include "nodemanager.h"
#include "heartbeat.h"
#include "masklog.h"
#include "sys.h"

/* for now we operate under the assertion that there can be only one
 * cluster active at a time.  Changing this will require trickling
 * cluster references throughout where nodes are looked up */
struct o2nm_cluster *o2nm_single_cluster = NULL;

static const char *o2nm_fence_method_desc[O2NM_FENCE_METHODS] = {
        "reset",        /* O2NM_FENCE_RESET */
        "panic",        /* O2NM_FENCE_PANIC */
};

static inline void o2nm_lock_subsystem(void);
static inline void o2nm_unlock_subsystem(void);

struct o2nm_node *o2nm_get_node_by_num(u8 node_num)
{
        struct o2nm_node *node = NULL;

        if (node_num >= O2NM_MAX_NODES || o2nm_single_cluster == NULL)
                goto out;

        read_lock(&o2nm_single_cluster->cl_nodes_lock);
        node = o2nm_single_cluster->cl_nodes[node_num];
        if (node)
                config_item_get(&node->nd_item);
        read_unlock(&o2nm_single_cluster->cl_nodes_lock);
out:
        return node;
}
EXPORT_SYMBOL_GPL(o2nm_get_node_by_num);

int o2nm_configured_node_map(unsigned long *map, unsigned bytes)
{
        struct o2nm_cluster *cluster = o2nm_single_cluster;

        BUG_ON(bytes < (sizeof(cluster->cl_nodes_bitmap)));

        if (cluster == NULL)
                return -EINVAL;

        read_lock(&cluster->cl_nodes_lock);
        bitmap_copy(map, cluster->cl_nodes_bitmap, O2NM_MAX_NODES);
        read_unlock(&cluster->cl_nodes_lock);

        return 0;
}
EXPORT_SYMBOL_GPL(o2nm_configured_node_map);

static struct o2nm_node *o2nm_node_ip_tree_lookup(struct o2nm_cluster *cluster,
                                                  __be32 ip_needle,
                                                  struct rb_node ***ret_p,
                                                  struct rb_node **ret_parent)
{
        struct rb_node **p = &cluster->cl_node_ip_tree.rb_node;
        struct rb_node *parent = NULL;
        struct o2nm_node *node, *ret = NULL;

        while (*p) {
                int cmp;

                parent = *p;
                node = rb_entry(parent, struct o2nm_node, nd_ip_node);

                cmp = memcmp(&ip_needle, &node->nd_ipv4_address,
                                sizeof(ip_needle));
                if (cmp < 0)
                        p = &(*p)->rb_left;
                else if (cmp > 0)
                        p = &(*p)->rb_right;
                else {
                        ret = node;
                        break;
                }
        }

        if (ret_p != NULL)
                *ret_p = p;
        if (ret_parent != NULL)
                *ret_parent = parent;

        return ret;
}

struct o2nm_node *o2nm_get_node_by_ip(__be32 addr)
{
        struct o2nm_node *node = NULL;
        struct o2nm_cluster *cluster = o2nm_single_cluster;

        if (cluster == NULL)
                goto out;

        read_lock(&cluster->cl_nodes_lock);
        node = o2nm_node_ip_tree_lookup(cluster, addr, NULL, NULL);
        if (node)
                config_item_get(&node->nd_item);
        read_unlock(&cluster->cl_nodes_lock);

out:
        return node;
}
EXPORT_SYMBOL_GPL(o2nm_get_node_by_ip);

void o2nm_node_put(struct o2nm_node *node)
{
        config_item_put(&node->nd_item);
}
EXPORT_SYMBOL_GPL(o2nm_node_put);

void o2nm_node_get(struct o2nm_node *node)
{
        config_item_get(&node->nd_item);
}
EXPORT_SYMBOL_GPL(o2nm_node_get);

u8 o2nm_this_node(void)
{
        u8 node_num = O2NM_MAX_NODES;

        if (o2nm_single_cluster && o2nm_single_cluster->cl_has_local)
                node_num = o2nm_single_cluster->cl_local_node;

        return node_num;
}
EXPORT_SYMBOL_GPL(o2nm_this_node);

/* node configfs bits */

static struct o2nm_cluster *to_o2nm_cluster(struct config_item *item)
{
        return item ?
                container_of(to_config_group(item), struct o2nm_cluster,
                             cl_group)
                : NULL;
}

static struct o2nm_node *to_o2nm_node(struct config_item *item)
{
        return item ? container_of(item, struct o2nm_node, nd_item) : NULL;
}

static void o2nm_node_release(struct config_item *item)
{
        struct o2nm_node *node = to_o2nm_node(item);
        kfree(node);
}

static ssize_t o2nm_node_num_show(struct config_item *item, char *page)
{
        return sprintf(page, "%d\n", to_o2nm_node(item)->nd_num);
}

static struct o2nm_cluster *to_o2nm_cluster_from_node(struct o2nm_node *node)
{
        /* through the first node_set .parent
         * mycluster/nodes/mynode == o2nm_cluster->o2nm_node_group->o2nm_node */
        if (node->nd_item.ci_parent)
                return to_o2nm_cluster(node->nd_item.ci_parent->ci_parent);
        else
                return NULL;
}

enum {
        O2NM_NODE_ATTR_NUM = 0,
        O2NM_NODE_ATTR_PORT,
        O2NM_NODE_ATTR_ADDRESS,
};

static ssize_t o2nm_node_num_store(struct config_item *item, const char *page,
                                   size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster;
        unsigned long tmp;
        char *p = (char *)page;
        int ret = 0;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        if (tmp >= O2NM_MAX_NODES)
                return -ERANGE;

        /* once we're in the cl_nodes tree networking can look us up by
         * node number and try to use our address and port attributes
         * to connect to this node.. make sure that they've been set
         * before writing the node attribute? */
        if (!test_bit(O2NM_NODE_ATTR_ADDRESS, &node->nd_set_attributes) ||
            !test_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
                return -EINVAL; /* XXX */

        o2nm_lock_subsystem();
        cluster = to_o2nm_cluster_from_node(node);
        if (!cluster) {
                o2nm_unlock_subsystem();
                return -EINVAL;
        }

        write_lock(&cluster->cl_nodes_lock);
        if (cluster->cl_nodes[tmp])
                ret = -EEXIST;
        else if (test_and_set_bit(O2NM_NODE_ATTR_NUM,
                        &node->nd_set_attributes))
                ret = -EBUSY;
        else  {
                cluster->cl_nodes[tmp] = node;
                node->nd_num = tmp;
                set_bit(tmp, cluster->cl_nodes_bitmap);
        }
        write_unlock(&cluster->cl_nodes_lock);
        o2nm_unlock_subsystem();

        if (ret)
                return ret;

        return count;
}
static ssize_t o2nm_node_ipv4_port_show(struct config_item *item, char *page)
{
        return sprintf(page, "%u\n", ntohs(to_o2nm_node(item)->nd_ipv4_port));
}

static ssize_t o2nm_node_ipv4_port_store(struct config_item *item,
                                         const char *page, size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        unsigned long tmp;
        char *p = (char *)page;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        if (tmp == 0)
                return -EINVAL;
        if (tmp >= (u16)-1)
                return -ERANGE;

        if (test_and_set_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
                return -EBUSY;
        node->nd_ipv4_port = htons(tmp);

        return count;
}

static ssize_t o2nm_node_ipv4_address_show(struct config_item *item, char *page)
{
        return sprintf(page, "%pI4\n", &to_o2nm_node(item)->nd_ipv4_address);
}

static ssize_t o2nm_node_ipv4_address_store(struct config_item *item,
                                            const char *page,
                                            size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster;
        int ret, i;
        struct rb_node **p, *parent;
        unsigned int octets[4];
        __be32 ipv4_addr = 0;

        ret = sscanf(page, "%3u.%3u.%3u.%3u", &octets[3], &octets[2],
                     &octets[1], &octets[0]);
        if (ret != 4)
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(octets); i++) {
                if (octets[i] > 255)
                        return -ERANGE;
                be32_add_cpu(&ipv4_addr, octets[i] << (i * 8));
        }

        o2nm_lock_subsystem();
        cluster = to_o2nm_cluster_from_node(node);
        if (!cluster) {
                o2nm_unlock_subsystem();
                return -EINVAL;
        }

        ret = 0;
        write_lock(&cluster->cl_nodes_lock);
        if (o2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))
                ret = -EEXIST;
        else if (test_and_set_bit(O2NM_NODE_ATTR_ADDRESS,
                        &node->nd_set_attributes))
                ret = -EBUSY;
        else {
                rb_link_node(&node->nd_ip_node, parent, p);
                rb_insert_color(&node->nd_ip_node, &cluster->cl_node_ip_tree);
        }
        write_unlock(&cluster->cl_nodes_lock);
        o2nm_unlock_subsystem();

        if (ret)
                return ret;

        memcpy(&node->nd_ipv4_address, &ipv4_addr, sizeof(ipv4_addr));

        return count;
}

static ssize_t o2nm_node_local_show(struct config_item *item, char *page)
{
        return sprintf(page, "%d\n", to_o2nm_node(item)->nd_local);
}

static ssize_t o2nm_node_local_store(struct config_item *item, const char *page,
                                     size_t count)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster;
        unsigned long tmp;
        char *p = (char *)page;
        ssize_t ret;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        tmp = !!tmp; /* boolean of whether this node wants to be local */

        /* setting local turns on networking rx for now so we require having
         * set everything else first */
        if (!test_bit(O2NM_NODE_ATTR_ADDRESS, &node->nd_set_attributes) ||
            !test_bit(O2NM_NODE_ATTR_NUM, &node->nd_set_attributes) ||
            !test_bit(O2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
                return -EINVAL; /* XXX */

        o2nm_lock_subsystem();
        cluster = to_o2nm_cluster_from_node(node);
        if (!cluster) {
                ret = -EINVAL;
                goto out;
        }

        /* the only failure case is trying to set a new local node
         * when a different one is already set */
        if (tmp && tmp == cluster->cl_has_local &&
            cluster->cl_local_node != node->nd_num) {
                ret = -EBUSY;
                goto out;
        }

        /* bring up the rx thread if we're setting the new local node. */
        if (tmp && !cluster->cl_has_local) {
                ret = o2net_start_listening(node);
                if (ret)
                        goto out;
        }

        if (!tmp && cluster->cl_has_local &&
            cluster->cl_local_node == node->nd_num) {
                o2net_stop_listening(node);
                cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
        }

        node->nd_local = tmp;
        if (node->nd_local) {
                cluster->cl_has_local = tmp;
                cluster->cl_local_node = node->nd_num;
        }

        ret = count;

out:
        o2nm_unlock_subsystem();
        return ret;
}

CONFIGFS_ATTR(o2nm_node_, num);
CONFIGFS_ATTR(o2nm_node_, ipv4_port);
CONFIGFS_ATTR(o2nm_node_, ipv4_address);
CONFIGFS_ATTR(o2nm_node_, local);

static struct configfs_attribute *o2nm_node_attrs[] = {
        &o2nm_node_attr_num,
        &o2nm_node_attr_ipv4_port,
        &o2nm_node_attr_ipv4_address,
        &o2nm_node_attr_local,
        NULL,
};

static struct configfs_item_operations o2nm_node_item_ops = {
        .release                = o2nm_node_release,
};

static const struct config_item_type o2nm_node_type = {
        .ct_item_ops        = &o2nm_node_item_ops,
        .ct_attrs        = o2nm_node_attrs,
        .ct_owner        = THIS_MODULE,
};

/* node set */

struct o2nm_node_group {
        struct config_group ns_group;
        /* some stuff? */
};

#if 0
static struct o2nm_node_group *to_o2nm_node_group(struct config_group *group)
{
        return group ?
                container_of(group, struct o2nm_node_group, ns_group)
                : NULL;
}
#endif

static ssize_t o2nm_cluster_attr_write(const char *page, ssize_t count,
                                       unsigned int *val)
{
        unsigned long tmp;
        char *p = (char *)page;

        tmp = simple_strtoul(p, &p, 0);
        if (!p || (*p && (*p != '\n')))
                return -EINVAL;

        if (tmp == 0)
                return -EINVAL;
        if (tmp >= (u32)-1)
                return -ERANGE;

        *val = tmp;

        return count;
}

static ssize_t o2nm_cluster_idle_timeout_ms_show(struct config_item *item,
        char *page)
{
        return sprintf(page, "%u\n", to_o2nm_cluster(item)->cl_idle_timeout_ms);
}

static ssize_t o2nm_cluster_idle_timeout_ms_store(struct config_item *item,
        const char *page, size_t count)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);
        ssize_t ret;
        unsigned int val;

        ret =  o2nm_cluster_attr_write(page, count, &val);

        if (ret > 0) {
                if (cluster->cl_idle_timeout_ms != val
                        && o2net_num_connected_peers()) {
                        mlog(ML_NOTICE,
                             "o2net: cannot change idle timeout after "
                             "the first peer has agreed to it."
                             "  %d connected peers\n",
                             o2net_num_connected_peers());
                        ret = -EINVAL;
                } else if (val <= cluster->cl_keepalive_delay_ms) {
                        mlog(ML_NOTICE, "o2net: idle timeout must be larger "
                             "than keepalive delay\n");
                        ret = -EINVAL;
                } else {
                        cluster->cl_idle_timeout_ms = val;
                }
        }

        return ret;
}

static ssize_t o2nm_cluster_keepalive_delay_ms_show(
        struct config_item *item, char *page)
{
        return sprintf(page, "%u\n",
                        to_o2nm_cluster(item)->cl_keepalive_delay_ms);
}

static ssize_t o2nm_cluster_keepalive_delay_ms_store(
        struct config_item *item, const char *page, size_t count)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);
        ssize_t ret;
        unsigned int val;

        ret =  o2nm_cluster_attr_write(page, count, &val);

        if (ret > 0) {
                if (cluster->cl_keepalive_delay_ms != val
                    && o2net_num_connected_peers()) {
                        mlog(ML_NOTICE,
                             "o2net: cannot change keepalive delay after"
                             " the first peer has agreed to it."
                             "  %d connected peers\n",
                             o2net_num_connected_peers());
                        ret = -EINVAL;
                } else if (val >= cluster->cl_idle_timeout_ms) {
                        mlog(ML_NOTICE, "o2net: keepalive delay must be "
                             "smaller than idle timeout\n");
                        ret = -EINVAL;
                } else {
                        cluster->cl_keepalive_delay_ms = val;
                }
        }

        return ret;
}

static ssize_t o2nm_cluster_reconnect_delay_ms_show(
        struct config_item *item, char *page)
{
        return sprintf(page, "%u\n",
                        to_o2nm_cluster(item)->cl_reconnect_delay_ms);
}

static ssize_t o2nm_cluster_reconnect_delay_ms_store(
        struct config_item *item, const char *page, size_t count)
{
        return o2nm_cluster_attr_write(page, count,
                               &to_o2nm_cluster(item)->cl_reconnect_delay_ms);
}

static ssize_t o2nm_cluster_fence_method_show(
        struct config_item *item, char *page)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);
        ssize_t ret = 0;

        if (cluster)
                ret = sprintf(page, "%s\n",
                              o2nm_fence_method_desc[cluster->cl_fence_method]);
        return ret;
}

static ssize_t o2nm_cluster_fence_method_store(
        struct config_item *item, const char *page, size_t count)
{
        unsigned int i;

        if (page[count - 1] != '\n')
                goto bail;

        for (i = 0; i < O2NM_FENCE_METHODS; ++i) {
                if (count != strlen(o2nm_fence_method_desc[i]) + 1)
                        continue;
                if (strncasecmp(page, o2nm_fence_method_desc[i], count - 1))
                        continue;
                if (to_o2nm_cluster(item)->cl_fence_method != i) {
                        printk(KERN_INFO "ocfs2: Changing fence method to %s\n",
                               o2nm_fence_method_desc[i]);
                        to_o2nm_cluster(item)->cl_fence_method = i;
                }
                return count;
        }

bail:
        return -EINVAL;
}

CONFIGFS_ATTR(o2nm_cluster_, idle_timeout_ms);
CONFIGFS_ATTR(o2nm_cluster_, keepalive_delay_ms);
CONFIGFS_ATTR(o2nm_cluster_, reconnect_delay_ms);
CONFIGFS_ATTR(o2nm_cluster_, fence_method);

static struct configfs_attribute *o2nm_cluster_attrs[] = {
        &o2nm_cluster_attr_idle_timeout_ms,
        &o2nm_cluster_attr_keepalive_delay_ms,
        &o2nm_cluster_attr_reconnect_delay_ms,
        &o2nm_cluster_attr_fence_method,
        NULL,
};

static struct config_item *o2nm_node_group_make_item(struct config_group *group,
                                                     const char *name)
{
        struct o2nm_node *node = NULL;

        if (strlen(name) > O2NM_MAX_NAME_LEN)
                return ERR_PTR(-ENAMETOOLONG);

        node = kzalloc(sizeof(struct o2nm_node), GFP_KERNEL);
        if (node == NULL)
                return ERR_PTR(-ENOMEM);

        strcpy(node->nd_name, name); /* use item.ci_namebuf instead? */
        config_item_init_type_name(&node->nd_item, name, &o2nm_node_type);
        spin_lock_init(&node->nd_lock);

        mlog(ML_CLUSTER, "o2nm: Registering node %s\n", name);

        return &node->nd_item;
}

static void o2nm_node_group_drop_item(struct config_group *group,
                                      struct config_item *item)
{
        struct o2nm_node *node = to_o2nm_node(item);
        struct o2nm_cluster *cluster = to_o2nm_cluster(group->cg_item.ci_parent);

        if (cluster->cl_nodes[node->nd_num] == node) {
                o2net_disconnect_node(node);

                if (cluster->cl_has_local &&
                    (cluster->cl_local_node == node->nd_num)) {
                        cluster->cl_has_local = 0;
                        cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
                        o2net_stop_listening(node);
                }
        }

        /* XXX call into net to stop this node from trading messages */

        write_lock(&cluster->cl_nodes_lock);

        /* XXX sloppy */
        if (node->nd_ipv4_address)
                rb_erase(&node->nd_ip_node, &cluster->cl_node_ip_tree);

        /* nd_num might be 0 if the node number hasn't been set.. */
        if (cluster->cl_nodes[node->nd_num] == node) {
                cluster->cl_nodes[node->nd_num] = NULL;
                clear_bit(node->nd_num, cluster->cl_nodes_bitmap);
        }
        write_unlock(&cluster->cl_nodes_lock);

        mlog(ML_CLUSTER, "o2nm: Unregistered node %s\n",
             config_item_name(&node->nd_item));

        config_item_put(item);
}

static struct configfs_group_operations o2nm_node_group_group_ops = {
        .make_item        = o2nm_node_group_make_item,
        .drop_item        = o2nm_node_group_drop_item,
};

static const struct config_item_type o2nm_node_group_type = {
        .ct_group_ops        = &o2nm_node_group_group_ops,
        .ct_owner        = THIS_MODULE,
};

/* cluster */

static void o2nm_cluster_release(struct config_item *item)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);

        kfree(cluster);
}

static struct configfs_item_operations o2nm_cluster_item_ops = {
        .release        = o2nm_cluster_release,
};

static const struct config_item_type o2nm_cluster_type = {
        .ct_item_ops        = &o2nm_cluster_item_ops,
        .ct_attrs        = o2nm_cluster_attrs,
        .ct_owner        = THIS_MODULE,
};

/* cluster set */

struct o2nm_cluster_group {
        struct configfs_subsystem cs_subsys;
        /* some stuff? */
};

#if 0
static struct o2nm_cluster_group *to_o2nm_cluster_group(struct config_group *group)
{
        return group ?
                container_of(to_configfs_subsystem(group), struct o2nm_cluster_group, cs_subsys)
               : NULL;
}
#endif

static struct config_group *o2nm_cluster_group_make_group(struct config_group *group,
                                                          const char *name)
{
        struct o2nm_cluster *cluster = NULL;
        struct o2nm_node_group *ns = NULL;
        struct config_group *o2hb_group = NULL, *ret = NULL;

        /* this runs under the parent dir's i_rwsem; there can be only
         * one caller in here at a time */
        if (o2nm_single_cluster)
                return ERR_PTR(-ENOSPC);

        cluster = kzalloc(sizeof(struct o2nm_cluster), GFP_KERNEL);
        ns = kzalloc(sizeof(struct o2nm_node_group), GFP_KERNEL);
        o2hb_group = o2hb_alloc_hb_set();
        if (cluster == NULL || ns == NULL || o2hb_group == NULL)
                goto out;

        config_group_init_type_name(&cluster->cl_group, name,
                                    &o2nm_cluster_type);
        configfs_add_default_group(&ns->ns_group, &cluster->cl_group);

        config_group_init_type_name(&ns->ns_group, "node",
                                    &o2nm_node_group_type);
        configfs_add_default_group(o2hb_group, &cluster->cl_group);

        rwlock_init(&cluster->cl_nodes_lock);
        cluster->cl_node_ip_tree = RB_ROOT;
        cluster->cl_reconnect_delay_ms = O2NET_RECONNECT_DELAY_MS_DEFAULT;
        cluster->cl_idle_timeout_ms    = O2NET_IDLE_TIMEOUT_MS_DEFAULT;
        cluster->cl_keepalive_delay_ms = O2NET_KEEPALIVE_DELAY_MS_DEFAULT;
        cluster->cl_fence_method       = O2NM_FENCE_RESET;

        ret = &cluster->cl_group;
        o2nm_single_cluster = cluster;

out:
        if (ret == NULL) {
                kfree(cluster);
                kfree(ns);
                o2hb_free_hb_set(o2hb_group);
                ret = ERR_PTR(-ENOMEM);
        }

        return ret;
}

static void o2nm_cluster_group_drop_item(struct config_group *group, struct config_item *item)
{
        struct o2nm_cluster *cluster = to_o2nm_cluster(item);

        BUG_ON(o2nm_single_cluster != cluster);
        o2nm_single_cluster = NULL;

        configfs_remove_default_groups(&cluster->cl_group);
        config_item_put(item);
}

static struct configfs_group_operations o2nm_cluster_group_group_ops = {
        .make_group        = o2nm_cluster_group_make_group,
        .drop_item        = o2nm_cluster_group_drop_item,
};

static const struct config_item_type o2nm_cluster_group_type = {
        .ct_group_ops        = &o2nm_cluster_group_group_ops,
        .ct_owner        = THIS_MODULE,
};

static struct o2nm_cluster_group o2nm_cluster_group = {
        .cs_subsys = {
                .su_group = {
                        .cg_item = {
                                .ci_namebuf = "cluster",
                                .ci_type = &o2nm_cluster_group_type,
                        },
                },
        },
};

static inline void o2nm_lock_subsystem(void)
{
        mutex_lock(&o2nm_cluster_group.cs_subsys.su_mutex);
}

static inline void o2nm_unlock_subsystem(void)
{
        mutex_unlock(&o2nm_cluster_group.cs_subsys.su_mutex);
}

int o2nm_depend_item(struct config_item *item)
{
        return configfs_depend_item(&o2nm_cluster_group.cs_subsys, item);
}

void o2nm_undepend_item(struct config_item *item)
{
        configfs_undepend_item(item);
}

int o2nm_depend_this_node(void)
{
        int ret = 0;
        struct o2nm_node *local_node;

        local_node = o2nm_get_node_by_num(o2nm_this_node());
        if (!local_node) {
                ret = -EINVAL;
                goto out;
        }

        ret = o2nm_depend_item(&local_node->nd_item);
        o2nm_node_put(local_node);

out:
        return ret;
}

void o2nm_undepend_this_node(void)
{
        struct o2nm_node *local_node;

        local_node = o2nm_get_node_by_num(o2nm_this_node());
        BUG_ON(!local_node);

        o2nm_undepend_item(&local_node->nd_item);
        o2nm_node_put(local_node);
}


static void __exit exit_o2nm(void)
{
        /* XXX sync with hb callbacks and shut down hb? */
        o2net_unregister_hb_callbacks();
        configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
        o2cb_sys_shutdown();

        o2net_exit();
        o2hb_exit();
}

static int __init init_o2nm(void)
{
        int ret;

        o2hb_init();

        ret = o2net_init();
        if (ret)
                goto out_o2hb;

        ret = o2net_register_hb_callbacks();
        if (ret)
                goto out_o2net;

        config_group_init(&o2nm_cluster_group.cs_subsys.su_group);
        mutex_init(&o2nm_cluster_group.cs_subsys.su_mutex);
        ret = configfs_register_subsystem(&o2nm_cluster_group.cs_subsys);
        if (ret) {
                printk(KERN_ERR "nodemanager: Registration returned %d\n", ret);
                goto out_callbacks;
        }

        ret = o2cb_sys_init();
        if (!ret)
                goto out;

        configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
out_callbacks:
        o2net_unregister_hb_callbacks();
out_o2net:
        o2net_exit();
out_o2hb:
        o2hb_exit();
out:
        return ret;
}

MODULE_AUTHOR("Oracle");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("OCFS2 cluster management");

module_init(init_o2nm)
module_exit(exit_o2nm)






















































































































































































































































































































































































































































































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/* SPDX-License-Identifier: GPL-2.0 */
/*
 * sysfs.h - definitions for the device driver filesystem
 *
 * Copyright (c) 2001,2002 Patrick Mochel
 * Copyright (c) 2004 Silicon Graphics, Inc.
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
 *
 * Please see Documentation/filesystems/sysfs.rst for more information.
 */

#ifndef _SYSFS_H_
#define _SYSFS_H_

#include <linux/kernfs.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/kobject_ns.h>
#include <linux/stat.h>
#include <linux/atomic.h>

struct kobject;
struct module;
struct bin_attribute;
enum kobj_ns_type;

struct attribute {
        const char                *name;
        umode_t                        mode;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
        bool                        ignore_lockdep:1;
        struct lock_class_key        *key;
        struct lock_class_key        skey;
#endif
};

/**
 *        sysfs_attr_init - initialize a dynamically allocated sysfs attribute
 *        @attr: struct attribute to initialize
 *
 *        Initialize a dynamically allocated struct attribute so we can
 *        make lockdep happy.  This is a new requirement for attributes
 *        and initially this is only needed when lockdep is enabled.
 *        Lockdep gives a nice error when your attribute is added to
 *        sysfs if you don't have this.
 */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define sysfs_attr_init(attr)                                \
do {                                                        \
        static struct lock_class_key __key;                \
                                                        \
        (attr)->key = &__key;                                \
} while (0)
#else
#define sysfs_attr_init(attr) do {} while (0)
#endif

/**
 * struct attribute_group - data structure used to declare an attribute group.
 * @name:        Optional: Attribute group name
 *                If specified, the attribute group will be created in a
 *                new subdirectory with this name. Additionally when a
 *                group is named, @is_visible and @is_bin_visible may
 *                return SYSFS_GROUP_INVISIBLE to control visibility of
 *                the directory itself.
 * @is_visible:        Optional: Function to return permissions associated with an
 *                attribute of the group. Will be called repeatedly for
 *                each non-binary attribute in the group. Only read/write
 *                permissions as well as SYSFS_PREALLOC are accepted. Must
 *                return 0 if an attribute is not visible. The returned
 *                value will replace static permissions defined in struct
 *                attribute. Use SYSFS_GROUP_VISIBLE() when assigning this
 *                callback to specify separate _group_visible() and
 *                _attr_visible() handlers.
 * @is_bin_visible:
 *                Optional: Function to return permissions associated with a
 *                binary attribute of the group. Will be called repeatedly
 *                for each binary attribute in the group. Only read/write
 *                permissions as well as SYSFS_PREALLOC (and the
 *                visibility flags for named groups) are accepted. Must
 *                return 0 if a binary attribute is not visible. The
 *                returned value will replace static permissions defined
 *                in struct bin_attribute. If @is_visible is not set, Use
 *                SYSFS_GROUP_VISIBLE() when assigning this callback to
 *                specify separate _group_visible() and _attr_visible()
 *                handlers.
 * @bin_size:
 *                Optional: Function to return the size of a binary attribute
 *                of the group. Will be called repeatedly for each binary
 *                attribute in the group. Overwrites the size field embedded
 *                inside the attribute itself.
 * @attrs:        Pointer to NULL terminated list of attributes.
 * @bin_attrs:        Pointer to NULL terminated list of binary attributes.
 *                Either attrs or bin_attrs or both must be provided.
 */
struct attribute_group {
        const char                *name;
        umode_t                        (*is_visible)(struct kobject *,
                                              struct attribute *, int);
        umode_t                        (*is_bin_visible)(struct kobject *,
                                                  const struct bin_attribute *, int);
        size_t                        (*bin_size)(struct kobject *,
                                            const struct bin_attribute *,
                                            int);
        struct attribute        **attrs;
        const struct bin_attribute        *const *bin_attrs;
};

#define SYSFS_PREALLOC                010000
#define SYSFS_GROUP_INVISIBLE        020000

/*
 * DEFINE_SYSFS_GROUP_VISIBLE(name):
 *        A helper macro to pair with the assignment of ".is_visible =
 *        SYSFS_GROUP_VISIBLE(name)", that arranges for the directory
 *        associated with a named attribute_group to optionally be hidden.
 *        This allows for static declaration of attribute_groups, and the
 *        simplification of attribute visibility lifetime that implies,
 *        without polluting sysfs with empty attribute directories.
 * Ex.
 *
 * static umode_t example_attr_visible(struct kobject *kobj,
 *                                   struct attribute *attr, int n)
 * {
 *       if (example_attr_condition)
 *               return 0;
 *       else if (ro_attr_condition)
 *               return 0444;
 *       return a->mode;
 * }
 *
 * static bool example_group_visible(struct kobject *kobj)
 * {
 *       if (example_group_condition)
 *               return false;
 *       return true;
 * }
 *
 * DEFINE_SYSFS_GROUP_VISIBLE(example);
 *
 * static struct attribute_group example_group = {
 *       .name = "example",
 *       .is_visible = SYSFS_GROUP_VISIBLE(example),
 *       .attrs = &example_attrs,
 * };
 *
 * Note that it expects <name>_attr_visible and <name>_group_visible to
 * be defined. For cases where individual attributes do not need
 * separate visibility consideration, only entire group visibility at
 * once, see DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE().
 */
#define DEFINE_SYSFS_GROUP_VISIBLE(name)                             \
        static inline umode_t sysfs_group_visible_##name(            \
                struct kobject *kobj, struct attribute *attr, int n) \
        {                                                            \
                if (n == 0 && !name##_group_visible(kobj))           \
                        return SYSFS_GROUP_INVISIBLE;                \
                return name##_attr_visible(kobj, attr, n);           \
        }

/*
 * DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(name):
 *        A helper macro to pair with SYSFS_GROUP_VISIBLE() that like
 *        DEFINE_SYSFS_GROUP_VISIBLE() controls group visibility, but does
 *        not require the implementation of a per-attribute visibility
 *        callback.
 * Ex.
 *
 * static bool example_group_visible(struct kobject *kobj)
 * {
 *       if (example_group_condition)
 *               return false;
 *       return true;
 * }
 *
 * DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(example);
 *
 * static struct attribute_group example_group = {
 *       .name = "example",
 *       .is_visible = SYSFS_GROUP_VISIBLE(example),
 *       .attrs = &example_attrs,
 * };
 */
#define DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE(name)                   \
        static inline umode_t sysfs_group_visible_##name(         \
                struct kobject *kobj, struct attribute *a, int n) \
        {                                                         \
                if (n == 0 && !name##_group_visible(kobj))        \
                        return SYSFS_GROUP_INVISIBLE;             \
                return a->mode;                                   \
        }

/*
 * Same as DEFINE_SYSFS_GROUP_VISIBLE, but for groups with only binary
 * attributes. If an attribute_group defines both text and binary
 * attributes, the group visibility is determined by the function
 * specified to is_visible() not is_bin_visible()
 */
#define DEFINE_SYSFS_BIN_GROUP_VISIBLE(name)                                   \
        static inline umode_t sysfs_group_visible_##name(                      \
                struct kobject *kobj, const struct bin_attribute *attr, int n) \
        {                                                                      \
                if (n == 0 && !name##_group_visible(kobj))                     \
                        return SYSFS_GROUP_INVISIBLE;                          \
                return name##_attr_visible(kobj, attr, n);                     \
        }

#define DEFINE_SIMPLE_SYSFS_BIN_GROUP_VISIBLE(name)                         \
        static inline umode_t sysfs_group_visible_##name(                   \
                struct kobject *kobj, const struct bin_attribute *a, int n) \
        {                                                                   \
                if (n == 0 && !name##_group_visible(kobj))                  \
                        return SYSFS_GROUP_INVISIBLE;                       \
                return a->mode;                                             \
        }

#define SYSFS_GROUP_VISIBLE(fn) sysfs_group_visible_##fn

/*
 * Use these macros to make defining attributes easier.
 * See include/linux/device.h for examples..
 */

#define __ATTR(_name, _mode, _show, _store) {                                \
        .attr = {.name = __stringify(_name),                                \
                 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) },                \
        .show        = _show,                                                \
        .store        = _store,                                                \
}

#define __ATTR_PREALLOC(_name, _mode, _show, _store) {                        \
        .attr = {.name = __stringify(_name),                                \
                 .mode = SYSFS_PREALLOC | VERIFY_OCTAL_PERMISSIONS(_mode) },\
        .show        = _show,                                                \
        .store        = _store,                                                \
}

#define __ATTR_RO(_name) {                                                \
        .attr        = { .name = __stringify(_name), .mode = 0444 },                \
        .show        = _name##_show,                                                \
}

#define __ATTR_RO_MODE(_name, _mode) {                                        \
        .attr        = { .name = __stringify(_name),                                \
                    .mode = VERIFY_OCTAL_PERMISSIONS(_mode) },                \
        .show        = _name##_show,                                                \
}

#define __ATTR_RW_MODE(_name, _mode) {                                        \
        .attr        = { .name = __stringify(_name),                                \
                    .mode = VERIFY_OCTAL_PERMISSIONS(_mode) },                \
        .show        = _name##_show,                                                \
        .store        = _name##_store,                                        \
}

#define __ATTR_WO(_name) {                                                \
        .attr        = { .name = __stringify(_name), .mode = 0200 },                \
        .store        = _name##_store,                                        \
}

#define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store)

#define __ATTR_NULL { .attr = { .name = NULL } }

#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) {        \
        .attr = {.name = __stringify(_name), .mode = _mode,        \
                        .ignore_lockdep = true },                \
        .show                = _show,                                \
        .store                = _store,                                \
}
#else
#define __ATTR_IGNORE_LOCKDEP        __ATTR
#endif

#define __ATTRIBUTE_GROUPS(_name)                                \
static const struct attribute_group *_name##_groups[] = {        \
        &_name##_group,                                                \
        NULL,                                                        \
}

#define ATTRIBUTE_GROUPS(_name)                                        \
static const struct attribute_group _name##_group = {                \
        .attrs = _name##_attrs,                                        \
};                                                                \
__ATTRIBUTE_GROUPS(_name)

#define BIN_ATTRIBUTE_GROUPS(_name)                                \
static const struct attribute_group _name##_group = {                \
        .bin_attrs = _name##_attrs,                                \
};                                                                \
__ATTRIBUTE_GROUPS(_name)

struct file;
struct vm_area_struct;
struct address_space;

struct bin_attribute {
        struct attribute        attr;
        size_t                        size;
        void                        *private;
        struct address_space *(*f_mapping)(void);
        ssize_t (*read)(struct file *, struct kobject *, const struct bin_attribute *,
                        char *, loff_t, size_t);
        ssize_t (*write)(struct file *, struct kobject *, const struct bin_attribute *,
                         char *, loff_t, size_t);
        loff_t (*llseek)(struct file *, struct kobject *, const struct bin_attribute *,
                         loff_t, int);
        int (*mmap)(struct file *, struct kobject *, const struct bin_attribute *attr,
                    struct vm_area_struct *vma);
};

/**
 *        sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
 *        @attr: struct bin_attribute to initialize
 *
 *        Initialize a dynamically allocated struct bin_attribute so we
 *        can make lockdep happy.  This is a new requirement for
 *        attributes and initially this is only needed when lockdep is
 *        enabled.  Lockdep gives a nice error when your attribute is
 *        added to sysfs if you don't have this.
 */
#define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)

/* macros to create static binary attributes easier */
#define __BIN_ATTR(_name, _mode, _read, _write, _size) {                \
        .attr = { .name = __stringify(_name), .mode = _mode },                \
        .read = _read,                                                        \
        .write = _write,                                                \
        .size        = _size,                                                \
}

#define __BIN_ATTR_RO(_name, _size)                                        \
        __BIN_ATTR(_name, 0444, _name##_read, NULL, _size)

#define __BIN_ATTR_WO(_name, _size)                                        \
        __BIN_ATTR(_name, 0200, NULL, _name##_write, _size)

#define __BIN_ATTR_RW(_name, _size)                                        \
        __BIN_ATTR(_name, 0644, _name##_read, _name##_write, _size)

#define __BIN_ATTR_NULL __ATTR_NULL

#define BIN_ATTR(_name, _mode, _read, _write, _size)                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read,        \
                                        _write, _size)

#define BIN_ATTR_RO(_name, _size)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)

#define BIN_ATTR_WO(_name, _size)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size)

#define BIN_ATTR_RW(_name, _size)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)


#define __BIN_ATTR_ADMIN_RO(_name, _size)                                \
        __BIN_ATTR(_name, 0400, _name##_read, NULL, _size)

#define __BIN_ATTR_ADMIN_RW(_name, _size)                                        \
        __BIN_ATTR(_name, 0600, _name##_read, _name##_write, _size)

#define BIN_ATTR_ADMIN_RO(_name, _size)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size)

#define BIN_ATTR_ADMIN_RW(_name, _size)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size)

#define __BIN_ATTR_SIMPLE_RO(_name, _mode)                                \
        __BIN_ATTR(_name, _mode, sysfs_bin_attr_simple_read, NULL, 0)

#define BIN_ATTR_SIMPLE_RO(_name)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_SIMPLE_RO(_name, 0444)

#define BIN_ATTR_SIMPLE_ADMIN_RO(_name)                                        \
struct bin_attribute bin_attr_##_name = __BIN_ATTR_SIMPLE_RO(_name, 0400)

struct sysfs_ops {
        ssize_t        (*show)(struct kobject *, struct attribute *, char *);
        ssize_t        (*store)(struct kobject *, struct attribute *, const char *, size_t);
};

#ifdef CONFIG_SYSFS

int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
void sysfs_remove_dir(struct kobject *kobj);
int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
                                     const void *new_ns);
int __must_check sysfs_move_dir_ns(struct kobject *kobj,
                                   struct kobject *new_parent_kobj,
                                   const void *new_ns);
int __must_check sysfs_create_mount_point(struct kobject *parent_kobj,
                                          const char *name);
void sysfs_remove_mount_point(struct kobject *parent_kobj,
                              const char *name);

int __must_check sysfs_create_file_ns(struct kobject *kobj,
                                      const struct attribute *attr,
                                      const void *ns);
int __must_check sysfs_create_files(struct kobject *kobj,
                                   const struct attribute * const *attr);
int __must_check sysfs_chmod_file(struct kobject *kobj,
                                  const struct attribute *attr, umode_t mode);
struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
                                                  const struct attribute *attr);
void sysfs_unbreak_active_protection(struct kernfs_node *kn);
void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
                          const void *ns);
bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr);
void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr);

int __must_check sysfs_create_bin_file(struct kobject *kobj,
                                       const struct bin_attribute *attr);
void sysfs_remove_bin_file(struct kobject *kobj,
                           const struct bin_attribute *attr);

int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
                                   const char *name);
int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
                                          struct kobject *target,
                                          const char *name);
void sysfs_remove_link(struct kobject *kobj, const char *name);

int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
                         const char *old_name, const char *new_name,
                         const void *new_ns);

void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
                        const char *name);

int __must_check sysfs_create_group(struct kobject *kobj,
                                    const struct attribute_group *grp);
int __must_check sysfs_create_groups(struct kobject *kobj,
                                     const struct attribute_group **groups);
int __must_check sysfs_update_groups(struct kobject *kobj,
                                     const struct attribute_group **groups);
int sysfs_update_group(struct kobject *kobj,
                       const struct attribute_group *grp);
void sysfs_remove_group(struct kobject *kobj,
                        const struct attribute_group *grp);
void sysfs_remove_groups(struct kobject *kobj,
                         const struct attribute_group **groups);
int sysfs_add_file_to_group(struct kobject *kobj,
                        const struct attribute *attr, const char *group);
void sysfs_remove_file_from_group(struct kobject *kobj,
                        const struct attribute *attr, const char *group);
int sysfs_merge_group(struct kobject *kobj,
                       const struct attribute_group *grp);
void sysfs_unmerge_group(struct kobject *kobj,
                       const struct attribute_group *grp);
int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
                            struct kobject *target, const char *link_name);
void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
                                  const char *link_name);
int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
                                         struct kobject *target_kobj,
                                         const char *target_name,
                                         const char *symlink_name);

void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);

int __must_check sysfs_init(void);

static inline void sysfs_enable_ns(struct kernfs_node *kn)
{
        return kernfs_enable_ns(kn);
}

int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid,
                            kgid_t kgid);
int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid);
int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ,
                            const char *name, kuid_t kuid, kgid_t kgid);
int sysfs_groups_change_owner(struct kobject *kobj,
                              const struct attribute_group **groups,
                              kuid_t kuid, kgid_t kgid);
int sysfs_group_change_owner(struct kobject *kobj,
                             const struct attribute_group *groups, kuid_t kuid,
                             kgid_t kgid);
__printf(2, 3)
int sysfs_emit(char *buf, const char *fmt, ...);
__printf(3, 4)
int sysfs_emit_at(char *buf, int at, const char *fmt, ...);

ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj,
                                   const struct bin_attribute *attr, char *buf,
                                   loff_t off, size_t count);

#else /* CONFIG_SYSFS */

static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
{
        return 0;
}

static inline void sysfs_remove_dir(struct kobject *kobj)
{
}

static inline int sysfs_rename_dir_ns(struct kobject *kobj,
                                      const char *new_name, const void *new_ns)
{
        return 0;
}

static inline int sysfs_move_dir_ns(struct kobject *kobj,
                                    struct kobject *new_parent_kobj,
                                    const void *new_ns)
{
        return 0;
}

static inline int sysfs_create_mount_point(struct kobject *parent_kobj,
                                           const char *name)
{
        return 0;
}

static inline void sysfs_remove_mount_point(struct kobject *parent_kobj,
                                            const char *name)
{
}

static inline int sysfs_create_file_ns(struct kobject *kobj,
                                       const struct attribute *attr,
                                       const void *ns)
{
        return 0;
}

static inline int sysfs_create_files(struct kobject *kobj,
                                    const struct attribute * const *attr)
{
        return 0;
}

static inline int sysfs_chmod_file(struct kobject *kobj,
                                   const struct attribute *attr, umode_t mode)
{
        return 0;
}

static inline struct kernfs_node *
sysfs_break_active_protection(struct kobject *kobj,
                              const struct attribute *attr)
{
        return NULL;
}

static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn)
{
}

static inline void sysfs_remove_file_ns(struct kobject *kobj,
                                        const struct attribute *attr,
                                        const void *ns)
{
}

static inline bool sysfs_remove_file_self(struct kobject *kobj,
                                          const struct attribute *attr)
{
        return false;
}

static inline void sysfs_remove_files(struct kobject *kobj,
                                     const struct attribute * const *attr)
{
}

static inline int sysfs_create_bin_file(struct kobject *kobj,
                                        const struct bin_attribute *attr)
{
        return 0;
}

static inline void sysfs_remove_bin_file(struct kobject *kobj,
                                         const struct bin_attribute *attr)
{
}

static inline int sysfs_create_link(struct kobject *kobj,
                                    struct kobject *target, const char *name)
{
        return 0;
}

static inline int sysfs_create_link_nowarn(struct kobject *kobj,
                                           struct kobject *target,
                                           const char *name)
{
        return 0;
}

static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
{
}

static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
                                       const char *old_name,
                                       const char *new_name, const void *ns)
{
        return 0;
}

static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
                                     const char *name)
{
}

static inline int sysfs_create_group(struct kobject *kobj,
                                     const struct attribute_group *grp)
{
        return 0;
}

static inline int sysfs_create_groups(struct kobject *kobj,
                                      const struct attribute_group **groups)
{
        return 0;
}

static inline int sysfs_update_groups(struct kobject *kobj,
                                      const struct attribute_group **groups)
{
        return 0;
}

static inline int sysfs_update_group(struct kobject *kobj,
                                const struct attribute_group *grp)
{
        return 0;
}

static inline void sysfs_remove_group(struct kobject *kobj,
                                      const struct attribute_group *grp)
{
}

static inline void sysfs_remove_groups(struct kobject *kobj,
                                       const struct attribute_group **groups)
{
}

static inline int sysfs_add_file_to_group(struct kobject *kobj,
                const struct attribute *attr, const char *group)
{
        return 0;
}

static inline void sysfs_remove_file_from_group(struct kobject *kobj,
                const struct attribute *attr, const char *group)
{
}

static inline int sysfs_merge_group(struct kobject *kobj,
                       const struct attribute_group *grp)
{
        return 0;
}

static inline void sysfs_unmerge_group(struct kobject *kobj,
                       const struct attribute_group *grp)
{
}

static inline int sysfs_add_link_to_group(struct kobject *kobj,
                const char *group_name, struct kobject *target,
                const char *link_name)
{
        return 0;
}

static inline void sysfs_remove_link_from_group(struct kobject *kobj,
                const char *group_name, const char *link_name)
{
}

static inline int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
                                                       struct kobject *target_kobj,
                                                       const char *target_name,
                                                       const char *symlink_name)
{
        return 0;
}

static inline void sysfs_notify(struct kobject *kobj, const char *dir,
                                const char *attr)
{
}

static inline int __must_check sysfs_init(void)
{
        return 0;
}

static inline void sysfs_enable_ns(struct kernfs_node *kn)
{
}

static inline int sysfs_file_change_owner(struct kobject *kobj,
                                          const char *name, kuid_t kuid,
                                          kgid_t kgid)
{
        return 0;
}

static inline int sysfs_link_change_owner(struct kobject *kobj,
                                          struct kobject *targ,
                                          const char *name, kuid_t kuid,
                                          kgid_t kgid)
{
        return 0;
}

static inline int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid)
{
        return 0;
}

static inline int sysfs_groups_change_owner(struct kobject *kobj,
                          const struct attribute_group **groups,
                          kuid_t kuid, kgid_t kgid)
{
        return 0;
}

static inline int sysfs_group_change_owner(struct kobject *kobj,
                                           const struct attribute_group *groups,
                                           kuid_t kuid, kgid_t kgid)
{
        return 0;
}

__printf(2, 3)
static inline int sysfs_emit(char *buf, const char *fmt, ...)
{
        return 0;
}

__printf(3, 4)
static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
{
        return 0;
}

static inline ssize_t sysfs_bin_attr_simple_read(struct file *file,
                                                 struct kobject *kobj,
                                                 const struct bin_attribute *attr,
                                                 char *buf, loff_t off,
                                                 size_t count)
{
        return 0;
}
#endif /* CONFIG_SYSFS */

static inline int __must_check sysfs_create_file(struct kobject *kobj,
                                                 const struct attribute *attr)
{
        return sysfs_create_file_ns(kobj, attr, NULL);
}

static inline void sysfs_remove_file(struct kobject *kobj,
                                     const struct attribute *attr)
{
        sysfs_remove_file_ns(kobj, attr, NULL);
}

static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
                                    const char *old_name, const char *new_name)
{
        return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
}

static inline void sysfs_notify_dirent(struct kernfs_node *kn)
{
        kernfs_notify(kn);
}

static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
                                                   const char *name)
{
        return kernfs_find_and_get(parent, name);
}

static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
{
        kernfs_get(kn);
        return kn;
}

static inline void sysfs_put(struct kernfs_node *kn)
{
        kernfs_put(kn);
}

#endif /* _SYSFS_H_ */





































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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>
#include <linux/bits.h>

#include <sound/control.h>
#include <sound/core.h>
#include <sound/info.h>
#include <sound/pcm.h>

#include "usbaudio.h"
#include "card.h"
#include "mixer.h"
#include "mixer_quirks.h"
#include "midi.h"
#include "midi2.h"
#include "quirks.h"
#include "helper.h"
#include "endpoint.h"
#include "pcm.h"
#include "clock.h"
#include "stream.h"

/*
 * handle the quirks for the contained interfaces
 */
static int create_composite_quirk(struct snd_usb_audio *chip,
                                  struct usb_interface *iface,
                                  struct usb_driver *driver,
                                  const struct snd_usb_audio_quirk *quirk_comp)
{
        int probed_ifnum = get_iface_desc(iface->altsetting)->bInterfaceNumber;
        const struct snd_usb_audio_quirk *quirk;
        int err;

        for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
                iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
                if (!iface)
                        continue;
                if (quirk->ifnum != probed_ifnum &&
                    usb_interface_claimed(iface))
                        continue;
                err = snd_usb_create_quirk(chip, iface, driver, quirk);
                if (err < 0)
                        return err;
        }

        for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
                iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
                if (!iface)
                        continue;
                if (quirk->ifnum != probed_ifnum &&
                    !usb_interface_claimed(iface)) {
                        err = usb_driver_claim_interface(driver, iface,
                                                         USB_AUDIO_IFACE_UNUSED);
                        if (err < 0)
                                return err;
                }
        }

        return 0;
}

static int ignore_interface_quirk(struct snd_usb_audio *chip,
                                  struct usb_interface *iface,
                                  struct usb_driver *driver,
                                  const struct snd_usb_audio_quirk *quirk)
{
        return 0;
}


static int create_any_midi_quirk(struct snd_usb_audio *chip,
                                 struct usb_interface *intf,
                                 struct usb_driver *driver,
                                 const struct snd_usb_audio_quirk *quirk)
{
        return snd_usb_midi_v2_create(chip, intf, quirk, 0);
}

/*
 * create a stream for an interface with proper descriptors
 */
static int create_standard_audio_quirk(struct snd_usb_audio *chip,
                                       struct usb_interface *iface,
                                       struct usb_driver *driver,
                                       const struct snd_usb_audio_quirk *quirk)
{
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        int err;

        alts = &iface->altsetting[0];
        altsd = get_iface_desc(alts);
        err = snd_usb_parse_audio_interface(chip, altsd->bInterfaceNumber);
        if (err < 0) {
                usb_audio_err(chip, "cannot setup if %d: error %d\n",
                           altsd->bInterfaceNumber, err);
                return err;
        }
        /* reset the current interface */
        usb_set_interface(chip->dev, altsd->bInterfaceNumber, 0);
        return 0;
}

/* create the audio stream and the corresponding endpoints from the fixed
 * audioformat object; this is used for quirks with the fixed EPs
 */
static int add_audio_stream_from_fixed_fmt(struct snd_usb_audio *chip,
                                           struct audioformat *fp)
{
        int stream, err;

        stream = (fp->endpoint & USB_DIR_IN) ?
                SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;

        snd_usb_audioformat_set_sync_ep(chip, fp);

        err = snd_usb_add_audio_stream(chip, stream, fp);
        if (err < 0)
                return err;

        err = snd_usb_add_endpoint(chip, fp->endpoint,
                                   SND_USB_ENDPOINT_TYPE_DATA);
        if (err < 0)
                return err;

        if (fp->sync_ep) {
                err = snd_usb_add_endpoint(chip, fp->sync_ep,
                                           fp->implicit_fb ?
                                           SND_USB_ENDPOINT_TYPE_DATA :
                                           SND_USB_ENDPOINT_TYPE_SYNC);
                if (err < 0)
                        return err;
        }

        return 0;
}

/*
 * create a stream for an endpoint/altsetting without proper descriptors
 */
static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
                                     struct usb_interface *iface,
                                     struct usb_driver *driver,
                                     const struct snd_usb_audio_quirk *quirk)
{
        struct audioformat *fp;
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        unsigned *rate_table = NULL;
        int err;

        fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL);
        if (!fp)
                return -ENOMEM;

        INIT_LIST_HEAD(&fp->list);
        if (fp->nr_rates > MAX_NR_RATES) {
                kfree(fp);
                return -EINVAL;
        }
        if (fp->nr_rates > 0) {
                rate_table = kmemdup_array(fp->rate_table, fp->nr_rates, sizeof(int),
                                           GFP_KERNEL);
                if (!rate_table) {
                        kfree(fp);
                        return -ENOMEM;
                }
                fp->rate_table = rate_table;
        }

        if (fp->iface != get_iface_desc(&iface->altsetting[0])->bInterfaceNumber ||
            fp->altset_idx >= iface->num_altsetting) {
                err = -EINVAL;
                goto error;
        }
        alts = &iface->altsetting[fp->altset_idx];
        altsd = get_iface_desc(alts);
        if (altsd->bNumEndpoints <= fp->ep_idx) {
                err = -EINVAL;
                goto error;
        }

        fp->protocol = altsd->bInterfaceProtocol;

        if (fp->datainterval == 0)
                fp->datainterval = snd_usb_parse_datainterval(chip, alts);
        if (fp->maxpacksize == 0)
                fp->maxpacksize = le16_to_cpu(get_endpoint(alts, fp->ep_idx)->wMaxPacketSize);
        if (!fp->fmt_type)
                fp->fmt_type = UAC_FORMAT_TYPE_I;

        err = add_audio_stream_from_fixed_fmt(chip, fp);
        if (err < 0)
                goto error;

        usb_set_interface(chip->dev, fp->iface, 0);
        snd_usb_init_pitch(chip, fp);
        snd_usb_init_sample_rate(chip, fp, fp->rate_max);
        return 0;

 error:
        list_del(&fp->list); /* unlink for avoiding double-free */
        kfree(fp);
        kfree(rate_table);
        return err;
}

static int create_auto_pcm_quirk(struct snd_usb_audio *chip,
                                 struct usb_interface *iface,
                                 struct usb_driver *driver)
{
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        struct usb_endpoint_descriptor *epd;
        struct uac1_as_header_descriptor *ashd;
        struct uac_format_type_i_discrete_descriptor *fmtd;

        /*
         * Most Roland/Yamaha audio streaming interfaces have more or less
         * standard descriptors, but older devices might lack descriptors, and
         * future ones might change, so ensure that we fail silently if the
         * interface doesn't look exactly right.
         */

        /* must have a non-zero altsetting for streaming */
        if (iface->num_altsetting < 2)
                return -ENODEV;
        alts = &iface->altsetting[1];
        altsd = get_iface_desc(alts);

        /* must have an isochronous endpoint for streaming */
        if (altsd->bNumEndpoints < 1)
                return -ENODEV;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_xfer_isoc(epd))
                return -ENODEV;

        /* must have format descriptors */
        ashd = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
                                       UAC_AS_GENERAL);
        fmtd = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
                                       UAC_FORMAT_TYPE);
        if (!ashd || ashd->bLength < 7 ||
            !fmtd || fmtd->bLength < 8)
                return -ENODEV;

        return create_standard_audio_quirk(chip, iface, driver, NULL);
}

static int create_yamaha_midi_quirk(struct snd_usb_audio *chip,
                                    struct usb_interface *iface,
                                    struct usb_driver *driver,
                                    struct usb_host_interface *alts)
{
        static const struct snd_usb_audio_quirk yamaha_midi_quirk = {
                .type = QUIRK_MIDI_YAMAHA
        };
        struct usb_midi_in_jack_descriptor *injd;
        struct usb_midi_out_jack_descriptor *outjd;

        /* must have some valid jack descriptors */
        injd = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                       NULL, USB_MS_MIDI_IN_JACK);
        outjd = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                        NULL, USB_MS_MIDI_OUT_JACK);
        if (!injd && !outjd)
                return -ENODEV;
        if ((injd && !snd_usb_validate_midi_desc(injd)) ||
            (outjd && !snd_usb_validate_midi_desc(outjd)))
                return -ENODEV;
        if (injd && (injd->bLength < 5 ||
                     (injd->bJackType != USB_MS_EMBEDDED &&
                      injd->bJackType != USB_MS_EXTERNAL)))
                return -ENODEV;
        if (outjd && (outjd->bLength < 6 ||
                      (outjd->bJackType != USB_MS_EMBEDDED &&
                       outjd->bJackType != USB_MS_EXTERNAL)))
                return -ENODEV;
        return create_any_midi_quirk(chip, iface, driver, &yamaha_midi_quirk);
}

static int create_roland_midi_quirk(struct snd_usb_audio *chip,
                                    struct usb_interface *iface,
                                    struct usb_driver *driver,
                                    struct usb_host_interface *alts)
{
        static const struct snd_usb_audio_quirk roland_midi_quirk = {
                .type = QUIRK_MIDI_ROLAND
        };
        u8 *roland_desc = NULL;

        /* might have a vendor-specific descriptor <06 24 F1 02 ...> */
        for (;;) {
                roland_desc = snd_usb_find_csint_desc(alts->extra,
                                                      alts->extralen,
                                                      roland_desc, 0xf1);
                if (!roland_desc)
                        return -ENODEV;
                if (roland_desc[0] < 6 || roland_desc[3] != 2)
                        continue;
                return create_any_midi_quirk(chip, iface, driver,
                                             &roland_midi_quirk);
        }
}

static int create_std_midi_quirk(struct snd_usb_audio *chip,
                                 struct usb_interface *iface,
                                 struct usb_driver *driver,
                                 struct usb_host_interface *alts)
{
        struct usb_ms_header_descriptor *mshd;
        struct usb_ms_endpoint_descriptor *msepd;

        /* must have the MIDIStreaming interface header descriptor*/
        mshd = (struct usb_ms_header_descriptor *)alts->extra;
        if (alts->extralen < 7 ||
            mshd->bLength < 7 ||
            mshd->bDescriptorType != USB_DT_CS_INTERFACE ||
            mshd->bDescriptorSubtype != USB_MS_HEADER)
                return -ENODEV;
        /* must have the MIDIStreaming endpoint descriptor*/
        msepd = (struct usb_ms_endpoint_descriptor *)alts->endpoint[0].extra;
        if (alts->endpoint[0].extralen < 4 ||
            msepd->bLength < 4 ||
            msepd->bDescriptorType != USB_DT_CS_ENDPOINT ||
            msepd->bDescriptorSubtype != UAC_MS_GENERAL ||
            msepd->bNumEmbMIDIJack < 1 ||
            msepd->bNumEmbMIDIJack > 16)
                return -ENODEV;

        return create_any_midi_quirk(chip, iface, driver, NULL);
}

static int create_auto_midi_quirk(struct snd_usb_audio *chip,
                                  struct usb_interface *iface,
                                  struct usb_driver *driver)
{
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        struct usb_endpoint_descriptor *epd;
        int err;

        alts = &iface->altsetting[0];
        altsd = get_iface_desc(alts);

        /* must have at least one bulk/interrupt endpoint for streaming */
        if (altsd->bNumEndpoints < 1)
                return -ENODEV;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_xfer_bulk(epd) &&
            !usb_endpoint_xfer_int(epd))
                return -ENODEV;

        switch (USB_ID_VENDOR(chip->usb_id)) {
        case 0x0499: /* Yamaha */
                err = create_yamaha_midi_quirk(chip, iface, driver, alts);
                if (err != -ENODEV)
                        return err;
                break;
        case 0x0582: /* Roland */
                err = create_roland_midi_quirk(chip, iface, driver, alts);
                if (err != -ENODEV)
                        return err;
                break;
        }

        return create_std_midi_quirk(chip, iface, driver, alts);
}

static int create_autodetect_quirk(struct snd_usb_audio *chip,
                                   struct usb_interface *iface,
                                   struct usb_driver *driver,
                                   const struct snd_usb_audio_quirk *quirk)
{
        int err;

        err = create_auto_pcm_quirk(chip, iface, driver);
        if (err == -ENODEV)
                err = create_auto_midi_quirk(chip, iface, driver);
        return err;
}

/*
 * Create a stream for an Edirol UA-700/UA-25/UA-4FX interface.  
 * The only way to detect the sample rate is by looking at wMaxPacketSize.
 */
static int create_uaxx_quirk(struct snd_usb_audio *chip,
                             struct usb_interface *iface,
                             struct usb_driver *driver,
                             const struct snd_usb_audio_quirk *quirk)
{
        static const struct audioformat ua_format = {
                .formats = SNDRV_PCM_FMTBIT_S24_3LE,
                .channels = 2,
                .fmt_type = UAC_FORMAT_TYPE_I,
                .altsetting = 1,
                .altset_idx = 1,
                .rates = SNDRV_PCM_RATE_CONTINUOUS,
        };
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        struct audioformat *fp;
        int err;

        /* both PCM and MIDI interfaces have 2 or more altsettings */
        if (iface->num_altsetting < 2)
                return -ENXIO;
        alts = &iface->altsetting[1];
        altsd = get_iface_desc(alts);

        if (altsd->bNumEndpoints == 2) {
                static const struct snd_usb_midi_endpoint_info ua700_ep = {
                        .out_cables = 0x0003,
                        .in_cables  = 0x0003
                };
                static const struct snd_usb_audio_quirk ua700_quirk = {
                        .type = QUIRK_MIDI_FIXED_ENDPOINT,
                        .data = &ua700_ep
                };
                static const struct snd_usb_midi_endpoint_info uaxx_ep = {
                        .out_cables = 0x0001,
                        .in_cables  = 0x0001
                };
                static const struct snd_usb_audio_quirk uaxx_quirk = {
                        .type = QUIRK_MIDI_FIXED_ENDPOINT,
                        .data = &uaxx_ep
                };
                const struct snd_usb_audio_quirk *quirk =
                        chip->usb_id == USB_ID(0x0582, 0x002b)
                        ? &ua700_quirk : &uaxx_quirk;
                return __snd_usbmidi_create(chip->card, iface,
                                            &chip->midi_list, quirk,
                                            chip->usb_id,
                                            &chip->num_rawmidis);
        }

        if (altsd->bNumEndpoints != 1)
                return -ENXIO;

        fp = kmemdup(&ua_format, sizeof(*fp), GFP_KERNEL);
        if (!fp)
                return -ENOMEM;

        fp->iface = altsd->bInterfaceNumber;
        fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
        fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
        fp->datainterval = 0;
        fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
        INIT_LIST_HEAD(&fp->list);

        switch (fp->maxpacksize) {
        case 0x120:
                fp->rate_max = fp->rate_min = 44100;
                break;
        case 0x138:
        case 0x140:
                fp->rate_max = fp->rate_min = 48000;
                break;
        case 0x258:
        case 0x260:
                fp->rate_max = fp->rate_min = 96000;
                break;
        default:
                usb_audio_err(chip, "unknown sample rate\n");
                kfree(fp);
                return -ENXIO;
        }

        err = add_audio_stream_from_fixed_fmt(chip, fp);
        if (err < 0) {
                list_del(&fp->list); /* unlink for avoiding double-free */
                kfree(fp);
                return err;
        }
        usb_set_interface(chip->dev, fp->iface, 0);
        return 0;
}

/*
 * Create a standard mixer for the specified interface.
 */
static int create_standard_mixer_quirk(struct snd_usb_audio *chip,
                                       struct usb_interface *iface,
                                       struct usb_driver *driver,
                                       const struct snd_usb_audio_quirk *quirk)
{
        if (quirk->ifnum < 0)
                return 0;

        return snd_usb_create_mixer(chip, quirk->ifnum);
}

/*
 * audio-interface quirks
 *
 * returns zero if no standard audio/MIDI parsing is needed.
 * returns a positive value if standard audio/midi interfaces are parsed
 * after this.
 * returns a negative value at error.
 */
int snd_usb_create_quirk(struct snd_usb_audio *chip,
                         struct usb_interface *iface,
                         struct usb_driver *driver,
                         const struct snd_usb_audio_quirk *quirk)
{
        typedef int (*quirk_func_t)(struct snd_usb_audio *,
                                    struct usb_interface *,
                                    struct usb_driver *,
                                    const struct snd_usb_audio_quirk *);
        static const quirk_func_t quirk_funcs[] = {
                [QUIRK_IGNORE_INTERFACE] = ignore_interface_quirk,
                [QUIRK_COMPOSITE] = create_composite_quirk,
                [QUIRK_AUTODETECT] = create_autodetect_quirk,
                [QUIRK_MIDI_STANDARD_INTERFACE] = create_any_midi_quirk,
                [QUIRK_MIDI_FIXED_ENDPOINT] = create_any_midi_quirk,
                [QUIRK_MIDI_YAMAHA] = create_any_midi_quirk,
                [QUIRK_MIDI_ROLAND] = create_any_midi_quirk,
                [QUIRK_MIDI_MIDIMAN] = create_any_midi_quirk,
                [QUIRK_MIDI_NOVATION] = create_any_midi_quirk,
                [QUIRK_MIDI_RAW_BYTES] = create_any_midi_quirk,
                [QUIRK_MIDI_EMAGIC] = create_any_midi_quirk,
                [QUIRK_MIDI_CME] = create_any_midi_quirk,
                [QUIRK_MIDI_AKAI] = create_any_midi_quirk,
                [QUIRK_MIDI_FTDI] = create_any_midi_quirk,
                [QUIRK_MIDI_CH345] = create_any_midi_quirk,
                [QUIRK_AUDIO_STANDARD_INTERFACE] = create_standard_audio_quirk,
                [QUIRK_AUDIO_FIXED_ENDPOINT] = create_fixed_stream_quirk,
                [QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk,
                [QUIRK_AUDIO_STANDARD_MIXER] = create_standard_mixer_quirk,
        };

        if (quirk->type < QUIRK_TYPE_COUNT) {
                return quirk_funcs[quirk->type](chip, iface, driver, quirk);
        } else {
                usb_audio_err(chip, "invalid quirk type %d\n", quirk->type);
                return -ENXIO;
        }
}

/*
 * boot quirks
 */

#define EXTIGY_FIRMWARE_SIZE_OLD 794
#define EXTIGY_FIRMWARE_SIZE_NEW 483

static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interface *intf)
{
        struct usb_host_config *config = dev->actconfig;
        struct usb_device_descriptor *new_device_descriptor __free(kfree) = NULL;
        int err;

        if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD ||
            le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_NEW) {
                dev_dbg(&dev->dev, "sending Extigy boot sequence...\n");
                /* Send message to force it to reconnect with full interface. */
                err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev,0),
                                      0x10, 0x43, 0x0001, 0x000a, NULL, 0);
                if (err < 0)
                        dev_dbg(&dev->dev, "error sending boot message: %d\n", err);

                new_device_descriptor = kmalloc(sizeof(*new_device_descriptor), GFP_KERNEL);
                if (!new_device_descriptor)
                        return -ENOMEM;
                err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
                                new_device_descriptor, sizeof(*new_device_descriptor));
                if (err < 0)
                        dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err);
                if (new_device_descriptor->bNumConfigurations > dev->descriptor.bNumConfigurations)
                        dev_dbg(&dev->dev, "error too large bNumConfigurations: %d\n",
                                new_device_descriptor->bNumConfigurations);
                else
                        memcpy(&dev->descriptor, new_device_descriptor, sizeof(dev->descriptor));
                err = usb_reset_configuration(dev);
                if (err < 0)
                        dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err);
                dev_dbg(&dev->dev, "extigy_boot: new boot length = %d\n",
                            le16_to_cpu(get_cfg_desc(config)->wTotalLength));
                return -ENODEV; /* quit this anyway */
        }
        return 0;
}

static int snd_usb_audigy2nx_boot_quirk(struct usb_device *dev)
{
        u8 buf = 1;

        snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), 0x2a,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
                        0, 0, &buf, 1);
        if (buf == 0) {
                snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0x29,
                                USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
                                1, 2000, NULL, 0);
                return -ENODEV;
        }
        return 0;
}

static int snd_usb_fasttrackpro_boot_quirk(struct usb_device *dev)
{
        int err;

        if (dev->actconfig->desc.bConfigurationValue == 1) {
                dev_info(&dev->dev,
                           "Fast Track Pro switching to config #2\n");
                /* This function has to be available by the usb core module.
                 * if it is not avialable the boot quirk has to be left out
                 * and the configuration has to be set by udev or hotplug
                 * rules
                 */
                err = usb_driver_set_configuration(dev, 2);
                if (err < 0)
                        dev_dbg(&dev->dev,
                                "error usb_driver_set_configuration: %d\n",
                                err);
                /* Always return an error, so that we stop creating a device
                   that will just be destroyed and recreated with a new
                   configuration */
                return -ENODEV;
        } else
                dev_info(&dev->dev, "Fast Track Pro config OK\n");

        return 0;
}

/*
 * C-Media CM106/CM106+ have four 16-bit internal registers that are nicely
 * documented in the device's data sheet.
 */
static int snd_usb_cm106_write_int_reg(struct usb_device *dev, int reg, u16 value)
{
        u8 buf[4];
        buf[0] = 0x20;
        buf[1] = value & 0xff;
        buf[2] = (value >> 8) & 0xff;
        buf[3] = reg;
        return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION,
                               USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
                               0, 0, &buf, 4);
}

static int snd_usb_cm106_boot_quirk(struct usb_device *dev)
{
        /*
         * Enable line-out driver mode, set headphone source to front
         * channels, enable stereo mic.
         */
        return snd_usb_cm106_write_int_reg(dev, 2, 0x8004);
}

/*
 * CM6206 registers from the CM6206 datasheet rev 2.1
 */
#define CM6206_REG0_DMA_MASTER BIT(15)
#define CM6206_REG0_SPDIFO_RATE_48K (2 << 12)
#define CM6206_REG0_SPDIFO_RATE_96K (7 << 12)
/* Bit 4 thru 11 is the S/PDIF category code */
#define CM6206_REG0_SPDIFO_CAT_CODE_GENERAL (0 << 4)
#define CM6206_REG0_SPDIFO_EMPHASIS_CD BIT(3)
#define CM6206_REG0_SPDIFO_COPYRIGHT_NA BIT(2)
#define CM6206_REG0_SPDIFO_NON_AUDIO BIT(1)
#define CM6206_REG0_SPDIFO_PRO_FORMAT BIT(0)

#define CM6206_REG1_TEST_SEL_CLK BIT(14)
#define CM6206_REG1_PLLBIN_EN BIT(13)
#define CM6206_REG1_SOFT_MUTE_EN BIT(12)
#define CM6206_REG1_GPIO4_OUT BIT(11)
#define CM6206_REG1_GPIO4_OE BIT(10)
#define CM6206_REG1_GPIO3_OUT BIT(9)
#define CM6206_REG1_GPIO3_OE BIT(8)
#define CM6206_REG1_GPIO2_OUT BIT(7)
#define CM6206_REG1_GPIO2_OE BIT(6)
#define CM6206_REG1_GPIO1_OUT BIT(5)
#define CM6206_REG1_GPIO1_OE BIT(4)
#define CM6206_REG1_SPDIFO_INVALID BIT(3)
#define CM6206_REG1_SPDIF_LOOP_EN BIT(2)
#define CM6206_REG1_SPDIFO_DIS BIT(1)
#define CM6206_REG1_SPDIFI_MIX BIT(0)

#define CM6206_REG2_DRIVER_ON BIT(15)
#define CM6206_REG2_HEADP_SEL_SIDE_CHANNELS (0 << 13)
#define CM6206_REG2_HEADP_SEL_SURROUND_CHANNELS (1 << 13)
#define CM6206_REG2_HEADP_SEL_CENTER_SUBW (2 << 13)
#define CM6206_REG2_HEADP_SEL_FRONT_CHANNELS (3 << 13)
#define CM6206_REG2_MUTE_HEADPHONE_RIGHT BIT(12)
#define CM6206_REG2_MUTE_HEADPHONE_LEFT BIT(11)
#define CM6206_REG2_MUTE_REAR_SURROUND_RIGHT BIT(10)
#define CM6206_REG2_MUTE_REAR_SURROUND_LEFT BIT(9)
#define CM6206_REG2_MUTE_SIDE_SURROUND_RIGHT BIT(8)
#define CM6206_REG2_MUTE_SIDE_SURROUND_LEFT BIT(7)
#define CM6206_REG2_MUTE_SUBWOOFER BIT(6)
#define CM6206_REG2_MUTE_CENTER BIT(5)
#define CM6206_REG2_MUTE_RIGHT_FRONT BIT(3)
#define CM6206_REG2_MUTE_LEFT_FRONT BIT(3)
#define CM6206_REG2_EN_BTL BIT(2)
#define CM6206_REG2_MCUCLKSEL_1_5_MHZ (0)
#define CM6206_REG2_MCUCLKSEL_3_MHZ (1)
#define CM6206_REG2_MCUCLKSEL_6_MHZ (2)
#define CM6206_REG2_MCUCLKSEL_12_MHZ (3)

/* Bit 11..13 sets the sensitivity to FLY tuner volume control VP/VD signal */
#define CM6206_REG3_FLYSPEED_DEFAULT (2 << 11)
#define CM6206_REG3_VRAP25EN BIT(10)
#define CM6206_REG3_MSEL1 BIT(9)
#define CM6206_REG3_SPDIFI_RATE_44_1K BIT(0 << 7)
#define CM6206_REG3_SPDIFI_RATE_48K BIT(2 << 7)
#define CM6206_REG3_SPDIFI_RATE_32K BIT(3 << 7)
#define CM6206_REG3_PINSEL BIT(6)
#define CM6206_REG3_FOE BIT(5)
#define CM6206_REG3_ROE BIT(4)
#define CM6206_REG3_CBOE BIT(3)
#define CM6206_REG3_LOSE BIT(2)
#define CM6206_REG3_HPOE BIT(1)
#define CM6206_REG3_SPDIFI_CANREC BIT(0)

#define CM6206_REG5_DA_RSTN BIT(13)
#define CM6206_REG5_AD_RSTN BIT(12)
#define CM6206_REG5_SPDIFO_AD2SPDO BIT(12)
#define CM6206_REG5_SPDIFO_SEL_FRONT (0 << 9)
#define CM6206_REG5_SPDIFO_SEL_SIDE_SUR (1 << 9)
#define CM6206_REG5_SPDIFO_SEL_CEN_LFE (2 << 9)
#define CM6206_REG5_SPDIFO_SEL_REAR_SUR (3 << 9)
#define CM6206_REG5_CODECM BIT(8)
#define CM6206_REG5_EN_HPF BIT(7)
#define CM6206_REG5_T_SEL_DSDA4 BIT(6)
#define CM6206_REG5_T_SEL_DSDA3 BIT(5)
#define CM6206_REG5_T_SEL_DSDA2 BIT(4)
#define CM6206_REG5_T_SEL_DSDA1 BIT(3)
#define CM6206_REG5_T_SEL_DSDAD_NORMAL 0
#define CM6206_REG5_T_SEL_DSDAD_FRONT 4
#define CM6206_REG5_T_SEL_DSDAD_S_SURROUND 5
#define CM6206_REG5_T_SEL_DSDAD_CEN_LFE 6
#define CM6206_REG5_T_SEL_DSDAD_R_SURROUND 7

static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
{
        int err  = 0, reg;
        int val[] = {
                /*
                 * Values here are chosen based on sniffing USB traffic
                 * under Windows.
                 *
                 * REG0: DAC is master, sample rate 48kHz, no copyright
                 */
                CM6206_REG0_SPDIFO_RATE_48K |
                CM6206_REG0_SPDIFO_COPYRIGHT_NA,
                /*
                 * REG1: PLL binary search enable, soft mute enable.
                 */
                CM6206_REG1_PLLBIN_EN |
                CM6206_REG1_SOFT_MUTE_EN,
                /*
                 * REG2: enable output drivers,
                 * select front channels to the headphone output,
                 * then mute the headphone channels, run the MCU
                 * at 1.5 MHz.
                 */
                CM6206_REG2_DRIVER_ON |
                CM6206_REG2_HEADP_SEL_FRONT_CHANNELS |
                CM6206_REG2_MUTE_HEADPHONE_RIGHT |
                CM6206_REG2_MUTE_HEADPHONE_LEFT,
                /*
                 * REG3: default flyspeed, set 2.5V mic bias
                 * enable all line out ports and enable SPDIF
                 */
                CM6206_REG3_FLYSPEED_DEFAULT |
                CM6206_REG3_VRAP25EN |
                CM6206_REG3_FOE |
                CM6206_REG3_ROE |
                CM6206_REG3_CBOE |
                CM6206_REG3_LOSE |
                CM6206_REG3_HPOE |
                CM6206_REG3_SPDIFI_CANREC,
                /* REG4 is just a bunch of GPIO lines */
                0x0000,
                /* REG5: de-assert AD/DA reset signals */
                CM6206_REG5_DA_RSTN |
                CM6206_REG5_AD_RSTN };

        for (reg = 0; reg < ARRAY_SIZE(val); reg++) {
                err = snd_usb_cm106_write_int_reg(dev, reg, val[reg]);
                if (err < 0)
                        return err;
        }

        return err;
}

/* quirk for Plantronics GameCom 780 with CM6302 chip */
static int snd_usb_gamecon780_boot_quirk(struct usb_device *dev)
{
        /* set the initial volume and don't change; other values are either
         * too loud or silent due to firmware bug (bko#65251)
         */
        u8 buf[2] = { 0x74, 0xe3 };
        return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
                        UAC_FU_VOLUME << 8, 9 << 8, buf, 2);
}

/*
 * Novation Twitch DJ controller
 * Focusrite Novation Saffire 6 USB audio card
 */
static int snd_usb_novation_boot_quirk(struct usb_device *dev)
{
        /* preemptively set up the device because otherwise the
         * raw MIDI endpoints are not active */
        usb_set_interface(dev, 0, 1);
        return 0;
}

/*
 * This call will put the synth in "USB send" mode, i.e it will send MIDI
 * messages through USB (this is disabled at startup). The synth will
 * acknowledge by sending a sysex on endpoint 0x85 and by displaying a USB
 * sign on its LCD. Values here are chosen based on sniffing USB traffic
 * under Windows.
 */
static int snd_usb_accessmusic_boot_quirk(struct usb_device *dev)
{
        int err, actual_length;
        /* "midi send" enable */
        static const u8 seq[] = { 0x4e, 0x73, 0x52, 0x01 };
        void *buf;

        if (usb_pipe_type_check(dev, usb_sndintpipe(dev, 0x05)))
                return -EINVAL;
        buf = kmemdup(seq, ARRAY_SIZE(seq), GFP_KERNEL);
        if (!buf)
                return -ENOMEM;
        err = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x05), buf,
                        ARRAY_SIZE(seq), &actual_length, 1000);
        kfree(buf);
        if (err < 0)
                return err;

        return 0;
}

/*
 * Some sound cards from Native Instruments are in fact compliant to the USB
 * audio standard of version 2 and other approved USB standards, even though
 * they come up as vendor-specific device when first connected.
 *
 * However, they can be told to come up with a new set of descriptors
 * upon their next enumeration, and the interfaces announced by the new
 * descriptors will then be handled by the kernel's class drivers. As the
 * product ID will also change, no further checks are required.
 */

static int snd_usb_nativeinstruments_boot_quirk(struct usb_device *dev)
{
        int ret;

        ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                                  0xaf, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                  1, 0, NULL, 0, 1000);

        if (ret < 0)
                return ret;

        usb_reset_device(dev);

        /* return -EAGAIN, so the creation of an audio interface for this
         * temporary device is aborted. The device will reconnect with a
         * new product ID */
        return -EAGAIN;
}

static void mbox2_setup_48_24_magic(struct usb_device *dev)
{
        u8 srate[3];
        u8 temp[12];

        /* Choose 48000Hz permanently */
        srate[0] = 0x80;
        srate[1] = 0xbb;
        srate[2] = 0x00;

        /* Send the magic! */
        snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
                0x01, 0x22, 0x0100, 0x0085, &temp, 0x0003);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x81, 0xa2, 0x0100, 0x0085, &srate, 0x0003);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x81, 0xa2, 0x0100, 0x0086, &srate, 0x0003);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x81, 0xa2, 0x0100, 0x0003, &srate, 0x0003);
        return;
}

/* Digidesign Mbox 2 needs to load firmware onboard
 * and driver must wait a few seconds for initialisation.
 */

#define MBOX2_FIRMWARE_SIZE    646
#define MBOX2_BOOT_LOADING     0x01 /* Hard coded into the device */
#define MBOX2_BOOT_READY       0x02 /* Hard coded into the device */

static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
{
        struct usb_host_config *config = dev->actconfig;
        struct usb_device_descriptor *new_device_descriptor __free(kfree) = NULL;
        int err;
        u8 bootresponse[0x12];
        int fwsize;
        int count;

        fwsize = le16_to_cpu(get_cfg_desc(config)->wTotalLength);

        if (fwsize != MBOX2_FIRMWARE_SIZE) {
                dev_err(&dev->dev, "Invalid firmware size=%d.\n", fwsize);
                return -ENODEV;
        }

        dev_dbg(&dev->dev, "Sending Digidesign Mbox 2 boot sequence...\n");

        count = 0;
        bootresponse[0] = MBOX2_BOOT_LOADING;
        while ((bootresponse[0] == MBOX2_BOOT_LOADING) && (count < 10)) {
                msleep(500); /* 0.5 second delay */
                snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
                        /* Control magic - load onboard firmware */
                        0x85, 0xc0, 0x0001, 0x0000, &bootresponse, 0x0012);
                if (bootresponse[0] == MBOX2_BOOT_READY)
                        break;
                dev_dbg(&dev->dev, "device not ready, resending boot sequence...\n");
                count++;
        }

        if (bootresponse[0] != MBOX2_BOOT_READY) {
                dev_err(&dev->dev, "Unknown bootresponse=%d, or timed out, ignoring device.\n", bootresponse[0]);
                return -ENODEV;
        }

        dev_dbg(&dev->dev, "device initialised!\n");

        new_device_descriptor = kmalloc(sizeof(*new_device_descriptor), GFP_KERNEL);
        if (!new_device_descriptor)
                return -ENOMEM;

        err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
                new_device_descriptor, sizeof(*new_device_descriptor));
        if (err < 0)
                dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err);
        if (new_device_descriptor->bNumConfigurations > dev->descriptor.bNumConfigurations)
                dev_dbg(&dev->dev, "error too large bNumConfigurations: %d\n",
                        new_device_descriptor->bNumConfigurations);
        else
                memcpy(&dev->descriptor, new_device_descriptor, sizeof(dev->descriptor));

        err = usb_reset_configuration(dev);
        if (err < 0)
                dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err);
        dev_dbg(&dev->dev, "mbox2_boot: new boot length = %d\n",
                le16_to_cpu(get_cfg_desc(config)->wTotalLength));

        mbox2_setup_48_24_magic(dev);

        dev_info(&dev->dev, "Digidesign Mbox 2: 24bit 48kHz");

        return 0; /* Successful boot */
}

static int snd_usb_axefx3_boot_quirk(struct usb_device *dev)
{
        int err;

        dev_dbg(&dev->dev, "Waiting for Axe-Fx III to boot up...\n");

        /* If the Axe-Fx III has not fully booted, it will timeout when trying
         * to enable the audio streaming interface. A more generous timeout is
         * used here to detect when the Axe-Fx III has finished booting as the
         * set interface message will be acked once it has
         */
        err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                                USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
                                1, 1, NULL, 0, 120000);
        if (err < 0) {
                dev_err(&dev->dev,
                        "failed waiting for Axe-Fx III to boot: %d\n", err);
                return err;
        }

        dev_dbg(&dev->dev, "Axe-Fx III is now ready\n");

        err = usb_set_interface(dev, 1, 0);
        if (err < 0)
                dev_dbg(&dev->dev,
                        "error stopping Axe-Fx III interface: %d\n", err);

        return 0;
}

static void mbox3_setup_defaults(struct usb_device *dev)
{
        /* The Mbox 3 is "little endian" */
        /* max volume is: 0x0000. */
        /* min volume is: 0x0080 (shown in little endian form) */

        u8 com_buff[2];

        /* Deactivate Tuner */
        /* on  = 0x01*/
        /* off = 0x00*/
        com_buff[0] = 0x00;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x01, 0x21, 0x0003, 0x2001, &com_buff, 1);

        /* Set clock source to Internal (as opposed to S/PDIF) */
        /* Internal  = 0x01*/
        /* S/PDIF    = 0x02*/
        com_buff[0] = 0x01;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0100, 0x8001, &com_buff, 1);

        /* Mute the hardware loopbacks to start the device in a known state. */
        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* Analogue input 1 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0110, 0x4001, &com_buff, 2);
        /* Analogue input 1 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0111, 0x4001, &com_buff, 2);
        /* Analogue input 2 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0114, 0x4001, &com_buff, 2);
        /* Analogue input 2 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0115, 0x4001, &com_buff, 2);
        /* Analogue input 3 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0118, 0x4001, &com_buff, 2);
        /* Analogue input 3 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0119, 0x4001, &com_buff, 2);
        /* Analogue input 4 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x011c, 0x4001, &com_buff, 2);
        /* Analogue input 4 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x011d, 0x4001, &com_buff, 2);

        /* Set software sends to output */
        com_buff[0] = 0x00;
        com_buff[1] = 0x00;
        /* Analogue software return 1 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0100, 0x4001, &com_buff, 2);
        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* Analogue software return 1 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0101, 0x4001, &com_buff, 2);
        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* Analogue software return 2 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0104, 0x4001, &com_buff, 2);
        com_buff[0] = 0x00;
        com_buff[1] = 0x00;
        /* Analogue software return 2 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0105, 0x4001, &com_buff, 2);

        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* Analogue software return 3 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0108, 0x4001, &com_buff, 2);
        /* Analogue software return 3 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0109, 0x4001, &com_buff, 2);
        /* Analogue software return 4 left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x010c, 0x4001, &com_buff, 2);
        /* Analogue software return 4 right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x010d, 0x4001, &com_buff, 2);

        /* Return to muting sends */
        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* Analogue fx return left channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0120, 0x4001, &com_buff, 2);
        /* Analogue fx return right channel: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0121, 0x4001, &com_buff, 2);

        /* Analogue software input 1 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0100, 0x4201, &com_buff, 2);
        /* Analogue software input 2 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0101, 0x4201, &com_buff, 2);
        /* Analogue software input 3 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0102, 0x4201, &com_buff, 2);
        /* Analogue software input 4 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0103, 0x4201, &com_buff, 2);
        /* Analogue input 1 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0104, 0x4201, &com_buff, 2);
        /* Analogue input 2 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0105, 0x4201, &com_buff, 2);
        /* Analogue input 3 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0106, 0x4201, &com_buff, 2);
        /* Analogue input 4 fx send: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0107, 0x4201, &com_buff, 2);

        /* Toggle allowing host control */
        /* Not needed
        com_buff[0] = 0x02;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        3, 0x21, 0x0000, 0x2001, &com_buff, 1);
         */

        /* Do not dim fx returns */
        com_buff[0] = 0x00;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        3, 0x21, 0x0002, 0x2001, &com_buff, 1);

        /* Do not set fx returns to mono */
        com_buff[0] = 0x00;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        3, 0x21, 0x0001, 0x2001, &com_buff, 1);

        /* Mute the S/PDIF hardware loopback
         * same odd volume logic here as above
         */
        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* S/PDIF hardware input 1 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0112, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 1 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0113, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 2 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0116, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 2 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0117, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 3 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x011a, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 3 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x011b, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 4 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x011e, 0x4001, &com_buff, 2);
        /* S/PDIF hardware input 4 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x011f, 0x4001, &com_buff, 2);
        /* S/PDIF software return 1 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0102, 0x4001, &com_buff, 2);
        /* S/PDIF software return 1 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0103, 0x4001, &com_buff, 2);
        /* S/PDIF software return 2 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0106, 0x4001, &com_buff, 2);
        /* S/PDIF software return 2 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0107, 0x4001, &com_buff, 2);

        com_buff[0] = 0x00;
        com_buff[1] = 0x00;
        /* S/PDIF software return 3 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x010a, 0x4001, &com_buff, 2);

        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* S/PDIF software return 3 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x010b, 0x4001, &com_buff, 2);
        /* S/PDIF software return 4 left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x010e, 0x4001, &com_buff, 2);

        com_buff[0] = 0x00;
        com_buff[1] = 0x00;
        /* S/PDIF software return 4 right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x010f, 0x4001, &com_buff, 2);

        com_buff[0] = 0x00;
        com_buff[1] = 0x80;
        /* S/PDIF fx returns left channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0122, 0x4001, &com_buff, 2);
        /* S/PDIF fx returns right channel */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0123, 0x4001, &com_buff, 2);

        /* Set the dropdown "Effect" to the first option */
        /* Room1  = 0x00 */
        /* Room2  = 0x01 */
        /* Room3  = 0x02 */
        /* Hall 1 = 0x03 */
        /* Hall 2 = 0x04 */
        /* Plate  = 0x05 */
        /* Delay  = 0x06 */
        /* Echo   = 0x07 */
        com_buff[0] = 0x00;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0200, 0x4301, &com_buff, 1);        /* max is 0xff */
        /* min is 0x00 */


        /* Set the effect duration to 0 */
        /* max is 0xffff */
        /* min is 0x0000 */
        com_buff[0] = 0x00;
        com_buff[1] = 0x00;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0400, 0x4301, &com_buff, 2);

        /* Set the effect volume and feedback to 0 */
        /* max is 0xff */
        /* min is 0x00 */
        com_buff[0] = 0x00;
        /* feedback: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0500, 0x4301, &com_buff, 1);
        /* volume: */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        1, 0x21, 0x0300, 0x4301, &com_buff, 1);

        /* Set soft button hold duration */
        /* 0x03 = 250ms */
        /* 0x05 = 500ms DEFAULT */
        /* 0x08 = 750ms */
        /* 0x0a = 1sec */
        com_buff[0] = 0x05;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        3, 0x21, 0x0005, 0x2001, &com_buff, 1);

        /* Use dim LEDs for button of state */
        com_buff[0] = 0x00;
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        3, 0x21, 0x0004, 0x2001, &com_buff, 1);
}

#define MBOX3_DESCRIPTOR_SIZE        464

static int snd_usb_mbox3_boot_quirk(struct usb_device *dev)
{
        struct usb_host_config *config = dev->actconfig;
        struct usb_device_descriptor *new_device_descriptor __free(kfree) = NULL;
        int err;
        int descriptor_size;

        descriptor_size = le16_to_cpu(get_cfg_desc(config)->wTotalLength);

        if (descriptor_size != MBOX3_DESCRIPTOR_SIZE) {
                dev_err(&dev->dev, "MBOX3: Invalid descriptor size=%d.\n", descriptor_size);
                return -ENODEV;
        }

        dev_dbg(&dev->dev, "MBOX3: device initialised!\n");

        new_device_descriptor = kmalloc(sizeof(*new_device_descriptor), GFP_KERNEL);
        if (!new_device_descriptor)
                return -ENOMEM;

        err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
                new_device_descriptor, sizeof(*new_device_descriptor));
        if (err < 0)
                dev_dbg(&dev->dev, "MBOX3: error usb_get_descriptor: %d\n", err);
        if (new_device_descriptor->bNumConfigurations > dev->descriptor.bNumConfigurations)
                dev_dbg(&dev->dev, "MBOX3: error too large bNumConfigurations: %d\n",
                        new_device_descriptor->bNumConfigurations);
        else
                memcpy(&dev->descriptor, new_device_descriptor, sizeof(dev->descriptor));

        err = usb_reset_configuration(dev);
        if (err < 0)
                dev_dbg(&dev->dev, "MBOX3: error usb_reset_configuration: %d\n", err);

        dev_dbg(&dev->dev, "MBOX3: new boot length = %d\n",
                le16_to_cpu(get_cfg_desc(config)->wTotalLength));

        mbox3_setup_defaults(dev);
        dev_info(&dev->dev, "MBOX3: Initialized.");

        return 0; /* Successful boot */
}

#define MICROBOOK_BUF_SIZE 128

static int snd_usb_motu_microbookii_communicate(struct usb_device *dev, u8 *buf,
                                                int buf_size, int *length)
{
        int err, actual_length;

        if (usb_pipe_type_check(dev, usb_sndintpipe(dev, 0x01)))
                return -EINVAL;
        err = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x01), buf, *length,
                                &actual_length, 1000);
        if (err < 0)
                return err;

        print_hex_dump(KERN_DEBUG, "MicroBookII snd: ", DUMP_PREFIX_NONE, 16, 1,
                       buf, actual_length, false);

        memset(buf, 0, buf_size);

        if (usb_pipe_type_check(dev, usb_rcvintpipe(dev, 0x82)))
                return -EINVAL;
        err = usb_interrupt_msg(dev, usb_rcvintpipe(dev, 0x82), buf, buf_size,
                                &actual_length, 1000);
        if (err < 0)
                return err;

        print_hex_dump(KERN_DEBUG, "MicroBookII rcv: ", DUMP_PREFIX_NONE, 16, 1,
                       buf, actual_length, false);

        *length = actual_length;
        return 0;
}

static int snd_usb_motu_microbookii_boot_quirk(struct usb_device *dev)
{
        int err, actual_length, poll_attempts = 0;
        static const u8 set_samplerate_seq[] = { 0x00, 0x00, 0x00, 0x00,
                                                 0x00, 0x00, 0x0b, 0x14,
                                                 0x00, 0x00, 0x00, 0x01 };
        static const u8 poll_ready_seq[] = { 0x00, 0x04, 0x00, 0x00,
                                             0x00, 0x00, 0x0b, 0x18 };
        u8 *buf = kzalloc(MICROBOOK_BUF_SIZE, GFP_KERNEL);

        if (!buf)
                return -ENOMEM;

        dev_info(&dev->dev, "Waiting for MOTU Microbook II to boot up...\n");

        /* First we tell the device which sample rate to use. */
        memcpy(buf, set_samplerate_seq, sizeof(set_samplerate_seq));
        actual_length = sizeof(set_samplerate_seq);
        err = snd_usb_motu_microbookii_communicate(dev, buf, MICROBOOK_BUF_SIZE,
                                                   &actual_length);

        if (err < 0) {
                dev_err(&dev->dev,
                        "failed setting the sample rate for Motu MicroBook II: %d\n",
                        err);
                goto free_buf;
        }

        /* Then we poll every 100 ms until the device informs of its readiness. */
        while (true) {
                if (++poll_attempts > 100) {
                        dev_err(&dev->dev,
                                "failed booting Motu MicroBook II: timeout\n");
                        err = -ENODEV;
                        goto free_buf;
                }

                memset(buf, 0, MICROBOOK_BUF_SIZE);
                memcpy(buf, poll_ready_seq, sizeof(poll_ready_seq));

                actual_length = sizeof(poll_ready_seq);
                err = snd_usb_motu_microbookii_communicate(
                        dev, buf, MICROBOOK_BUF_SIZE, &actual_length);
                if (err < 0) {
                        dev_err(&dev->dev,
                                "failed booting Motu MicroBook II: communication error %d\n",
                                err);
                        goto free_buf;
                }

                /* the device signals its readiness through a message of the
                 * form
                 *           XX 06 00 00 00 00 0b 18  00 00 00 01
                 * If the device is not yet ready to accept audio data, the
                 * last byte of that sequence is 00.
                 */
                if (actual_length == 12 && buf[actual_length - 1] == 1)
                        break;

                msleep(100);
        }

        dev_info(&dev->dev, "MOTU MicroBook II ready\n");

free_buf:
        kfree(buf);
        return err;
}

static int snd_usb_motu_m_series_boot_quirk(struct usb_device *dev)
{
        msleep(4000);

        return 0;
}

static int snd_usb_rme_digiface_boot_quirk(struct usb_device *dev)
{
        /* Disable mixer, internal clock, all outputs ADAT, 48kHz, TMS off */
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        16, 0x40, 0x2410, 0x7fff, NULL, 0);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                        18, 0x40, 0x0104, 0xffff, NULL, 0);

        /* Disable loopback for all inputs */
        for (int ch = 0; ch < 32; ch++)
                snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                                22, 0x40, 0x400, ch, NULL, 0);

        /* Unity gain for all outputs */
        for (int ch = 0; ch < 34; ch++)
                snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                                21, 0x40, 0x9000, 0x100 + ch, NULL, 0);

        return 0;
}

/*
 * Setup quirks
 */
#define MAUDIO_SET                0x01 /* parse device_setup */
#define MAUDIO_SET_COMPATIBLE        0x80 /* use only "win-compatible" interfaces */
#define MAUDIO_SET_DTS                0x02 /* enable DTS Digital Output */
#define MAUDIO_SET_96K                0x04 /* 48-96kHz rate if set, 8-48kHz otherwise */
#define MAUDIO_SET_24B                0x08 /* 24bits sample if set, 16bits otherwise */
#define MAUDIO_SET_DI                0x10 /* enable Digital Input */
#define MAUDIO_SET_MASK                0x1f /* bit mask for setup value */
#define MAUDIO_SET_24B_48K_DI         0x19 /* 24bits+48kHz+Digital Input */
#define MAUDIO_SET_24B_48K_NOTDI 0x09 /* 24bits+48kHz+No Digital Input */
#define MAUDIO_SET_16B_48K_DI         0x11 /* 16bits+48kHz+Digital Input */
#define MAUDIO_SET_16B_48K_NOTDI 0x01 /* 16bits+48kHz+No Digital Input */

static int quattro_skip_setting_quirk(struct snd_usb_audio *chip,
                                      int iface, int altno)
{
        /* Reset ALL ifaces to 0 altsetting.
         * Call it for every possible altsetting of every interface.
         */
        usb_set_interface(chip->dev, iface, 0);
        if (chip->setup & MAUDIO_SET) {
                if (chip->setup & MAUDIO_SET_COMPATIBLE) {
                        if (iface != 1 && iface != 2)
                                return 1; /* skip all interfaces but 1 and 2 */
                } else {
                        unsigned int mask;
                        if (iface == 1 || iface == 2)
                                return 1; /* skip interfaces 1 and 2 */
                        if ((chip->setup & MAUDIO_SET_96K) && altno != 1)
                                return 1; /* skip this altsetting */
                        mask = chip->setup & MAUDIO_SET_MASK;
                        if (mask == MAUDIO_SET_24B_48K_DI && altno != 2)
                                return 1; /* skip this altsetting */
                        if (mask == MAUDIO_SET_24B_48K_NOTDI && altno != 3)
                                return 1; /* skip this altsetting */
                        if (mask == MAUDIO_SET_16B_48K_NOTDI && altno != 4)
                                return 1; /* skip this altsetting */
                }
        }
        usb_audio_dbg(chip,
                    "using altsetting %d for interface %d config %d\n",
                    altno, iface, chip->setup);
        return 0; /* keep this altsetting */
}

static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
                                         int iface,
                                         int altno)
{
        /* Reset ALL ifaces to 0 altsetting.
         * Call it for every possible altsetting of every interface.
         */
        usb_set_interface(chip->dev, iface, 0);

        if (chip->setup & MAUDIO_SET) {
                unsigned int mask;
                if ((chip->setup & MAUDIO_SET_DTS) && altno != 6)
                        return 1; /* skip this altsetting */
                if ((chip->setup & MAUDIO_SET_96K) && altno != 1)
                        return 1; /* skip this altsetting */
                mask = chip->setup & MAUDIO_SET_MASK;
                if (mask == MAUDIO_SET_24B_48K_DI && altno != 2)
                        return 1; /* skip this altsetting */
                if (mask == MAUDIO_SET_24B_48K_NOTDI && altno != 3)
                        return 1; /* skip this altsetting */
                if (mask == MAUDIO_SET_16B_48K_DI && altno != 4)
                        return 1; /* skip this altsetting */
                if (mask == MAUDIO_SET_16B_48K_NOTDI && altno != 5)
                        return 1; /* skip this altsetting */
        }

        return 0; /* keep this altsetting */
}

static int fasttrackpro_skip_setting_quirk(struct snd_usb_audio *chip,
                                           int iface, int altno)
{
        /* Reset ALL ifaces to 0 altsetting.
         * Call it for every possible altsetting of every interface.
         */
        usb_set_interface(chip->dev, iface, 0);

        /* possible configuration where both inputs and only one output is
         *used is not supported by the current setup
         */
        if (chip->setup & (MAUDIO_SET | MAUDIO_SET_24B)) {
                if (chip->setup & MAUDIO_SET_96K) {
                        if (altno != 3 && altno != 6)
                                return 1;
                } else if (chip->setup & MAUDIO_SET_DI) {
                        if (iface == 4)
                                return 1; /* no analog input */
                        if (altno != 2 && altno != 5)
                                return 1; /* enable only altsets 2 and 5 */
                } else {
                        if (iface == 5)
                                return 1; /* disable digialt input */
                        if (altno != 2 && altno != 5)
                                return 1; /* enalbe only altsets 2 and 5 */
                }
        } else {
                /* keep only 16-Bit mode */
                if (altno != 1)
                        return 1;
        }

        usb_audio_dbg(chip,
                    "using altsetting %d for interface %d config %d\n",
                    altno, iface, chip->setup);
        return 0; /* keep this altsetting */
}

static int s1810c_skip_setting_quirk(struct snd_usb_audio *chip,
                                           int iface, int altno)
{
        /*
         * Altno settings:
         *
         * Playback (Interface 1):
         * 1: 6 Analog + 2 S/PDIF
         * 2: 6 Analog + 2 S/PDIF
         * 3: 6 Analog
         *
         * Capture (Interface 2):
         * 1: 8 Analog + 2 S/PDIF + 8 ADAT
         * 2: 8 Analog + 2 S/PDIF + 4 ADAT
         * 3: 8 Analog
         */

        /*
         * I'll leave 2 as the default one and
         * use device_setup to switch to the
         * other two.
         */
        if ((chip->setup == 0 || chip->setup > 2) && altno != 2)
                return 1;
        else if (chip->setup == 1 && altno != 1)
                return 1;
        else if (chip->setup == 2 && altno != 3)
                return 1;

        return 0;
}

int snd_usb_apply_interface_quirk(struct snd_usb_audio *chip,
                                  int iface,
                                  int altno)
{
        /* audiophile usb: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x0763, 0x2003))
                return audiophile_skip_setting_quirk(chip, iface, altno);
        /* quattro usb: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x0763, 0x2001))
                return quattro_skip_setting_quirk(chip, iface, altno);
        /* fasttrackpro usb: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x0763, 0x2012))
                return fasttrackpro_skip_setting_quirk(chip, iface, altno);
        /* presonus studio 1810c: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x194f, 0x010c))
                return s1810c_skip_setting_quirk(chip, iface, altno);

        return 0;
}

int snd_usb_apply_boot_quirk(struct usb_device *dev,
                             struct usb_interface *intf,
                             const struct snd_usb_audio_quirk *quirk,
                             unsigned int id)
{
        switch (id) {
        case USB_ID(0x041e, 0x3000):
                /* SB Extigy needs special boot-up sequence */
                /* if more models come, this will go to the quirk list. */
                return snd_usb_extigy_boot_quirk(dev, intf);

        case USB_ID(0x041e, 0x3020):
                /* SB Audigy 2 NX needs its own boot-up magic, too */
                return snd_usb_audigy2nx_boot_quirk(dev);

        case USB_ID(0x10f5, 0x0200):
                /* C-Media CM106 / Turtle Beach Audio Advantage Roadie */
                return snd_usb_cm106_boot_quirk(dev);

        case USB_ID(0x0d8c, 0x0102):
                /* C-Media CM6206 / CM106-Like Sound Device */
        case USB_ID(0x0ccd, 0x00b1): /* Terratec Aureon 7.1 USB */
                return snd_usb_cm6206_boot_quirk(dev);

        case USB_ID(0x0dba, 0x3000):
                /* Digidesign Mbox 2 */
                return snd_usb_mbox2_boot_quirk(dev);
        case USB_ID(0x0dba, 0x5000):
                /* Digidesign Mbox 3 */
                return snd_usb_mbox3_boot_quirk(dev);


        case USB_ID(0x1235, 0x0010): /* Focusrite Novation Saffire 6 USB */
        case USB_ID(0x1235, 0x0018): /* Focusrite Novation Twitch */
                return snd_usb_novation_boot_quirk(dev);

        case USB_ID(0x133e, 0x0815):
                /* Access Music VirusTI Desktop */
                return snd_usb_accessmusic_boot_quirk(dev);

        case USB_ID(0x17cc, 0x1000): /* Komplete Audio 6 */
        case USB_ID(0x17cc, 0x1010): /* Traktor Audio 6 */
        case USB_ID(0x17cc, 0x1020): /* Traktor Audio 10 */
                return snd_usb_nativeinstruments_boot_quirk(dev);
        case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
                return snd_usb_fasttrackpro_boot_quirk(dev);
        case USB_ID(0x047f, 0xc010): /* Plantronics Gamecom 780 */
                return snd_usb_gamecon780_boot_quirk(dev);
        case USB_ID(0x2466, 0x8010): /* Fractal Audio Axe-Fx 3 */
                return snd_usb_axefx3_boot_quirk(dev);
        case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II */
                /*
                 * For some reason interface 3 with vendor-spec class is
                 * detected on MicroBook IIc.
                 */
                if (get_iface_desc(intf->altsetting)->bInterfaceClass ==
                    USB_CLASS_VENDOR_SPEC &&
                    get_iface_desc(intf->altsetting)->bInterfaceNumber < 3)
                        return snd_usb_motu_microbookii_boot_quirk(dev);
                break;
        case USB_ID(0x2a39, 0x3f8c): /* RME Digiface USB */
        case USB_ID(0x2a39, 0x3fa0): /* RME Digiface USB (alternate) */
                return snd_usb_rme_digiface_boot_quirk(dev);
        }

        return 0;
}

int snd_usb_apply_boot_quirk_once(struct usb_device *dev,
                                  struct usb_interface *intf,
                                  const struct snd_usb_audio_quirk *quirk,
                                  unsigned int id)
{
        switch (id) {
        case USB_ID(0x07fd, 0x0008): /* MOTU M Series, 1st hardware version */
                return snd_usb_motu_m_series_boot_quirk(dev);
        }

        return 0;
}

/*
 * check if the device uses big-endian samples
 */
int snd_usb_is_big_endian_format(struct snd_usb_audio *chip,
                                 const struct audioformat *fp)
{
        /* it depends on altsetting whether the device is big-endian or not */
        switch (chip->usb_id) {
        case USB_ID(0x0763, 0x2001): /* M-Audio Quattro: captured data only */
                if (fp->altsetting == 2 || fp->altsetting == 3 ||
                        fp->altsetting == 5 || fp->altsetting == 6)
                        return 1;
                break;
        case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
                if (chip->setup == 0x00 ||
                        fp->altsetting == 1 || fp->altsetting == 2 ||
                        fp->altsetting == 3)
                        return 1;
                break;
        case USB_ID(0x0763, 0x2012): /* M-Audio Fast Track Pro */
                if (fp->altsetting == 2 || fp->altsetting == 3 ||
                        fp->altsetting == 5 || fp->altsetting == 6)
                        return 1;
                break;
        }
        return 0;
}

/*
 * For E-Mu 0404USB/0202USB/TrackerPre/0204 sample rate should be set for device,
 * not for interface.
 */

enum {
        EMU_QUIRK_SR_44100HZ = 0,
        EMU_QUIRK_SR_48000HZ,
        EMU_QUIRK_SR_88200HZ,
        EMU_QUIRK_SR_96000HZ,
        EMU_QUIRK_SR_176400HZ,
        EMU_QUIRK_SR_192000HZ
};

static void set_format_emu_quirk(struct snd_usb_substream *subs,
                                 const struct audioformat *fmt)
{
        unsigned char emu_samplerate_id = 0;

        /* When capture is active
         * sample rate shouldn't be changed
         * by playback substream
         */
        if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
                if (subs->stream->substream[SNDRV_PCM_STREAM_CAPTURE].cur_audiofmt)
                        return;
        }

        switch (fmt->rate_min) {
        case 48000:
                emu_samplerate_id = EMU_QUIRK_SR_48000HZ;
                break;
        case 88200:
                emu_samplerate_id = EMU_QUIRK_SR_88200HZ;
                break;
        case 96000:
                emu_samplerate_id = EMU_QUIRK_SR_96000HZ;
                break;
        case 176400:
                emu_samplerate_id = EMU_QUIRK_SR_176400HZ;
                break;
        case 192000:
                emu_samplerate_id = EMU_QUIRK_SR_192000HZ;
                break;
        default:
                emu_samplerate_id = EMU_QUIRK_SR_44100HZ;
                break;
        }
        snd_emuusb_set_samplerate(subs->stream->chip, emu_samplerate_id);
        subs->pkt_offset_adj = (emu_samplerate_id >= EMU_QUIRK_SR_176400HZ) ? 4 : 0;
}

static int pioneer_djm_set_format_quirk(struct snd_usb_substream *subs,
                                        u16 windex)
{
        unsigned int cur_rate = subs->data_endpoint->cur_rate;
        u8 sr[3];
        // Convert to little endian
        sr[0] = cur_rate & 0xff;
        sr[1] = (cur_rate >> 8) & 0xff;
        sr[2] = (cur_rate >> 16) & 0xff;
        usb_set_interface(subs->dev, 0, 1);
        // we should derive windex from fmt-sync_ep but it's not set
        snd_usb_ctl_msg(subs->stream->chip->dev,
                usb_sndctrlpipe(subs->stream->chip->dev, 0),
                0x01, 0x22, 0x0100, windex, &sr, 0x0003);
        return 0;
}

static void mbox3_set_format_quirk(struct snd_usb_substream *subs,
                                const struct audioformat *fmt)
{
        __le32 buff4 = 0;
        u8 buff1 = 0x01;
        u32 new_rate = subs->data_endpoint->cur_rate;
        u32 current_rate;

        // Get current rate from card and check if changing it is needed
        snd_usb_ctl_msg(subs->dev, usb_rcvctrlpipe(subs->dev, 0),
                                        0x01, 0x21 | USB_DIR_IN, 0x0100, 0x8101, &buff4, 4);
        current_rate = le32_to_cpu(buff4);
        dev_dbg(&subs->dev->dev,
                         "MBOX3: Current configured sample rate: %d", current_rate);
        if (current_rate == new_rate) {
                dev_dbg(&subs->dev->dev,
                        "MBOX3: No change needed (current rate:%d == new rate:%d)",
                        current_rate, new_rate);
                return;
        }

        // Set new rate
        dev_info(&subs->dev->dev,
                         "MBOX3: Changing sample rate to: %d", new_rate);
        buff4 = cpu_to_le32(new_rate);
        snd_usb_ctl_msg(subs->dev, usb_sndctrlpipe(subs->dev, 0),
                                        0x01, 0x21, 0x0100, 0x8101, &buff4, 4);

        // Set clock source to Internal
        snd_usb_ctl_msg(subs->dev, usb_sndctrlpipe(subs->dev, 0),
                                        0x01, 0x21, 0x0100, 0x8001, &buff1, 1);

        // Check whether the change was successful
        buff4 = 0;
        snd_usb_ctl_msg(subs->dev, usb_rcvctrlpipe(subs->dev, 0),
                                        0x01, 0x21 | USB_DIR_IN, 0x0100, 0x8101, &buff4, 4);
        if (new_rate != le32_to_cpu(buff4))
                dev_warn(&subs->dev->dev, "MBOX3: Couldn't set the sample rate");
}

static const int rme_digiface_rate_table[] = {
        32000, 44100, 48000, 0,
        64000, 88200, 96000, 0,
        128000, 176400, 192000, 0,
};

static int rme_digiface_set_format_quirk(struct snd_usb_substream *subs)
{
        unsigned int cur_rate = subs->data_endpoint->cur_rate;
        u16 val;
        int speed_mode;
        int id;

        for (id = 0; id < ARRAY_SIZE(rme_digiface_rate_table); id++) {
                if (rme_digiface_rate_table[id] == cur_rate)
                        break;
        }

        if (id >= ARRAY_SIZE(rme_digiface_rate_table))
                return -EINVAL;

        /* 2, 3, 4 for 1x, 2x, 4x */
        speed_mode = (id >> 2) + 2;
        val = (id << 3) | (speed_mode << 12);

        /* Set the sample rate */
        snd_usb_ctl_msg(subs->stream->chip->dev,
                usb_sndctrlpipe(subs->stream->chip->dev, 0),
                16, 0x40, val, 0x7078, NULL, 0);
        return 0;
}

void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
                              const struct audioformat *fmt)
{
        switch (subs->stream->chip->usb_id) {
        case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
        case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
        case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
        case USB_ID(0x041e, 0x3f19): /* E-Mu 0204 USB */
                set_format_emu_quirk(subs, fmt);
                break;
        case USB_ID(0x534d, 0x0021): /* MacroSilicon MS2100/MS2106 */
        case USB_ID(0x534d, 0x2109): /* MacroSilicon MS2109 */
                subs->stream_offset_adj = 2;
                break;
        case USB_ID(0x2b73, 0x000a): /* Pioneer DJM-900NXS2 */
        case USB_ID(0x2b73, 0x0013): /* Pioneer DJM-450 */
        case USB_ID(0x2b73, 0x0034): /* Pioneer DJM-V10 */
                pioneer_djm_set_format_quirk(subs, 0x0082);
                break;
        case USB_ID(0x08e4, 0x017f): /* Pioneer DJM-750 */
        case USB_ID(0x08e4, 0x0163): /* Pioneer DJM-850 */
                pioneer_djm_set_format_quirk(subs, 0x0086);
                break;
        case USB_ID(0x0dba, 0x5000):
                mbox3_set_format_quirk(subs, fmt); /* Digidesign Mbox 3 */
                break;
        case USB_ID(0x2a39, 0x3f8c): /* RME Digiface USB */
        case USB_ID(0x2a39, 0x3fa0): /* RME Digiface USB (alternate) */
                rme_digiface_set_format_quirk(subs);
                break;
        }
}

int snd_usb_select_mode_quirk(struct snd_usb_audio *chip,
                              const struct audioformat *fmt)
{
        struct usb_device *dev = chip->dev;
        int err;

        if (chip->quirk_flags & QUIRK_FLAG_ITF_USB_DSD_DAC) {
                /* First switch to alt set 0, otherwise the mode switch cmd
                 * will not be accepted by the DAC
                 */
                err = usb_set_interface(dev, fmt->iface, 0);
                if (err < 0)
                        return err;

                msleep(20); /* Delay needed after setting the interface */

                /* Vendor mode switch cmd is required. */
                if (fmt->formats & SNDRV_PCM_FMTBIT_DSD_U32_BE) {
                        /* DSD mode (DSD_U32) requested */
                        err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
                                              USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                                              1, 1, NULL, 0);
                        if (err < 0)
                                return err;

                } else {
                        /* PCM or DOP mode (S32) requested */
                        /* PCM mode (S16) requested */
                        err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
                                              USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                                              0, 1, NULL, 0);
                        if (err < 0)
                                return err;

                }
                msleep(20);
        }
        return 0;
}

void snd_usb_endpoint_start_quirk(struct snd_usb_endpoint *ep)
{
        /*
         * "Playback Design" products send bogus feedback data at the start
         * of the stream. Ignore them.
         */
        if (USB_ID_VENDOR(ep->chip->usb_id) == 0x23ba &&
            ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
                ep->skip_packets = 4;

        /*
         * M-Audio Fast Track C400/C600 - when packets are not skipped, real
         * world latency varies by approx. +/- 50 frames (at 96kHz) each time
         * the stream is (re)started. When skipping packets 16 at endpoint
         * start up, the real world latency is stable within +/- 1 frame (also
         * across power cycles).
         */
        if ((ep->chip->usb_id == USB_ID(0x0763, 0x2030) ||
             ep->chip->usb_id == USB_ID(0x0763, 0x2031)) &&
            ep->type == SND_USB_ENDPOINT_TYPE_DATA)
                ep->skip_packets = 16;

        /* Work around devices that report unreasonable feedback data */
        if ((ep->chip->usb_id == USB_ID(0x0644, 0x8038) ||  /* TEAC UD-H01 */
             ep->chip->usb_id == USB_ID(0x1852, 0x5034)) && /* T+A Dac8 */
            ep->syncmaxsize == 4)
                ep->tenor_fb_quirk = 1;
}

/* quirk applied after snd_usb_ctl_msg(); not applied during boot quirks */
void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
                           __u8 request, __u8 requesttype, __u16 value,
                           __u16 index, void *data, __u16 size)
{
        struct snd_usb_audio *chip = dev_get_drvdata(&dev->dev);

        if (!chip || (requesttype & USB_TYPE_MASK) != USB_TYPE_CLASS)
                return;

        if (chip->quirk_flags & QUIRK_FLAG_CTL_MSG_DELAY)
                msleep(20);
        else if (chip->quirk_flags & QUIRK_FLAG_CTL_MSG_DELAY_1M)
                usleep_range(1000, 2000);
        else if (chip->quirk_flags & QUIRK_FLAG_CTL_MSG_DELAY_5M)
                usleep_range(5000, 6000);
}

/*
 * snd_usb_interface_dsd_format_quirks() is called from format.c to
 * augment the PCM format bit-field for DSD types. The UAC standards
 * don't have a designated bit field to denote DSD-capable interfaces,
 * hence all hardware that is known to support this format has to be
 * listed here.
 */
u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
                                        struct audioformat *fp,
                                        unsigned int sample_bytes)
{
        struct usb_interface *iface;

        /* Playback Designs */
        if (USB_ID_VENDOR(chip->usb_id) == 0x23ba &&
            USB_ID_PRODUCT(chip->usb_id) < 0x0110) {
                switch (fp->altsetting) {
                case 1:
                        fp->dsd_dop = true;
                        return SNDRV_PCM_FMTBIT_DSD_U16_LE;
                case 2:
                        fp->dsd_bitrev = true;
                        return SNDRV_PCM_FMTBIT_DSD_U8;
                case 3:
                        fp->dsd_bitrev = true;
                        return SNDRV_PCM_FMTBIT_DSD_U16_LE;
                }
        }

        /* XMOS based USB DACs */
        switch (chip->usb_id) {
        case USB_ID(0x139f, 0x5504): /* Nagra DAC */
        case USB_ID(0x20b1, 0x3089): /* Mola-Mola DAC */
        case USB_ID(0x2522, 0x0007): /* LH Labs Geek Out 1V5 */
        case USB_ID(0x2522, 0x0009): /* LH Labs Geek Pulse X Inifinity 2V0 */
        case USB_ID(0x2522, 0x0012): /* LH Labs VI DAC Infinity */
        case USB_ID(0x2772, 0x0230): /* Pro-Ject Pre Box S2 Digital */
                if (fp->altsetting == 2)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
                break;

        case USB_ID(0x0d8c, 0x0316): /* Hegel HD12 DSD */
        case USB_ID(0x10cb, 0x0103): /* The Bit Opus #3; with fp->dsd_raw */
        case USB_ID(0x16d0, 0x06b2): /* NuPrime DAC-10 */
        case USB_ID(0x16d0, 0x06b4): /* NuPrime Audio HD-AVP/AVA */
        case USB_ID(0x16d0, 0x0733): /* Furutech ADL Stratos */
        case USB_ID(0x16d0, 0x09d8): /* NuPrime IDA-8 */
        case USB_ID(0x16d0, 0x09db): /* NuPrime Audio DAC-9 */
        case USB_ID(0x16d0, 0x09dd): /* Encore mDSD */
        case USB_ID(0x1db5, 0x0003): /* Bryston BDA3 */
        case USB_ID(0x20a0, 0x4143): /* WaveIO USB Audio 2.0 */
        case USB_ID(0x22e1, 0xca01): /* HDTA Serenade DSD */
        case USB_ID(0x249c, 0x9326): /* M2Tech Young MkIII */
        case USB_ID(0x2616, 0x0106): /* PS Audio NuWave DAC */
        case USB_ID(0x2622, 0x0041): /* Audiolab M-DAC+ */
        case USB_ID(0x278b, 0x5100): /* Rotel RC-1590 */
        case USB_ID(0x27f7, 0x3002): /* W4S DAC-2v2SE */
        case USB_ID(0x29a2, 0x0086): /* Mutec MC3+ USB */
        case USB_ID(0x6b42, 0x0042): /* MSB Technology */
                if (fp->altsetting == 3)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
                break;

        /* Amanero Combo384 USB based DACs with native DSD support */
        case USB_ID(0x16d0, 0x071a):  /* Amanero - Combo384 */
                if (fp->altsetting == 2) {
                        switch (le16_to_cpu(chip->dev->descriptor.bcdDevice)) {
                        case 0x199:
                                return SNDRV_PCM_FMTBIT_DSD_U32_LE;
                        case 0x19b:
                        case 0x203:
                                return SNDRV_PCM_FMTBIT_DSD_U32_BE;
                        default:
                                break;
                        }
                }
                break;
        case USB_ID(0x16d0, 0x0a23):
                if (fp->altsetting == 2)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
                break;

        default:
                break;
        }

        /* ITF-USB DSD based DACs */
        if (chip->quirk_flags & QUIRK_FLAG_ITF_USB_DSD_DAC) {
                iface = usb_ifnum_to_if(chip->dev, fp->iface);

                /* Altsetting 2 support native DSD if the num of altsets is
                 * three (0-2),
                 * Altsetting 3 support native DSD if the num of altsets is
                 * four (0-3).
                 */
                if (fp->altsetting == iface->num_altsetting - 1)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
        }

        /* Mostly generic method to detect many DSD-capable implementations */
        if ((chip->quirk_flags & QUIRK_FLAG_DSD_RAW) && fp->dsd_raw)
                return SNDRV_PCM_FMTBIT_DSD_U32_BE;

        return 0;
}

void snd_usb_audioformat_attributes_quirk(struct snd_usb_audio *chip,
                                          struct audioformat *fp,
                                          int stream)
{
        switch (chip->usb_id) {
        case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
                /* Optoplay sets the sample rate attribute although
                 * it seems not supporting it in fact.
                 */
                fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
                break;
        case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
        case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
                /* doesn't set the sample rate attribute, but supports it */
                fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
                break;
        case USB_ID(0x0763, 0x2001):  /* M-Audio Quattro USB */
        case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
        case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
        case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
                                        an older model 77d:223) */
        /*
         * plantronics headset and Griffin iMic have set adaptive-in
         * although it's really not...
         */
                fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
                if (stream == SNDRV_PCM_STREAM_PLAYBACK)
                        fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
                else
                        fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
                break;
        case USB_ID(0x07fd, 0x0004):  /* MOTU MicroBook IIc */
                /*
                 * MaxPacketsOnly attribute is erroneously set in endpoint
                 * descriptors. As a result this card produces noise with
                 * all sample rates other than 96 kHz.
                 */
                fp->attributes &= ~UAC_EP_CS_ATTR_FILL_MAX;
                break;
        case USB_ID(0x1224, 0x2a25):  /* Jieli Technology USB PHY 2.0 */
                /* mic works only when ep packet size is set to wMaxPacketSize */
                fp->attributes |= UAC_EP_CS_ATTR_FILL_MAX;
                break;
        case USB_ID(0x3511, 0x2b1e): /* Opencomm2 UC USB Bluetooth dongle */
                /* mic works only when ep pitch control is not set */
                if (stream == SNDRV_PCM_STREAM_CAPTURE)
                        fp->attributes &= ~UAC_EP_CS_ATTR_PITCH_CONTROL;
                break;
        }
}

/*
 * driver behavior quirk flags
 */
struct usb_audio_quirk_flags_table {
        u32 id;
        u32 flags;
};

#define DEVICE_FLG(vid, pid, _flags) \
        { .id = USB_ID(vid, pid), .flags = (_flags) }
#define VENDOR_FLG(vid, _flags) DEVICE_FLG(vid, 0, _flags)

static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
        /* Device matches */
        DEVICE_FLG(0x03f0, 0x654a, /* HP 320 FHD Webcam */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_MIC_RES_16),
        DEVICE_FLG(0x041e, 0x3000, /* Creative SB Extigy */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x041e, 0x4080, /* Creative Live Cam VF0610 */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x045e, 0x083c, /* MS USB Link headset */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_CTL_MSG_DELAY |
                   QUIRK_FLAG_DISABLE_AUTOSUSPEND),
        DEVICE_FLG(0x045e, 0x070f, /* MS LifeChat LX-3000 Headset */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x046d, 0x0807, /* Logitech Webcam C500 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x0808, /* Logitech Webcam C600 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x0809,
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x0819, /* Logitech Webcam C210 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x081b, /* HD Webcam c310 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x081d, /* HD Webcam c510 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x0825, /* HD Webcam c270 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x0826, /* HD Webcam c525 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x084c, /* Logitech ConferenceCam Connect */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x046d, 0x08ca, /* Logitech Quickcam Fusion */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x0991, /* Logitech QuickCam Pro */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_IGNORE_CTL_ERROR |
                   QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x09a2, /* QuickCam Communicate Deluxe/S7500 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
        DEVICE_FLG(0x046d, 0x09a4, /* Logitech QuickCam E 3500 */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x046d, 0x0a8f, /* Logitech H390 headset */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M |
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x0499, 0x1506, /* Yamaha THR5 */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x0499, 0x1509, /* Steinberg UR22 */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x0499, 0x3108, /* Yamaha YIT-W12TX */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x04d8, 0xfeea, /* Benchmark DAC1 Pre */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x04e8, 0xa051, /* Samsung USBC Headset (AKG) */
                   QUIRK_FLAG_SKIP_CLOCK_SELECTOR | QUIRK_FLAG_CTL_MSG_DELAY_5M),
        DEVICE_FLG(0x0525, 0xa4ad, /* Hamedal C20 usb camero */
                   QUIRK_FLAG_IFACE_SKIP_CLOSE),
        DEVICE_FLG(0x054c, 0x0b8c, /* Sony WALKMAN NW-A45 DAC */
                   QUIRK_FLAG_SET_IFACE_FIRST),
        DEVICE_FLG(0x0556, 0x0014, /* Phoenix Audio TMX320VC */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x0572, 0x1b08, /* Conexant Systems (Rockwell), Inc. */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x0572, 0x1b09, /* Conexant Systems (Rockwell), Inc. */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x05a3, 0x9420, /* ELP HD USB Camera */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x05a7, 0x1020, /* Bose Companion 5 */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x05e1, 0x0408, /* Syntek STK1160 */
                   QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x05e1, 0x0480, /* Hauppauge Woodbury */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x0644, 0x8043, /* TEAC UD-501/UD-501V2/UD-503/NT-503 */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY |
                   QUIRK_FLAG_IFACE_DELAY),
        DEVICE_FLG(0x0644, 0x8044, /* Esoteric D-05X */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY |
                   QUIRK_FLAG_IFACE_DELAY),
        DEVICE_FLG(0x0644, 0x804a, /* TEAC UD-301 */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY |
                   QUIRK_FLAG_IFACE_DELAY),
        DEVICE_FLG(0x0644, 0x805f, /* TEAC Model 12 */
                   QUIRK_FLAG_FORCE_IFACE_RESET),
        DEVICE_FLG(0x0644, 0x806b, /* TEAC UD-701 */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY |
                   QUIRK_FLAG_IFACE_DELAY),
        DEVICE_FLG(0x06f8, 0xb000, /* Hercules DJ Console (Windows Edition) */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x06f8, 0xd002, /* Hercules DJ Console (Macintosh Edition) */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x0711, 0x5800, /* MCT Trigger 5 USB-to-HDMI */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x074d, 0x3553, /* Outlaw RR2150 (Micronas UAC3553B) */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x0763, 0x2030, /* M-Audio Fast Track C400 */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x0763, 0x2031, /* M-Audio Fast Track C600 */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x07fd, 0x000b, /* MOTU M Series 2nd hardware revision */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x08bb, 0x2702, /* LineX FM Transmitter */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x0951, 0x16ad, /* Kingston HyperX */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x0b05, 0x18a6, /* ASUSTek Computer, Inc. */
                   QUIRK_FLAG_MIXER_CAPTURE_MIN_MUTE),
        DEVICE_FLG(0x0b0e, 0x0349, /* Jabra 550a */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x0bda, 0x498a, /* Realtek Semiconductor Corp. */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE | QUIRK_FLAG_MIXER_CAPTURE_MIN_MUTE),
        DEVICE_FLG(0x0c45, 0x6340, /* Sonix HD USB Camera */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x0c45, 0x636b, /* Microdia JP001 USB Camera */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x0d8c, 0x000c, /* C-Media */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x0d8c, 0x0012, /* C-Media */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x0d8c, 0x0014, /* C-Media */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x0ecb, 0x205c, /* JBL Quantum610 Wireless */
                   QUIRK_FLAG_FIXED_RATE),
        DEVICE_FLG(0x0ecb, 0x2069, /* JBL Quantum810 Wireless */
                   QUIRK_FLAG_FIXED_RATE),
        DEVICE_FLG(0x0fd9, 0x0008, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x1101, 0x0003, /* Audioengine D1 */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x12d1, 0x3a07, /* Huawei Technologies Co., Ltd. */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE | QUIRK_FLAG_MIXER_CAPTURE_MIN_MUTE),
        DEVICE_FLG(0x1224, 0x2a25, /* Jieli Technology USB PHY 2.0 */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_MIC_RES_16),
        DEVICE_FLG(0x1395, 0x740a, /* Sennheiser DECT */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x1397, 0x0507, /* Behringer UMC202HD */
                   QUIRK_FLAG_PLAYBACK_FIRST | QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x1397, 0x0508, /* Behringer UMC204HD */
                   QUIRK_FLAG_PLAYBACK_FIRST | QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x1397, 0x0509, /* Behringer UMC404HD */
                   QUIRK_FLAG_PLAYBACK_FIRST | QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x13e5, 0x0001, /* Serato Phono */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x154e, 0x1002, /* Denon DCD-1500RE */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY),
        DEVICE_FLG(0x154e, 0x1003, /* Denon DA-300USB */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY),
        DEVICE_FLG(0x154e, 0x3005, /* Marantz HD-DAC1 */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY),
        DEVICE_FLG(0x154e, 0x3006, /* Marantz SA-14S1 */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY),
        DEVICE_FLG(0x154e, 0x300b, /* Marantz SA-KI RUBY / SA-12 */
                   QUIRK_FLAG_DSD_RAW),
        DEVICE_FLG(0x154e, 0x500e, /* Denon DN-X1600 */
                   QUIRK_FLAG_IGNORE_CLOCK_SOURCE),
        DEVICE_FLG(0x1686, 0x00dd, /* Zoom R16/24 */
                   QUIRK_FLAG_TX_LENGTH | QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x17aa, 0x1046, /* Lenovo ThinkStation P620 Rear Line-in, Line-out and Microphone */
                   QUIRK_FLAG_DISABLE_AUTOSUSPEND),
        DEVICE_FLG(0x17aa, 0x104d, /* Lenovo ThinkStation P620 Internal Speaker + Front Headset */
                   QUIRK_FLAG_DISABLE_AUTOSUSPEND),
        DEVICE_FLG(0x17ef, 0x3083, /* Lenovo TBT3 dock */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x1852, 0x5062, /* Luxman D-08u */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY),
        DEVICE_FLG(0x1852, 0x5065, /* Luxman DA-06 */
                   QUIRK_FLAG_ITF_USB_DSD_DAC | QUIRK_FLAG_CTL_MSG_DELAY),
        DEVICE_FLG(0x1901, 0x0191, /* GE B850V3 CP2114 audio interface */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x19f7, 0x0003, /* RODE NT-USB */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x19f7, 0x0035, /* RODE NT-USB+ */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x1bcf, 0x2281, /* HD Webcam */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_MIC_RES_16),
        DEVICE_FLG(0x1bcf, 0x2283, /* NexiGo N930AF FHD Webcam */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_MIC_RES_16),
        DEVICE_FLG(0x2040, 0x7200, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7201, /* Hauppauge HVR-950Q-MXL */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7210, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7211, /* Hauppauge HVR-950Q-MXL */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7213, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7217, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x721b, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x721e, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x721f, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7240, /* Hauppauge HVR-850 */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7260, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7270, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7280, /* Hauppauge HVR-950Q */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x7281, /* Hauppauge HVR-950Q-MXL */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x2040, 0x8200, /* Hauppauge Woodbury */
                   QUIRK_FLAG_SHARE_MEDIA_DEVICE | QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x21b4, 0x0081, /* AudioQuest DragonFly */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x21b4, 0x0230, /* Ayre QB-9 Twenty */
                   QUIRK_FLAG_DSD_RAW),
        DEVICE_FLG(0x21b4, 0x0232, /* Ayre QX-5 Twenty */
                   QUIRK_FLAG_DSD_RAW),
        DEVICE_FLG(0x2522, 0x0007, /* LH Labs Geek Out HD Audio 1V5 */
                   QUIRK_FLAG_SET_IFACE_FIRST),
        DEVICE_FLG(0x262a, 0x9302, /* ddHiFi TC44C */
                   QUIRK_FLAG_DSD_RAW),
        DEVICE_FLG(0x2708, 0x0002, /* Audient iD14 */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x2912, 0x30c8, /* Audioengine D1 */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x2a70, 0x1881, /* OnePlus Technology (Shenzhen) Co., Ltd. BE02T */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE | QUIRK_FLAG_MIXER_CAPTURE_MIN_MUTE),
        DEVICE_FLG(0x2b53, 0x0023, /* Fiero SC-01 (firmware v1.0.0 @ 48 kHz) */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x2b53, 0x0024, /* Fiero SC-01 (firmware v1.0.0 @ 96 kHz) */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x2b53, 0x0031, /* Fiero SC-01 (firmware v1.1.0) */
                   QUIRK_FLAG_GENERIC_IMPLICIT_FB),
        DEVICE_FLG(0x2d95, 0x8011, /* VIVO USB-C HEADSET */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x2d95, 0x8021, /* VIVO USB-C-XE710 HEADSET */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x2d99, 0x0026, /* HECATE G2 GAMING HEADSET */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x2fc6, 0xf0b7, /* iBasso DC07 Pro */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        DEVICE_FLG(0x30be, 0x0101, /* Schiit Hel */
                   QUIRK_FLAG_IGNORE_CTL_ERROR),
        DEVICE_FLG(0x339b, 0x3a07, /* Synaptics HONOR USB-C HEADSET */
                   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
        DEVICE_FLG(0x413c, 0xa506, /* Dell AE515 sound bar */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        DEVICE_FLG(0x534d, 0x0021, /* MacroSilicon MS2100/MS2106 */
                   QUIRK_FLAG_ALIGN_TRANSFER),
        DEVICE_FLG(0x534d, 0x2109, /* MacroSilicon MS2109 */
                   QUIRK_FLAG_ALIGN_TRANSFER),

        /* Vendor matches */
        VENDOR_FLG(0x045e, /* MS Lifecam */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        VENDOR_FLG(0x046d, /* Logitech */
                   QUIRK_FLAG_CTL_MSG_DELAY_1M),
        VENDOR_FLG(0x047f, /* Plantronics */
                   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_CTL_MSG_DELAY),
        VENDOR_FLG(0x0644, /* TEAC Corp. */
                   QUIRK_FLAG_CTL_MSG_DELAY | QUIRK_FLAG_IFACE_DELAY),
        VENDOR_FLG(0x07fd, /* MOTU */
                   QUIRK_FLAG_VALIDATE_RATES),
        VENDOR_FLG(0x1235, /* Focusrite Novation */
                   QUIRK_FLAG_VALIDATE_RATES),
        VENDOR_FLG(0x1511, /* AURALiC */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x152a, /* Thesycon devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x18d1, /* iBasso devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x1de7, /* Phoenix Audio */
                   QUIRK_FLAG_GET_SAMPLE_RATE),
        VENDOR_FLG(0x20b1, /* XMOS based devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x21ed, /* Accuphase Laboratory */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x22d9, /* Oppo */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x23ba, /* Playback Design */
                   QUIRK_FLAG_CTL_MSG_DELAY | QUIRK_FLAG_IFACE_DELAY |
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x25ce, /* Mytek devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x278b, /* Rotel? */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x292b, /* Gustard/Ess based devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x2972, /* FiiO devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x2ab6, /* T+A devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x2afd, /* McIntosh Laboratory, Inc. */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x2d87, /* Cayin device */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x2fc6, /* Comture-inc devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x3336, /* HEM devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x3353, /* Khadas devices */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x35f4, /* MSB Technology */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0x3842, /* EVGA */
                   QUIRK_FLAG_DSD_RAW),
        VENDOR_FLG(0xc502, /* HiBy devices */
                   QUIRK_FLAG_DSD_RAW),

        {} /* terminator */
};

#define QUIRK_STRING_ENTRY(x) \
        [QUIRK_TYPE_ ## x] = __stringify(x)

static const char *const snd_usb_audio_quirk_flag_names[] = {
        QUIRK_STRING_ENTRY(GET_SAMPLE_RATE),
        QUIRK_STRING_ENTRY(SHARE_MEDIA_DEVICE),
        QUIRK_STRING_ENTRY(ALIGN_TRANSFER),
        QUIRK_STRING_ENTRY(TX_LENGTH),
        QUIRK_STRING_ENTRY(PLAYBACK_FIRST),
        QUIRK_STRING_ENTRY(SKIP_CLOCK_SELECTOR),
        QUIRK_STRING_ENTRY(IGNORE_CLOCK_SOURCE),
        QUIRK_STRING_ENTRY(ITF_USB_DSD_DAC),
        QUIRK_STRING_ENTRY(CTL_MSG_DELAY),
        QUIRK_STRING_ENTRY(CTL_MSG_DELAY_1M),
        QUIRK_STRING_ENTRY(CTL_MSG_DELAY_5M),
        QUIRK_STRING_ENTRY(IFACE_DELAY),
        QUIRK_STRING_ENTRY(VALIDATE_RATES),
        QUIRK_STRING_ENTRY(DISABLE_AUTOSUSPEND),
        QUIRK_STRING_ENTRY(IGNORE_CTL_ERROR),
        QUIRK_STRING_ENTRY(DSD_RAW),
        QUIRK_STRING_ENTRY(SET_IFACE_FIRST),
        QUIRK_STRING_ENTRY(GENERIC_IMPLICIT_FB),
        QUIRK_STRING_ENTRY(SKIP_IMPLICIT_FB),
        QUIRK_STRING_ENTRY(IFACE_SKIP_CLOSE),
        QUIRK_STRING_ENTRY(FORCE_IFACE_RESET),
        QUIRK_STRING_ENTRY(FIXED_RATE),
        QUIRK_STRING_ENTRY(MIC_RES_16),
        QUIRK_STRING_ENTRY(MIC_RES_384),
        QUIRK_STRING_ENTRY(MIXER_PLAYBACK_MIN_MUTE),
        QUIRK_STRING_ENTRY(MIXER_CAPTURE_MIN_MUTE),
        NULL
};

const char *snd_usb_quirk_flag_find_name(unsigned long index)
{
        if (index >= ARRAY_SIZE(snd_usb_audio_quirk_flag_names))
                return NULL;

        return snd_usb_audio_quirk_flag_names[index];
}

u32 snd_usb_quirk_flags_from_name(const char *name)
{
        int i;

        if (!name || !*name)
                return 0;

        for (i = 0; snd_usb_audio_quirk_flag_names[i]; i++) {
                if (strcasecmp(name, snd_usb_audio_quirk_flag_names[i]) == 0)
                        return BIT_U32(i);
        }

        return 0;
}

void snd_usb_apply_flag_dbg(const char *reason,
                            struct snd_usb_audio *chip,
                            unsigned long flag)
{
        unsigned long bit;

        for_each_set_bit(bit, &flag, BYTES_TO_BITS(sizeof(flag))) {
                const char *name = snd_usb_audio_quirk_flag_names[bit];

                if (name)
                        usb_audio_dbg(chip,
                                      "From %s apply quirk flag %s for device %04x:%04x\n",
                                      reason, name, USB_ID_VENDOR(chip->usb_id),
                                      USB_ID_PRODUCT(chip->usb_id));
                else
                        usb_audio_warn(chip,
                                       "From %s apply unknown quirk flag 0x%lx for device %04x:%04x\n",
                                       reason, bit, USB_ID_VENDOR(chip->usb_id),
                                       USB_ID_PRODUCT(chip->usb_id));
        }
}

void snd_usb_init_quirk_flags_table(struct snd_usb_audio *chip)
{
        const struct usb_audio_quirk_flags_table *p;

        for (p = quirk_flags_table; p->id; p++) {
                if (chip->usb_id == p->id ||
                    (!USB_ID_PRODUCT(p->id) &&
                     USB_ID_VENDOR(chip->usb_id) == USB_ID_VENDOR(p->id))) {
                        snd_usb_apply_flag_dbg("builtin table", chip, p->flags);
                        chip->quirk_flags |= p->flags;
                        return;
                }
        }
}

void snd_usb_init_quirk_flags_parse_string(struct snd_usb_audio *chip,
                                           const char *str)
{
        u16 chip_vid = USB_ID_VENDOR(chip->usb_id);
        u16 chip_pid = USB_ID_PRODUCT(chip->usb_id);
        u32 mask_flags, unmask_flags, bit;
        char *p, *field, *flag;
        bool is_unmask;
        u16 vid, pid;

        char *val __free(kfree) = kstrdup(str, GFP_KERNEL);

        if (!val)
                return;

        for (p = val; p && *p;) {
                /* Each entry consists of VID:PID:flags */
                field = strsep(&p, ":");
                if (!field)
                        break;

                if (strcmp(field, "*") == 0)
                        vid = 0;
                else if (kstrtou16(field, 16, &vid))
                        break;

                field = strsep(&p, ":");
                if (!field)
                        break;

                if (strcmp(field, "*") == 0)
                        pid = 0;
                else if (kstrtou16(field, 16, &pid))
                        break;

                field = strsep(&p, ";");
                if (!field || !*field)
                        break;

                if ((vid != 0 && vid != chip_vid) ||
                    (pid != 0 && pid != chip_pid))
                        continue;

                /* Collect the flags */
                mask_flags = 0;
                unmask_flags = 0;
                while (field && *field) {
                        flag = strsep(&field, "|");

                        if (!flag)
                                break;

                        if (*flag == '!') {
                                is_unmask = true;
                                flag++;
                        } else {
                                is_unmask = false;
                        }

                        if (!kstrtou32(flag, 16, &bit)) {
                                if (is_unmask)
                                        unmask_flags |= bit;
                                else
                                        mask_flags |= bit;

                                break;
                        }

                        bit = snd_usb_quirk_flags_from_name(flag);

                        if (bit) {
                                if (is_unmask)
                                        unmask_flags |= bit;
                                else
                                        mask_flags |= bit;
                        } else {
                                pr_warn("snd_usb_audio: unknown flag %s while parsing param quirk_flags\n",
                                        flag);
                        }
                }

                chip->quirk_flags &= ~unmask_flags;
                chip->quirk_flags |= mask_flags;
                snd_usb_apply_flag_dbg("module param", chip,
                                       chip->quirk_flags);
        }
}










































































































































































































































































































































































































































































































































































































































































































































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    5 















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   73 

    2 


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   31 


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/*
 * Performance events x86 architecture code
 *
 *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
 *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
 *  Copyright (C) 2009 Jaswinder Singh Rajput
 *  Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
 *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
 *  Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
 *  Copyright (C) 2009 Google, Inc., Stephane Eranian
 *
 *  For licencing details see kernel-base/COPYING
 */

#include <linux/perf_event.h>
#include <linux/capability.h>
#include <linux/notifier.h>
#include <linux/hardirq.h>
#include <linux/kprobes.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/kdebug.h>
#include <linux/sched/mm.h>
#include <linux/sched/clock.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/nospec.h>
#include <linux/static_call.h>

#include <asm/apic.h>
#include <asm/stacktrace.h>
#include <asm/msr.h>
#include <asm/nmi.h>
#include <asm/smp.h>
#include <asm/alternative.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
#include <asm/timer.h>
#include <asm/desc.h>
#include <asm/ldt.h>
#include <asm/unwind.h>
#include <asm/uprobes.h>
#include <asm/ibt.h>

#include "perf_event.h"

struct x86_pmu x86_pmu __read_mostly;
static struct pmu pmu;

DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
        .enabled = 1,
        .pmu = &pmu,
};

DEFINE_STATIC_KEY_FALSE(rdpmc_never_available_key);
DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key);
DEFINE_STATIC_KEY_FALSE(perf_is_hybrid);

/*
 * This here uses DEFINE_STATIC_CALL_NULL() to get a static_call defined
 * from just a typename, as opposed to an actual function.
 */
DEFINE_STATIC_CALL_NULL(x86_pmu_handle_irq,  *x86_pmu.handle_irq);
DEFINE_STATIC_CALL_NULL(x86_pmu_disable_all, *x86_pmu.disable_all);
DEFINE_STATIC_CALL_NULL(x86_pmu_enable_all,  *x86_pmu.enable_all);
DEFINE_STATIC_CALL_NULL(x86_pmu_enable,             *x86_pmu.enable);
DEFINE_STATIC_CALL_NULL(x86_pmu_disable,     *x86_pmu.disable);

DEFINE_STATIC_CALL_NULL(x86_pmu_assign, *x86_pmu.assign);

DEFINE_STATIC_CALL_NULL(x86_pmu_add,  *x86_pmu.add);
DEFINE_STATIC_CALL_NULL(x86_pmu_del,  *x86_pmu.del);
DEFINE_STATIC_CALL_NULL(x86_pmu_read, *x86_pmu.read);

DEFINE_STATIC_CALL_NULL(x86_pmu_set_period,   *x86_pmu.set_period);
DEFINE_STATIC_CALL_NULL(x86_pmu_update,       *x86_pmu.update);
DEFINE_STATIC_CALL_NULL(x86_pmu_limit_period, *x86_pmu.limit_period);

DEFINE_STATIC_CALL_NULL(x86_pmu_schedule_events,       *x86_pmu.schedule_events);
DEFINE_STATIC_CALL_NULL(x86_pmu_get_event_constraints, *x86_pmu.get_event_constraints);
DEFINE_STATIC_CALL_NULL(x86_pmu_put_event_constraints, *x86_pmu.put_event_constraints);

DEFINE_STATIC_CALL_NULL(x86_pmu_start_scheduling,  *x86_pmu.start_scheduling);
DEFINE_STATIC_CALL_NULL(x86_pmu_commit_scheduling, *x86_pmu.commit_scheduling);
DEFINE_STATIC_CALL_NULL(x86_pmu_stop_scheduling,   *x86_pmu.stop_scheduling);

DEFINE_STATIC_CALL_NULL(x86_pmu_sched_task,    *x86_pmu.sched_task);

DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs,   *x86_pmu.drain_pebs);
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);

DEFINE_STATIC_CALL_NULL(x86_pmu_filter, *x86_pmu.filter);

DEFINE_STATIC_CALL_NULL(x86_pmu_late_setup, *x86_pmu.late_setup);

DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_enable, *x86_pmu.pebs_enable);
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_disable, *x86_pmu.pebs_disable);
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_enable_all, *x86_pmu.pebs_enable_all);
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_disable_all, *x86_pmu.pebs_disable_all);

/*
 * This one is magic, it will get called even when PMU init fails (because
 * there is no PMU), in which case it should simply return NULL.
 */
DEFINE_STATIC_CALL_RET0(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs);

u64 __read_mostly hw_cache_event_ids
                                [PERF_COUNT_HW_CACHE_MAX]
                                [PERF_COUNT_HW_CACHE_OP_MAX]
                                [PERF_COUNT_HW_CACHE_RESULT_MAX];
u64 __read_mostly hw_cache_extra_regs
                                [PERF_COUNT_HW_CACHE_MAX]
                                [PERF_COUNT_HW_CACHE_OP_MAX]
                                [PERF_COUNT_HW_CACHE_RESULT_MAX];

/*
 * Propagate event elapsed time into the generic event.
 * Can only be executed on the CPU where the event is active.
 * Returns the delta events processed.
 */
u64 x86_perf_event_update(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        int shift = 64 - x86_pmu.cntval_bits;
        u64 prev_raw_count, new_raw_count;
        u64 delta;

        if (unlikely(!hwc->event_base))
                return 0;

        /*
         * Careful: an NMI might modify the previous event value.
         *
         * Our tactic to handle this is to first atomically read and
         * exchange a new raw count - then add that new-prev delta
         * count to the generic event atomically:
         */
        prev_raw_count = local64_read(&hwc->prev_count);
        do {
                new_raw_count = rdpmc(hwc->event_base_rdpmc);
        } while (!local64_try_cmpxchg(&hwc->prev_count,
                                      &prev_raw_count, new_raw_count));

        /*
         * Now we have the new raw value and have updated the prev
         * timestamp already. We can now calculate the elapsed delta
         * (event-)time and add that to the generic event.
         *
         * Careful, not all hw sign-extends above the physical width
         * of the count.
         */
        delta = (new_raw_count << shift) - (prev_raw_count << shift);
        delta >>= shift;

        local64_add(delta, &event->count);
        local64_sub(delta, &hwc->period_left);

        return new_raw_count;
}

/*
 * Find and validate any extra registers to set up.
 */
static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
{
        struct extra_reg *extra_regs = hybrid(event->pmu, extra_regs);
        struct hw_perf_event_extra *reg;
        struct extra_reg *er;

        reg = &event->hw.extra_reg;

        if (!extra_regs)
                return 0;

        for (er = extra_regs; er->msr; er++) {
                if (er->event != (config & er->config_mask))
                        continue;
                if (event->attr.config1 & ~er->valid_mask)
                        return -EINVAL;
                /* Check if the extra msrs can be safely accessed*/
                if (!er->extra_msr_access)
                        return -ENXIO;

                reg->idx = er->idx;
                reg->config = event->attr.config1;
                reg->reg = er->msr;
                break;
        }
        return 0;
}

static atomic_t active_events;
static atomic_t pmc_refcount;
static DEFINE_MUTEX(pmc_reserve_mutex);

#ifdef CONFIG_X86_LOCAL_APIC

static inline u64 get_possible_counter_mask(void)
{
        u64 cntr_mask = x86_pmu.cntr_mask64;
        int i;

        if (!is_hybrid())
                return cntr_mask;

        for (i = 0; i < x86_pmu.num_hybrid_pmus; i++)
                cntr_mask |= x86_pmu.hybrid_pmu[i].cntr_mask64;

        return cntr_mask;
}

static bool reserve_pmc_hardware(void)
{
        u64 cntr_mask = get_possible_counter_mask();
        int i, end;

        for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
                if (!reserve_perfctr_nmi(x86_pmu_event_addr(i)))
                        goto perfctr_fail;
        }

        for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
                if (!reserve_evntsel_nmi(x86_pmu_config_addr(i)))
                        goto eventsel_fail;
        }

        return true;

eventsel_fail:
        end = i;
        for_each_set_bit(i, (unsigned long *)&cntr_mask, end)
                release_evntsel_nmi(x86_pmu_config_addr(i));
        i = X86_PMC_IDX_MAX;

perfctr_fail:
        end = i;
        for_each_set_bit(i, (unsigned long *)&cntr_mask, end)
                release_perfctr_nmi(x86_pmu_event_addr(i));

        return false;
}

static void release_pmc_hardware(void)
{
        u64 cntr_mask = get_possible_counter_mask();
        int i;

        for_each_set_bit(i, (unsigned long *)&cntr_mask, X86_PMC_IDX_MAX) {
                release_perfctr_nmi(x86_pmu_event_addr(i));
                release_evntsel_nmi(x86_pmu_config_addr(i));
        }
}

#else

static bool reserve_pmc_hardware(void) { return true; }
static void release_pmc_hardware(void) {}

#endif

bool check_hw_exists(struct pmu *pmu, unsigned long *cntr_mask,
                     unsigned long *fixed_cntr_mask)
{
        u64 val, val_fail = -1, val_new= ~0;
        int i, reg, reg_fail = -1, ret = 0;
        int bios_fail = 0;
        int reg_safe = -1;

        /*
         * Check to see if the BIOS enabled any of the counters, if so
         * complain and bail.
         */
        for_each_set_bit(i, cntr_mask, X86_PMC_IDX_MAX) {
                reg = x86_pmu_config_addr(i);
                ret = rdmsrq_safe(reg, &val);
                if (ret)
                        goto msr_fail;
                if (val & ARCH_PERFMON_EVENTSEL_ENABLE) {
                        bios_fail = 1;
                        val_fail = val;
                        reg_fail = reg;
                } else {
                        reg_safe = i;
                }
        }

        if (*(u64 *)fixed_cntr_mask) {
                reg = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
                ret = rdmsrq_safe(reg, &val);
                if (ret)
                        goto msr_fail;
                for_each_set_bit(i, fixed_cntr_mask, X86_PMC_IDX_MAX) {
                        if (fixed_counter_disabled(i, pmu))
                                continue;
                        if (val & (0x03ULL << i*4)) {
                                bios_fail = 1;
                                val_fail = val;
                                reg_fail = reg;
                        }
                }
        }

        /*
         * If all the counters are enabled, the below test will always
         * fail.  The tools will also become useless in this scenario.
         * Just fail and disable the hardware counters.
         */

        if (reg_safe == -1) {
                reg = reg_safe;
                goto msr_fail;
        }

        /*
         * Read the current value, change it and read it back to see if it
         * matches, this is needed to detect certain hardware emulators
         * (qemu/kvm) that don't trap on the MSR access and always return 0s.
         */
        reg = x86_pmu_event_addr(reg_safe);
        if (rdmsrq_safe(reg, &val))
                goto msr_fail;
        val ^= 0xffffUL;
        ret = wrmsrq_safe(reg, val);
        ret |= rdmsrq_safe(reg, &val_new);
        if (ret || val != val_new)
                goto msr_fail;

        /*
         * We still allow the PMU driver to operate:
         */
        if (bios_fail) {
                pr_cont("Broken BIOS detected, complain to your hardware vendor.\n");
                pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n",
                              reg_fail, val_fail);
        }

        return true;

msr_fail:
        if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {
                pr_cont("PMU not available due to virtualization, using software events only.\n");
        } else {
                pr_cont("Broken PMU hardware detected, using software events only.\n");
                pr_err("Failed to access perfctr msr (MSR %x is %Lx)\n",
                       reg, val_new);
        }

        return false;
}

static void hw_perf_event_destroy(struct perf_event *event)
{
        x86_release_hardware();
        atomic_dec(&active_events);
}

void hw_perf_lbr_event_destroy(struct perf_event *event)
{
        hw_perf_event_destroy(event);

        /* undo the lbr/bts event accounting */
        x86_del_exclusive(x86_lbr_exclusive_lbr);
}

static inline int x86_pmu_initialized(void)
{
        return x86_pmu.handle_irq != NULL;
}

static inline int
set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
{
        struct perf_event_attr *attr = &event->attr;
        unsigned int cache_type, cache_op, cache_result;
        u64 config, val;

        config = attr->config;

        cache_type = (config >> 0) & 0xff;
        if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
                return -EINVAL;
        cache_type = array_index_nospec(cache_type, PERF_COUNT_HW_CACHE_MAX);

        cache_op = (config >>  8) & 0xff;
        if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
                return -EINVAL;
        cache_op = array_index_nospec(cache_op, PERF_COUNT_HW_CACHE_OP_MAX);

        cache_result = (config >> 16) & 0xff;
        if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
                return -EINVAL;
        cache_result = array_index_nospec(cache_result, PERF_COUNT_HW_CACHE_RESULT_MAX);

        val = hybrid_var(event->pmu, hw_cache_event_ids)[cache_type][cache_op][cache_result];
        if (val == 0)
                return -ENOENT;

        if (val == -1)
                return -EINVAL;

        hwc->config |= val;
        attr->config1 = hybrid_var(event->pmu, hw_cache_extra_regs)[cache_type][cache_op][cache_result];
        return x86_pmu_extra_regs(val, event);
}

int x86_reserve_hardware(void)
{
        int err = 0;

        if (!atomic_inc_not_zero(&pmc_refcount)) {
                mutex_lock(&pmc_reserve_mutex);
                if (atomic_read(&pmc_refcount) == 0) {
                        if (!reserve_pmc_hardware()) {
                                err = -EBUSY;
                        } else {
                                reserve_ds_buffers();
                                reserve_lbr_buffers();
                        }
                }
                if (!err)
                        atomic_inc(&pmc_refcount);
                mutex_unlock(&pmc_reserve_mutex);
        }

        return err;
}

void x86_release_hardware(void)
{
        if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) {
                release_pmc_hardware();
                release_ds_buffers();
                release_lbr_buffers();
                mutex_unlock(&pmc_reserve_mutex);
        }
}

/*
 * Check if we can create event of a certain type (that no conflicting events
 * are present).
 */
int x86_add_exclusive(unsigned int what)
{
        int i;

        /*
         * When lbr_pt_coexist we allow PT to coexist with either LBR or BTS.
         * LBR and BTS are still mutually exclusive.
         */
        if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
                goto out;

        if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) {
                mutex_lock(&pmc_reserve_mutex);
                for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
                        if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
                                goto fail_unlock;
                }
                atomic_inc(&x86_pmu.lbr_exclusive[what]);
                mutex_unlock(&pmc_reserve_mutex);
        }

out:
        atomic_inc(&active_events);
        return 0;

fail_unlock:
        mutex_unlock(&pmc_reserve_mutex);
        return -EBUSY;
}

void x86_del_exclusive(unsigned int what)
{
        atomic_dec(&active_events);

        /*
         * See the comment in x86_add_exclusive().
         */
        if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt)
                return;

        atomic_dec(&x86_pmu.lbr_exclusive[what]);
}

int x86_setup_perfctr(struct perf_event *event)
{
        struct perf_event_attr *attr = &event->attr;
        struct hw_perf_event *hwc = &event->hw;
        u64 config;

        if (!is_sampling_event(event)) {
                hwc->sample_period = x86_pmu.max_period;
                hwc->last_period = hwc->sample_period;
                local64_set(&hwc->period_left, hwc->sample_period);
        }

        if (attr->type == event->pmu->type)
                return x86_pmu_extra_regs(event->attr.config, event);

        if (attr->type == PERF_TYPE_HW_CACHE)
                return set_ext_hw_attr(hwc, event);

        if (attr->config >= x86_pmu.max_events)
                return -EINVAL;

        attr->config = array_index_nospec((unsigned long)attr->config, x86_pmu.max_events);

        /*
         * The generic map:
         */
        config = x86_pmu.event_map(attr->config);

        if (config == 0)
                return -ENOENT;

        if (config == -1LL)
                return -EINVAL;

        hwc->config |= config;

        return 0;
}

/*
 * check that branch_sample_type is compatible with
 * settings needed for precise_ip > 1 which implies
 * using the LBR to capture ALL taken branches at the
 * priv levels of the measurement
 */
static inline int precise_br_compat(struct perf_event *event)
{
        u64 m = event->attr.branch_sample_type;
        u64 b = 0;

        /* must capture all branches */
        if (!(m & PERF_SAMPLE_BRANCH_ANY))
                return 0;

        m &= PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER;

        if (!event->attr.exclude_user)
                b |= PERF_SAMPLE_BRANCH_USER;

        if (!event->attr.exclude_kernel)
                b |= PERF_SAMPLE_BRANCH_KERNEL;

        /*
         * ignore PERF_SAMPLE_BRANCH_HV, not supported on x86
         */

        return m == b;
}

int x86_pmu_max_precise(void)
{
        int precise = 0;

        /* Support for constant skid */
        if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) {
                precise++;

                /* Support for IP fixup */
                if (x86_pmu.lbr_nr || x86_pmu.intel_cap.pebs_format >= 2)
                        precise++;

                if (x86_pmu.pebs_prec_dist)
                        precise++;
        }
        return precise;
}

int x86_pmu_hw_config(struct perf_event *event)
{
        if (event->attr.precise_ip) {
                int precise = x86_pmu_max_precise();

                if (event->attr.precise_ip > precise)
                        return -EOPNOTSUPP;

                /* There's no sense in having PEBS for non sampling events: */
                if (!is_sampling_event(event))
                        return -EINVAL;
        }
        /*
         * check that PEBS LBR correction does not conflict with
         * whatever the user is asking with attr->branch_sample_type
         */
        if (event->attr.precise_ip > 1 && x86_pmu.intel_cap.pebs_format < 2) {
                u64 *br_type = &event->attr.branch_sample_type;

                if (has_branch_stack(event)) {
                        if (!precise_br_compat(event))
                                return -EOPNOTSUPP;

                        /* branch_sample_type is compatible */

                } else {
                        /*
                         * user did not specify  branch_sample_type
                         *
                         * For PEBS fixups, we capture all
                         * the branches at the priv level of the
                         * event.
                         */
                        *br_type = PERF_SAMPLE_BRANCH_ANY;

                        if (!event->attr.exclude_user)
                                *br_type |= PERF_SAMPLE_BRANCH_USER;

                        if (!event->attr.exclude_kernel)
                                *br_type |= PERF_SAMPLE_BRANCH_KERNEL;
                }
        }

        if (branch_sample_call_stack(event))
                event->attach_state |= PERF_ATTACH_TASK_DATA;

        /*
         * Generate PMC IRQs:
         * (keep 'enabled' bit clear for now)
         */
        event->hw.config = ARCH_PERFMON_EVENTSEL_INT;

        /*
         * Count user and OS events unless requested not to
         */
        if (!event->attr.exclude_user)
                event->hw.config |= ARCH_PERFMON_EVENTSEL_USR;
        if (!event->attr.exclude_kernel)
                event->hw.config |= ARCH_PERFMON_EVENTSEL_OS;

        if (event->attr.type == event->pmu->type)
                event->hw.config |= x86_pmu_get_event_config(event);

        if (is_sampling_event(event) && !event->attr.freq && x86_pmu.limit_period) {
                s64 left = event->attr.sample_period;
                x86_pmu.limit_period(event, &left);
                if (left > event->attr.sample_period)
                        return -EINVAL;
        }

        /* sample_regs_user never support XMM registers */
        if (unlikely(event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK))
                return -EINVAL;
        /*
         * Besides the general purpose registers, XMM registers may
         * be collected in PEBS on some platforms, e.g. Icelake
         */
        if (unlikely(event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK)) {
                if (!(event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS))
                        return -EINVAL;

                if (!event->attr.precise_ip)
                        return -EINVAL;
        }

        return x86_setup_perfctr(event);
}

/*
 * Setup the hardware configuration for a given attr_type
 */
static int __x86_pmu_event_init(struct perf_event *event)
{
        int err;

        if (!x86_pmu_initialized())
                return -ENODEV;

        err = x86_reserve_hardware();
        if (err)
                return err;

        atomic_inc(&active_events);
        event->destroy = hw_perf_event_destroy;

        event->hw.idx = -1;
        event->hw.last_cpu = -1;
        event->hw.last_tag = ~0ULL;
        event->hw.dyn_constraint = ~0ULL;

        /* mark unused */
        event->hw.extra_reg.idx = EXTRA_REG_NONE;
        event->hw.branch_reg.idx = EXTRA_REG_NONE;

        return x86_pmu.hw_config(event);
}

void x86_pmu_disable_all(void)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int idx;

        for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
                u64 val;

                if (!test_bit(idx, cpuc->active_mask))
                        continue;
                rdmsrq(x86_pmu_config_addr(idx), val);
                if (!(val & ARCH_PERFMON_EVENTSEL_ENABLE))
                        continue;
                val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
                wrmsrq(x86_pmu_config_addr(idx), val);
                if (is_counter_pair(hwc))
                        wrmsrq(x86_pmu_config_addr(idx + 1), 0);
        }
}

struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data)
{
        return static_call(x86_pmu_guest_get_msrs)(nr, data);
}
EXPORT_SYMBOL_GPL(perf_guest_get_msrs);

/*
 * There may be PMI landing after enabled=0. The PMI hitting could be before or
 * after disable_all.
 *
 * If PMI hits before disable_all, the PMU will be disabled in the NMI handler.
 * It will not be re-enabled in the NMI handler again, because enabled=0. After
 * handling the NMI, disable_all will be called, which will not change the
 * state either. If PMI hits after disable_all, the PMU is already disabled
 * before entering NMI handler. The NMI handler will not change the state
 * either.
 *
 * So either situation is harmless.
 */
static void x86_pmu_disable(struct pmu *pmu)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);

        if (!x86_pmu_initialized())
                return;

        if (!cpuc->enabled)
                return;

        cpuc->n_added = 0;
        cpuc->enabled = 0;
        barrier();

        static_call(x86_pmu_disable_all)();
}

void x86_pmu_enable_all(int added)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int idx;

        for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                struct hw_perf_event *hwc = &cpuc->events[idx]->hw;

                if (!test_bit(idx, cpuc->active_mask))
                        continue;

                __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
        }
}

int is_x86_event(struct perf_event *event)
{
        /*
         * For a non-hybrid platforms, the type of X86 pmu is
         * always PERF_TYPE_RAW.
         * For a hybrid platform, the PERF_PMU_CAP_EXTENDED_HW_TYPE
         * is a unique capability for the X86 PMU.
         * Use them to detect a X86 event.
         */
        if (event->pmu->type == PERF_TYPE_RAW ||
            event->pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE)
                return true;

        return false;
}

struct pmu *x86_get_pmu(unsigned int cpu)
{
        struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);

        /*
         * All CPUs of the hybrid type have been offline.
         * The x86_get_pmu() should not be invoked.
         */
        if (WARN_ON_ONCE(!cpuc->pmu))
                return &pmu;

        return cpuc->pmu;
}
/*
 * Event scheduler state:
 *
 * Assign events iterating over all events and counters, beginning
 * with events with least weights first. Keep the current iterator
 * state in struct sched_state.
 */
struct sched_state {
        int        weight;
        int        event;                /* event index */
        int        counter;        /* counter index */
        int        unassigned;        /* number of events to be assigned left */
        int        nr_gp;                /* number of GP counters used */
        u64        used;
};

/* Total max is X86_PMC_IDX_MAX, but we are O(n!) limited */
#define        SCHED_STATES_MAX        2

struct perf_sched {
        int                        max_weight;
        int                        max_events;
        int                        max_gp;
        int                        saved_states;
        struct event_constraint        **constraints;
        struct sched_state        state;
        struct sched_state        saved[SCHED_STATES_MAX];
};

/*
 * Initialize iterator that runs through all events and counters.
 */
static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
                            int num, int wmin, int wmax, int gpmax)
{
        int idx;

        memset(sched, 0, sizeof(*sched));
        sched->max_events        = num;
        sched->max_weight        = wmax;
        sched->max_gp                = gpmax;
        sched->constraints        = constraints;

        for (idx = 0; idx < num; idx++) {
                if (constraints[idx]->weight == wmin)
                        break;
        }

        sched->state.event        = idx;                /* start with min weight */
        sched->state.weight        = wmin;
        sched->state.unassigned        = num;
}

static void perf_sched_save_state(struct perf_sched *sched)
{
        if (WARN_ON_ONCE(sched->saved_states >= SCHED_STATES_MAX))
                return;

        sched->saved[sched->saved_states] = sched->state;
        sched->saved_states++;
}

static bool perf_sched_restore_state(struct perf_sched *sched)
{
        if (!sched->saved_states)
                return false;

        sched->saved_states--;
        sched->state = sched->saved[sched->saved_states];

        /* this assignment didn't work out */
        /* XXX broken vs EVENT_PAIR */
        sched->state.used &= ~BIT_ULL(sched->state.counter);

        /* try the next one */
        sched->state.counter++;

        return true;
}

/*
 * Select a counter for the current event to schedule. Return true on
 * success.
 */
static bool __perf_sched_find_counter(struct perf_sched *sched)
{
        struct event_constraint *c;
        int idx;

        if (!sched->state.unassigned)
                return false;

        if (sched->state.event >= sched->max_events)
                return false;

        c = sched->constraints[sched->state.event];
        /* Prefer fixed purpose counters */
        if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
                idx = INTEL_PMC_IDX_FIXED;
                for_each_set_bit_from(idx, c->idxmsk, X86_PMC_IDX_MAX) {
                        u64 mask = BIT_ULL(idx);

                        if (sched->state.used & mask)
                                continue;

                        sched->state.used |= mask;
                        goto done;
                }
        }

        /* Grab the first unused counter starting with idx */
        idx = sched->state.counter;
        for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
                u64 mask = BIT_ULL(idx);

                if (c->flags & PERF_X86_EVENT_PAIR)
                        mask |= mask << 1;

                if (sched->state.used & mask)
                        continue;

                if (sched->state.nr_gp++ >= sched->max_gp)
                        return false;

                sched->state.used |= mask;
                goto done;
        }

        return false;

done:
        sched->state.counter = idx;

        if (c->overlap)
                perf_sched_save_state(sched);

        return true;
}

static bool perf_sched_find_counter(struct perf_sched *sched)
{
        while (!__perf_sched_find_counter(sched)) {
                if (!perf_sched_restore_state(sched))
                        return false;
        }

        return true;
}

/*
 * Go through all unassigned events and find the next one to schedule.
 * Take events with the least weight first. Return true on success.
 */
static bool perf_sched_next_event(struct perf_sched *sched)
{
        struct event_constraint *c;

        if (!sched->state.unassigned || !--sched->state.unassigned)
                return false;

        do {
                /* next event */
                sched->state.event++;
                if (sched->state.event >= sched->max_events) {
                        /* next weight */
                        sched->state.event = 0;
                        sched->state.weight++;
                        if (sched->state.weight > sched->max_weight)
                                return false;
                }
                c = sched->constraints[sched->state.event];
        } while (c->weight != sched->state.weight);

        sched->state.counter = 0;        /* start with first counter */

        return true;
}

/*
 * Assign a counter for each event.
 */
int perf_assign_events(struct event_constraint **constraints, int n,
                        int wmin, int wmax, int gpmax, int *assign)
{
        struct perf_sched sched;

        perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);

        do {
                if (!perf_sched_find_counter(&sched))
                        break;        /* failed */
                if (assign)
                        assign[sched.state.event] = sched.state.counter;
        } while (perf_sched_next_event(&sched));

        return sched.state.unassigned;
}
EXPORT_SYMBOL_GPL(perf_assign_events);

int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
{
        struct event_constraint *c;
        struct perf_event *e;
        int n0, i, wmin, wmax, unsched = 0;
        struct hw_perf_event *hwc;
        u64 used_mask = 0;

        /*
         * Compute the number of events already present; see x86_pmu_add(),
         * validate_group() and x86_pmu_commit_txn(). For the former two
         * cpuc->n_events hasn't been updated yet, while for the latter
         * cpuc->n_txn contains the number of events added in the current
         * transaction.
         */
        n0 = cpuc->n_events;
        if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
                n0 -= cpuc->n_txn;

        static_call_cond(x86_pmu_start_scheduling)(cpuc);

        for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
                c = cpuc->event_constraint[i];

                /*
                 * Previously scheduled events should have a cached constraint,
                 * while new events should not have one.
                 */
                WARN_ON_ONCE((c && i >= n0) || (!c && i < n0));

                /*
                 * Request constraints for new events; or for those events that
                 * have a dynamic constraint -- for those the constraint can
                 * change due to external factors (sibling state, allow_tfa).
                 */
                if (!c || (c->flags & PERF_X86_EVENT_DYNAMIC)) {
                        c = static_call(x86_pmu_get_event_constraints)(cpuc, i, cpuc->event_list[i]);
                        cpuc->event_constraint[i] = c;
                }

                wmin = min(wmin, c->weight);
                wmax = max(wmax, c->weight);
        }

        /*
         * fastpath, try to reuse previous register
         */
        for (i = 0; i < n; i++) {
                u64 mask;

                hwc = &cpuc->event_list[i]->hw;
                c = cpuc->event_constraint[i];

                /* never assigned */
                if (hwc->idx == -1)
                        break;

                /* constraint still honored */
                if (!test_bit(hwc->idx, c->idxmsk))
                        break;

                mask = BIT_ULL(hwc->idx);
                if (is_counter_pair(hwc))
                        mask |= mask << 1;

                /* not already used */
                if (used_mask & mask)
                        break;

                used_mask |= mask;

                if (assign)
                        assign[i] = hwc->idx;
        }

        /* slow path */
        if (i != n) {
                int gpmax = x86_pmu_max_num_counters(cpuc->pmu);

                /*
                 * Do not allow scheduling of more than half the available
                 * generic counters.
                 *
                 * This helps avoid counter starvation of sibling thread by
                 * ensuring at most half the counters cannot be in exclusive
                 * mode. There is no designated counters for the limits. Any
                 * N/2 counters can be used. This helps with events with
                 * specific counter constraints.
                 */
                if (is_ht_workaround_enabled() && !cpuc->is_fake &&
                    READ_ONCE(cpuc->excl_cntrs->exclusive_present))
                        gpmax /= 2;

                /*
                 * Reduce the amount of available counters to allow fitting
                 * the extra Merge events needed by large increment events.
                 */
                if (x86_pmu.flags & PMU_FL_PAIR) {
                        gpmax -= cpuc->n_pair;
                        WARN_ON(gpmax <= 0);
                }

                unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
                                             wmax, gpmax, assign);
        }

        /*
         * In case of success (unsched = 0), mark events as committed,
         * so we do not put_constraint() in case new events are added
         * and fail to be scheduled
         *
         * We invoke the lower level commit callback to lock the resource
         *
         * We do not need to do all of this in case we are called to
         * validate an event group (assign == NULL)
         */
        if (!unsched && assign) {
                for (i = 0; i < n; i++)
                        static_call_cond(x86_pmu_commit_scheduling)(cpuc, i, assign[i]);
        } else {
                for (i = n0; i < n; i++) {
                        e = cpuc->event_list[i];

                        /*
                         * release events that failed scheduling
                         */
                        static_call_cond(x86_pmu_put_event_constraints)(cpuc, e);

                        cpuc->event_constraint[i] = NULL;
                }
        }

        static_call_cond(x86_pmu_stop_scheduling)(cpuc);

        return unsched ? -EINVAL : 0;
}

static int add_nr_metric_event(struct cpu_hw_events *cpuc,
                               struct perf_event *event)
{
        if (is_metric_event(event)) {
                if (cpuc->n_metric == INTEL_TD_METRIC_NUM)
                        return -EINVAL;
                cpuc->n_metric++;
                cpuc->n_txn_metric++;
        }

        return 0;
}

static void del_nr_metric_event(struct cpu_hw_events *cpuc,
                                struct perf_event *event)
{
        if (is_metric_event(event))
                cpuc->n_metric--;
}

static int collect_event(struct cpu_hw_events *cpuc, struct perf_event *event,
                         int max_count, int n)
{
        union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap);

        if (intel_cap.perf_metrics && add_nr_metric_event(cpuc, event))
                return -EINVAL;

        if (n >= max_count + cpuc->n_metric)
                return -EINVAL;

        cpuc->event_list[n] = event;
        if (is_counter_pair(&event->hw)) {
                cpuc->n_pair++;
                cpuc->n_txn_pair++;
        }

        return 0;
}

/*
 * dogrp: true if must collect siblings events (group)
 * returns total number of events and error code
 */
static int collect_events(struct cpu_hw_events *cpuc, struct perf_event *leader, bool dogrp)
{
        struct perf_event *event;
        int n, max_count;

        max_count = x86_pmu_num_counters(cpuc->pmu) + x86_pmu_num_counters_fixed(cpuc->pmu);

        /* current number of events already accepted */
        n = cpuc->n_events;
        if (!cpuc->n_events)
                cpuc->pebs_output = 0;

        if (!cpuc->is_fake && leader->attr.precise_ip) {
                /*
                 * For PEBS->PT, if !aux_event, the group leader (PT) went
                 * away, the group was broken down and this singleton event
                 * can't schedule any more.
                 */
                if (is_pebs_pt(leader) && !leader->aux_event)
                        return -EINVAL;

                /*
                 * pebs_output: 0: no PEBS so far, 1: PT, 2: DS
                 */
                if (cpuc->pebs_output &&
                    cpuc->pebs_output != is_pebs_pt(leader) + 1)
                        return -EINVAL;

                cpuc->pebs_output = is_pebs_pt(leader) + 1;
        }

        if (is_x86_event(leader)) {
                if (collect_event(cpuc, leader, max_count, n))
                        return -EINVAL;
                n++;
        }

        if (!dogrp)
                return n;

        for_each_sibling_event(event, leader) {
                if (!is_x86_event(event) || event->state <= PERF_EVENT_STATE_OFF)
                        continue;

                if (collect_event(cpuc, event, max_count, n))
                        return -EINVAL;

                n++;
        }
        return n;
}

static inline void x86_assign_hw_event(struct perf_event *event,
                                struct cpu_hw_events *cpuc, int i)
{
        struct hw_perf_event *hwc = &event->hw;
        int idx;

        idx = hwc->idx = cpuc->assign[i];
        hwc->last_cpu = smp_processor_id();
        hwc->last_tag = ++cpuc->tags[i];

        static_call_cond(x86_pmu_assign)(event, idx);

        switch (hwc->idx) {
        case INTEL_PMC_IDX_FIXED_BTS:
        case INTEL_PMC_IDX_FIXED_VLBR:
                hwc->config_base = 0;
                hwc->event_base        = 0;
                break;

        case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END:
                /* All the metric events are mapped onto the fixed counter 3. */
                idx = INTEL_PMC_IDX_FIXED_SLOTS;
                fallthrough;
        case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS-1:
                hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
                hwc->event_base = x86_pmu_fixed_ctr_addr(idx - INTEL_PMC_IDX_FIXED);
                hwc->event_base_rdpmc = (idx - INTEL_PMC_IDX_FIXED) |
                                        INTEL_PMC_FIXED_RDPMC_BASE;
                break;

        default:
                hwc->config_base = x86_pmu_config_addr(hwc->idx);
                hwc->event_base  = x86_pmu_event_addr(hwc->idx);
                hwc->event_base_rdpmc = x86_pmu_rdpmc_index(hwc->idx);
                break;
        }
}

/**
 * x86_perf_rdpmc_index - Return PMC counter used for event
 * @event: the perf_event to which the PMC counter was assigned
 *
 * The counter assigned to this performance event may change if interrupts
 * are enabled. This counter should thus never be used while interrupts are
 * enabled. Before this function is used to obtain the assigned counter the
 * event should be checked for validity using, for example,
 * perf_event_read_local(), within the same interrupt disabled section in
 * which this counter is planned to be used.
 *
 * Return: The index of the performance monitoring counter assigned to
 * @perf_event.
 */
int x86_perf_rdpmc_index(struct perf_event *event)
{
        lockdep_assert_irqs_disabled();

        return event->hw.event_base_rdpmc;
}

static inline int match_prev_assignment(struct hw_perf_event *hwc,
                                        struct cpu_hw_events *cpuc,
                                        int i)
{
        return hwc->idx == cpuc->assign[i] &&
                hwc->last_cpu == smp_processor_id() &&
                hwc->last_tag == cpuc->tags[i];
}

static void x86_pmu_start(struct perf_event *event, int flags);

static void x86_pmu_enable(struct pmu *pmu)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        struct perf_event *event;
        struct hw_perf_event *hwc;
        int i, added = cpuc->n_added;

        if (!x86_pmu_initialized())
                return;

        if (cpuc->enabled)
                return;

        if (cpuc->n_added) {
                int n_running = cpuc->n_events - cpuc->n_added;

                /*
                 * The late setup (after counters are scheduled)
                 * is required for some cases, e.g., PEBS counters
                 * snapshotting. Because an accurate counter index
                 * is needed.
                 */
                static_call_cond(x86_pmu_late_setup)();

                /*
                 * apply assignment obtained either from
                 * hw_perf_group_sched_in() or x86_pmu_enable()
                 *
                 * step1: save events moving to new counters
                 */
                for (i = 0; i < n_running; i++) {
                        event = cpuc->event_list[i];
                        hwc = &event->hw;

                        /*
                         * we can avoid reprogramming counter if:
                         * - assigned same counter as last time
                         * - running on same CPU as last time
                         * - no other event has used the counter since
                         */
                        if (hwc->idx == -1 ||
                            match_prev_assignment(hwc, cpuc, i))
                                continue;

                        /*
                         * Ensure we don't accidentally enable a stopped
                         * counter simply because we rescheduled.
                         */
                        if (hwc->state & PERF_HES_STOPPED)
                                hwc->state |= PERF_HES_ARCH;

                        x86_pmu_stop(event, PERF_EF_UPDATE);
                }

                /*
                 * step2: reprogram moved events into new counters
                 */
                for (i = 0; i < cpuc->n_events; i++) {
                        event = cpuc->event_list[i];
                        hwc = &event->hw;

                        if (!match_prev_assignment(hwc, cpuc, i))
                                x86_assign_hw_event(event, cpuc, i);
                        else if (i < n_running)
                                continue;

                        if (hwc->state & PERF_HES_ARCH)
                                continue;

                        /*
                         * if cpuc->enabled = 0, then no wrmsr as
                         * per x86_pmu_enable_event()
                         */
                        x86_pmu_start(event, PERF_EF_RELOAD);
                }
                cpuc->n_added = 0;
                perf_events_lapic_init();
        }

        cpuc->enabled = 1;
        barrier();

        static_call(x86_pmu_enable_all)(added);
}

DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);

/*
 * Set the next IRQ period, based on the hwc->period_left value.
 * To be called with the event disabled in hw:
 */
int x86_perf_event_set_period(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        s64 left = local64_read(&hwc->period_left);
        s64 period = hwc->sample_period;
        int ret = 0, idx = hwc->idx;

        if (unlikely(!hwc->event_base))
                return 0;

        /*
         * If we are way outside a reasonable range then just skip forward:
         */
        if (unlikely(left <= -period)) {
                left = period;
                local64_set(&hwc->period_left, left);
                hwc->last_period = period;
                ret = 1;
        }

        if (unlikely(left <= 0)) {
                left += period;
                local64_set(&hwc->period_left, left);
                hwc->last_period = period;
                ret = 1;
        }
        /*
         * Quirk: certain CPUs dont like it if just 1 hw_event is left:
         */
        if (unlikely(left < 2))
                left = 2;

        if (left > x86_pmu.max_period)
                left = x86_pmu.max_period;

        static_call_cond(x86_pmu_limit_period)(event, &left);

        this_cpu_write(pmc_prev_left[idx], left);

        /*
         * The hw event starts counting from this event offset,
         * mark it to be able to extra future deltas:
         */
        local64_set(&hwc->prev_count, (u64)-left);

        wrmsrq(hwc->event_base, (u64)(-left) & x86_pmu.cntval_mask);

        /*
         * Sign extend the Merge event counter's upper 16 bits since
         * we currently declare a 48-bit counter width
         */
        if (is_counter_pair(hwc))
                wrmsrq(x86_pmu_event_addr(idx + 1), 0xffff);

        perf_event_update_userpage(event);

        return ret;
}

void x86_pmu_enable_event(struct perf_event *event)
{
        if (__this_cpu_read(cpu_hw_events.enabled))
                __x86_pmu_enable_event(&event->hw,
                                       ARCH_PERFMON_EVENTSEL_ENABLE);
}

/*
 * Add a single event to the PMU.
 *
 * The event is added to the group of enabled events
 * but only if it can be scheduled with existing events.
 */
static int x86_pmu_add(struct perf_event *event, int flags)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        struct hw_perf_event *hwc;
        int assign[X86_PMC_IDX_MAX];
        int n, n0, ret;

        hwc = &event->hw;

        n0 = cpuc->n_events;
        ret = n = collect_events(cpuc, event, false);
        if (ret < 0)
                goto out;

        hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
        if (!(flags & PERF_EF_START))
                hwc->state |= PERF_HES_ARCH;

        /*
         * If group events scheduling transaction was started,
         * skip the schedulability test here, it will be performed
         * at commit time (->commit_txn) as a whole.
         *
         * If commit fails, we'll call ->del() on all events
         * for which ->add() was called.
         */
        if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
                goto done_collect;

        ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign);
        if (ret)
                goto out;
        /*
         * copy new assignment, now we know it is possible
         * will be used by hw_perf_enable()
         */
        memcpy(cpuc->assign, assign, n*sizeof(int));

done_collect:
        /*
         * Commit the collect_events() state. See x86_pmu_del() and
         * x86_pmu_*_txn().
         */
        cpuc->n_events = n;
        cpuc->n_added += n - n0;
        cpuc->n_txn += n - n0;

        /*
         * This is before x86_pmu_enable() will call x86_pmu_start(),
         * so we enable LBRs before an event needs them etc..
         */
        static_call_cond(x86_pmu_add)(event);

        ret = 0;
out:
        return ret;
}

static void x86_pmu_start(struct perf_event *event, int flags)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int idx = event->hw.idx;

        if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
                return;

        if (WARN_ON_ONCE(idx == -1))
                return;

        if (flags & PERF_EF_RELOAD) {
                WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
                static_call(x86_pmu_set_period)(event);
        }

        event->hw.state = 0;

        cpuc->events[idx] = event;
        __set_bit(idx, cpuc->active_mask);
        static_call(x86_pmu_enable)(event);
        perf_event_update_userpage(event);
}

void perf_event_print_debug(void)
{
        u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
        unsigned long *cntr_mask, *fixed_cntr_mask;
        struct event_constraint *pebs_constraints;
        struct cpu_hw_events *cpuc;
        u64 pebs, debugctl;
        int cpu, idx;

        guard(irqsave)();

        cpu = smp_processor_id();
        cpuc = &per_cpu(cpu_hw_events, cpu);
        cntr_mask = hybrid(cpuc->pmu, cntr_mask);
        fixed_cntr_mask = hybrid(cpuc->pmu, fixed_cntr_mask);
        pebs_constraints = hybrid(cpuc->pmu, pebs_constraints);

        if (!*(u64 *)cntr_mask)
                return;

        if (x86_pmu.version >= 2) {
                rdmsrq(MSR_CORE_PERF_GLOBAL_CTRL, ctrl);
                rdmsrq(MSR_CORE_PERF_GLOBAL_STATUS, status);
                rdmsrq(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
                rdmsrq(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);

                pr_info("\n");
                pr_info("CPU#%d: ctrl:       %016llx\n", cpu, ctrl);
                pr_info("CPU#%d: status:     %016llx\n", cpu, status);
                pr_info("CPU#%d: overflow:   %016llx\n", cpu, overflow);
                pr_info("CPU#%d: fixed:      %016llx\n", cpu, fixed);
                if (pebs_constraints) {
                        rdmsrq(MSR_IA32_PEBS_ENABLE, pebs);
                        pr_info("CPU#%d: pebs:       %016llx\n", cpu, pebs);
                }
                if (x86_pmu.lbr_nr) {
                        rdmsrq(MSR_IA32_DEBUGCTLMSR, debugctl);
                        pr_info("CPU#%d: debugctl:   %016llx\n", cpu, debugctl);
                }
        }
        pr_info("CPU#%d: active:     %016llx\n", cpu, *(u64 *)cpuc->active_mask);

        for_each_set_bit(idx, cntr_mask, X86_PMC_IDX_MAX) {
                rdmsrq(x86_pmu_config_addr(idx), pmc_ctrl);
                rdmsrq(x86_pmu_event_addr(idx), pmc_count);

                prev_left = per_cpu(pmc_prev_left[idx], cpu);

                pr_info("CPU#%d:   gen-PMC%d ctrl:  %016llx\n",
                        cpu, idx, pmc_ctrl);
                pr_info("CPU#%d:   gen-PMC%d count: %016llx\n",
                        cpu, idx, pmc_count);
                pr_info("CPU#%d:   gen-PMC%d left:  %016llx\n",
                        cpu, idx, prev_left);
        }
        for_each_set_bit(idx, fixed_cntr_mask, X86_PMC_IDX_MAX) {
                if (fixed_counter_disabled(idx, cpuc->pmu))
                        continue;
                rdmsrq(x86_pmu_fixed_ctr_addr(idx), pmc_count);

                pr_info("CPU#%d: fixed-PMC%d count: %016llx\n",
                        cpu, idx, pmc_count);
        }
}

void x86_pmu_stop(struct perf_event *event, int flags)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        struct hw_perf_event *hwc = &event->hw;

        if (test_bit(hwc->idx, cpuc->active_mask)) {
                static_call(x86_pmu_disable)(event);
                __clear_bit(hwc->idx, cpuc->active_mask);
                cpuc->events[hwc->idx] = NULL;
                WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
                hwc->state |= PERF_HES_STOPPED;
        }

        if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
                /*
                 * Drain the remaining delta count out of a event
                 * that we are disabling:
                 */
                static_call(x86_pmu_update)(event);
                hwc->state |= PERF_HES_UPTODATE;
        }
}

static void x86_pmu_del(struct perf_event *event, int flags)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        union perf_capabilities intel_cap = hybrid(cpuc->pmu, intel_cap);
        int i;

        /*
         * If we're called during a txn, we only need to undo x86_pmu.add.
         * The events never got scheduled and ->cancel_txn will truncate
         * the event_list.
         *
         * XXX assumes any ->del() called during a TXN will only be on
         * an event added during that same TXN.
         */
        if (cpuc->txn_flags & PERF_PMU_TXN_ADD)
                goto do_del;

        __set_bit(event->hw.idx, cpuc->dirty);

        /*
         * Not a TXN, therefore cleanup properly.
         */
        x86_pmu_stop(event, PERF_EF_UPDATE);

        for (i = 0; i < cpuc->n_events; i++) {
                if (event == cpuc->event_list[i])
                        break;
        }

        if (WARN_ON_ONCE(i == cpuc->n_events)) /* called ->del() without ->add() ? */
                return;

        /* If we have a newly added event; make sure to decrease n_added. */
        if (i >= cpuc->n_events - cpuc->n_added)
                --cpuc->n_added;

        static_call_cond(x86_pmu_put_event_constraints)(cpuc, event);

        /* Delete the array entry. */
        while (++i < cpuc->n_events) {
                cpuc->event_list[i-1] = cpuc->event_list[i];
                cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
                cpuc->assign[i-1] = cpuc->assign[i];
        }
        cpuc->event_constraint[i-1] = NULL;
        --cpuc->n_events;
        if (intel_cap.perf_metrics)
                del_nr_metric_event(cpuc, event);

        perf_event_update_userpage(event);

do_del:

        /*
         * This is after x86_pmu_stop(); so we disable LBRs after any
         * event can need them etc..
         */
        static_call_cond(x86_pmu_del)(event);
}

int x86_pmu_handle_irq(struct pt_regs *regs)
{
        struct perf_sample_data data;
        struct cpu_hw_events *cpuc;
        struct perf_event *event;
        int idx, handled = 0;
        u64 last_period;
        u64 val;

        cpuc = this_cpu_ptr(&cpu_hw_events);

        /*
         * Some chipsets need to unmask the LVTPC in a particular spot
         * inside the nmi handler.  As a result, the unmasking was pushed
         * into all the nmi handlers.
         *
         * This generic handler doesn't seem to have any issues where the
         * unmasking occurs so it was left at the top.
         */
        apic_write(APIC_LVTPC, APIC_DM_NMI);

        for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                if (!test_bit(idx, cpuc->active_mask))
                        continue;

                event = cpuc->events[idx];
                last_period = event->hw.last_period;

                val = static_call(x86_pmu_update)(event);
                if (val & (1ULL << (x86_pmu.cntval_bits - 1)))
                        continue;

                /*
                 * event overflow
                 */
                handled++;

                if (!static_call(x86_pmu_set_period)(event))
                        continue;

                perf_sample_data_init(&data, 0, last_period);

                perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);

                perf_event_overflow(event, &data, regs);
        }

        if (handled)
                inc_irq_stat(apic_perf_irqs);

        return handled;
}

void perf_events_lapic_init(void)
{
        if (!x86_pmu.apic || !x86_pmu_initialized())
                return;

        /*
         * Always use NMI for PMU
         */
        apic_write(APIC_LVTPC, APIC_DM_NMI);
}

static int
perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
{
        u64 start_clock;
        u64 finish_clock;
        int ret;

        /*
         * All PMUs/events that share this PMI handler should make sure to
         * increment active_events for their events.
         */
        if (!atomic_read(&active_events))
                return NMI_DONE;

        start_clock = sched_clock();
        ret = static_call(x86_pmu_handle_irq)(regs);
        finish_clock = sched_clock();

        perf_sample_event_took(finish_clock - start_clock);

        return ret;
}
NOKPROBE_SYMBOL(perf_event_nmi_handler);

struct event_constraint emptyconstraint;
struct event_constraint unconstrained;

static int x86_pmu_prepare_cpu(unsigned int cpu)
{
        struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
        int i;

        for (i = 0 ; i < X86_PERF_KFREE_MAX; i++)
                cpuc->kfree_on_online[i] = NULL;
        if (x86_pmu.cpu_prepare)
                return x86_pmu.cpu_prepare(cpu);
        return 0;
}

static int x86_pmu_dead_cpu(unsigned int cpu)
{
        if (x86_pmu.cpu_dead)
                x86_pmu.cpu_dead(cpu);
        return 0;
}

static int x86_pmu_online_cpu(unsigned int cpu)
{
        struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
        int i;

        for (i = 0 ; i < X86_PERF_KFREE_MAX; i++) {
                kfree(cpuc->kfree_on_online[i]);
                cpuc->kfree_on_online[i] = NULL;
        }
        return 0;
}

static int x86_pmu_starting_cpu(unsigned int cpu)
{
        if (x86_pmu.cpu_starting)
                x86_pmu.cpu_starting(cpu);
        return 0;
}

static int x86_pmu_dying_cpu(unsigned int cpu)
{
        if (x86_pmu.cpu_dying)
                x86_pmu.cpu_dying(cpu);
        return 0;
}

static void __init pmu_check_apic(void)
{
        if (boot_cpu_has(X86_FEATURE_APIC))
                return;

        x86_pmu.apic = 0;
        pr_info("no APIC, boot with the \"lapic\" boot parameter to force-enable it.\n");
        pr_info("no hardware sampling interrupt available.\n");

        /*
         * If we have a PMU initialized but no APIC
         * interrupts, we cannot sample hardware
         * events (user-space has to fall back and
         * sample via a hrtimer based software event):
         */
        pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

}

static struct attribute_group x86_pmu_format_group __ro_after_init = {
        .name = "format",
        .attrs = NULL,
};

ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr, char *page)
{
        struct perf_pmu_events_attr *pmu_attr =
                container_of(attr, struct perf_pmu_events_attr, attr);
        u64 config = 0;

        if (pmu_attr->id < x86_pmu.max_events)
                config = x86_pmu.event_map(pmu_attr->id);

        /* string trumps id */
        if (pmu_attr->event_str)
                return sprintf(page, "%s\n", pmu_attr->event_str);

        return x86_pmu.events_sysfs_show(page, config);
}
EXPORT_SYMBOL_GPL(events_sysfs_show);

ssize_t events_ht_sysfs_show(struct device *dev, struct device_attribute *attr,
                          char *page)
{
        struct perf_pmu_events_ht_attr *pmu_attr =
                container_of(attr, struct perf_pmu_events_ht_attr, attr);

        /*
         * Report conditional events depending on Hyper-Threading.
         *
         * This is overly conservative as usually the HT special
         * handling is not needed if the other CPU thread is idle.
         *
         * Note this does not (and cannot) handle the case when thread
         * siblings are invisible, for example with virtualization
         * if they are owned by some other guest.  The user tool
         * has to re-read when a thread sibling gets onlined later.
         */
        return sprintf(page, "%s",
                        topology_max_smt_threads() > 1 ?
                        pmu_attr->event_str_ht :
                        pmu_attr->event_str_noht);
}

ssize_t events_hybrid_sysfs_show(struct device *dev,
                                 struct device_attribute *attr,
                                 char *page)
{
        struct perf_pmu_events_hybrid_attr *pmu_attr =
                container_of(attr, struct perf_pmu_events_hybrid_attr, attr);
        struct x86_hybrid_pmu *pmu;
        const char *str, *next_str;
        int i;

        if (hweight64(pmu_attr->pmu_type) == 1)
                return sprintf(page, "%s", pmu_attr->event_str);

        /*
         * Hybrid PMUs may support the same event name, but with different
         * event encoding, e.g., the mem-loads event on an Atom PMU has
         * different event encoding from a Core PMU.
         *
         * The event_str includes all event encodings. Each event encoding
         * is divided by ";". The order of the event encodings must follow
         * the order of the hybrid PMU index.
         */
        pmu = container_of(dev_get_drvdata(dev), struct x86_hybrid_pmu, pmu);

        str = pmu_attr->event_str;
        for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
                if (!(x86_pmu.hybrid_pmu[i].pmu_type & pmu_attr->pmu_type))
                        continue;
                if (x86_pmu.hybrid_pmu[i].pmu_type & pmu->pmu_type) {
                        next_str = strchr(str, ';');
                        if (next_str)
                                return snprintf(page, next_str - str + 1, "%s", str);
                        else
                                return sprintf(page, "%s", str);
                }
                str = strchr(str, ';');
                str++;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(events_hybrid_sysfs_show);

EVENT_ATTR(cpu-cycles,                        CPU_CYCLES                );
EVENT_ATTR(instructions,                INSTRUCTIONS                );
EVENT_ATTR(cache-references,                CACHE_REFERENCES        );
EVENT_ATTR(cache-misses,                 CACHE_MISSES                );
EVENT_ATTR(branch-instructions,                BRANCH_INSTRUCTIONS        );
EVENT_ATTR(branch-misses,                BRANCH_MISSES                );
EVENT_ATTR(bus-cycles,                        BUS_CYCLES                );
EVENT_ATTR(stalled-cycles-frontend,        STALLED_CYCLES_FRONTEND        );
EVENT_ATTR(stalled-cycles-backend,        STALLED_CYCLES_BACKEND        );
EVENT_ATTR(ref-cycles,                        REF_CPU_CYCLES                );

static struct attribute *empty_attrs;

static struct attribute *events_attr[] = {
        EVENT_PTR(CPU_CYCLES),
        EVENT_PTR(INSTRUCTIONS),
        EVENT_PTR(CACHE_REFERENCES),
        EVENT_PTR(CACHE_MISSES),
        EVENT_PTR(BRANCH_INSTRUCTIONS),
        EVENT_PTR(BRANCH_MISSES),
        EVENT_PTR(BUS_CYCLES),
        EVENT_PTR(STALLED_CYCLES_FRONTEND),
        EVENT_PTR(STALLED_CYCLES_BACKEND),
        EVENT_PTR(REF_CPU_CYCLES),
        NULL,
};

/*
 * Remove all undefined events (x86_pmu.event_map(id) == 0)
 * out of events_attr attributes.
 */
static umode_t
is_visible(struct kobject *kobj, struct attribute *attr, int idx)
{
        struct perf_pmu_events_attr *pmu_attr;

        if (idx >= x86_pmu.max_events)
                return 0;

        pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
        /* str trumps id */
        return pmu_attr->event_str || x86_pmu.event_map(idx) ? attr->mode : 0;
}

static struct attribute_group x86_pmu_events_group __ro_after_init = {
        .name = "events",
        .attrs = events_attr,
        .is_visible = is_visible,
};

ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
{
        u64 umask  = (config & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
        u64 cmask  = (config & ARCH_PERFMON_EVENTSEL_CMASK) >> 24;
        bool edge  = (config & ARCH_PERFMON_EVENTSEL_EDGE);
        bool pc    = (config & ARCH_PERFMON_EVENTSEL_PIN_CONTROL);
        bool any   = (config & ARCH_PERFMON_EVENTSEL_ANY);
        bool inv   = (config & ARCH_PERFMON_EVENTSEL_INV);
        ssize_t ret;

        /*
        * We have whole page size to spend and just little data
        * to write, so we can safely use sprintf.
        */
        ret = sprintf(page, "event=0x%02llx", event);

        if (umask)
                ret += sprintf(page + ret, ",umask=0x%02llx", umask);

        if (edge)
                ret += sprintf(page + ret, ",edge");

        if (pc)
                ret += sprintf(page + ret, ",pc");

        if (any)
                ret += sprintf(page + ret, ",any");

        if (inv)
                ret += sprintf(page + ret, ",inv");

        if (cmask)
                ret += sprintf(page + ret, ",cmask=0x%02llx", cmask);

        ret += sprintf(page + ret, "\n");

        return ret;
}

static struct attribute_group x86_pmu_attr_group;
static struct attribute_group x86_pmu_caps_group;

static void x86_pmu_static_call_update(void)
{
        static_call_update(x86_pmu_handle_irq, x86_pmu.handle_irq);
        static_call_update(x86_pmu_disable_all, x86_pmu.disable_all);
        static_call_update(x86_pmu_enable_all, x86_pmu.enable_all);
        static_call_update(x86_pmu_enable, x86_pmu.enable);
        static_call_update(x86_pmu_disable, x86_pmu.disable);

        static_call_update(x86_pmu_assign, x86_pmu.assign);

        static_call_update(x86_pmu_add, x86_pmu.add);
        static_call_update(x86_pmu_del, x86_pmu.del);
        static_call_update(x86_pmu_read, x86_pmu.read);

        static_call_update(x86_pmu_set_period, x86_pmu.set_period);
        static_call_update(x86_pmu_update, x86_pmu.update);
        static_call_update(x86_pmu_limit_period, x86_pmu.limit_period);

        static_call_update(x86_pmu_schedule_events, x86_pmu.schedule_events);
        static_call_update(x86_pmu_get_event_constraints, x86_pmu.get_event_constraints);
        static_call_update(x86_pmu_put_event_constraints, x86_pmu.put_event_constraints);

        static_call_update(x86_pmu_start_scheduling, x86_pmu.start_scheduling);
        static_call_update(x86_pmu_commit_scheduling, x86_pmu.commit_scheduling);
        static_call_update(x86_pmu_stop_scheduling, x86_pmu.stop_scheduling);

        static_call_update(x86_pmu_sched_task, x86_pmu.sched_task);

        static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs);
        static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases);

        static_call_update(x86_pmu_guest_get_msrs, x86_pmu.guest_get_msrs);
        static_call_update(x86_pmu_filter, x86_pmu.filter);

        static_call_update(x86_pmu_late_setup, x86_pmu.late_setup);

        static_call_update(x86_pmu_pebs_enable, x86_pmu.pebs_enable);
        static_call_update(x86_pmu_pebs_disable, x86_pmu.pebs_disable);
        static_call_update(x86_pmu_pebs_enable_all, x86_pmu.pebs_enable_all);
        static_call_update(x86_pmu_pebs_disable_all, x86_pmu.pebs_disable_all);
}

static void _x86_pmu_read(struct perf_event *event)
{
        static_call(x86_pmu_update)(event);
}

void x86_pmu_show_pmu_cap(struct pmu *pmu)
{
        pr_info("... version:                   %d\n", x86_pmu.version);
        pr_info("... bit width:                 %d\n", x86_pmu.cntval_bits);
        pr_info("... generic counters:          %d\n", x86_pmu_num_counters(pmu));
        pr_info("... generic bitmap:            %016llx\n", hybrid(pmu, cntr_mask64));
        pr_info("... fixed-purpose counters:    %d\n", x86_pmu_num_counters_fixed(pmu));
        pr_info("... fixed-purpose bitmap:      %016llx\n", hybrid(pmu, fixed_cntr_mask64));
        pr_info("... value mask:                %016llx\n", x86_pmu.cntval_mask);
        pr_info("... max period:                %016llx\n", x86_pmu.max_period);
        pr_info("... global_ctrl mask:          %016llx\n", hybrid(pmu, intel_ctrl));
}

static int __init init_hw_perf_events(void)
{
        struct x86_pmu_quirk *quirk;
        int err;

        pr_info("Performance Events: ");

        switch (boot_cpu_data.x86_vendor) {
        case X86_VENDOR_INTEL:
                err = intel_pmu_init();
                break;
        case X86_VENDOR_AMD:
                err = amd_pmu_init();
                break;
        case X86_VENDOR_HYGON:
                err = amd_pmu_init();
                x86_pmu.name = "HYGON";
                break;
        case X86_VENDOR_ZHAOXIN:
        case X86_VENDOR_CENTAUR:
                err = zhaoxin_pmu_init();
                break;
        default:
                err = -ENOTSUPP;
        }
        if (err != 0) {
                pr_cont("no PMU driver, software events only.\n");
                err = 0;
                goto out_bad_pmu;
        }

        pmu_check_apic();

        /* sanity check that the hardware exists or is emulated */
        if (!check_hw_exists(&pmu, x86_pmu.cntr_mask, x86_pmu.fixed_cntr_mask))
                goto out_bad_pmu;

        pr_cont("%s PMU driver.\n", x86_pmu.name);

        x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */

        for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next)
                quirk->func();

        if (!x86_pmu.intel_ctrl)
                x86_pmu.intel_ctrl = x86_pmu.cntr_mask64;

        if (!x86_pmu.config_mask)
                x86_pmu.config_mask = X86_RAW_EVENT_MASK;

        perf_events_lapic_init();
        register_nmi_handler(NMI_LOCAL, perf_event_nmi_handler, 0, "PMI");

        unconstrained = (struct event_constraint)
                __EVENT_CONSTRAINT(0, x86_pmu.cntr_mask64,
                                   0, x86_pmu_num_counters(NULL), 0, 0);

        x86_pmu_format_group.attrs = x86_pmu.format_attrs;

        if (!x86_pmu.events_sysfs_show)
                x86_pmu_events_group.attrs = &empty_attrs;

        pmu.attr_update = x86_pmu.attr_update;

        if (!is_hybrid())
                x86_pmu_show_pmu_cap(NULL);

        if (!x86_pmu.read)
                x86_pmu.read = _x86_pmu_read;

        if (!x86_pmu.guest_get_msrs)
                x86_pmu.guest_get_msrs = (void *)&__static_call_return0;

        if (!x86_pmu.set_period)
                x86_pmu.set_period = x86_perf_event_set_period;

        if (!x86_pmu.update)
                x86_pmu.update = x86_perf_event_update;

        x86_pmu_static_call_update();

        /*
         * Install callbacks. Core will call them for each online
         * cpu.
         */
        err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "perf/x86:prepare",
                                x86_pmu_prepare_cpu, x86_pmu_dead_cpu);
        if (err)
                return err;

        err = cpuhp_setup_state(CPUHP_AP_PERF_X86_STARTING,
                                "perf/x86:starting", x86_pmu_starting_cpu,
                                x86_pmu_dying_cpu);
        if (err)
                goto out;

        err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "perf/x86:online",
                                x86_pmu_online_cpu, NULL);
        if (err)
                goto out1;

        if (!is_hybrid()) {
                err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
                if (err)
                        goto out2;
        } else {
                struct x86_hybrid_pmu *hybrid_pmu;
                int i, j;

                for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) {
                        hybrid_pmu = &x86_pmu.hybrid_pmu[i];

                        hybrid_pmu->pmu = pmu;
                        hybrid_pmu->pmu.type = -1;
                        hybrid_pmu->pmu.attr_update = x86_pmu.attr_update;
                        hybrid_pmu->pmu.capabilities |= PERF_PMU_CAP_EXTENDED_HW_TYPE;

                        err = perf_pmu_register(&hybrid_pmu->pmu, hybrid_pmu->name,
                                                (hybrid_pmu->pmu_type == hybrid_big) ? PERF_TYPE_RAW : -1);
                        if (err)
                                break;
                }

                if (i < x86_pmu.num_hybrid_pmus) {
                        for (j = 0; j < i; j++)
                                perf_pmu_unregister(&x86_pmu.hybrid_pmu[j].pmu);
                        pr_warn("Failed to register hybrid PMUs\n");
                        kfree(x86_pmu.hybrid_pmu);
                        x86_pmu.hybrid_pmu = NULL;
                        x86_pmu.num_hybrid_pmus = 0;
                        goto out2;
                }
        }

        return 0;

out2:
        cpuhp_remove_state(CPUHP_AP_PERF_X86_ONLINE);
out1:
        cpuhp_remove_state(CPUHP_AP_PERF_X86_STARTING);
out:
        cpuhp_remove_state(CPUHP_PERF_X86_PREPARE);
out_bad_pmu:
        memset(&x86_pmu, 0, sizeof(x86_pmu));
        return err;
}
early_initcall(init_hw_perf_events);

static void x86_pmu_read(struct perf_event *event)
{
        static_call(x86_pmu_read)(event);
}

/*
 * Start group events scheduling transaction
 * Set the flag to make pmu::enable() not perform the
 * schedulability test, it will be performed at commit time
 *
 * We only support PERF_PMU_TXN_ADD transactions. Save the
 * transaction flags but otherwise ignore non-PERF_PMU_TXN_ADD
 * transactions.
 */
static void x86_pmu_start_txn(struct pmu *pmu, unsigned int txn_flags)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);

        WARN_ON_ONCE(cpuc->txn_flags);                /* txn already in flight */

        cpuc->txn_flags = txn_flags;
        if (txn_flags & ~PERF_PMU_TXN_ADD)
                return;

        perf_pmu_disable(pmu);
        __this_cpu_write(cpu_hw_events.n_txn, 0);
        __this_cpu_write(cpu_hw_events.n_txn_pair, 0);
        __this_cpu_write(cpu_hw_events.n_txn_metric, 0);
}

/*
 * Stop group events scheduling transaction
 * Clear the flag and pmu::enable() will perform the
 * schedulability test.
 */
static void x86_pmu_cancel_txn(struct pmu *pmu)
{
        unsigned int txn_flags;
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);

        WARN_ON_ONCE(!cpuc->txn_flags);        /* no txn in flight */

        txn_flags = cpuc->txn_flags;
        cpuc->txn_flags = 0;
        if (txn_flags & ~PERF_PMU_TXN_ADD)
                return;

        /*
         * Truncate collected array by the number of events added in this
         * transaction. See x86_pmu_add() and x86_pmu_*_txn().
         */
        __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
        __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
        __this_cpu_sub(cpu_hw_events.n_pair, __this_cpu_read(cpu_hw_events.n_txn_pair));
        __this_cpu_sub(cpu_hw_events.n_metric, __this_cpu_read(cpu_hw_events.n_txn_metric));
        perf_pmu_enable(pmu);
}

/*
 * Commit group events scheduling transaction
 * Perform the group schedulability test as a whole
 * Return 0 if success
 *
 * Does not cancel the transaction on failure; expects the caller to do this.
 */
static int x86_pmu_commit_txn(struct pmu *pmu)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int assign[X86_PMC_IDX_MAX];
        int n, ret;

        WARN_ON_ONCE(!cpuc->txn_flags);        /* no txn in flight */

        if (cpuc->txn_flags & ~PERF_PMU_TXN_ADD) {
                cpuc->txn_flags = 0;
                return 0;
        }

        n = cpuc->n_events;

        if (!x86_pmu_initialized())
                return -EAGAIN;

        ret = static_call(x86_pmu_schedule_events)(cpuc, n, assign);
        if (ret)
                return ret;

        /*
         * copy new assignment, now we know it is possible
         * will be used by hw_perf_enable()
         */
        memcpy(cpuc->assign, assign, n*sizeof(int));

        cpuc->txn_flags = 0;
        perf_pmu_enable(pmu);
        return 0;
}
/*
 * a fake_cpuc is used to validate event groups. Due to
 * the extra reg logic, we need to also allocate a fake
 * per_core and per_cpu structure. Otherwise, group events
 * using extra reg may conflict without the kernel being
 * able to catch this when the last event gets added to
 * the group.
 */
static void free_fake_cpuc(struct cpu_hw_events *cpuc)
{
        intel_cpuc_finish(cpuc);
        kfree(cpuc);
}

static struct cpu_hw_events *allocate_fake_cpuc(struct pmu *event_pmu)
{
        struct cpu_hw_events *cpuc;
        int cpu;

        cpuc = kzalloc(sizeof(*cpuc), GFP_KERNEL);
        if (!cpuc)
                return ERR_PTR(-ENOMEM);
        cpuc->is_fake = 1;

        if (is_hybrid()) {
                struct x86_hybrid_pmu *h_pmu;

                h_pmu = hybrid_pmu(event_pmu);
                if (cpumask_empty(&h_pmu->supported_cpus))
                        goto error;
                cpu = cpumask_first(&h_pmu->supported_cpus);
        } else
                cpu = raw_smp_processor_id();
        cpuc->pmu = event_pmu;

        if (intel_cpuc_prepare(cpuc, cpu))
                goto error;

        return cpuc;
error:
        free_fake_cpuc(cpuc);
        return ERR_PTR(-ENOMEM);
}

/*
 * validate that we can schedule this event
 */
static int validate_event(struct perf_event *event)
{
        struct cpu_hw_events *fake_cpuc;
        struct event_constraint *c;
        int ret = 0;

        fake_cpuc = allocate_fake_cpuc(event->pmu);
        if (IS_ERR(fake_cpuc))
                return PTR_ERR(fake_cpuc);

        c = x86_pmu.get_event_constraints(fake_cpuc, 0, event);

        if (!c || !c->weight)
                ret = -EINVAL;

        if (x86_pmu.put_event_constraints)
                x86_pmu.put_event_constraints(fake_cpuc, event);

        free_fake_cpuc(fake_cpuc);

        return ret;
}

/*
 * validate a single event group
 *
 * validation include:
 *        - check events are compatible which each other
 *        - events do not compete for the same counter
 *        - number of events <= number of counters
 *
 * validation ensures the group can be loaded onto the
 * PMU if it was the only group available.
 */
static int validate_group(struct perf_event *event)
{
        struct perf_event *leader = event->group_leader;
        struct cpu_hw_events *fake_cpuc;
        int ret = -EINVAL, n;

        /*
         * Reject events from different hybrid PMUs.
         */
        if (is_hybrid()) {
                struct perf_event *sibling;
                struct pmu *pmu = NULL;

                if (is_x86_event(leader))
                        pmu = leader->pmu;

                for_each_sibling_event(sibling, leader) {
                        if (!is_x86_event(sibling))
                                continue;
                        if (!pmu)
                                pmu = sibling->pmu;
                        else if (pmu != sibling->pmu)
                                return ret;
                }
        }

        fake_cpuc = allocate_fake_cpuc(event->pmu);
        if (IS_ERR(fake_cpuc))
                return PTR_ERR(fake_cpuc);
        /*
         * the event is not yet connected with its
         * siblings therefore we must first collect
         * existing siblings, then add the new event
         * before we can simulate the scheduling
         */
        n = collect_events(fake_cpuc, leader, true);
        if (n < 0)
                goto out;

        fake_cpuc->n_events = n;
        n = collect_events(fake_cpuc, event, false);
        if (n < 0)
                goto out;

        fake_cpuc->n_events = 0;
        ret = x86_pmu.schedule_events(fake_cpuc, n, NULL);

out:
        free_fake_cpuc(fake_cpuc);
        return ret;
}

static int x86_pmu_event_init(struct perf_event *event)
{
        struct x86_hybrid_pmu *pmu = NULL;
        int err;

        if ((event->attr.type != event->pmu->type) &&
            (event->attr.type != PERF_TYPE_HARDWARE) &&
            (event->attr.type != PERF_TYPE_HW_CACHE))
                return -ENOENT;

        if (is_hybrid() && (event->cpu != -1)) {
                pmu = hybrid_pmu(event->pmu);
                if (!cpumask_test_cpu(event->cpu, &pmu->supported_cpus))
                        return -ENOENT;
        }

        err = __x86_pmu_event_init(event);
        if (!err) {
                if (event->group_leader != event)
                        err = validate_group(event);
                else
                        err = validate_event(event);
        }
        if (err) {
                if (event->destroy)
                        event->destroy(event);
                event->destroy = NULL;
        }

        if (READ_ONCE(x86_pmu.attr_rdpmc) &&
            !(event->hw.flags & PERF_X86_EVENT_LARGE_PEBS))
                event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;

        return err;
}

void perf_clear_dirty_counters(void)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int i;

         /* Don't need to clear the assigned counter. */
        for (i = 0; i < cpuc->n_events; i++)
                __clear_bit(cpuc->assign[i], cpuc->dirty);

        if (bitmap_empty(cpuc->dirty, X86_PMC_IDX_MAX))
                return;

        for_each_set_bit(i, cpuc->dirty, X86_PMC_IDX_MAX) {
                if (i >= INTEL_PMC_IDX_FIXED) {
                        /* Metrics and fake events don't have corresponding HW counters. */
                        if (!test_bit(i - INTEL_PMC_IDX_FIXED, hybrid(cpuc->pmu, fixed_cntr_mask)))
                                continue;

                        wrmsrq(x86_pmu_fixed_ctr_addr(i - INTEL_PMC_IDX_FIXED), 0);
                } else {
                        wrmsrq(x86_pmu_event_addr(i), 0);
                }
        }

        bitmap_zero(cpuc->dirty, X86_PMC_IDX_MAX);
}

static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
{
        if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
                return;

        /*
         * This function relies on not being called concurrently in two
         * tasks in the same mm.  Otherwise one task could observe
         * perf_rdpmc_allowed > 1 and return all the way back to
         * userspace with CR4.PCE clear while another task is still
         * doing on_each_cpu_mask() to propagate CR4.PCE.
         *
         * For now, this can't happen because all callers hold mmap_lock
         * for write.  If this changes, we'll need a different solution.
         */
        mmap_assert_write_locked(mm);

        if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1)
                on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
}

static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)
{
        if (!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT))
                return;

        if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
                on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
}

static int x86_pmu_event_idx(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        if (!(hwc->flags & PERF_EVENT_FLAG_USER_READ_CNT))
                return 0;

        if (is_metric_idx(hwc->idx))
                return INTEL_PMC_FIXED_RDPMC_METRICS + 1;
        else
                return hwc->event_base_rdpmc + 1;
}

static ssize_t get_attr_rdpmc(struct device *cdev,
                              struct device_attribute *attr,
                              char *buf)
{
        return snprintf(buf, 40, "%d\n", x86_pmu.attr_rdpmc);
}

static ssize_t set_attr_rdpmc(struct device *cdev,
                              struct device_attribute *attr,
                              const char *buf, size_t count)
{
        static DEFINE_MUTEX(rdpmc_mutex);
        unsigned long val;
        ssize_t ret;

        ret = kstrtoul(buf, 0, &val);
        if (ret)
                return ret;

        if (val > 2)
                return -EINVAL;

        if (x86_pmu.attr_rdpmc_broken)
                return -ENOTSUPP;

        guard(mutex)(&rdpmc_mutex);

        if (val != x86_pmu.attr_rdpmc) {
                /*
                 * Changing into or out of never available or always available,
                 * aka perf-event-bypassing mode. This path is extremely slow,
                 * but only root can trigger it, so it's okay.
                 */
                if (val == 0)
                        static_branch_inc(&rdpmc_never_available_key);
                else if (x86_pmu.attr_rdpmc == 0)
                        static_branch_dec(&rdpmc_never_available_key);

                if (val == 2)
                        static_branch_inc(&rdpmc_always_available_key);
                else if (x86_pmu.attr_rdpmc == 2)
                        static_branch_dec(&rdpmc_always_available_key);

                on_each_cpu(cr4_update_pce, NULL, 1);
                x86_pmu.attr_rdpmc = val;
        }

        return count;
}

static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc);

static struct attribute *x86_pmu_attrs[] = {
        &dev_attr_rdpmc.attr,
        NULL,
};

static struct attribute_group x86_pmu_attr_group __ro_after_init = {
        .attrs = x86_pmu_attrs,
};

static ssize_t max_precise_show(struct device *cdev,
                                  struct device_attribute *attr,
                                  char *buf)
{
        return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu_max_precise());
}

static DEVICE_ATTR_RO(max_precise);

static struct attribute *x86_pmu_caps_attrs[] = {
        &dev_attr_max_precise.attr,
        NULL
};

static struct attribute_group x86_pmu_caps_group __ro_after_init = {
        .name = "caps",
        .attrs = x86_pmu_caps_attrs,
};

static const struct attribute_group *x86_pmu_attr_groups[] = {
        &x86_pmu_attr_group,
        &x86_pmu_format_group,
        &x86_pmu_events_group,
        &x86_pmu_caps_group,
        NULL,
};

static void x86_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx,
                               struct task_struct *task, bool sched_in)
{
        static_call_cond(x86_pmu_sched_task)(pmu_ctx, task, sched_in);
}

void perf_check_microcode(void)
{
        if (x86_pmu.check_microcode)
                x86_pmu.check_microcode();
}

static int x86_pmu_check_period(struct perf_event *event, u64 value)
{
        if (x86_pmu.check_period && x86_pmu.check_period(event, value))
                return -EINVAL;

        if (value && x86_pmu.limit_period) {
                s64 left = value;
                x86_pmu.limit_period(event, &left);
                if (left > value)
                        return -EINVAL;
        }

        return 0;
}

static int x86_pmu_aux_output_match(struct perf_event *event)
{
        if (!(pmu.capabilities & PERF_PMU_CAP_AUX_OUTPUT))
                return 0;

        if (x86_pmu.aux_output_match)
                return x86_pmu.aux_output_match(event);

        return 0;
}

static bool x86_pmu_filter(struct pmu *pmu, int cpu)
{
        bool ret = false;

        static_call_cond(x86_pmu_filter)(pmu, cpu, &ret);

        return ret;
}

static struct pmu pmu = {
        .pmu_enable                = x86_pmu_enable,
        .pmu_disable                = x86_pmu_disable,

        .attr_groups                = x86_pmu_attr_groups,

        .event_init                = x86_pmu_event_init,

        .event_mapped                = x86_pmu_event_mapped,
        .event_unmapped                = x86_pmu_event_unmapped,

        .add                        = x86_pmu_add,
        .del                        = x86_pmu_del,
        .start                        = x86_pmu_start,
        .stop                        = x86_pmu_stop,
        .read                        = x86_pmu_read,

        .start_txn                = x86_pmu_start_txn,
        .cancel_txn                = x86_pmu_cancel_txn,
        .commit_txn                = x86_pmu_commit_txn,

        .event_idx                = x86_pmu_event_idx,
        .sched_task                = x86_pmu_sched_task,
        .check_period                = x86_pmu_check_period,

        .aux_output_match        = x86_pmu_aux_output_match,

        .filter                        = x86_pmu_filter,
};

void arch_perf_update_userpage(struct perf_event *event,
                               struct perf_event_mmap_page *userpg, u64 now)
{
        struct cyc2ns_data data;
        u64 offset;

        userpg->cap_user_time = 0;
        userpg->cap_user_time_zero = 0;
        userpg->cap_user_rdpmc =
                !!(event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT);
        userpg->pmc_width = x86_pmu.cntval_bits;

        if (!using_native_sched_clock() || !sched_clock_stable())
                return;

        cyc2ns_read_begin(&data);

        offset = data.cyc2ns_offset + __sched_clock_offset;

        /*
         * Internal timekeeping for enabled/running/stopped times
         * is always in the local_clock domain.
         */
        userpg->cap_user_time = 1;
        userpg->time_mult = data.cyc2ns_mul;
        userpg->time_shift = data.cyc2ns_shift;
        userpg->time_offset = offset - now;

        /*
         * cap_user_time_zero doesn't make sense when we're using a different
         * time base for the records.
         */
        if (!event->attr.use_clockid) {
                userpg->cap_user_time_zero = 1;
                userpg->time_zero = offset;
        }

        cyc2ns_read_end();
}

/*
 * Determine whether the regs were taken from an irq/exception handler rather
 * than from perf_arch_fetch_caller_regs().
 */
static bool perf_hw_regs(struct pt_regs *regs)
{
        return regs->flags & X86_EFLAGS_FIXED;
}

void
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
        struct unwind_state state;
        unsigned long addr;

        if (perf_guest_state()) {
                /* TODO: We don't support guest os callchain now */
                return;
        }

        if (perf_callchain_store(entry, regs->ip))
                return;

        if (perf_hw_regs(regs))
                unwind_start(&state, current, regs, NULL);
        else
                unwind_start(&state, current, NULL, (void *)regs->sp);

        for (; !unwind_done(&state); unwind_next_frame(&state)) {
                addr = unwind_get_return_address(&state);
                if (!addr || perf_callchain_store(entry, addr))
                        return;
        }
}

static inline int
valid_user_frame(const void __user *fp, unsigned long size)
{
        return __access_ok(fp, size);
}

static unsigned long get_segment_base(unsigned int segment)
{
        struct desc_struct *desc;
        unsigned int idx = segment >> 3;

        if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
#ifdef CONFIG_MODIFY_LDT_SYSCALL
                struct ldt_struct *ldt;

                /*
                 * If we're not in a valid context with a real (not just lazy)
                 * user mm, then don't even try.
                 */
                if (!nmi_uaccess_okay())
                        return 0;

                /* IRQs are off, so this synchronizes with smp_store_release */
                ldt = smp_load_acquire(&current->mm->context.ldt);
                if (!ldt || idx >= ldt->nr_entries)
                        return 0;

                desc = &ldt->entries[idx];
#else
                return 0;
#endif
        } else {
                if (idx >= GDT_ENTRIES)
                        return 0;

                desc = raw_cpu_ptr(gdt_page.gdt) + idx;
        }

        return get_desc_base(desc);
}

#ifdef CONFIG_UPROBES
/*
 * Heuristic-based check if uprobe is installed at the function entry.
 *
 * Under assumption of user code being compiled with frame pointers,
 * `push %rbp/%ebp` is a good indicator that we indeed are.
 *
 * Similarly, `endbr64` (assuming 64-bit mode) is also a common pattern.
 * If we get this wrong, captured stack trace might have one extra bogus
 * entry, but the rest of stack trace will still be meaningful.
 */
static bool is_uprobe_at_func_entry(struct pt_regs *regs)
{
        struct arch_uprobe *auprobe;

        if (!current->utask)
                return false;

        auprobe = current->utask->auprobe;
        if (!auprobe)
                return false;

        /* push %rbp/%ebp */
        if (auprobe->insn[0] == 0x55)
                return true;

        /* endbr64 (64-bit only) */
        if (user_64bit_mode(regs) && is_endbr((u32 *)auprobe->insn))
                return true;

        return false;
}

#else
static bool is_uprobe_at_func_entry(struct pt_regs *regs)
{
        return false;
}
#endif /* CONFIG_UPROBES */

#ifdef CONFIG_IA32_EMULATION

#include <linux/compat.h>

static inline int
perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
{
        /* 32-bit process in 64-bit kernel. */
        unsigned long ss_base, cs_base;
        struct stack_frame_ia32 frame;
        const struct stack_frame_ia32 __user *fp;
        u32 ret_addr;

        if (user_64bit_mode(regs))
                return 0;

        cs_base = get_segment_base(regs->cs);
        ss_base = get_segment_base(regs->ss);

        fp = compat_ptr(ss_base + regs->bp);
        pagefault_disable();

        /* see perf_callchain_user() below for why we do this */
        if (is_uprobe_at_func_entry(regs) &&
            !get_user(ret_addr, (const u32 __user *)regs->sp))
                perf_callchain_store(entry, ret_addr);

        while (entry->nr < entry->max_stack) {
                if (!valid_user_frame(fp, sizeof(frame)))
                        break;

                if (__get_user(frame.next_frame, &fp->next_frame))
                        break;
                if (__get_user(frame.return_address, &fp->return_address))
                        break;

                perf_callchain_store(entry, cs_base + frame.return_address);
                fp = compat_ptr(ss_base + frame.next_frame);
        }
        pagefault_enable();
        return 1;
}
#else
static inline int
perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *entry)
{
    return 0;
}
#endif

void
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
        struct stack_frame frame;
        const struct stack_frame __user *fp;
        unsigned long ret_addr;

        if (perf_guest_state()) {
                /* TODO: We don't support guest os callchain now */
                return;
        }

        /*
         * We don't know what to do with VM86 stacks.. ignore them for now.
         */
        if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
                return;

        fp = (void __user *)regs->bp;

        perf_callchain_store(entry, regs->ip);

        if (!nmi_uaccess_okay())
                return;

        if (perf_callchain_user32(regs, entry))
                return;

        pagefault_disable();

        /*
         * If we are called from uprobe handler, and we are indeed at the very
         * entry to user function (which is normally a `push %rbp` instruction,
         * under assumption of application being compiled with frame pointers),
         * we should read return address from *regs->sp before proceeding
         * to follow frame pointers, otherwise we'll skip immediate caller
         * as %rbp is not yet setup.
         */
        if (is_uprobe_at_func_entry(regs) &&
            !get_user(ret_addr, (const unsigned long __user *)regs->sp))
                perf_callchain_store(entry, ret_addr);

        while (entry->nr < entry->max_stack) {
                if (!valid_user_frame(fp, sizeof(frame)))
                        break;

                if (__get_user(frame.next_frame, &fp->next_frame))
                        break;
                if (__get_user(frame.return_address, &fp->return_address))
                        break;

                perf_callchain_store(entry, frame.return_address);
                fp = (void __user *)frame.next_frame;
        }
        pagefault_enable();
}

/*
 * Deal with code segment offsets for the various execution modes:
 *
 *   VM86 - the good olde 16 bit days, where the linear address is
 *          20 bits and we use regs->ip + 0x10 * regs->cs.
 *
 *   IA32 - Where we need to look at GDT/LDT segment descriptor tables
 *          to figure out what the 32bit base address is.
 *
 *    X32 - has TIF_X32 set, but is running in x86_64
 *
 * X86_64 - CS,DS,SS,ES are all zero based.
 */
static unsigned long code_segment_base(struct pt_regs *regs)
{
        /*
         * For IA32 we look at the GDT/LDT segment base to convert the
         * effective IP to a linear address.
         */

#ifdef CONFIG_X86_32
        /*
         * If we are in VM86 mode, add the segment offset to convert to a
         * linear address.
         */
        if (regs->flags & X86_VM_MASK)
                return 0x10 * regs->cs;

        if (user_mode(regs) && regs->cs != __USER_CS)
                return get_segment_base(regs->cs);
#else
        if (user_mode(regs) && !user_64bit_mode(regs) &&
            regs->cs != __USER32_CS)
                return get_segment_base(regs->cs);
#endif
        return 0;
}

unsigned long perf_arch_instruction_pointer(struct pt_regs *regs)
{
        return regs->ip + code_segment_base(regs);
}

static unsigned long common_misc_flags(struct pt_regs *regs)
{
        if (regs->flags & PERF_EFLAGS_EXACT)
                return PERF_RECORD_MISC_EXACT_IP;

        return 0;
}

static unsigned long guest_misc_flags(struct pt_regs *regs)
{
        unsigned long guest_state = perf_guest_state();

        if (!(guest_state & PERF_GUEST_ACTIVE))
                return 0;

        if (guest_state & PERF_GUEST_USER)
                return PERF_RECORD_MISC_GUEST_USER;
        else
                return PERF_RECORD_MISC_GUEST_KERNEL;

}

static unsigned long host_misc_flags(struct pt_regs *regs)
{
        if (user_mode(regs))
                return PERF_RECORD_MISC_USER;
        else
                return PERF_RECORD_MISC_KERNEL;
}

unsigned long perf_arch_guest_misc_flags(struct pt_regs *regs)
{
        unsigned long flags = common_misc_flags(regs);

        flags |= guest_misc_flags(regs);

        return flags;
}

unsigned long perf_arch_misc_flags(struct pt_regs *regs)
{
        unsigned long flags = common_misc_flags(regs);

        flags |= host_misc_flags(regs);

        return flags;
}

void perf_get_x86_pmu_capability(struct x86_pmu_capability *cap)
{
        /* This API doesn't currently support enumerating hybrid PMUs. */
        if (WARN_ON_ONCE(cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) ||
            !x86_pmu_initialized()) {
                memset(cap, 0, sizeof(*cap));
                return;
        }

        /*
         * Note, hybrid CPU models get tracked as having hybrid PMUs even when
         * all E-cores are disabled via BIOS.  When E-cores are disabled, the
         * base PMU holds the correct number of counters for P-cores.
         */
        cap->version                = x86_pmu.version;
        cap->num_counters_gp        = x86_pmu_num_counters(NULL);
        cap->num_counters_fixed        = x86_pmu_num_counters_fixed(NULL);
        cap->bit_width_gp        = x86_pmu.cntval_bits;
        cap->bit_width_fixed        = x86_pmu.cntval_bits;
        cap->events_mask        = (unsigned int)x86_pmu.events_maskl;
        cap->events_mask_len        = x86_pmu.events_mask_len;
        cap->pebs_ept                = x86_pmu.pebs_ept;
}
EXPORT_SYMBOL_GPL(perf_get_x86_pmu_capability);

u64 perf_get_hw_event_config(int hw_event)
{
        int max = x86_pmu.max_events;

        if (hw_event < max)
                return x86_pmu.event_map(array_index_nospec(hw_event, max));

        return 0;
}
EXPORT_SYMBOL_GPL(perf_get_hw_event_config);








































































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// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause

/* Authors: Bernard Metzler <bmt@zurich.ibm.com> */
/* Copyright (c) 2008-2019, IBM Corporation */

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <net/net_namespace.h>
#include <linux/rtnetlink.h>
#include <linux/if_arp.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>

#include <net/addrconf.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_user_verbs.h>
#include <rdma/rdma_netlink.h>
#include <linux/kthread.h>

#include "siw.h"
#include "siw_verbs.h"

MODULE_AUTHOR("Bernard Metzler");
MODULE_DESCRIPTION("Software iWARP Driver");
MODULE_LICENSE("Dual BSD/GPL");

/* transmit from user buffer, if possible */
const bool zcopy_tx = true;

/* Restrict usage of GSO, if hardware peer iwarp is unable to process
 * large packets. try_gso = true lets siw try to use local GSO,
 * if peer agrees.  Not using GSO severly limits siw maximum tx bandwidth.
 */
const bool try_gso;

/* Attach siw also with loopback devices */
const bool loopback_enabled = true;

/* We try to negotiate CRC on, if true */
const bool mpa_crc_required;

/* MPA CRC on/off enforced */
const bool mpa_crc_strict;

/* Control TCP_NODELAY socket option */
const bool siw_tcp_nagle;

/* Select MPA version to be used during connection setup */
u_char mpa_version = MPA_REVISION_2;

/* Selects MPA P2P mode (additional handshake during connection
 * setup, if true.
 */
const bool peer_to_peer;

struct task_struct *siw_tx_thread[NR_CPUS];

static int siw_device_register(struct siw_device *sdev, const char *name)
{
        struct ib_device *base_dev = &sdev->base_dev;
        static int dev_id = 1;
        int rv;

        sdev->vendor_part_id = dev_id++;

        rv = ib_register_device(base_dev, name, NULL);
        if (rv) {
                pr_warn("siw: device registration error %d\n", rv);
                return rv;
        }

        siw_dbg(base_dev, "HWaddr=%pM\n", sdev->raw_gid);
        return 0;
}

static void siw_device_cleanup(struct ib_device *base_dev)
{
        struct siw_device *sdev = to_siw_dev(base_dev);

        xa_destroy(&sdev->qp_xa);
        xa_destroy(&sdev->mem_xa);
}

static int siw_dev_qualified(struct net_device *netdev)
{
        /*
         * Additional hardware support can be added here
         * (e.g. ARPHRD_FDDI, ARPHRD_ATM, ...) - see
         * <linux/if_arp.h> for type identifiers.
         */
        if (netdev->type == ARPHRD_ETHER || netdev->type == ARPHRD_IEEE802 ||
            netdev->type == ARPHRD_NONE ||
            (netdev->type == ARPHRD_LOOPBACK && loopback_enabled))
                return 1;

        return 0;
}

static DEFINE_PER_CPU(atomic_t, siw_use_cnt);

static struct {
        struct cpumask **tx_valid_cpus;
        int num_nodes;
} siw_cpu_info;

static void siw_destroy_cpulist(int number)
{
        int i = 0;

        while (i < number)
                kfree(siw_cpu_info.tx_valid_cpus[i++]);

        kfree(siw_cpu_info.tx_valid_cpus);
        siw_cpu_info.tx_valid_cpus = NULL;
}

static int siw_init_cpulist(void)
{
        int i, num_nodes = nr_node_ids;

        memset(siw_tx_thread, 0, sizeof(siw_tx_thread));

        siw_cpu_info.num_nodes = num_nodes;

        siw_cpu_info.tx_valid_cpus =
                kcalloc(num_nodes, sizeof(struct cpumask *), GFP_KERNEL);
        if (!siw_cpu_info.tx_valid_cpus) {
                siw_cpu_info.num_nodes = 0;
                return -ENOMEM;
        }
        for (i = 0; i < siw_cpu_info.num_nodes; i++) {
                siw_cpu_info.tx_valid_cpus[i] =
                        kzalloc(sizeof(struct cpumask), GFP_KERNEL);
                if (!siw_cpu_info.tx_valid_cpus[i])
                        goto out_err;

                cpumask_clear(siw_cpu_info.tx_valid_cpus[i]);
        }
        for_each_possible_cpu(i)
                cpumask_set_cpu(i, siw_cpu_info.tx_valid_cpus[cpu_to_node(i)]);

        return 0;

out_err:
        siw_cpu_info.num_nodes = 0;
        siw_destroy_cpulist(i);

        return -ENOMEM;
}

/*
 * Choose CPU with least number of active QP's from NUMA node of
 * TX interface.
 */
int siw_get_tx_cpu(struct siw_device *sdev)
{
        const struct cpumask *tx_cpumask;
        int i, num_cpus, cpu, min_use, node = sdev->numa_node, tx_cpu = -1;

        if (node < 0)
                tx_cpumask = cpu_online_mask;
        else
                tx_cpumask = siw_cpu_info.tx_valid_cpus[node];

        num_cpus = cpumask_weight(tx_cpumask);
        if (!num_cpus) {
                /* no CPU on this NUMA node */
                tx_cpumask = cpu_online_mask;
                num_cpus = cpumask_weight(tx_cpumask);
        }
        if (!num_cpus)
                goto out;

        cpu = cpumask_first(tx_cpumask);

        for (i = 0, min_use = SIW_MAX_QP; i < num_cpus;
             i++, cpu = cpumask_next(cpu, tx_cpumask)) {
                int usage;

                /* Skip any cores which have no TX thread */
                if (!siw_tx_thread[cpu])
                        continue;

                usage = atomic_read(&per_cpu(siw_use_cnt, cpu));
                if (usage <= min_use) {
                        tx_cpu = cpu;
                        min_use = usage;
                }
        }
        siw_dbg(&sdev->base_dev,
                "tx cpu %d, node %d, %d qp's\n", tx_cpu, node, min_use);

out:
        if (tx_cpu >= 0)
                atomic_inc(&per_cpu(siw_use_cnt, tx_cpu));
        else
                pr_warn("siw: no tx cpu found\n");

        return tx_cpu;
}

void siw_put_tx_cpu(int cpu)
{
        atomic_dec(&per_cpu(siw_use_cnt, cpu));
}

static struct ib_qp *siw_get_base_qp(struct ib_device *base_dev, int id)
{
        struct siw_qp *qp = siw_qp_id2obj(to_siw_dev(base_dev), id);

        if (qp) {
                /*
                 * siw_qp_id2obj() increments object reference count
                 */
                siw_qp_put(qp);
                return &qp->base_qp;
        }
        return NULL;
}

static const struct ib_device_ops siw_device_ops = {
        .owner = THIS_MODULE,
        .uverbs_abi_ver = SIW_ABI_VERSION,
        .driver_id = RDMA_DRIVER_SIW,

        .alloc_mr = siw_alloc_mr,
        .alloc_pd = siw_alloc_pd,
        .alloc_ucontext = siw_alloc_ucontext,
        .create_cq = siw_create_cq,
        .create_qp = siw_create_qp,
        .create_srq = siw_create_srq,
        .dealloc_driver = siw_device_cleanup,
        .dealloc_pd = siw_dealloc_pd,
        .dealloc_ucontext = siw_dealloc_ucontext,
        .dereg_mr = siw_dereg_mr,
        .destroy_cq = siw_destroy_cq,
        .destroy_qp = siw_destroy_qp,
        .destroy_srq = siw_destroy_srq,
        .get_dma_mr = siw_get_dma_mr,
        .get_port_immutable = siw_get_port_immutable,
        .iw_accept = siw_accept,
        .iw_add_ref = siw_qp_get_ref,
        .iw_connect = siw_connect,
        .iw_create_listen = siw_create_listen,
        .iw_destroy_listen = siw_destroy_listen,
        .iw_get_qp = siw_get_base_qp,
        .iw_reject = siw_reject,
        .iw_rem_ref = siw_qp_put_ref,
        .map_mr_sg = siw_map_mr_sg,
        .mmap = siw_mmap,
        .mmap_free = siw_mmap_free,
        .modify_qp = siw_verbs_modify_qp,
        .modify_srq = siw_modify_srq,
        .poll_cq = siw_poll_cq,
        .post_recv = siw_post_receive,
        .post_send = siw_post_send,
        .post_srq_recv = siw_post_srq_recv,
        .query_device = siw_query_device,
        .query_gid = siw_query_gid,
        .query_port = siw_query_port,
        .query_qp = siw_query_qp,
        .query_srq = siw_query_srq,
        .req_notify_cq = siw_req_notify_cq,
        .reg_user_mr = siw_reg_user_mr,

        INIT_RDMA_OBJ_SIZE(ib_cq, siw_cq, base_cq),
        INIT_RDMA_OBJ_SIZE(ib_pd, siw_pd, base_pd),
        INIT_RDMA_OBJ_SIZE(ib_qp, siw_qp, base_qp),
        INIT_RDMA_OBJ_SIZE(ib_srq, siw_srq, base_srq),
        INIT_RDMA_OBJ_SIZE(ib_ucontext, siw_ucontext, base_ucontext),
};

static struct siw_device *siw_device_create(struct net_device *netdev)
{
        struct siw_device *sdev = NULL;
        struct ib_device *base_dev;
        int rv;

        sdev = ib_alloc_device(siw_device, base_dev);
        if (!sdev)
                return NULL;

        base_dev = &sdev->base_dev;

        if (netdev->addr_len) {
                memcpy(sdev->raw_gid, netdev->dev_addr,
                       min_t(unsigned int, netdev->addr_len, ETH_ALEN));
        } else {
                /*
                 * This device does not have a HW address, but
                 * connection mangagement requires a unique gid.
                 */
                eth_random_addr(sdev->raw_gid);
        }
        addrconf_addr_eui48((u8 *)&base_dev->node_guid, sdev->raw_gid);

        base_dev->uverbs_cmd_mask |= BIT_ULL(IB_USER_VERBS_CMD_POST_SEND);

        base_dev->node_type = RDMA_NODE_RNIC;
        memcpy(base_dev->node_desc, SIW_NODE_DESC_COMMON,
               sizeof(SIW_NODE_DESC_COMMON));

        /*
         * Current model (one-to-one device association):
         * One Softiwarp device per net_device or, equivalently,
         * per physical port.
         */
        base_dev->phys_port_cnt = 1;
        base_dev->num_comp_vectors = num_possible_cpus();

        xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
        xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);

        ib_set_device_ops(base_dev, &siw_device_ops);
        rv = ib_device_set_netdev(base_dev, netdev, 1);
        if (rv)
                goto error;

        memcpy(base_dev->iw_ifname, netdev->name,
               sizeof(base_dev->iw_ifname));

        /* Disable TCP port mapping */
        base_dev->iw_driver_flags = IW_F_NO_PORT_MAP;

        sdev->attrs.max_qp = SIW_MAX_QP;
        sdev->attrs.max_qp_wr = SIW_MAX_QP_WR;
        sdev->attrs.max_ord = SIW_MAX_ORD_QP;
        sdev->attrs.max_ird = SIW_MAX_IRD_QP;
        sdev->attrs.max_sge = SIW_MAX_SGE;
        sdev->attrs.max_sge_rd = SIW_MAX_SGE_RD;
        sdev->attrs.max_cq = SIW_MAX_CQ;
        sdev->attrs.max_cqe = SIW_MAX_CQE;
        sdev->attrs.max_mr = SIW_MAX_MR;
        sdev->attrs.max_pd = SIW_MAX_PD;
        sdev->attrs.max_mw = SIW_MAX_MW;
        sdev->attrs.max_srq = SIW_MAX_SRQ;
        sdev->attrs.max_srq_wr = SIW_MAX_SRQ_WR;
        sdev->attrs.max_srq_sge = SIW_MAX_SGE;

        INIT_LIST_HEAD(&sdev->cep_list);
        INIT_LIST_HEAD(&sdev->qp_list);

        atomic_set(&sdev->num_ctx, 0);
        atomic_set(&sdev->num_srq, 0);
        atomic_set(&sdev->num_qp, 0);
        atomic_set(&sdev->num_cq, 0);
        atomic_set(&sdev->num_mr, 0);
        atomic_set(&sdev->num_pd, 0);

        sdev->numa_node = dev_to_node(&netdev->dev);
        spin_lock_init(&sdev->lock);

        return sdev;
error:
        ib_dealloc_device(base_dev);

        return NULL;
}

static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
                            void *arg)
{
        struct net_device *netdev = netdev_notifier_info_to_dev(arg);
        struct ib_device *base_dev;
        struct siw_device *sdev;

        dev_dbg(&netdev->dev, "siw: event %lu\n", event);

        base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
        if (!base_dev)
                return NOTIFY_OK;

        sdev = to_siw_dev(base_dev);

        switch (event) {
        case NETDEV_REGISTER:
                /*
                 * Device registration now handled only by
                 * rdma netlink commands. So it shall be impossible
                 * to end up here with a valid siw device.
                 */
                siw_dbg(base_dev, "unexpected NETDEV_REGISTER event\n");
                break;

        case NETDEV_UNREGISTER:
                ib_unregister_device_queued(&sdev->base_dev);
                break;

        case NETDEV_CHANGEADDR:
                siw_port_event(sdev, 1, IB_EVENT_LID_CHANGE);
                break;
        /*
         * All other events are not handled
         */
        default:
                break;
        }
        ib_device_put(&sdev->base_dev);

        return NOTIFY_OK;
}

static struct notifier_block siw_netdev_nb = {
        .notifier_call = siw_netdev_event,
};

static int siw_newlink(const char *basedev_name, struct net_device *netdev)
{
        struct ib_device *base_dev;
        struct siw_device *sdev = NULL;
        int rv = -ENOMEM;

        if (!siw_dev_qualified(netdev))
                return -EINVAL;

        base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
        if (base_dev) {
                ib_device_put(base_dev);
                return -EEXIST;
        }
        sdev = siw_device_create(netdev);
        if (sdev) {
                dev_dbg(&netdev->dev, "siw: new device\n");
                ib_mark_name_assigned_by_user(&sdev->base_dev);
                rv = siw_device_register(sdev, basedev_name);
                if (rv)
                        ib_dealloc_device(&sdev->base_dev);
        }
        return rv;
}

static struct rdma_link_ops siw_link_ops = {
        .type = "siw",
        .newlink = siw_newlink,
};

/*
 * siw_init_module - Initialize Softiwarp module and register with netdev
 *                   subsystem.
 */
static __init int siw_init_module(void)
{
        int rv;

        if (SENDPAGE_THRESH < SIW_MAX_INLINE) {
                pr_info("siw: sendpage threshold too small: %u\n",
                        (int)SENDPAGE_THRESH);
                rv = -EINVAL;
                goto out_error;
        }
        rv = siw_init_cpulist();
        if (rv)
                goto out_error;

        rv = siw_cm_init();
        if (rv)
                goto out_error;

        if (!siw_create_tx_threads()) {
                pr_info("siw: Could not start any TX thread\n");
                rv = -ENOMEM;
                goto out_error;
        }

        rv = register_netdevice_notifier(&siw_netdev_nb);
        if (rv)
                goto out_error;

        rdma_link_register(&siw_link_ops);

        pr_info("SoftiWARP attached\n");
        return 0;

out_error:
        siw_stop_tx_threads();

        pr_info("SoftIWARP attach failed. Error: %d\n", rv);

        siw_cm_exit();
        siw_destroy_cpulist(siw_cpu_info.num_nodes);

        return rv;
}

static void __exit siw_exit_module(void)
{
        siw_stop_tx_threads();

        unregister_netdevice_notifier(&siw_netdev_nb);
        rdma_link_unregister(&siw_link_ops);
        ib_unregister_driver(RDMA_DRIVER_SIW);

        siw_cm_exit();

        siw_destroy_cpulist(siw_cpu_info.num_nodes);

        pr_info("SoftiWARP detached\n");
}

module_init(siw_init_module);
module_exit(siw_exit_module);

MODULE_ALIAS_RDMA_LINK("siw");


















































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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __MEMTYPE_H_
#define __MEMTYPE_H_

extern int pat_debug_enable;

#define dprintk(fmt, arg...) \
        do { if (pat_debug_enable) pr_info("x86/PAT: " fmt, ##arg); } while (0)

struct memtype {
        u64                        start;
        u64                        end;
        u64                        subtree_max_end;
        enum page_cache_mode        type;
        struct rb_node                rb;
};

static inline char *cattr_name(enum page_cache_mode pcm)
{
        switch (pcm) {
        case _PAGE_CACHE_MODE_UC:                return "uncached";
        case _PAGE_CACHE_MODE_UC_MINUS:                return "uncached-minus";
        case _PAGE_CACHE_MODE_WB:                return "write-back";
        case _PAGE_CACHE_MODE_WC:                return "write-combining";
        case _PAGE_CACHE_MODE_WT:                return "write-through";
        case _PAGE_CACHE_MODE_WP:                return "write-protected";
        default:                                return "broken";
        }
}

#ifdef CONFIG_X86_PAT
extern int memtype_check_insert(struct memtype *entry_new,
                                enum page_cache_mode *new_type);
extern struct memtype *memtype_erase(u64 start, u64 end);
extern struct memtype *memtype_lookup(u64 addr);
extern int memtype_copy_nth_element(struct memtype *entry_out, loff_t pos);
#else
static inline int memtype_check_insert(struct memtype *entry_new,
                                       enum page_cache_mode *new_type)
{ return 0; }
static inline struct memtype *memtype_erase(u64 start, u64 end)
{ return NULL; }
static inline struct memtype *memtype_lookup(u64 addr)
{ return NULL; }
static inline int memtype_copy_nth_element(struct memtype *out, loff_t pos)
{ return 0; }
#endif

#endif /* __MEMTYPE_H_ */






































































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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2010-2011 EIA Electronics,
//                         Pieter Beyens <pieter.beyens@eia.be>
// Copyright (c) 2010-2011 EIA Electronics,
//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
// Copyright (c) 2018 Protonic,
//                         Robin van der Gracht <robin@protonic.nl>
// Copyright (c) 2017-2019 Pengutronix,
//                         Marc Kleine-Budde <kernel@pengutronix.de>
// Copyright (c) 2017-2019 Pengutronix,
//                         Oleksij Rempel <kernel@pengutronix.de>

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/can/can-ml.h>
#include <linux/can/core.h>
#include <linux/can/skb.h>
#include <linux/errqueue.h>
#include <linux/if_arp.h>

#include "j1939-priv.h"

#define J1939_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.j1939)

/* conversion function between struct sock::sk_priority from linux and
 * j1939 priority field
 */
static inline priority_t j1939_prio(u32 sk_priority)
{
        sk_priority = min(sk_priority, 7U);

        return 7 - sk_priority;
}

static inline u32 j1939_to_sk_priority(priority_t prio)
{
        return 7 - prio;
}

/* function to see if pgn is to be evaluated */
static inline bool j1939_pgn_is_valid(pgn_t pgn)
{
        return pgn <= J1939_PGN_MAX;
}

/* test function to avoid non-zero DA placeholder for pdu1 pgn's */
static inline bool j1939_pgn_is_clean_pdu(pgn_t pgn)
{
        if (j1939_pgn_is_pdu1(pgn))
                return !(pgn & 0xff);
        else
                return true;
}

static inline void j1939_sock_pending_add(struct sock *sk)
{
        struct j1939_sock *jsk = j1939_sk(sk);

        atomic_inc(&jsk->skb_pending);
}

static int j1939_sock_pending_get(struct sock *sk)
{
        struct j1939_sock *jsk = j1939_sk(sk);

        return atomic_read(&jsk->skb_pending);
}

void j1939_sock_pending_del(struct sock *sk)
{
        struct j1939_sock *jsk = j1939_sk(sk);

        /* atomic_dec_return returns the new value */
        if (!atomic_dec_return(&jsk->skb_pending))
                wake_up(&jsk->waitq);        /* no pending SKB's */
}

static void j1939_jsk_add(struct j1939_priv *priv, struct j1939_sock *jsk)
{
        jsk->state |= J1939_SOCK_BOUND;
        j1939_priv_get(priv);

        write_lock_bh(&priv->j1939_socks_lock);
        list_add_tail(&jsk->list, &priv->j1939_socks);
        write_unlock_bh(&priv->j1939_socks_lock);
}

static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
{
        write_lock_bh(&priv->j1939_socks_lock);
        list_del_init(&jsk->list);
        write_unlock_bh(&priv->j1939_socks_lock);

        j1939_priv_put(priv);
        jsk->state &= ~J1939_SOCK_BOUND;
}

static bool j1939_sk_queue_session(struct j1939_session *session)
{
        struct j1939_sock *jsk = j1939_sk(session->sk);
        bool empty;

        spin_lock_bh(&jsk->sk_session_queue_lock);
        empty = list_empty(&jsk->sk_session_queue);
        j1939_session_get(session);
        list_add_tail(&session->sk_session_queue_entry, &jsk->sk_session_queue);
        spin_unlock_bh(&jsk->sk_session_queue_lock);
        j1939_sock_pending_add(&jsk->sk);

        return empty;
}

static struct
j1939_session *j1939_sk_get_incomplete_session(struct j1939_sock *jsk)
{
        struct j1939_session *session = NULL;

        spin_lock_bh(&jsk->sk_session_queue_lock);
        if (!list_empty(&jsk->sk_session_queue)) {
                session = list_last_entry(&jsk->sk_session_queue,
                                          struct j1939_session,
                                          sk_session_queue_entry);
                if (session->total_queued_size == session->total_message_size)
                        session = NULL;
                else
                        j1939_session_get(session);
        }
        spin_unlock_bh(&jsk->sk_session_queue_lock);

        return session;
}

static void j1939_sk_queue_drop_all(struct j1939_priv *priv,
                                    struct j1939_sock *jsk, int err)
{
        struct j1939_session *session, *tmp;

        netdev_dbg(priv->ndev, "%s: err: %i\n", __func__, err);
        spin_lock_bh(&jsk->sk_session_queue_lock);
        list_for_each_entry_safe(session, tmp, &jsk->sk_session_queue,
                                 sk_session_queue_entry) {
                list_del_init(&session->sk_session_queue_entry);
                session->err = err;
                j1939_session_put(session);
        }
        spin_unlock_bh(&jsk->sk_session_queue_lock);
}

static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
{
        struct j1939_sock *jsk;
        struct j1939_session *first;
        int err;

        /* RX-Session don't have a socket (yet) */
        if (!session->sk)
                return;

        jsk = j1939_sk(session->sk);
        lockdep_assert_held(&jsk->sk_session_queue_lock);

        err = session->err;

        first = list_first_entry_or_null(&jsk->sk_session_queue,
                                         struct j1939_session,
                                         sk_session_queue_entry);

        /* Some else has already activated the next session */
        if (first != session)
                return;

activate_next:
        list_del_init(&first->sk_session_queue_entry);
        j1939_session_put(first);
        first = list_first_entry_or_null(&jsk->sk_session_queue,
                                         struct j1939_session,
                                         sk_session_queue_entry);
        if (!first)
                return;

        if (j1939_session_activate(first)) {
                netdev_warn_once(first->priv->ndev,
                                 "%s: 0x%p: Identical session is already activated.\n",
                                 __func__, first);
                first->err = -EBUSY;
                goto activate_next;
        } else {
                /* Give receiver some time (arbitrary chosen) to recover */
                int time_ms = 0;

                if (err)
                        time_ms = 10 + get_random_u32_below(16);

                j1939_tp_schedule_txtimer(first, time_ms);
        }
}

void j1939_sk_queue_activate_next(struct j1939_session *session)
{
        struct j1939_sock *jsk;

        if (!session->sk)
                return;

        jsk = j1939_sk(session->sk);

        spin_lock_bh(&jsk->sk_session_queue_lock);
        j1939_sk_queue_activate_next_locked(session);
        spin_unlock_bh(&jsk->sk_session_queue_lock);
}

static bool j1939_sk_match_dst(struct j1939_sock *jsk,
                               const struct j1939_sk_buff_cb *skcb)
{
        if ((jsk->state & J1939_SOCK_PROMISC))
                return true;

        /* Destination address filter */
        if (jsk->addr.src_name && skcb->addr.dst_name) {
                if (jsk->addr.src_name != skcb->addr.dst_name)
                        return false;
        } else {
                /* receive (all sockets) if
                 * - all packages that match our bind() address
                 * - all broadcast on a socket if SO_BROADCAST
                 *   is set
                 */
                if (j1939_address_is_unicast(skcb->addr.da)) {
                        if (jsk->addr.sa != skcb->addr.da)
                                return false;
                } else if (!sock_flag(&jsk->sk, SOCK_BROADCAST)) {
                        /* receiving broadcast without SO_BROADCAST
                         * flag is not allowed
                         */
                        return false;
                }
        }

        /* Source address filter */
        if (jsk->state & J1939_SOCK_CONNECTED) {
                /* receive (all sockets) if
                 * - all packages that match our connect() name or address
                 */
                if (jsk->addr.dst_name && skcb->addr.src_name) {
                        if (jsk->addr.dst_name != skcb->addr.src_name)
                                return false;
                } else {
                        if (jsk->addr.da != skcb->addr.sa)
                                return false;
                }
        }

        /* PGN filter */
        if (j1939_pgn_is_valid(jsk->pgn_rx_filter) &&
            jsk->pgn_rx_filter != skcb->addr.pgn)
                return false;

        return true;
}

/* matches skb control buffer (addr) with a j1939 filter */
static bool j1939_sk_match_filter(struct j1939_sock *jsk,
                                  const struct j1939_sk_buff_cb *skcb)
{
        const struct j1939_filter *f;
        int nfilter;

        spin_lock_bh(&jsk->filters_lock);

        f = jsk->filters;
        nfilter = jsk->nfilters;

        if (!nfilter)
                /* receive all when no filters are assigned */
                goto filter_match_found;

        for (; nfilter; ++f, --nfilter) {
                if ((skcb->addr.pgn & f->pgn_mask) != f->pgn)
                        continue;
                if ((skcb->addr.sa & f->addr_mask) != f->addr)
                        continue;
                if ((skcb->addr.src_name & f->name_mask) != f->name)
                        continue;
                goto filter_match_found;
        }

        spin_unlock_bh(&jsk->filters_lock);
        return false;

filter_match_found:
        spin_unlock_bh(&jsk->filters_lock);
        return true;
}

static bool j1939_sk_recv_match_one(struct j1939_sock *jsk,
                                    const struct j1939_sk_buff_cb *skcb)
{
        if (!(jsk->state & J1939_SOCK_BOUND))
                return false;

        if (!j1939_sk_match_dst(jsk, skcb))
                return false;

        if (!j1939_sk_match_filter(jsk, skcb))
                return false;

        return true;
}

static void j1939_sk_recv_one(struct j1939_sock *jsk, struct sk_buff *oskb)
{
        const struct j1939_sk_buff_cb *oskcb = j1939_skb_to_cb(oskb);
        struct j1939_sk_buff_cb *skcb;
        enum skb_drop_reason reason;
        struct sk_buff *skb;

        if (oskb->sk == &jsk->sk)
                return;

        if (!j1939_sk_recv_match_one(jsk, oskcb))
                return;

        skb = skb_clone(oskb, GFP_ATOMIC);
        if (!skb) {
                pr_warn("skb clone failed\n");
                return;
        }
        can_skb_set_owner(skb, oskb->sk);

        skcb = j1939_skb_to_cb(skb);
        skcb->msg_flags &= ~(MSG_DONTROUTE);
        if (skb->sk)
                skcb->msg_flags |= MSG_DONTROUTE;

        if (sock_queue_rcv_skb_reason(&jsk->sk, skb, &reason) < 0)
                sk_skb_reason_drop(&jsk->sk, skb, reason);
}

bool j1939_sk_recv_match(struct j1939_priv *priv, struct j1939_sk_buff_cb *skcb)
{
        struct j1939_sock *jsk;
        bool match = false;

        read_lock_bh(&priv->j1939_socks_lock);
        list_for_each_entry(jsk, &priv->j1939_socks, list) {
                match = j1939_sk_recv_match_one(jsk, skcb);
                if (match)
                        break;
        }
        read_unlock_bh(&priv->j1939_socks_lock);

        return match;
}

void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
{
        struct j1939_sock *jsk;

        read_lock_bh(&priv->j1939_socks_lock);
        list_for_each_entry(jsk, &priv->j1939_socks, list) {
                j1939_sk_recv_one(jsk, skb);
        }
        read_unlock_bh(&priv->j1939_socks_lock);
}

static void j1939_sk_sock_destruct(struct sock *sk)
{
        struct j1939_sock *jsk = j1939_sk(sk);

        /* This function will be called by the generic networking code, when
         * the socket is ultimately closed (sk->sk_destruct).
         *
         * The race between
         * - processing a received CAN frame
         *   (can_receive -> j1939_can_recv)
         *   and accessing j1939_priv
         * ... and ...
         * - closing a socket
         *   (j1939_can_rx_unregister -> can_rx_unregister)
         *   and calling the final j1939_priv_put()
         *
         * is avoided by calling the final j1939_priv_put() from this
         * RCU deferred cleanup call.
         */
        if (jsk->priv) {
                j1939_priv_put(jsk->priv);
                jsk->priv = NULL;
        }

        /* call generic CAN sock destruct */
        can_sock_destruct(sk);
}

static int j1939_sk_init(struct sock *sk)
{
        struct j1939_sock *jsk = j1939_sk(sk);

        /* Ensure that "sk" is first member in "struct j1939_sock", so that we
         * can skip it during memset().
         */
        BUILD_BUG_ON(offsetof(struct j1939_sock, sk) != 0);
        memset((void *)jsk + sizeof(jsk->sk), 0x0,
               sizeof(*jsk) - sizeof(jsk->sk));

        INIT_LIST_HEAD(&jsk->list);
        init_waitqueue_head(&jsk->waitq);
        jsk->sk.sk_priority = j1939_to_sk_priority(6);
        jsk->sk.sk_reuse = 1; /* per default */
        jsk->addr.sa = J1939_NO_ADDR;
        jsk->addr.da = J1939_NO_ADDR;
        jsk->addr.pgn = J1939_NO_PGN;
        jsk->pgn_rx_filter = J1939_NO_PGN;
        atomic_set(&jsk->skb_pending, 0);
        spin_lock_init(&jsk->sk_session_queue_lock);
        INIT_LIST_HEAD(&jsk->sk_session_queue);
        spin_lock_init(&jsk->filters_lock);

        /* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */
        sock_set_flag(sk, SOCK_RCU_FREE);
        sk->sk_destruct = j1939_sk_sock_destruct;
        sk->sk_protocol = CAN_J1939;

        return 0;
}

static int j1939_sk_sanity_check(struct sockaddr_can *addr, int len)
{
        if (!addr)
                return -EDESTADDRREQ;
        if (len < J1939_MIN_NAMELEN)
                return -EINVAL;
        if (addr->can_family != AF_CAN)
                return -EINVAL;
        if (!addr->can_ifindex)
                return -ENODEV;
        if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
            !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
                return -EINVAL;

        return 0;
}

static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len)
{
        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
        struct j1939_sock *jsk = j1939_sk(sock->sk);
        struct j1939_priv *priv;
        struct sock *sk;
        struct net *net;
        int ret = 0;

        ret = j1939_sk_sanity_check(addr, len);
        if (ret)
                return ret;

        lock_sock(sock->sk);

        priv = jsk->priv;
        sk = sock->sk;
        net = sock_net(sk);

        /* Already bound to an interface? */
        if (jsk->state & J1939_SOCK_BOUND) {
                /* A re-bind() to a different interface is not
                 * supported.
                 */
                if (jsk->ifindex != addr->can_ifindex) {
                        ret = -EINVAL;
                        goto out_release_sock;
                }

                /* drop old references */
                j1939_jsk_del(priv, jsk);
                j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
        } else {
                struct can_ml_priv *can_ml;
                struct net_device *ndev;

                ndev = dev_get_by_index(net, addr->can_ifindex);
                if (!ndev) {
                        ret = -ENODEV;
                        goto out_release_sock;
                }

                can_ml = can_get_ml_priv(ndev);
                if (!can_ml) {
                        dev_put(ndev);
                        ret = -ENODEV;
                        goto out_release_sock;
                }

                if (!(ndev->flags & IFF_UP)) {
                        dev_put(ndev);
                        ret = -ENETDOWN;
                        goto out_release_sock;
                }

                priv = j1939_netdev_start(ndev);
                dev_put(ndev);
                if (IS_ERR(priv)) {
                        ret = PTR_ERR(priv);
                        goto out_release_sock;
                }

                jsk->ifindex = addr->can_ifindex;

                /* the corresponding j1939_priv_put() is called via
                 * sk->sk_destruct, which points to j1939_sk_sock_destruct()
                 */
                j1939_priv_get(priv);
                jsk->priv = priv;
        }

        /* set default transmit pgn */
        if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
                jsk->pgn_rx_filter = addr->can_addr.j1939.pgn;
        jsk->addr.src_name = addr->can_addr.j1939.name;
        jsk->addr.sa = addr->can_addr.j1939.addr;

        /* get new references */
        ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa);
        if (ret) {
                j1939_netdev_stop(priv);
                jsk->priv = NULL;
                synchronize_rcu();
                j1939_priv_put(priv);
                goto out_release_sock;
        }

        j1939_jsk_add(priv, jsk);

 out_release_sock: /* fall through */
        release_sock(sock->sk);

        return ret;
}

static int j1939_sk_connect(struct socket *sock, struct sockaddr *uaddr,
                            int len, int flags)
{
        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
        struct j1939_sock *jsk = j1939_sk(sock->sk);
        int ret = 0;

        ret = j1939_sk_sanity_check(addr, len);
        if (ret)
                return ret;

        lock_sock(sock->sk);

        /* bind() before connect() is mandatory */
        if (!(jsk->state & J1939_SOCK_BOUND)) {
                ret = -EINVAL;
                goto out_release_sock;
        }

        /* A connect() to a different interface is not supported. */
        if (jsk->ifindex != addr->can_ifindex) {
                ret = -EINVAL;
                goto out_release_sock;
        }

        if (!addr->can_addr.j1939.name &&
            addr->can_addr.j1939.addr == J1939_NO_ADDR &&
            !sock_flag(&jsk->sk, SOCK_BROADCAST)) {
                /* broadcast, but SO_BROADCAST not set */
                ret = -EACCES;
                goto out_release_sock;
        }

        jsk->addr.dst_name = addr->can_addr.j1939.name;
        jsk->addr.da = addr->can_addr.j1939.addr;

        if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
                jsk->addr.pgn = addr->can_addr.j1939.pgn;

        jsk->state |= J1939_SOCK_CONNECTED;

 out_release_sock: /* fall through */
        release_sock(sock->sk);

        return ret;
}

static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
                                       const struct j1939_sock *jsk, int peer)
{
        /* There are two holes (2 bytes and 3 bytes) to clear to avoid
         * leaking kernel information to user space.
         */
        memset(addr, 0, J1939_MIN_NAMELEN);

        addr->can_family = AF_CAN;
        addr->can_ifindex = jsk->ifindex;
        addr->can_addr.j1939.pgn = jsk->addr.pgn;
        if (peer) {
                addr->can_addr.j1939.name = jsk->addr.dst_name;
                addr->can_addr.j1939.addr = jsk->addr.da;
        } else {
                addr->can_addr.j1939.name = jsk->addr.src_name;
                addr->can_addr.j1939.addr = jsk->addr.sa;
        }
}

static int j1939_sk_getname(struct socket *sock, struct sockaddr *uaddr,
                            int peer)
{
        struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
        struct sock *sk = sock->sk;
        struct j1939_sock *jsk = j1939_sk(sk);
        int ret = 0;

        lock_sock(sk);

        if (peer && !(jsk->state & J1939_SOCK_CONNECTED)) {
                ret = -EADDRNOTAVAIL;
                goto failure;
        }

        j1939_sk_sock2sockaddr_can(addr, jsk, peer);
        ret = J1939_MIN_NAMELEN;

 failure:
        release_sock(sk);

        return ret;
}

static int j1939_sk_release(struct socket *sock)
{
        struct sock *sk = sock->sk;
        struct j1939_sock *jsk;

        if (!sk)
                return 0;

        lock_sock(sk);
        jsk = j1939_sk(sk);

        if (jsk->state & J1939_SOCK_BOUND) {
                struct j1939_priv *priv = jsk->priv;

                if (wait_event_interruptible(jsk->waitq,
                                             !j1939_sock_pending_get(&jsk->sk))) {
                        j1939_cancel_active_session(priv, sk);
                        j1939_sk_queue_drop_all(priv, jsk, ESHUTDOWN);
                }

                j1939_jsk_del(priv, jsk);

                j1939_local_ecu_put(priv, jsk->addr.src_name,
                                    jsk->addr.sa);

                j1939_netdev_stop(priv);
        }

        kfree(jsk->filters);
        sock_orphan(sk);
        sock->sk = NULL;

        release_sock(sk);
        sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
        sock_put(sk);

        return 0;
}

static int j1939_sk_setsockopt_flag(struct j1939_sock *jsk, sockptr_t optval,
                                    unsigned int optlen, int flag)
{
        int tmp;

        if (optlen != sizeof(tmp))
                return -EINVAL;
        if (copy_from_sockptr(&tmp, optval, optlen))
                return -EFAULT;
        lock_sock(&jsk->sk);
        if (tmp)
                jsk->state |= flag;
        else
                jsk->state &= ~flag;
        release_sock(&jsk->sk);
        return tmp;
}

static int j1939_sk_setsockopt(struct socket *sock, int level, int optname,
                               sockptr_t optval, unsigned int optlen)
{
        struct sock *sk = sock->sk;
        struct j1939_sock *jsk = j1939_sk(sk);
        int tmp, count = 0, ret = 0;
        struct j1939_filter *filters = NULL, *ofilters;

        if (level != SOL_CAN_J1939)
                return -EINVAL;

        switch (optname) {
        case SO_J1939_FILTER:
                if (!sockptr_is_null(optval) && optlen != 0) {
                        struct j1939_filter *f;
                        int c;

                        if (optlen % sizeof(*filters) != 0)
                                return -EINVAL;

                        if (optlen > J1939_FILTER_MAX *
                            sizeof(struct j1939_filter))
                                return -EINVAL;

                        count = optlen / sizeof(*filters);
                        filters = memdup_sockptr(optval, optlen);
                        if (IS_ERR(filters))
                                return PTR_ERR(filters);

                        for (f = filters, c = count; c; f++, c--) {
                                f->name &= f->name_mask;
                                f->pgn &= f->pgn_mask;
                                f->addr &= f->addr_mask;
                        }
                }

                lock_sock(&jsk->sk);
                spin_lock_bh(&jsk->filters_lock);
                ofilters = jsk->filters;
                jsk->filters = filters;
                jsk->nfilters = count;
                spin_unlock_bh(&jsk->filters_lock);
                release_sock(&jsk->sk);
                kfree(ofilters);
                return 0;
        case SO_J1939_PROMISC:
                return j1939_sk_setsockopt_flag(jsk, optval, optlen,
                                                J1939_SOCK_PROMISC);
        case SO_J1939_ERRQUEUE:
                ret = j1939_sk_setsockopt_flag(jsk, optval, optlen,
                                               J1939_SOCK_ERRQUEUE);
                if (ret < 0)
                        return ret;

                if (!(jsk->state & J1939_SOCK_ERRQUEUE))
                        skb_queue_purge(&sk->sk_error_queue);
                return ret;
        case SO_J1939_SEND_PRIO:
                if (optlen != sizeof(tmp))
                        return -EINVAL;
                if (copy_from_sockptr(&tmp, optval, optlen))
                        return -EFAULT;
                if (tmp < 0 || tmp > 7)
                        return -EDOM;
                if (tmp < 2 && !capable(CAP_NET_ADMIN))
                        return -EPERM;
                lock_sock(&jsk->sk);
                jsk->sk.sk_priority = j1939_to_sk_priority(tmp);
                release_sock(&jsk->sk);
                return 0;
        default:
                return -ENOPROTOOPT;
        }
}

static int j1939_sk_getsockopt(struct socket *sock, int level, int optname,
                               char __user *optval, int __user *optlen)
{
        struct sock *sk = sock->sk;
        struct j1939_sock *jsk = j1939_sk(sk);
        int ret, ulen;
        /* set defaults for using 'int' properties */
        int tmp = 0;
        int len = sizeof(tmp);
        void *val = &tmp;

        if (level != SOL_CAN_J1939)
                return -EINVAL;
        if (get_user(ulen, optlen))
                return -EFAULT;
        if (ulen < 0)
                return -EINVAL;

        lock_sock(&jsk->sk);
        switch (optname) {
        case SO_J1939_PROMISC:
                tmp = (jsk->state & J1939_SOCK_PROMISC) ? 1 : 0;
                break;
        case SO_J1939_ERRQUEUE:
                tmp = (jsk->state & J1939_SOCK_ERRQUEUE) ? 1 : 0;
                break;
        case SO_J1939_SEND_PRIO:
                tmp = j1939_prio(jsk->sk.sk_priority);
                break;
        default:
                ret = -ENOPROTOOPT;
                goto no_copy;
        }

        /* copy to user, based on 'len' & 'val'
         * but most sockopt's are 'int' properties, and have 'len' & 'val'
         * left unchanged, but instead modified 'tmp'
         */
        if (len > ulen)
                ret = -EFAULT;
        else if (put_user(len, optlen))
                ret = -EFAULT;
        else if (copy_to_user(optval, val, len))
                ret = -EFAULT;
        else
                ret = 0;
 no_copy:
        release_sock(&jsk->sk);
        return ret;
}

static int j1939_sk_recvmsg(struct socket *sock, struct msghdr *msg,
                            size_t size, int flags)
{
        struct sock *sk = sock->sk;
        struct sk_buff *skb;
        struct j1939_sk_buff_cb *skcb;
        int ret = 0;

        if (flags & ~(MSG_DONTWAIT | MSG_ERRQUEUE | MSG_CMSG_COMPAT))
                return -EINVAL;

        if (flags & MSG_ERRQUEUE)
                return sock_recv_errqueue(sock->sk, msg, size, SOL_CAN_J1939,
                                          SCM_J1939_ERRQUEUE);

        skb = skb_recv_datagram(sk, flags, &ret);
        if (!skb)
                return ret;

        if (size < skb->len)
                msg->msg_flags |= MSG_TRUNC;
        else
                size = skb->len;

        ret = memcpy_to_msg(msg, skb->data, size);
        if (ret < 0) {
                skb_free_datagram(sk, skb);
                return ret;
        }

        skcb = j1939_skb_to_cb(skb);
        if (j1939_address_is_valid(skcb->addr.da))
                put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_ADDR,
                         sizeof(skcb->addr.da), &skcb->addr.da);

        if (skcb->addr.dst_name)
                put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_NAME,
                         sizeof(skcb->addr.dst_name), &skcb->addr.dst_name);

        put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_PRIO,
                 sizeof(skcb->priority), &skcb->priority);

        if (msg->msg_name) {
                struct sockaddr_can *paddr = msg->msg_name;

                msg->msg_namelen = J1939_MIN_NAMELEN;
                memset(msg->msg_name, 0, msg->msg_namelen);
                paddr->can_family = AF_CAN;
                paddr->can_ifindex = skb->skb_iif;
                paddr->can_addr.j1939.name = skcb->addr.src_name;
                paddr->can_addr.j1939.addr = skcb->addr.sa;
                paddr->can_addr.j1939.pgn = skcb->addr.pgn;
        }

        sock_recv_cmsgs(msg, sk, skb);
        msg->msg_flags |= skcb->msg_flags;
        skb_free_datagram(sk, skb);

        return size;
}

static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
                                          struct sock *sk,
                                          struct msghdr *msg, size_t size,
                                          int *errcode)
{
        struct j1939_sock *jsk = j1939_sk(sk);
        struct j1939_sk_buff_cb *skcb;
        struct sk_buff *skb;
        int ret;

        skb = sock_alloc_send_skb(sk,
                                  size +
                                  sizeof(struct can_frame) -
                                  sizeof(((struct can_frame *)NULL)->data) +
                                  sizeof(struct can_skb_priv),
                                  msg->msg_flags & MSG_DONTWAIT, &ret);
        if (!skb)
                goto failure;

        can_skb_reserve(skb);
        can_skb_prv(skb)->ifindex = ndev->ifindex;
        can_skb_prv(skb)->skbcnt = 0;
        skb_reserve(skb, offsetof(struct can_frame, data));

        ret = memcpy_from_msg(skb_put(skb, size), msg, size);
        if (ret < 0)
                goto free_skb;

        skb->dev = ndev;

        skcb = j1939_skb_to_cb(skb);
        memset(skcb, 0, sizeof(*skcb));
        skcb->addr = jsk->addr;
        skcb->priority = j1939_prio(READ_ONCE(sk->sk_priority));

        if (msg->msg_name) {
                struct sockaddr_can *addr = msg->msg_name;

                if (addr->can_addr.j1939.name ||
                    addr->can_addr.j1939.addr != J1939_NO_ADDR) {
                        skcb->addr.dst_name = addr->can_addr.j1939.name;
                        skcb->addr.da = addr->can_addr.j1939.addr;
                }
                if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
                        skcb->addr.pgn = addr->can_addr.j1939.pgn;
        }

        *errcode = ret;
        return skb;

free_skb:
        kfree_skb(skb);
failure:
        *errcode = ret;
        return NULL;
}

static size_t j1939_sk_opt_stats_get_size(enum j1939_sk_errqueue_type type)
{
        switch (type) {
        case J1939_ERRQUEUE_RX_RTS:
                return
                        nla_total_size(sizeof(u32)) + /* J1939_NLA_TOTAL_SIZE */
                        nla_total_size(sizeof(u32)) + /* J1939_NLA_PGN */
                        nla_total_size(sizeof(u64)) + /* J1939_NLA_SRC_NAME */
                        nla_total_size(sizeof(u64)) + /* J1939_NLA_DEST_NAME */
                        nla_total_size(sizeof(u8)) +  /* J1939_NLA_SRC_ADDR */
                        nla_total_size(sizeof(u8)) +  /* J1939_NLA_DEST_ADDR */
                        0;
        default:
                return
                        nla_total_size(sizeof(u32)) + /* J1939_NLA_BYTES_ACKED */
                        0;
        }
}

static struct sk_buff *
j1939_sk_get_timestamping_opt_stats(struct j1939_session *session,
                                    enum j1939_sk_errqueue_type type)
{
        struct sk_buff *stats;
        u32 size;

        stats = alloc_skb(j1939_sk_opt_stats_get_size(type), GFP_ATOMIC);
        if (!stats)
                return NULL;

        if (session->skcb.addr.type == J1939_SIMPLE)
                size = session->total_message_size;
        else
                size = min(session->pkt.tx_acked * 7,
                           session->total_message_size);

        switch (type) {
        case J1939_ERRQUEUE_RX_RTS:
                nla_put_u32(stats, J1939_NLA_TOTAL_SIZE,
                            session->total_message_size);
                nla_put_u32(stats, J1939_NLA_PGN,
                            session->skcb.addr.pgn);
                nla_put_u64_64bit(stats, J1939_NLA_SRC_NAME,
                                  session->skcb.addr.src_name, J1939_NLA_PAD);
                nla_put_u64_64bit(stats, J1939_NLA_DEST_NAME,
                                  session->skcb.addr.dst_name, J1939_NLA_PAD);
                nla_put_u8(stats, J1939_NLA_SRC_ADDR,
                           session->skcb.addr.sa);
                nla_put_u8(stats, J1939_NLA_DEST_ADDR,
                           session->skcb.addr.da);
                break;
        default:
                nla_put_u32(stats, J1939_NLA_BYTES_ACKED, size);
        }

        return stats;
}

static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
                                enum j1939_sk_errqueue_type type)
{
        struct j1939_priv *priv = session->priv;
        struct j1939_sock *jsk;
        struct sock_exterr_skb *serr;
        struct sk_buff *skb;
        char *state = "UNK";
        u32 tsflags;
        int err;

        jsk = j1939_sk(sk);

        if (!(jsk->state & J1939_SOCK_ERRQUEUE))
                return;

        tsflags = READ_ONCE(sk->sk_tsflags);
        switch (type) {
        case J1939_ERRQUEUE_TX_ACK:
                if (!(tsflags & SOF_TIMESTAMPING_TX_ACK))
                        return;
                break;
        case J1939_ERRQUEUE_TX_SCHED:
                if (!(tsflags & SOF_TIMESTAMPING_TX_SCHED))
                        return;
                break;
        case J1939_ERRQUEUE_TX_ABORT:
                break;
        case J1939_ERRQUEUE_RX_RTS:
                fallthrough;
        case J1939_ERRQUEUE_RX_DPO:
                fallthrough;
        case J1939_ERRQUEUE_RX_ABORT:
                if (!(tsflags & SOF_TIMESTAMPING_RX_SOFTWARE))
                        return;
                break;
        default:
                netdev_err(priv->ndev, "Unknown errqueue type %i\n", type);
        }

        skb = j1939_sk_get_timestamping_opt_stats(session, type);
        if (!skb)
                return;

        skb->tstamp = ktime_get_real();

        BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));

        serr = SKB_EXT_ERR(skb);
        memset(serr, 0, sizeof(*serr));
        switch (type) {
        case J1939_ERRQUEUE_TX_ACK:
                serr->ee.ee_errno = ENOMSG;
                serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
                serr->ee.ee_info = SCM_TSTAMP_ACK;
                state = "TX ACK";
                break;
        case J1939_ERRQUEUE_TX_SCHED:
                serr->ee.ee_errno = ENOMSG;
                serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
                serr->ee.ee_info = SCM_TSTAMP_SCHED;
                state = "TX SCH";
                break;
        case J1939_ERRQUEUE_TX_ABORT:
                serr->ee.ee_errno = session->err;
                serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
                serr->ee.ee_info = J1939_EE_INFO_TX_ABORT;
                state = "TX ABT";
                break;
        case J1939_ERRQUEUE_RX_RTS:
                serr->ee.ee_errno = ENOMSG;
                serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
                serr->ee.ee_info = J1939_EE_INFO_RX_RTS;
                state = "RX RTS";
                break;
        case J1939_ERRQUEUE_RX_DPO:
                serr->ee.ee_errno = ENOMSG;
                serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
                serr->ee.ee_info = J1939_EE_INFO_RX_DPO;
                state = "RX DPO";
                break;
        case J1939_ERRQUEUE_RX_ABORT:
                serr->ee.ee_errno = session->err;
                serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
                serr->ee.ee_info = J1939_EE_INFO_RX_ABORT;
                state = "RX ABT";
                break;
        }

        serr->opt_stats = true;
        if (tsflags & SOF_TIMESTAMPING_OPT_ID)
                serr->ee.ee_data = session->tskey;

        netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",
                   __func__, session, session->tskey, state);
        err = sock_queue_err_skb(sk, skb);

        if (err)
                kfree_skb(skb);
};

void j1939_sk_errqueue(struct j1939_session *session,
                       enum j1939_sk_errqueue_type type)
{
        struct j1939_priv *priv = session->priv;
        struct j1939_sock *jsk;

        if (session->sk) {
                /* send TX notifications to the socket of origin  */
                __j1939_sk_errqueue(session, session->sk, type);
                return;
        }

        /* spread RX notifications to all sockets subscribed to this session */
        read_lock_bh(&priv->j1939_socks_lock);
        list_for_each_entry(jsk, &priv->j1939_socks, list) {
                if (j1939_sk_recv_match_one(jsk, &session->skcb))
                        __j1939_sk_errqueue(session, &jsk->sk, type);
        }
        read_unlock_bh(&priv->j1939_socks_lock);
};

void j1939_sk_send_loop_abort(struct sock *sk, int err)
{
        struct j1939_sock *jsk = j1939_sk(sk);

        if (jsk->state & J1939_SOCK_ERRQUEUE)
                return;

        sk->sk_err = err;

        sk_error_report(sk);
}

static int j1939_sk_send_loop(struct j1939_priv *priv,  struct sock *sk,
                              struct msghdr *msg, size_t size)

{
        struct j1939_sock *jsk = j1939_sk(sk);
        struct j1939_session *session = j1939_sk_get_incomplete_session(jsk);
        struct sk_buff *skb;
        size_t segment_size, todo_size;
        int ret = 0;

        if (session &&
            session->total_message_size != session->total_queued_size + size) {
                j1939_session_put(session);
                return -EIO;
        }

        todo_size = size;

        do {
                struct j1939_sk_buff_cb *skcb;

                segment_size = min_t(size_t, J1939_MAX_TP_PACKET_SIZE,
                                     todo_size);

                /* Allocate skb for one segment */
                skb = j1939_sk_alloc_skb(priv->ndev, sk, msg, segment_size,
                                         &ret);
                if (ret)
                        break;

                skcb = j1939_skb_to_cb(skb);

                if (!session) {
                        /* at this point the size should be full size
                         * of the session
                         */
                        skcb->offset = 0;
                        session = j1939_tp_send(priv, skb, size);
                        if (IS_ERR(session)) {
                                ret = PTR_ERR(session);
                                goto kfree_skb;
                        }
                        if (j1939_sk_queue_session(session)) {
                                /* try to activate session if we a
                                 * fist in the queue
                                 */
                                if (!j1939_session_activate(session)) {
                                        j1939_tp_schedule_txtimer(session, 0);
                                } else {
                                        ret = -EBUSY;
                                        session->err = ret;
                                        j1939_sk_queue_drop_all(priv, jsk,
                                                                EBUSY);
                                        break;
                                }
                        }
                } else {
                        skcb->offset = session->total_queued_size;
                        j1939_session_skb_queue(session, skb);
                }

                todo_size -= segment_size;
                session->total_queued_size += segment_size;
        } while (todo_size);

        switch (ret) {
        case 0: /* OK */
                if (todo_size)
                        netdev_warn(priv->ndev,
                                    "no error found and not completely queued?! %zu\n",
                                    todo_size);
                ret = size;
                break;
        case -ERESTARTSYS:
                ret = -EINTR;
                fallthrough;
        case -EAGAIN: /* OK */
                if (todo_size != size)
                        ret = size - todo_size;
                break;
        default: /* ERROR */
                break;
        }

        if (session)
                j1939_session_put(session);

        return ret;

 kfree_skb:
        kfree_skb(skb);
        return ret;
}

static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
                            size_t size)
{
        struct sock *sk = sock->sk;
        struct j1939_sock *jsk = j1939_sk(sk);
        struct j1939_priv *priv;
        int ifindex;
        int ret;

        lock_sock(sock->sk);
        /* various socket state tests */
        if (!(jsk->state & J1939_SOCK_BOUND)) {
                ret = -EBADFD;
                goto sendmsg_done;
        }

        priv = jsk->priv;
        ifindex = jsk->ifindex;

        if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR) {
                /* no source address assigned yet */
                ret = -EBADFD;
                goto sendmsg_done;
        }

        /* deal with provided destination address info */
        if (msg->msg_name) {
                struct sockaddr_can *addr = msg->msg_name;

                if (msg->msg_namelen < J1939_MIN_NAMELEN) {
                        ret = -EINVAL;
                        goto sendmsg_done;
                }

                if (addr->can_family != AF_CAN) {
                        ret = -EINVAL;
                        goto sendmsg_done;
                }

                if (addr->can_ifindex && addr->can_ifindex != ifindex) {
                        ret = -EBADFD;
                        goto sendmsg_done;
                }

                if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
                    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn)) {
                        ret = -EINVAL;
                        goto sendmsg_done;
                }

                if (!addr->can_addr.j1939.name &&
                    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
                    !sock_flag(sk, SOCK_BROADCAST)) {
                        /* broadcast, but SO_BROADCAST not set */
                        ret = -EACCES;
                        goto sendmsg_done;
                }
        } else {
                if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
                    !sock_flag(sk, SOCK_BROADCAST)) {
                        /* broadcast, but SO_BROADCAST not set */
                        ret = -EACCES;
                        goto sendmsg_done;
                }
        }

        ret = j1939_sk_send_loop(priv, sk, msg, size);

sendmsg_done:
        release_sock(sock->sk);

        return ret;
}

void j1939_sk_netdev_event_netdown(struct j1939_priv *priv)
{
        struct j1939_sock *jsk;
        int error_code = ENETDOWN;

        read_lock_bh(&priv->j1939_socks_lock);
        list_for_each_entry(jsk, &priv->j1939_socks, list) {
                jsk->sk.sk_err = error_code;
                if (!sock_flag(&jsk->sk, SOCK_DEAD))
                        sk_error_report(&jsk->sk);

                j1939_sk_queue_drop_all(priv, jsk, error_code);
        }
        read_unlock_bh(&priv->j1939_socks_lock);
}

void j1939_sk_netdev_event_unregister(struct j1939_priv *priv)
{
        struct sock *sk;
        struct j1939_sock *jsk;
        bool wait_rcu = false;

rescan: /* The caller is holding a ref on this "priv" via j1939_priv_get_by_ndev(). */
        read_lock_bh(&priv->j1939_socks_lock);
        list_for_each_entry(jsk, &priv->j1939_socks, list) {
                /* Skip if j1939_jsk_add() is not called on this socket. */
                if (!(jsk->state & J1939_SOCK_BOUND))
                        continue;
                sk = &jsk->sk;
                sock_hold(sk);
                read_unlock_bh(&priv->j1939_socks_lock);
                /* Check if j1939_jsk_del() is not yet called on this socket after holding
                 * socket's lock, for both j1939_sk_bind() and j1939_sk_release() call
                 * j1939_jsk_del() with socket's lock held.
                 */
                lock_sock(sk);
                if (jsk->state & J1939_SOCK_BOUND) {
                        /* Neither j1939_sk_bind() nor j1939_sk_release() called j1939_jsk_del().
                         * Make this socket no longer bound, by pretending as if j1939_sk_bind()
                         * dropped old references but did not get new references.
                         */
                        j1939_jsk_del(priv, jsk);
                        j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
                        j1939_netdev_stop(priv);
                        /* Call j1939_priv_put() now and prevent j1939_sk_sock_destruct() from
                         * calling the corresponding j1939_priv_put().
                         *
                         * j1939_sk_sock_destruct() is supposed to call j1939_priv_put() after
                         * an RCU grace period. But since the caller is holding a ref on this
                         * "priv", we can defer synchronize_rcu() until immediately before
                         * the caller calls j1939_priv_put().
                         */
                        j1939_priv_put(priv);
                        jsk->priv = NULL;
                        wait_rcu = true;
                }
                release_sock(sk);
                sock_put(sk);
                goto rescan;
        }
        read_unlock_bh(&priv->j1939_socks_lock);
        if (wait_rcu)
                synchronize_rcu();
}

static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd,
                                unsigned long arg)
{
        /* no ioctls for socket layer -> hand it down to NIC layer */
        return -ENOIOCTLCMD;
}

static const struct proto_ops j1939_ops = {
        .family = PF_CAN,
        .release = j1939_sk_release,
        .bind = j1939_sk_bind,
        .connect = j1939_sk_connect,
        .socketpair = sock_no_socketpair,
        .accept = sock_no_accept,
        .getname = j1939_sk_getname,
        .poll = datagram_poll,
        .ioctl = j1939_sk_no_ioctlcmd,
        .listen = sock_no_listen,
        .shutdown = sock_no_shutdown,
        .setsockopt = j1939_sk_setsockopt,
        .getsockopt = j1939_sk_getsockopt,
        .sendmsg = j1939_sk_sendmsg,
        .recvmsg = j1939_sk_recvmsg,
        .mmap = sock_no_mmap,
};

static struct proto j1939_proto __read_mostly = {
        .name = "CAN_J1939",
        .owner = THIS_MODULE,
        .obj_size = sizeof(struct j1939_sock),
        .init = j1939_sk_init,
};

const struct can_proto j1939_can_proto = {
        .type = SOCK_DGRAM,
        .protocol = CAN_J1939,
        .ops = &j1939_ops,
        .prot = &j1939_proto,
};

































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// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Authors:
 * Alexander Aring <aar@pengutronix.de>
 *
 * Based on: net/mac80211/util.c
 */

#include "ieee802154_i.h"
#include "driver-ops.h"

/* privid for wpan_phys to determine whether they belong to us or not */
const void *const mac802154_wpan_phy_privid = &mac802154_wpan_phy_privid;

/**
 * ieee802154_wake_queue - wake ieee802154 queue
 * @hw: main hardware object
 *
 * Tranceivers usually have either one transmit framebuffer or one framebuffer
 * for both transmitting and receiving. Hence, the core currently only handles
 * one frame at a time for each phy, which means we had to stop the queue to
 * avoid new skb to come during the transmission. The queue then needs to be
 * woken up after the operation.
 */
static void ieee802154_wake_queue(struct ieee802154_hw *hw)
{
        struct ieee802154_local *local = hw_to_local(hw);
        struct ieee802154_sub_if_data *sdata;

        rcu_read_lock();
        clear_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags);
        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                if (!sdata->dev)
                        continue;

                netif_wake_queue(sdata->dev);
        }
        rcu_read_unlock();
}

/**
 * ieee802154_stop_queue - stop ieee802154 queue
 * @hw: main hardware object
 *
 * Tranceivers usually have either one transmit framebuffer or one framebuffer
 * for both transmitting and receiving. Hence, the core currently only handles
 * one frame at a time for each phy, which means we need to tell upper layers to
 * stop giving us new skbs while we are busy with the transmitted one. The queue
 * must then be stopped before transmitting.
 */
static void ieee802154_stop_queue(struct ieee802154_hw *hw)
{
        struct ieee802154_local *local = hw_to_local(hw);
        struct ieee802154_sub_if_data *sdata;

        rcu_read_lock();
        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                if (!sdata->dev)
                        continue;

                netif_stop_queue(sdata->dev);
        }
        rcu_read_unlock();
}

void ieee802154_hold_queue(struct ieee802154_local *local)
{
        unsigned long flags;

        spin_lock_irqsave(&local->phy->queue_lock, flags);
        if (!atomic_fetch_inc(&local->phy->hold_txs))
                ieee802154_stop_queue(&local->hw);
        spin_unlock_irqrestore(&local->phy->queue_lock, flags);
}

void ieee802154_release_queue(struct ieee802154_local *local)
{
        unsigned long flags;

        spin_lock_irqsave(&local->phy->queue_lock, flags);
        if (atomic_dec_and_test(&local->phy->hold_txs))
                ieee802154_wake_queue(&local->hw);
        spin_unlock_irqrestore(&local->phy->queue_lock, flags);
}

void ieee802154_disable_queue(struct ieee802154_local *local)
{
        struct ieee802154_sub_if_data *sdata;

        rcu_read_lock();
        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
                if (!sdata->dev)
                        continue;

                netif_tx_disable(sdata->dev);
        }
        rcu_read_unlock();
}

enum hrtimer_restart ieee802154_xmit_ifs_timer(struct hrtimer *timer)
{
        struct ieee802154_local *local =
                container_of(timer, struct ieee802154_local, ifs_timer);

        ieee802154_release_queue(local);

        return HRTIMER_NORESTART;
}

void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb,
                              bool ifs_handling)
{
        struct ieee802154_local *local = hw_to_local(hw);

        local->tx_result = IEEE802154_SUCCESS;

        if (ifs_handling) {
                u8 max_sifs_size;

                /* If transceiver sets CRC on his own we need to use lifs
                 * threshold len above 16 otherwise 18, because it's not
                 * part of skb->len.
                 */
                if (hw->flags & IEEE802154_HW_TX_OMIT_CKSUM)
                        max_sifs_size = IEEE802154_MAX_SIFS_FRAME_SIZE -
                                        IEEE802154_FCS_LEN;
                else
                        max_sifs_size = IEEE802154_MAX_SIFS_FRAME_SIZE;

                if (skb->len > max_sifs_size)
                        hrtimer_start(&local->ifs_timer,
                                      hw->phy->lifs_period * NSEC_PER_USEC,
                                      HRTIMER_MODE_REL);
                else
                        hrtimer_start(&local->ifs_timer,
                                      hw->phy->sifs_period * NSEC_PER_USEC,
                                      HRTIMER_MODE_REL);
        } else {
                ieee802154_release_queue(local);
        }

        dev_consume_skb_any(skb);
        if (atomic_dec_and_test(&hw->phy->ongoing_txs))
                wake_up(&hw->phy->sync_txq);
}
EXPORT_SYMBOL(ieee802154_xmit_complete);

void ieee802154_xmit_error(struct ieee802154_hw *hw, struct sk_buff *skb,
                           int reason)
{
        struct ieee802154_local *local = hw_to_local(hw);

        local->tx_result = reason;
        ieee802154_release_queue(local);
        dev_kfree_skb_any(skb);
        if (atomic_dec_and_test(&hw->phy->ongoing_txs))
                wake_up(&hw->phy->sync_txq);
}
EXPORT_SYMBOL(ieee802154_xmit_error);

void ieee802154_xmit_hw_error(struct ieee802154_hw *hw, struct sk_buff *skb)
{
        ieee802154_xmit_error(hw, skb, IEEE802154_SYSTEM_ERROR);
}
EXPORT_SYMBOL(ieee802154_xmit_hw_error);

void ieee802154_stop_device(struct ieee802154_local *local)
{
        flush_workqueue(local->workqueue);
        hrtimer_cancel(&local->ifs_timer);
        drv_stop(local);
}





























































































































































































































































































































































































































































































































































































































































































































































































































































































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// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright 2019, 2020 Amazon.com, Inc. or its affiliates. All rights reserved.
 *
 * User extended attribute client side cache functions.
 *
 * Author: Frank van der Linden <fllinden@amazon.com>
 */
#include <linux/errno.h>
#include <linux/nfs_fs.h>
#include <linux/hashtable.h>
#include <linux/refcount.h>
#include <uapi/linux/xattr.h>

#include "nfs4_fs.h"
#include "internal.h"

/*
 * User extended attributes client side caching is implemented by having
 * a cache structure attached to NFS inodes. This structure is allocated
 * when needed, and freed when the cache is zapped.
 *
 * The cache structure contains as hash table of entries, and a pointer
 * to a special-cased entry for the listxattr cache.
 *
 * Accessing and allocating / freeing the caches is done via reference
 * counting. The cache entries use a similar refcounting scheme.
 *
 * This makes freeing a cache, both from the shrinker and from the
 * zap cache path, easy. It also means that, in current use cases,
 * the large majority of inodes will not waste any memory, as they
 * will never have any user extended attributes assigned to them.
 *
 * Attribute entries are hashed in to a simple hash table. They are
 * also part of an LRU.
 *
 * There are three shrinkers.
 *
 * Two shrinkers deal with the cache entries themselves: one for
 * large entries (> PAGE_SIZE), and one for smaller entries. The
 * shrinker for the larger entries works more aggressively than
 * those for the smaller entries.
 *
 * The other shrinker frees the cache structures themselves.
 */

/*
 * 64 buckets is a good default. There is likely no reasonable
 * workload that uses more than even 64 user extended attributes.
 * You can certainly add a lot more - but you get what you ask for
 * in those circumstances.
 */
#define NFS4_XATTR_HASH_SIZE        64

#define NFSDBG_FACILITY        NFSDBG_XATTRCACHE

struct nfs4_xattr_cache;
struct nfs4_xattr_entry;

struct nfs4_xattr_bucket {
        spinlock_t lock;
        struct hlist_head hlist;
        struct nfs4_xattr_cache *cache;
        bool draining;
};

struct nfs4_xattr_cache {
        struct kref ref;
        struct nfs4_xattr_bucket buckets[NFS4_XATTR_HASH_SIZE];
        struct list_head lru;
        struct list_head dispose;
        atomic_long_t nent;
        spinlock_t listxattr_lock;
        struct inode *inode;
        struct nfs4_xattr_entry *listxattr;
};

struct nfs4_xattr_entry {
        struct kref ref;
        struct hlist_node hnode;
        struct list_head lru;
        struct list_head dispose;
        char *xattr_name;
        void *xattr_value;
        size_t xattr_size;
        struct nfs4_xattr_bucket *bucket;
        uint32_t flags;
};

#define        NFS4_XATTR_ENTRY_EXTVAL        0x0001

/*
 * LRU list of NFS inodes that have xattr caches.
 */
static struct list_lru nfs4_xattr_cache_lru;
static struct list_lru nfs4_xattr_entry_lru;
static struct list_lru nfs4_xattr_large_entry_lru;

static struct kmem_cache *nfs4_xattr_cache_cachep;

/*
 * Hashing helper functions.
 */
static void
nfs4_xattr_hash_init(struct nfs4_xattr_cache *cache)
{
        unsigned int i;

        for (i = 0; i < NFS4_XATTR_HASH_SIZE; i++) {
                INIT_HLIST_HEAD(&cache->buckets[i].hlist);
                spin_lock_init(&cache->buckets[i].lock);
                cache->buckets[i].cache = cache;
                cache->buckets[i].draining = false;
        }
}

/*
 * Locking order:
 * 1. inode i_lock or bucket lock
 * 2. list_lru lock (taken by list_lru_* functions)
 */

/*
 * Wrapper functions to add a cache entry to the right LRU.
 */
static bool
nfs4_xattr_entry_lru_add(struct nfs4_xattr_entry *entry)
{
        struct list_lru *lru;

        lru = (entry->flags & NFS4_XATTR_ENTRY_EXTVAL) ?
            &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;

        return list_lru_add_obj(lru, &entry->lru);
}

static bool
nfs4_xattr_entry_lru_del(struct nfs4_xattr_entry *entry)
{
        struct list_lru *lru;

        lru = (entry->flags & NFS4_XATTR_ENTRY_EXTVAL) ?
            &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;

        return list_lru_del_obj(lru, &entry->lru);
}

/*
 * This function allocates cache entries. They are the normal
 * extended attribute name/value pairs, but may also be a listxattr
 * cache. Those allocations use the same entry so that they can be
 * treated as one by the memory shrinker.
 *
 * xattr cache entries are allocated together with names. If the
 * value fits in to one page with the entry structure and the name,
 * it will also be part of the same allocation (kmalloc). This is
 * expected to be the vast majority of cases. Larger allocations
 * have a value pointer that is allocated separately by kvmalloc.
 *
 * Parameters:
 *
 * @name:  Name of the extended attribute. NULL for listxattr cache
 *         entry.
 * @value: Value of attribute, or listxattr cache. NULL if the
 *         value is to be copied from pages instead.
 * @pages: Pages to copy the value from, if not NULL. Passed in to
 *           make it easier to copy the value after an RPC, even if
 *           the value will not be passed up to application (e.g.
 *           for a 'query' getxattr with NULL buffer).
 * @len:   Length of the value. Can be 0 for zero-length attributes.
 *         @value and @pages will be NULL if @len is 0.
 */
static struct nfs4_xattr_entry *
nfs4_xattr_alloc_entry(const char *name, const void *value,
                       struct page **pages, size_t len)
{
        struct nfs4_xattr_entry *entry;
        void *valp;
        char *namep;
        size_t alloclen, slen;
        char *buf;
        uint32_t flags;

        BUILD_BUG_ON(sizeof(struct nfs4_xattr_entry) +
            XATTR_NAME_MAX + 1 > PAGE_SIZE);

        alloclen = sizeof(struct nfs4_xattr_entry);
        if (name != NULL) {
                slen = strlen(name) + 1;
                alloclen += slen;
        } else
                slen = 0;

        if (alloclen + len <= PAGE_SIZE) {
                alloclen += len;
                flags = 0;
        } else {
                flags = NFS4_XATTR_ENTRY_EXTVAL;
        }

        buf = kmalloc(alloclen, GFP_KERNEL);
        if (buf == NULL)
                return NULL;
        entry = (struct nfs4_xattr_entry *)buf;

        if (name != NULL) {
                namep = buf + sizeof(struct nfs4_xattr_entry);
                memcpy(namep, name, slen);
        } else {
                namep = NULL;
        }


        if (flags & NFS4_XATTR_ENTRY_EXTVAL) {
                valp = kvmalloc(len, GFP_KERNEL);
                if (valp == NULL) {
                        kfree(buf);
                        return NULL;
                }
        } else if (len != 0) {
                valp = buf + sizeof(struct nfs4_xattr_entry) + slen;
        } else
                valp = NULL;

        if (valp != NULL) {
                if (value != NULL)
                        memcpy(valp, value, len);
                else
                        _copy_from_pages(valp, pages, 0, len);
        }

        entry->flags = flags;
        entry->xattr_value = valp;
        kref_init(&entry->ref);
        entry->xattr_name = namep;
        entry->xattr_size = len;
        entry->bucket = NULL;
        INIT_LIST_HEAD(&entry->lru);
        INIT_LIST_HEAD(&entry->dispose);
        INIT_HLIST_NODE(&entry->hnode);

        return entry;
}

static void
nfs4_xattr_free_entry(struct nfs4_xattr_entry *entry)
{
        if (entry->flags & NFS4_XATTR_ENTRY_EXTVAL)
                kvfree(entry->xattr_value);
        kfree(entry);
}

static void
nfs4_xattr_free_entry_cb(struct kref *kref)
{
        struct nfs4_xattr_entry *entry;

        entry = container_of(kref, struct nfs4_xattr_entry, ref);

        if (WARN_ON(!list_empty(&entry->lru)))
                return;

        nfs4_xattr_free_entry(entry);
}

static void
nfs4_xattr_free_cache_cb(struct kref *kref)
{
        struct nfs4_xattr_cache *cache;
        int i;

        cache = container_of(kref, struct nfs4_xattr_cache, ref);

        for (i = 0; i < NFS4_XATTR_HASH_SIZE; i++) {
                if (WARN_ON(!hlist_empty(&cache->buckets[i].hlist)))
                        return;
                cache->buckets[i].draining = false;
        }

        cache->listxattr = NULL;

        kmem_cache_free(nfs4_xattr_cache_cachep, cache);

}

static struct nfs4_xattr_cache *
nfs4_xattr_alloc_cache(void)
{
        struct nfs4_xattr_cache *cache;

        cache = kmem_cache_alloc(nfs4_xattr_cache_cachep, GFP_KERNEL);
        if (cache == NULL)
                return NULL;

        kref_init(&cache->ref);
        atomic_long_set(&cache->nent, 0);

        return cache;
}

/*
 * Set the listxattr cache, which is a special-cased cache entry.
 * The special value ERR_PTR(-ESTALE) is used to indicate that
 * the cache is being drained - this prevents a new listxattr
 * cache from being added to what is now a stale cache.
 */
static int
nfs4_xattr_set_listcache(struct nfs4_xattr_cache *cache,
                         struct nfs4_xattr_entry *new)
{
        struct nfs4_xattr_entry *old;
        int ret = 1;

        spin_lock(&cache->listxattr_lock);

        old = cache->listxattr;

        if (old == ERR_PTR(-ESTALE)) {
                ret = 0;
                goto out;
        }

        cache->listxattr = new;
        if (new != NULL && new != ERR_PTR(-ESTALE))
                nfs4_xattr_entry_lru_add(new);

        if (old != NULL) {
                nfs4_xattr_entry_lru_del(old);
                kref_put(&old->ref, nfs4_xattr_free_entry_cb);
        }
out:
        spin_unlock(&cache->listxattr_lock);

        return ret;
}

/*
 * Unlink a cache from its parent inode, clearing out an invalid
 * cache. Must be called with i_lock held.
 */
static struct nfs4_xattr_cache *
nfs4_xattr_cache_unlink(struct inode *inode)
{
        struct nfs_inode *nfsi;
        struct nfs4_xattr_cache *oldcache;

        nfsi = NFS_I(inode);

        oldcache = nfsi->xattr_cache;
        if (oldcache != NULL) {
                list_lru_del_obj(&nfs4_xattr_cache_lru, &oldcache->lru);
                oldcache->inode = NULL;
        }
        nfsi->xattr_cache = NULL;
        nfsi->cache_validity &= ~NFS_INO_INVALID_XATTR;

        return oldcache;

}

/*
 * Discard a cache. Called by get_cache() if there was an old,
 * invalid cache. Can also be called from a shrinker callback.
 *
 * The cache is dead, it has already been unlinked from its inode,
 * and no longer appears on the cache LRU list.
 *
 * Mark all buckets as draining, so that no new entries are added. This
 * could still happen in the unlikely, but possible case that another
 * thread had grabbed a reference before it was unlinked from the inode,
 * and is still holding it for an add operation.
 *
 * Remove all entries from the LRU lists, so that there is no longer
 * any way to 'find' this cache. Then, remove the entries from the hash
 * table.
 *
 * At that point, the cache will remain empty and can be freed when the final
 * reference drops, which is very likely the kref_put at the end of
 * this function, or the one called immediately afterwards in the
 * shrinker callback.
 */
static void
nfs4_xattr_discard_cache(struct nfs4_xattr_cache *cache)
{
        unsigned int i;
        struct nfs4_xattr_entry *entry;
        struct nfs4_xattr_bucket *bucket;
        struct hlist_node *n;

        nfs4_xattr_set_listcache(cache, ERR_PTR(-ESTALE));

        for (i = 0; i < NFS4_XATTR_HASH_SIZE; i++) {
                bucket = &cache->buckets[i];

                spin_lock(&bucket->lock);
                bucket->draining = true;
                hlist_for_each_entry_safe(entry, n, &bucket->hlist, hnode) {
                        nfs4_xattr_entry_lru_del(entry);
                        hlist_del_init(&entry->hnode);
                        kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
                }
                spin_unlock(&bucket->lock);
        }

        atomic_long_set(&cache->nent, 0);

        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
}

/*
 * Get a referenced copy of the cache structure. Avoid doing allocs
 * while holding i_lock. Which means that we do some optimistic allocation,
 * and might have to free the result in rare cases.
 *
 * This function only checks the NFS_INO_INVALID_XATTR cache validity bit
 * and acts accordingly, replacing the cache when needed. For the read case
 * (!add), this means that the caller must make sure that the cache
 * is valid before caling this function. getxattr and listxattr call
 * revalidate_inode to do this. The attribute cache timeout (for the
 * non-delegated case) is expected to be dealt with in the revalidate
 * call.
 */

static struct nfs4_xattr_cache *
nfs4_xattr_get_cache(struct inode *inode, int add)
{
        struct nfs_inode *nfsi;
        struct nfs4_xattr_cache *cache, *oldcache, *newcache;

        nfsi = NFS_I(inode);

        cache = oldcache = NULL;

        spin_lock(&inode->i_lock);

        if (nfsi->cache_validity & NFS_INO_INVALID_XATTR)
                oldcache = nfs4_xattr_cache_unlink(inode);
        else
                cache = nfsi->xattr_cache;

        if (cache != NULL)
                kref_get(&cache->ref);

        spin_unlock(&inode->i_lock);

        if (add && cache == NULL) {
                newcache = NULL;

                cache = nfs4_xattr_alloc_cache();
                if (cache == NULL)
                        goto out;

                spin_lock(&inode->i_lock);
                if (nfsi->cache_validity & NFS_INO_INVALID_XATTR) {
                        /*
                         * The cache was invalidated again. Give up,
                         * since what we want to enter is now likely
                         * outdated anyway.
                         */
                        spin_unlock(&inode->i_lock);
                        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
                        cache = NULL;
                        goto out;
                }

                /*
                 * Check if someone beat us to it.
                 */
                if (nfsi->xattr_cache != NULL) {
                        newcache = nfsi->xattr_cache;
                        kref_get(&newcache->ref);
                } else {
                        kref_get(&cache->ref);
                        nfsi->xattr_cache = cache;
                        cache->inode = inode;
                        list_lru_add_obj(&nfs4_xattr_cache_lru, &cache->lru);
                }

                spin_unlock(&inode->i_lock);

                /*
                 * If there was a race, throw away the cache we just
                 * allocated, and use the new one allocated by someone
                 * else.
                 */
                if (newcache != NULL) {
                        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
                        cache = newcache;
                }
        }

out:
        /*
         * Discard the now orphaned old cache.
         */
        if (oldcache != NULL)
                nfs4_xattr_discard_cache(oldcache);

        return cache;
}

static inline struct nfs4_xattr_bucket *
nfs4_xattr_hash_bucket(struct nfs4_xattr_cache *cache, const char *name)
{
        return &cache->buckets[jhash(name, strlen(name), 0) &
            (ARRAY_SIZE(cache->buckets) - 1)];
}

static struct nfs4_xattr_entry *
nfs4_xattr_get_entry(struct nfs4_xattr_bucket *bucket, const char *name)
{
        struct nfs4_xattr_entry *entry;

        entry = NULL;

        hlist_for_each_entry(entry, &bucket->hlist, hnode) {
                if (!strcmp(entry->xattr_name, name))
                        break;
        }

        return entry;
}

static int
nfs4_xattr_hash_add(struct nfs4_xattr_cache *cache,
                    struct nfs4_xattr_entry *entry)
{
        struct nfs4_xattr_bucket *bucket;
        struct nfs4_xattr_entry *oldentry = NULL;
        int ret = 1;

        bucket = nfs4_xattr_hash_bucket(cache, entry->xattr_name);
        entry->bucket = bucket;

        spin_lock(&bucket->lock);

        if (bucket->draining) {
                ret = 0;
                goto out;
        }

        oldentry = nfs4_xattr_get_entry(bucket, entry->xattr_name);
        if (oldentry != NULL) {
                hlist_del_init(&oldentry->hnode);
                nfs4_xattr_entry_lru_del(oldentry);
        } else {
                atomic_long_inc(&cache->nent);
        }

        hlist_add_head(&entry->hnode, &bucket->hlist);
        nfs4_xattr_entry_lru_add(entry);

out:
        spin_unlock(&bucket->lock);

        if (oldentry != NULL)
                kref_put(&oldentry->ref, nfs4_xattr_free_entry_cb);

        return ret;
}

static void
nfs4_xattr_hash_remove(struct nfs4_xattr_cache *cache, const char *name)
{
        struct nfs4_xattr_bucket *bucket;
        struct nfs4_xattr_entry *entry;

        bucket = nfs4_xattr_hash_bucket(cache, name);

        spin_lock(&bucket->lock);

        entry = nfs4_xattr_get_entry(bucket, name);
        if (entry != NULL) {
                hlist_del_init(&entry->hnode);
                nfs4_xattr_entry_lru_del(entry);
                atomic_long_dec(&cache->nent);
        }

        spin_unlock(&bucket->lock);

        if (entry != NULL)
                kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
}

static struct nfs4_xattr_entry *
nfs4_xattr_hash_find(struct nfs4_xattr_cache *cache, const char *name)
{
        struct nfs4_xattr_bucket *bucket;
        struct nfs4_xattr_entry *entry;

        bucket = nfs4_xattr_hash_bucket(cache, name);

        spin_lock(&bucket->lock);

        entry = nfs4_xattr_get_entry(bucket, name);
        if (entry != NULL)
                kref_get(&entry->ref);

        spin_unlock(&bucket->lock);

        return entry;
}

/*
 * Entry point to retrieve an entry from the cache.
 */
ssize_t nfs4_xattr_cache_get(struct inode *inode, const char *name, char *buf,
                         ssize_t buflen)
{
        struct nfs4_xattr_cache *cache;
        struct nfs4_xattr_entry *entry;
        ssize_t ret;

        cache = nfs4_xattr_get_cache(inode, 0);
        if (cache == NULL)
                return -ENOENT;

        ret = 0;
        entry = nfs4_xattr_hash_find(cache, name);

        if (entry != NULL) {
                dprintk("%s: cache hit '%s', len %lu\n", __func__,
                    entry->xattr_name, (unsigned long)entry->xattr_size);
                if (buflen == 0) {
                        /* Length probe only */
                        ret = entry->xattr_size;
                } else if (buflen < entry->xattr_size)
                        ret = -ERANGE;
                else {
                        memcpy(buf, entry->xattr_value, entry->xattr_size);
                        ret = entry->xattr_size;
                }
                kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
        } else {
                dprintk("%s: cache miss '%s'\n", __func__, name);
                ret = -ENOENT;
        }

        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);

        return ret;
}

/*
 * Retrieve a cached list of xattrs from the cache.
 */
ssize_t nfs4_xattr_cache_list(struct inode *inode, char *buf, ssize_t buflen)
{
        struct nfs4_xattr_cache *cache;
        struct nfs4_xattr_entry *entry;
        ssize_t ret;

        cache = nfs4_xattr_get_cache(inode, 0);
        if (cache == NULL)
                return -ENOENT;

        spin_lock(&cache->listxattr_lock);

        entry = cache->listxattr;

        if (entry != NULL && entry != ERR_PTR(-ESTALE)) {
                if (buflen == 0) {
                        /* Length probe only */
                        ret = entry->xattr_size;
                } else if (entry->xattr_size > buflen)
                        ret = -ERANGE;
                else {
                        memcpy(buf, entry->xattr_value, entry->xattr_size);
                        ret = entry->xattr_size;
                }
        } else {
                ret = -ENOENT;
        }

        spin_unlock(&cache->listxattr_lock);

        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);

        return ret;
}

/*
 * Add an xattr to the cache.
 *
 * This also invalidates the xattr list cache.
 */
void nfs4_xattr_cache_add(struct inode *inode, const char *name,
                          const char *buf, struct page **pages, ssize_t buflen)
{
        struct nfs4_xattr_cache *cache;
        struct nfs4_xattr_entry *entry;

        dprintk("%s: add '%s' len %lu\n", __func__,
            name, (unsigned long)buflen);

        cache = nfs4_xattr_get_cache(inode, 1);
        if (cache == NULL)
                return;

        entry = nfs4_xattr_alloc_entry(name, buf, pages, buflen);
        if (entry == NULL)
                goto out;

        (void)nfs4_xattr_set_listcache(cache, NULL);

        if (!nfs4_xattr_hash_add(cache, entry))
                kref_put(&entry->ref, nfs4_xattr_free_entry_cb);

out:
        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
}


/*
 * Remove an xattr from the cache.
 *
 * This also invalidates the xattr list cache.
 */
void nfs4_xattr_cache_remove(struct inode *inode, const char *name)
{
        struct nfs4_xattr_cache *cache;

        dprintk("%s: remove '%s'\n", __func__, name);

        cache = nfs4_xattr_get_cache(inode, 0);
        if (cache == NULL)
                return;

        (void)nfs4_xattr_set_listcache(cache, NULL);
        nfs4_xattr_hash_remove(cache, name);

        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
}

/*
 * Cache listxattr output, replacing any possible old one.
 */
void nfs4_xattr_cache_set_list(struct inode *inode, const char *buf,
                               ssize_t buflen)
{
        struct nfs4_xattr_cache *cache;
        struct nfs4_xattr_entry *entry;

        cache = nfs4_xattr_get_cache(inode, 1);
        if (cache == NULL)
                return;

        entry = nfs4_xattr_alloc_entry(NULL, buf, NULL, buflen);
        if (entry == NULL)
                goto out;

        /*
         * This is just there to be able to get to bucket->cache,
         * which is obviously the same for all buckets, so just
         * use bucket 0.
         */
        entry->bucket = &cache->buckets[0];

        if (!nfs4_xattr_set_listcache(cache, entry))
                kref_put(&entry->ref, nfs4_xattr_free_entry_cb);

out:
        kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
}

/*
 * Zap the entire cache. Called when an inode is evicted.
 */
void nfs4_xattr_cache_zap(struct inode *inode)
{
        struct nfs4_xattr_cache *oldcache;

        spin_lock(&inode->i_lock);
        oldcache = nfs4_xattr_cache_unlink(inode);
        spin_unlock(&inode->i_lock);

        if (oldcache)
                nfs4_xattr_discard_cache(oldcache);
}

/*
 * The entry LRU is shrunk more aggressively than the cache LRU,
 * by settings @seeks to 1.
 *
 * Cache structures are freed only when they've become empty, after
 * pruning all but one entry.
 */

static unsigned long nfs4_xattr_cache_count(struct shrinker *shrink,
                                            struct shrink_control *sc);
static unsigned long nfs4_xattr_entry_count(struct shrinker *shrink,
                                            struct shrink_control *sc);
static unsigned long nfs4_xattr_cache_scan(struct shrinker *shrink,
                                           struct shrink_control *sc);
static unsigned long nfs4_xattr_entry_scan(struct shrinker *shrink,
                                           struct shrink_control *sc);

static struct shrinker *nfs4_xattr_cache_shrinker;
static struct shrinker *nfs4_xattr_entry_shrinker;
static struct shrinker *nfs4_xattr_large_entry_shrinker;

static enum lru_status
cache_lru_isolate(struct list_head *item,
        struct list_lru_one *lru, void *arg)
{
        struct list_head *dispose = arg;
        struct inode *inode;
        struct nfs4_xattr_cache *cache = container_of(item,
            struct nfs4_xattr_cache, lru);

        if (atomic_long_read(&cache->nent) > 1)
                return LRU_SKIP;

        /*
         * If a cache structure is on the LRU list, we know that
         * its inode is valid. Try to lock it to break the link.
         * Since we're inverting the lock order here, only try.
         */
        inode = cache->inode;

        if (!spin_trylock(&inode->i_lock))
                return LRU_SKIP;

        kref_get(&cache->ref);

        cache->inode = NULL;
        NFS_I(inode)->xattr_cache = NULL;
        NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_XATTR;
        list_lru_isolate(lru, &cache->lru);

        spin_unlock(&inode->i_lock);

        list_add_tail(&cache->dispose, dispose);
        return LRU_REMOVED;
}

static unsigned long
nfs4_xattr_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
        LIST_HEAD(dispose);
        unsigned long freed;
        struct nfs4_xattr_cache *cache;

        freed = list_lru_shrink_walk(&nfs4_xattr_cache_lru, sc,
            cache_lru_isolate, &dispose);
        while (!list_empty(&dispose)) {
                cache = list_first_entry(&dispose, struct nfs4_xattr_cache,
                    dispose);
                list_del_init(&cache->dispose);
                nfs4_xattr_discard_cache(cache);
                kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
        }

        return freed;
}


static unsigned long
nfs4_xattr_cache_count(struct shrinker *shrink, struct shrink_control *sc)
{
        unsigned long count;

        count = list_lru_shrink_count(&nfs4_xattr_cache_lru, sc);
        return vfs_pressure_ratio(count);
}

static enum lru_status
entry_lru_isolate(struct list_head *item,
        struct list_lru_one *lru, void *arg)
{
        struct list_head *dispose = arg;
        struct nfs4_xattr_bucket *bucket;
        struct nfs4_xattr_cache *cache;
        struct nfs4_xattr_entry *entry = container_of(item,
            struct nfs4_xattr_entry, lru);

        bucket = entry->bucket;
        cache = bucket->cache;

        /*
         * Unhook the entry from its parent (either a cache bucket
         * or a cache structure if it's a listxattr buf), so that
         * it's no longer found. Then add it to the isolate list,
         * to be freed later.
         *
         * In both cases, we're reverting lock order, so use
         * trylock and skip the entry if we can't get the lock.
         */
        if (entry->xattr_name != NULL) {
                /* Regular cache entry */
                if (!spin_trylock(&bucket->lock))
                        return LRU_SKIP;

                kref_get(&entry->ref);

                hlist_del_init(&entry->hnode);
                atomic_long_dec(&cache->nent);
                list_lru_isolate(lru, &entry->lru);

                spin_unlock(&bucket->lock);
        } else {
                /* Listxattr cache entry */
                if (!spin_trylock(&cache->listxattr_lock))
                        return LRU_SKIP;

                kref_get(&entry->ref);

                cache->listxattr = NULL;
                list_lru_isolate(lru, &entry->lru);

                spin_unlock(&cache->listxattr_lock);
        }

        list_add_tail(&entry->dispose, dispose);
        return LRU_REMOVED;
}

static unsigned long
nfs4_xattr_entry_scan(struct shrinker *shrink, struct shrink_control *sc)
{
        LIST_HEAD(dispose);
        unsigned long freed;
        struct nfs4_xattr_entry *entry;
        struct list_lru *lru;

        lru = (shrink == nfs4_xattr_large_entry_shrinker) ?
            &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;

        freed = list_lru_shrink_walk(lru, sc, entry_lru_isolate, &dispose);

        while (!list_empty(&dispose)) {
                entry = list_first_entry(&dispose, struct nfs4_xattr_entry,
                    dispose);
                list_del_init(&entry->dispose);

                /*
                 * Drop two references: the one that we just grabbed
                 * in entry_lru_isolate, and the one that was set
                 * when the entry was first allocated.
                 */
                kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
                kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
        }

        return freed;
}

static unsigned long
nfs4_xattr_entry_count(struct shrinker *shrink, struct shrink_control *sc)
{
        unsigned long count;
        struct list_lru *lru;

        lru = (shrink == nfs4_xattr_large_entry_shrinker) ?
            &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;

        count = list_lru_shrink_count(lru, sc);
        return vfs_pressure_ratio(count);
}


static void nfs4_xattr_cache_init_once(void *p)
{
        struct nfs4_xattr_cache *cache = p;

        spin_lock_init(&cache->listxattr_lock);
        atomic_long_set(&cache->nent, 0);
        nfs4_xattr_hash_init(cache);
        cache->listxattr = NULL;
        INIT_LIST_HEAD(&cache->lru);
        INIT_LIST_HEAD(&cache->dispose);
}

typedef unsigned long (*count_objects_cb)(struct shrinker *s,
                                          struct shrink_control *sc);
typedef unsigned long (*scan_objects_cb)(struct shrinker *s,
                                         struct shrink_control *sc);

static int __init nfs4_xattr_shrinker_init(struct shrinker **shrinker,
                                           struct list_lru *lru, const char *name,
                                           count_objects_cb count,
                                           scan_objects_cb scan, long batch, int seeks)
{
        int ret;

        *shrinker = shrinker_alloc(SHRINKER_MEMCG_AWARE, name);
        if (!*shrinker)
                return -ENOMEM;

        ret = list_lru_init_memcg(lru, *shrinker);
        if (ret) {
                shrinker_free(*shrinker);
                return ret;
        }

        (*shrinker)->count_objects = count;
        (*shrinker)->scan_objects = scan;
        (*shrinker)->batch = batch;
        (*shrinker)->seeks = seeks;

        shrinker_register(*shrinker);

        return ret;
}

static void nfs4_xattr_shrinker_destroy(struct shrinker *shrinker,
                                        struct list_lru *lru)
{
        shrinker_free(shrinker);
        list_lru_destroy(lru);
}

int __init nfs4_xattr_cache_init(void)
{
        int ret = 0;

        nfs4_xattr_cache_cachep = kmem_cache_create("nfs4_xattr_cache_cache",
            sizeof(struct nfs4_xattr_cache), 0,
            (SLAB_RECLAIM_ACCOUNT),
            nfs4_xattr_cache_init_once);
        if (nfs4_xattr_cache_cachep == NULL)
                return -ENOMEM;

        ret = nfs4_xattr_shrinker_init(&nfs4_xattr_cache_shrinker,
                                       &nfs4_xattr_cache_lru, "nfs-xattr_cache",
                                       nfs4_xattr_cache_count,
                                       nfs4_xattr_cache_scan, 0, DEFAULT_SEEKS);
        if (ret)
                goto out1;

        ret = nfs4_xattr_shrinker_init(&nfs4_xattr_entry_shrinker,
                                       &nfs4_xattr_entry_lru, "nfs-xattr_entry",
                                       nfs4_xattr_entry_count,
                                       nfs4_xattr_entry_scan, 512, DEFAULT_SEEKS);
        if (ret)
                goto out2;

        ret = nfs4_xattr_shrinker_init(&nfs4_xattr_large_entry_shrinker,
                                       &nfs4_xattr_large_entry_lru,
                                       "nfs-xattr_large_entry",
                                       nfs4_xattr_entry_count,
                                       nfs4_xattr_entry_scan, 512, 1);
        if (!ret)
                return 0;

        nfs4_xattr_shrinker_destroy(nfs4_xattr_entry_shrinker,
                                    &nfs4_xattr_entry_lru);
out2:
        nfs4_xattr_shrinker_destroy(nfs4_xattr_cache_shrinker,
                                    &nfs4_xattr_cache_lru);
out1:
        kmem_cache_destroy(nfs4_xattr_cache_cachep);

        return ret;
}

void nfs4_xattr_cache_exit(void)
{
        nfs4_xattr_shrinker_destroy(nfs4_xattr_large_entry_shrinker,
                                    &nfs4_xattr_large_entry_lru);
        nfs4_xattr_shrinker_destroy(nfs4_xattr_entry_shrinker,
                                    &nfs4_xattr_entry_lru);
        nfs4_xattr_shrinker_destroy(nfs4_xattr_cache_shrinker,
                                    &nfs4_xattr_cache_lru);
        kmem_cache_destroy(nfs4_xattr_cache_cachep);
}





































































































































































































































































































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// SPDX-License-Identifier: GPL-2.0-or-later
/* GTP according to GSM TS 09.60 / 3GPP TS 29.060
 *
 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * Author: Harald Welte <hwelte@sysmocom.de>
 *           Pablo Neira Ayuso <pablo@netfilter.org>
 *           Andreas Schultz <aschultz@travelping.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <linux/rculist.h>
#include <linux/jhash.h>
#include <linux/if_tunnel.h>
#include <linux/net.h>
#include <linux/file.h>
#include <linux/gtp.h>

#include <net/flow.h>
#include <net/inet_dscp.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/inet_sock.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/icmp.h>
#include <net/xfrm.h>
#include <net/genetlink.h>
#include <net/netns/generic.h>
#include <net/gtp.h>

/* An active session for the subscriber. */
struct pdp_ctx {
        struct hlist_node        hlist_tid;
        struct hlist_node        hlist_addr;

        union {
                struct {
                        u64        tid;
                        u16        flow;
                } v0;
                struct {
                        u32        i_tei;
                        u32        o_tei;
                } v1;
        } u;
        u8                        gtp_version;
        u16                        af;

        union {
                struct in_addr        addr;
                struct in6_addr        addr6;
        } ms;
        union {
                struct in_addr        addr;
                struct in6_addr        addr6;
        } peer;

        struct sock                *sk;
        struct net_device       *dev;

        atomic_t                tx_seq;
        struct rcu_head                rcu_head;
};

/* One instance of the GTP device. */
struct gtp_dev {
        struct list_head        list;

        struct sock                *sk0;
        struct sock                *sk1u;
        u8                        sk_created;

        struct net_device        *dev;
        struct net                *net;

        unsigned int                role;
        unsigned int                hash_size;
        struct hlist_head        *tid_hash;
        struct hlist_head        *addr_hash;

        u8                        restart_count;
};

struct echo_info {
        u16                        af;
        u8                        gtp_version;

        union {
                struct in_addr        addr;
        } ms;
        union {
                struct in_addr        addr;
        } peer;
};

static unsigned int gtp_net_id __read_mostly;

struct gtp_net {
        struct list_head gtp_dev_list;
};

static u32 gtp_h_initval;

static struct genl_family gtp_genl_family;

enum gtp_multicast_groups {
        GTP_GENL_MCGRP,
};

static const struct genl_multicast_group gtp_genl_mcgrps[] = {
        [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
};

static void pdp_context_delete(struct pdp_ctx *pctx);

static inline u32 gtp0_hashfn(u64 tid)
{
        u32 *tid32 = (u32 *) &tid;
        return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
}

static inline u32 gtp1u_hashfn(u32 tid)
{
        return jhash_1word(tid, gtp_h_initval);
}

static inline u32 ipv4_hashfn(__be32 ip)
{
        return jhash_1word((__force u32)ip, gtp_h_initval);
}

static u32 ipv6_hashfn(const struct in6_addr *ip6)
{
        return jhash_2words((__force u32)ip6->s6_addr32[0],
                            (__force u32)ip6->s6_addr32[1], gtp_h_initval);
}

/* Resolve a PDP context structure based on the 64bit TID. */
static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid, u16 family)
{
        struct hlist_head *head;
        struct pdp_ctx *pdp;

        head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];

        hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
                if (pdp->af == family &&
                    pdp->gtp_version == GTP_V0 &&
                    pdp->u.v0.tid == tid)
                        return pdp;
        }
        return NULL;
}

/* Resolve a PDP context structure based on the 32bit TEI. */
static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid, u16 family)
{
        struct hlist_head *head;
        struct pdp_ctx *pdp;

        head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];

        hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
                if (pdp->af == family &&
                    pdp->gtp_version == GTP_V1 &&
                    pdp->u.v1.i_tei == tid)
                        return pdp;
        }
        return NULL;
}

/* Resolve a PDP context based on IPv4 address of MS. */
static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
{
        struct hlist_head *head;
        struct pdp_ctx *pdp;

        head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];

        hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
                if (pdp->af == AF_INET &&
                    pdp->ms.addr.s_addr == ms_addr)
                        return pdp;
        }

        return NULL;
}

/* 3GPP TS 29.060: PDN Connection: the association between a MS represented by
 * [...] one IPv6 *prefix* and a PDN represented by an APN.
 *
 * Then, 3GPP TS 29.061, Section 11.2.1.3 says: The size of the prefix shall be
 * according to the maximum prefix length for a global IPv6 address as
 * specified in the IPv6 Addressing Architecture, see RFC 4291.
 *
 * Finally, RFC 4291 section 2.5.4 states: All Global Unicast addresses other
 * than those that start with binary 000 have a 64-bit interface ID field
 * (i.e., n + m = 64).
 */
static bool ipv6_pdp_addr_equal(const struct in6_addr *a,
                                const struct in6_addr *b)
{
        return a->s6_addr32[0] == b->s6_addr32[0] &&
               a->s6_addr32[1] == b->s6_addr32[1];
}

static struct pdp_ctx *ipv6_pdp_find(struct gtp_dev *gtp,
                                     const struct in6_addr *ms_addr)
{
        struct hlist_head *head;
        struct pdp_ctx *pdp;

        head = &gtp->addr_hash[ipv6_hashfn(ms_addr) % gtp->hash_size];

        hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
                if (pdp->af == AF_INET6 &&
                    ipv6_pdp_addr_equal(&pdp->ms.addr6, ms_addr))
                        return pdp;
        }

        return NULL;
}

static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
                                  unsigned int hdrlen, unsigned int role)
{
        struct iphdr *iph;

        if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
                return false;

        iph = (struct iphdr *)(skb->data + hdrlen);

        if (role == GTP_ROLE_SGSN)
                return iph->daddr == pctx->ms.addr.s_addr;
        else
                return iph->saddr == pctx->ms.addr.s_addr;
}

static bool gtp_check_ms_ipv6(struct sk_buff *skb, struct pdp_ctx *pctx,
                              unsigned int hdrlen, unsigned int role)
{
        struct ipv6hdr *ip6h;
        int ret;

        if (!pskb_may_pull(skb, hdrlen + sizeof(struct ipv6hdr)))
                return false;

        ip6h = (struct ipv6hdr *)(skb->data + hdrlen);

        if ((ipv6_addr_type(&ip6h->saddr) & IPV6_ADDR_LINKLOCAL) ||
            (ipv6_addr_type(&ip6h->daddr) & IPV6_ADDR_LINKLOCAL))
                return false;

        if (role == GTP_ROLE_SGSN) {
                ret = ipv6_pdp_addr_equal(&ip6h->daddr, &pctx->ms.addr6);
        } else {
                ret = ipv6_pdp_addr_equal(&ip6h->saddr, &pctx->ms.addr6);
        }

        return ret;
}

/* Check if the inner IP address in this packet is assigned to any
 * existing mobile subscriber.
 */
static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
                         unsigned int hdrlen, unsigned int role,
                         __u16 inner_proto)
{
        switch (inner_proto) {
        case ETH_P_IP:
                return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
        case ETH_P_IPV6:
                return gtp_check_ms_ipv6(skb, pctx, hdrlen, role);
        }
        return false;
}

static int gtp_inner_proto(struct sk_buff *skb, unsigned int hdrlen,
                           __u16 *inner_proto)
{
        __u8 *ip_version, _ip_version;

        ip_version = skb_header_pointer(skb, hdrlen, sizeof(*ip_version),
                                        &_ip_version);
        if (!ip_version)
                return -1;

        switch (*ip_version & 0xf0) {
        case 0x40:
                *inner_proto = ETH_P_IP;
                break;
        case 0x60:
                *inner_proto = ETH_P_IPV6;
                break;
        default:
                return -1;
        }

        return 0;
}

static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
                  unsigned int hdrlen, unsigned int role, __u16 inner_proto)
{
        if (!gtp_check_ms(skb, pctx, hdrlen, role, inner_proto)) {
                netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
                return 1;
        }

        /* Get rid of the GTP + UDP headers. */
        if (iptunnel_pull_header(skb, hdrlen, htons(inner_proto),
                         !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
                pctx->dev->stats.rx_length_errors++;
                goto err;
        }

        netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");

        /* Now that the UDP and the GTP header have been removed, set up the
         * new network header. This is required by the upper layer to
         * calculate the transport header.
         */
        skb_reset_network_header(skb);
        skb_reset_mac_header(skb);

        skb->dev = pctx->dev;

        dev_sw_netstats_rx_add(pctx->dev, skb->len);

        __netif_rx(skb);
        return 0;

err:
        pctx->dev->stats.rx_dropped++;
        return -1;
}

static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
                                           const struct sock *sk,
                                           __be32 daddr, __be32 saddr)
{
        memset(fl4, 0, sizeof(*fl4));
        fl4->flowi4_oif                = sk->sk_bound_dev_if;
        fl4->daddr                = daddr;
        fl4->saddr                = saddr;
        fl4->flowi4_dscp        = inet_sk_dscp(inet_sk(sk));
        fl4->flowi4_scope        = ip_sock_rt_scope(sk);
        fl4->flowi4_proto        = sk->sk_protocol;

        return ip_route_output_key(sock_net(sk), fl4);
}

static struct rt6_info *ip6_route_output_gtp(struct net *net,
                                             struct flowi6 *fl6,
                                             const struct sock *sk,
                                             const struct in6_addr *daddr,
                                             struct in6_addr *saddr)
{
        struct dst_entry *dst;

        memset(fl6, 0, sizeof(*fl6));
        fl6->flowi6_oif                = sk->sk_bound_dev_if;
        fl6->daddr                = *daddr;
        fl6->saddr                = *saddr;
        fl6->flowi6_proto        = sk->sk_protocol;

        dst = ipv6_stub->ipv6_dst_lookup_flow(net, sk, fl6, NULL);
        if (IS_ERR(dst))
                return ERR_PTR(-ENETUNREACH);

        return (struct rt6_info *)dst;
}

/* GSM TS 09.60. 7.3
 * In all Path Management messages:
 * - TID: is not used and shall be set to 0.
 * - Flow Label is not used and shall be set to 0
 * In signalling messages:
 * - number: this field is not yet used in signalling messages.
 *   It shall be set to 255 by the sender and shall be ignored
 *   by the receiver
 * Returns true if the echo req was correct, false otherwise.
 */
static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0)
{
        return !(gtp0->tid || (gtp0->flags ^ 0x1e) ||
                gtp0->number != 0xff || gtp0->flow);
}

/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type)
{
        int len_pkt, len_hdr;

        hdr->flags = 0x1e; /* v0, GTP-non-prime. */
        hdr->type = msg_type;
        /* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID
         * are not used and shall be set to 0.
         */
        hdr->flow = 0;
        hdr->tid = 0;
        hdr->number = 0xff;
        hdr->spare[0] = 0xff;
        hdr->spare[1] = 0xff;
        hdr->spare[2] = 0xff;

        len_pkt = sizeof(struct gtp0_packet);
        len_hdr = sizeof(struct gtp0_header);

        if (msg_type == GTP_ECHO_RSP)
                hdr->length = htons(len_pkt - len_hdr);
        else
                hdr->length = 0;
}

static int gtp0_send_echo_resp_ip(struct gtp_dev *gtp, struct sk_buff *skb)
{
        struct iphdr *iph = ip_hdr(skb);
        struct flowi4 fl4;
        struct rtable *rt;

        /* find route to the sender,
         * src address becomes dst address and vice versa.
         */
        rt = ip4_route_output_gtp(&fl4, gtp->sk0, iph->saddr, iph->daddr);
        if (IS_ERR(rt)) {
                netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
                           &iph->saddr);
                return -1;
        }

        udp_tunnel_xmit_skb(rt, gtp->sk0, skb,
                            fl4.saddr, fl4.daddr,
                            iph->tos,
                            ip4_dst_hoplimit(&rt->dst),
                            0,
                            htons(GTP0_PORT), htons(GTP0_PORT),
                            !net_eq(sock_net(gtp->sk1u),
                                    dev_net(gtp->dev)),
                            false,
                            0);

        return 0;
}

static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
{
        struct gtp0_packet *gtp_pkt;
        struct gtp0_header *gtp0;
        __be16 seq;

        gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));

        if (!gtp0_validate_echo_hdr(gtp0))
                return -1;

        seq = gtp0->seq;

        /* pull GTP and UDP headers */
        skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr));

        gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet));
        memset(gtp_pkt, 0, sizeof(struct gtp0_packet));

        gtp0_build_echo_msg(&gtp_pkt->gtp0_h, GTP_ECHO_RSP);

        /* GSM TS 09.60. 7.3 The Sequence Number in a signalling response
         * message shall be copied from the signalling request message
         * that the GSN is replying to.
         */
        gtp_pkt->gtp0_h.seq = seq;

        gtp_pkt->ie.tag = GTPIE_RECOVERY;
        gtp_pkt->ie.val = gtp->restart_count;

        switch (gtp->sk0->sk_family) {
        case AF_INET:
                if (gtp0_send_echo_resp_ip(gtp, skb) < 0)
                        return -1;
                break;
        case AF_INET6:
                return -1;
        }

        return 0;
}

static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
                              int flags, u32 type, struct echo_info echo)
{
        void *genlh;

        genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
                            type);
        if (!genlh)
                goto failure;

        if (nla_put_u32(skb, GTPA_VERSION, echo.gtp_version) ||
            nla_put_be32(skb, GTPA_PEER_ADDRESS, echo.peer.addr.s_addr) ||
            nla_put_be32(skb, GTPA_MS_ADDRESS, echo.ms.addr.s_addr))
                goto failure;

        genlmsg_end(skb, genlh);
        return 0;

failure:
        genlmsg_cancel(skb, genlh);
        return -EMSGSIZE;
}

static void gtp0_handle_echo_resp_ip(struct sk_buff *skb, struct echo_info *echo)
{
        struct iphdr *iph = ip_hdr(skb);

        echo->ms.addr.s_addr = iph->daddr;
        echo->peer.addr.s_addr = iph->saddr;
        echo->gtp_version = GTP_V0;
}

static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
{
        struct gtp0_header *gtp0;
        struct echo_info echo;
        struct sk_buff *msg;
        int ret;

        gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));

        if (!gtp0_validate_echo_hdr(gtp0))
                return -1;

        switch (gtp->sk0->sk_family) {
        case AF_INET:
                gtp0_handle_echo_resp_ip(skb, &echo);
                break;
        case AF_INET6:
                return -1;
        }

        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
        if (!msg)
                return -ENOMEM;

        ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
        if (ret < 0) {
                nlmsg_free(msg);
                return ret;
        }

        return genlmsg_multicast_netns(&gtp_genl_family, dev_net(gtp->dev),
                                       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
}

static int gtp_proto_to_family(__u16 proto)
{
        switch (proto) {
        case ETH_P_IP:
                return AF_INET;
        case ETH_P_IPV6:
                return AF_INET6;
        default:
                WARN_ON_ONCE(1);
                break;
        }

        return AF_UNSPEC;
}

/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
{
        unsigned int hdrlen = sizeof(struct udphdr) +
                              sizeof(struct gtp0_header);
        struct gtp0_header *gtp0;
        struct pdp_ctx *pctx;
        __u16 inner_proto;

        if (!pskb_may_pull(skb, hdrlen))
                return -1;

        gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));

        if ((gtp0->flags >> 5) != GTP_V0)
                return 1;

        /* If the sockets were created in kernel, it means that
         * there is no daemon running in userspace which would
         * handle echo request.
         */
        if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created)
                return gtp0_send_echo_resp(gtp, skb);

        if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created)
                return gtp0_handle_echo_resp(gtp, skb);

        if (gtp0->type != GTP_TPDU)
                return 1;

        if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {
                netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");
                return -1;
        }

        pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid),
                             gtp_proto_to_family(inner_proto));
        if (!pctx) {
                netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
                return 1;
        }

        return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);
}

/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type)
{
        int len_pkt, len_hdr;

        /* S flag must be set to 1 */
        hdr->flags = 0x32; /* v1, GTP-non-prime. */
        hdr->type = msg_type;
        /* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */
        hdr->tid = 0;

        /* seq, npdu and next should be counted to the length of the GTP packet
         * that's why szie of gtp1_header should be subtracted,
         * not size of gtp1_header_long.
         */

        len_hdr = sizeof(struct gtp1_header);

        if (msg_type == GTP_ECHO_RSP) {
                len_pkt = sizeof(struct gtp1u_packet);
                hdr->length = htons(len_pkt - len_hdr);
        } else {
                /* GTP_ECHO_REQ does not carry GTP Information Element,
                 * the why gtp1_header_long is used here.
                 */
                len_pkt = sizeof(struct gtp1_header_long);
                hdr->length = htons(len_pkt - len_hdr);
        }
}

static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
{
        struct gtp1_header_long *gtp1u;
        struct gtp1u_packet *gtp_pkt;
        struct rtable *rt;
        struct flowi4 fl4;
        struct iphdr *iph;

        gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));

        /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
         * Error Indication and Supported Extension Headers Notification
         * messages, the S flag shall be set to 1 and TEID shall be set to 0.
         */
        if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
                return -1;

        /* pull GTP and UDP headers */
        skb_pull_data(skb,
                      sizeof(struct gtp1_header_long) + sizeof(struct udphdr));

        gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet));
        memset(gtp_pkt, 0, sizeof(struct gtp1u_packet));

        gtp1u_build_echo_msg(&gtp_pkt->gtp1u_h, GTP_ECHO_RSP);

        /* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the
         * Recovery information element shall not be used, i.e. it shall
         * be set to zero by the sender and shall be ignored by the receiver.
         * The Recovery information element is mandatory due to backwards
         * compatibility reasons.
         */
        gtp_pkt->ie.tag = GTPIE_RECOVERY;
        gtp_pkt->ie.val = 0;

        iph = ip_hdr(skb);

        /* find route to the sender,
         * src address becomes dst address and vice versa.
         */
        rt = ip4_route_output_gtp(&fl4, gtp->sk1u, iph->saddr, iph->daddr);
        if (IS_ERR(rt)) {
                netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
                           &iph->saddr);
                return -1;
        }

        udp_tunnel_xmit_skb(rt, gtp->sk1u, skb,
                            fl4.saddr, fl4.daddr,
                            iph->tos,
                            ip4_dst_hoplimit(&rt->dst),
                            0,
                            htons(GTP1U_PORT), htons(GTP1U_PORT),
                            !net_eq(sock_net(gtp->sk1u),
                                    dev_net(gtp->dev)),
                            false,
                            0);
        return 0;
}

static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
{
        struct gtp1_header_long *gtp1u;
        struct echo_info echo;
        struct sk_buff *msg;
        struct iphdr *iph;
        int ret;

        gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));

        /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
         * Error Indication and Supported Extension Headers Notification
         * messages, the S flag shall be set to 1 and TEID shall be set to 0.
         */
        if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
                return -1;

        iph = ip_hdr(skb);
        echo.ms.addr.s_addr = iph->daddr;
        echo.peer.addr.s_addr = iph->saddr;
        echo.gtp_version = GTP_V1;

        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
        if (!msg)
                return -ENOMEM;

        ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
        if (ret < 0) {
                nlmsg_free(msg);
                return ret;
        }

        return genlmsg_multicast_netns(&gtp_genl_family, dev_net(gtp->dev),
                                       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
}

static int gtp_parse_exthdrs(struct sk_buff *skb, unsigned int *hdrlen)
{
        struct gtp_ext_hdr *gtp_exthdr, _gtp_exthdr;
        unsigned int offset = *hdrlen;
        __u8 *next_type, _next_type;

        /* From 29.060: "The Extension Header Length field specifies the length
         * of the particular Extension header in 4 octets units."
         *
         * This length field includes length field size itself (1 byte),
         * payload (variable length) and next type (1 byte). The extension
         * header is aligned to to 4 bytes.
         */

        do {
                gtp_exthdr = skb_header_pointer(skb, offset, sizeof(*gtp_exthdr),
                                                &_gtp_exthdr);
                if (!gtp_exthdr || !gtp_exthdr->len)
                        return -1;

                offset += gtp_exthdr->len * 4;

                /* From 29.060: "If no such Header follows, then the value of
                 * the Next Extension Header Type shall be 0."
                 */
                next_type = skb_header_pointer(skb, offset - 1,
                                               sizeof(_next_type), &_next_type);
                if (!next_type)
                        return -1;

        } while (*next_type != 0);

        *hdrlen = offset;

        return 0;
}

static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
{
        unsigned int hdrlen = sizeof(struct udphdr) +
                              sizeof(struct gtp1_header);
        struct gtp1_header *gtp1;
        struct pdp_ctx *pctx;
        __u16 inner_proto;

        if (!pskb_may_pull(skb, hdrlen))
                return -1;

        gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));

        if ((gtp1->flags >> 5) != GTP_V1)
                return 1;

        /* If the sockets were created in kernel, it means that
         * there is no daemon running in userspace which would
         * handle echo request.
         */
        if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created)
                return gtp1u_send_echo_resp(gtp, skb);

        if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created)
                return gtp1u_handle_echo_resp(gtp, skb);

        if (gtp1->type != GTP_TPDU)
                return 1;

        /* From 29.060: "This field shall be present if and only if any one or
         * more of the S, PN and E flags are set.".
         *
         * If any of the bit is set, then the remaining ones also have to be
         * set.
         */
        if (gtp1->flags & GTP1_F_MASK)
                hdrlen += 4;

        /* Make sure the header is larger enough, including extensions. */
        if (!pskb_may_pull(skb, hdrlen))
                return -1;

        if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {
                netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");
                return -1;
        }

        gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));

        pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid),
                             gtp_proto_to_family(inner_proto));
        if (!pctx) {
                netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
                return 1;
        }

        if (gtp1->flags & GTP1_F_EXTHDR &&
            gtp_parse_exthdrs(skb, &hdrlen) < 0)
                return -1;

        return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);
}

static void __gtp_encap_destroy(struct sock *sk)
{
        struct gtp_dev *gtp;

        lock_sock(sk);
        gtp = sk->sk_user_data;
        if (gtp) {
                if (gtp->sk0 == sk)
                        gtp->sk0 = NULL;
                else
                        gtp->sk1u = NULL;
                WRITE_ONCE(udp_sk(sk)->encap_type, 0);
                rcu_assign_sk_user_data(sk, NULL);
                release_sock(sk);
                sock_put(sk);
                return;
        }
        release_sock(sk);
}

static void gtp_encap_destroy(struct sock *sk)
{
        rtnl_lock();
        __gtp_encap_destroy(sk);
        rtnl_unlock();
}

static void gtp_encap_disable_sock(struct sock *sk)
{
        if (!sk)
                return;

        __gtp_encap_destroy(sk);
}

static void gtp_encap_disable(struct gtp_dev *gtp)
{
        if (gtp->sk_created) {
                udp_tunnel_sock_release(gtp->sk0->sk_socket);
                udp_tunnel_sock_release(gtp->sk1u->sk_socket);
                gtp->sk_created = false;
                gtp->sk0 = NULL;
                gtp->sk1u = NULL;
        } else {
                gtp_encap_disable_sock(gtp->sk0);
                gtp_encap_disable_sock(gtp->sk1u);
        }
}

/* UDP encapsulation receive handler. See net/ipv4/udp.c.
 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
 */
static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
{
        struct gtp_dev *gtp;
        int ret = 0;

        gtp = rcu_dereference_sk_user_data(sk);
        if (!gtp)
                return 1;

        netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);

        switch (READ_ONCE(udp_sk(sk)->encap_type)) {
        case UDP_ENCAP_GTP0:
                netdev_dbg(gtp->dev, "received GTP0 packet\n");
                ret = gtp0_udp_encap_recv(gtp, skb);
                break;
        case UDP_ENCAP_GTP1U:
                netdev_dbg(gtp->dev, "received GTP1U packet\n");
                ret = gtp1u_udp_encap_recv(gtp, skb);
                break;
        default:
                ret = -1; /* Shouldn't happen. */
        }

        switch (ret) {
        case 1:
                netdev_dbg(gtp->dev, "pass up to the process\n");
                break;
        case 0:
                break;
        case -1:
                netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
                kfree_skb(skb);
                ret = 0;
                break;
        }

        return ret;
}

static void gtp_dev_uninit(struct net_device *dev)
{
        struct gtp_dev *gtp = netdev_priv(dev);

        gtp_encap_disable(gtp);
}

static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
{
        int payload_len = skb->len;
        struct gtp0_header *gtp0;

        gtp0 = skb_push(skb, sizeof(*gtp0));

        gtp0->flags        = 0x1e; /* v0, GTP-non-prime. */
        gtp0->type        = GTP_TPDU;
        gtp0->length        = htons(payload_len);
        gtp0->seq        = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
        gtp0->flow        = htons(pctx->u.v0.flow);
        gtp0->number        = 0xff;
        gtp0->spare[0]        = gtp0->spare[1] = gtp0->spare[2] = 0xff;
        gtp0->tid        = cpu_to_be64(pctx->u.v0.tid);
}

static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
{
        int payload_len = skb->len;
        struct gtp1_header *gtp1;

        gtp1 = skb_push(skb, sizeof(*gtp1));

        /* Bits    8  7  6  5  4  3  2        1
         *          +--+--+--+--+--+--+--+--+
         *          |version |PT| 0| E| S|PN|
         *          +--+--+--+--+--+--+--+--+
         *            0  0  1  1        1  0  0  0
         */
        gtp1->flags        = 0x30; /* v1, GTP-non-prime. */
        gtp1->type        = GTP_TPDU;
        gtp1->length        = htons(payload_len);
        gtp1->tid        = htonl(pctx->u.v1.o_tei);

        /* TODO: Support for extension header, sequence number and N-PDU.
         *         Update the length field if any of them is available.
         */
}

struct gtp_pktinfo {
        struct sock                *sk;
        union {
                struct flowi4        fl4;
                struct flowi6        fl6;
        };
        union {
                struct rtable        *rt;
                struct rt6_info        *rt6;
        };
        struct pdp_ctx                *pctx;
        struct net_device        *dev;
        __u8                        tos;
        __be16                        gtph_port;
};

static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
{
        switch (pktinfo->pctx->gtp_version) {
        case GTP_V0:
                pktinfo->gtph_port = htons(GTP0_PORT);
                gtp0_push_header(skb, pktinfo->pctx);
                break;
        case GTP_V1:
                pktinfo->gtph_port = htons(GTP1U_PORT);
                gtp1_push_header(skb, pktinfo->pctx);
                break;
        }
}

static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
                                        struct sock *sk, __u8 tos,
                                        struct pdp_ctx *pctx, struct rtable *rt,
                                        struct flowi4 *fl4,
                                        struct net_device *dev)
{
        pktinfo->sk        = sk;
        pktinfo->tos        = tos;
        pktinfo->pctx        = pctx;
        pktinfo->rt        = rt;
        pktinfo->fl4        = *fl4;
        pktinfo->dev        = dev;
}

static void gtp_set_pktinfo_ipv6(struct gtp_pktinfo *pktinfo,
                                 struct sock *sk, __u8 tos,
                                 struct pdp_ctx *pctx, struct rt6_info *rt6,
                                 struct flowi6 *fl6,
                                 struct net_device *dev)
{
        pktinfo->sk        = sk;
        pktinfo->tos        = tos;
        pktinfo->pctx        = pctx;
        pktinfo->rt6        = rt6;
        pktinfo->fl6        = *fl6;
        pktinfo->dev        = dev;
}

static int gtp_build_skb_outer_ip4(struct sk_buff *skb, struct net_device *dev,
                                   struct gtp_pktinfo *pktinfo,
                                   struct pdp_ctx *pctx, __u8 tos,
                                   __be16 frag_off)
{
        struct rtable *rt;
        struct flowi4 fl4;
        __be16 df;
        int mtu;

        rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer.addr.s_addr,
                                  inet_sk(pctx->sk)->inet_saddr);
        if (IS_ERR(rt)) {
                netdev_dbg(dev, "no route to SSGN %pI4\n",
                           &pctx->peer.addr.s_addr);
                dev->stats.tx_carrier_errors++;
                goto err;
        }

        if (rt->dst.dev == dev) {
                netdev_dbg(dev, "circular route to SSGN %pI4\n",
                           &pctx->peer.addr.s_addr);
                dev->stats.collisions++;
                goto err_rt;
        }

        /* This is similar to tnl_update_pmtu(). */
        df = frag_off;
        if (df) {
                mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
                        sizeof(struct iphdr) - sizeof(struct udphdr);
                switch (pctx->gtp_version) {
                case GTP_V0:
                        mtu -= sizeof(struct gtp0_header);
                        break;
                case GTP_V1:
                        mtu -= sizeof(struct gtp1_header);
                        break;
                }
        } else {
                mtu = dst_mtu(&rt->dst);
        }

        skb_dst_update_pmtu_no_confirm(skb, mtu);

        if (frag_off & htons(IP_DF) &&
            ((!skb_is_gso(skb) && skb->len > mtu) ||
             (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) {
                netdev_dbg(dev, "packet too big, fragmentation needed\n");
                icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
                              htonl(mtu));
                goto err_rt;
        }

        gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, tos, pctx, rt, &fl4, dev);
        gtp_push_header(skb, pktinfo);

        return 0;
err_rt:
        ip_rt_put(rt);
err:
        return -EBADMSG;
}

static int gtp_build_skb_outer_ip6(struct net *net, struct sk_buff *skb,
                                   struct net_device *dev,
                                   struct gtp_pktinfo *pktinfo,
                                   struct pdp_ctx *pctx, __u8 tos)
{
        struct dst_entry *dst;
        struct rt6_info *rt;
        struct flowi6 fl6;
        int mtu;

        rt = ip6_route_output_gtp(net, &fl6, pctx->sk, &pctx->peer.addr6,
                                  &inet6_sk(pctx->sk)->saddr);
        if (IS_ERR(rt)) {
                netdev_dbg(dev, "no route to SSGN %pI6\n",
                           &pctx->peer.addr6);
                dev->stats.tx_carrier_errors++;
                goto err;
        }
        dst = &rt->dst;

        if (rt->dst.dev == dev) {
                netdev_dbg(dev, "circular route to SSGN %pI6\n",
                           &pctx->peer.addr6);
                dev->stats.collisions++;
                goto err_rt;
        }

        mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
                sizeof(struct ipv6hdr) - sizeof(struct udphdr);
        switch (pctx->gtp_version) {
        case GTP_V0:
                mtu -= sizeof(struct gtp0_header);
                break;
        case GTP_V1:
                mtu -= sizeof(struct gtp1_header);
                break;
        }

        skb_dst_update_pmtu_no_confirm(skb, mtu);

        if ((!skb_is_gso(skb) && skb->len > mtu) ||
            (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu))) {
                netdev_dbg(dev, "packet too big, fragmentation needed\n");
                icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
                goto err_rt;
        }

        gtp_set_pktinfo_ipv6(pktinfo, pctx->sk, tos, pctx, rt, &fl6, dev);
        gtp_push_header(skb, pktinfo);

        return 0;
err_rt:
        dst_release(dst);
err:
        return -EBADMSG;
}

static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
                             struct gtp_pktinfo *pktinfo)
{
        struct gtp_dev *gtp = netdev_priv(dev);
        struct net *net = gtp->net;
        struct pdp_ctx *pctx;
        struct iphdr *iph;
        int ret;

        /* Read the IP destination address and resolve the PDP context.
         * Prepend PDP header with TEI/TID from PDP ctx.
         */
        iph = ip_hdr(skb);
        if (gtp->role == GTP_ROLE_SGSN)
                pctx = ipv4_pdp_find(gtp, iph->saddr);
        else
                pctx = ipv4_pdp_find(gtp, iph->daddr);

        if (!pctx) {
                netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
                           &iph->daddr);
                return -ENOENT;
        }
        netdev_dbg(dev, "found PDP context %p\n", pctx);

        switch (pctx->sk->sk_family) {
        case AF_INET:
                ret = gtp_build_skb_outer_ip4(skb, dev, pktinfo, pctx,
                                              iph->tos, iph->frag_off);
                break;
        case AF_INET6:
                ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx,
                                              iph->tos);
                break;
        default:
                ret = -1;
                WARN_ON_ONCE(1);
                break;
        }

        if (ret < 0)
                return ret;

        netdev_dbg(dev, "gtp -> IP src: %pI4 dst: %pI4\n",
                   &iph->saddr, &iph->daddr);

        return 0;
}

static int gtp_build_skb_ip6(struct sk_buff *skb, struct net_device *dev,
                             struct gtp_pktinfo *pktinfo)
{
        struct gtp_dev *gtp = netdev_priv(dev);
        struct net *net = gtp->net;
        struct pdp_ctx *pctx;
        struct ipv6hdr *ip6h;
        __u8 tos;
        int ret;

        /* Read the IP destination address and resolve the PDP context.
         * Prepend PDP header with TEI/TID from PDP ctx.
         */
        ip6h = ipv6_hdr(skb);
        if (gtp->role == GTP_ROLE_SGSN)
                pctx = ipv6_pdp_find(gtp, &ip6h->saddr);
        else
                pctx = ipv6_pdp_find(gtp, &ip6h->daddr);

        if (!pctx) {
                netdev_dbg(dev, "no PDP ctx found for %pI6, skip\n",
                           &ip6h->daddr);
                return -ENOENT;
        }
        netdev_dbg(dev, "found PDP context %p\n", pctx);

        tos = ipv6_get_dsfield(ip6h);

        switch (pctx->sk->sk_family) {
        case AF_INET:
                ret = gtp_build_skb_outer_ip4(skb, dev, pktinfo, pctx, tos, 0);
                break;
        case AF_INET6:
                ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx, tos);
                break;
        default:
                ret = -1;
                WARN_ON_ONCE(1);
                break;
        }

        if (ret < 0)
                return ret;

        netdev_dbg(dev, "gtp -> IP src: %pI6 dst: %pI6\n",
                   &ip6h->saddr, &ip6h->daddr);

        return 0;
}

static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
        unsigned int proto = ntohs(skb->protocol);
        struct gtp_pktinfo pktinfo;
        int err;

        /* Ensure there is sufficient headroom. */
        if (skb_cow_head(skb, dev->needed_headroom))
                goto tx_err;

        if (!pskb_inet_may_pull(skb))
                goto tx_err;

        skb_reset_inner_headers(skb);

        /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
        rcu_read_lock();
        switch (proto) {
        case ETH_P_IP:
                err = gtp_build_skb_ip4(skb, dev, &pktinfo);
                break;
        case ETH_P_IPV6:
                err = gtp_build_skb_ip6(skb, dev, &pktinfo);
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }
        rcu_read_unlock();

        if (err < 0)
                goto tx_err;

        switch (pktinfo.pctx->sk->sk_family) {
        case AF_INET:
                udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
                                    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
                                    pktinfo.tos,
                                    ip4_dst_hoplimit(&pktinfo.rt->dst),
                                    0,
                                    pktinfo.gtph_port, pktinfo.gtph_port,
                                    !net_eq(sock_net(pktinfo.pctx->sk),
                                            dev_net(dev)),
                                    false, 0);
                break;
        case AF_INET6:
#if IS_ENABLED(CONFIG_IPV6)
                udp_tunnel6_xmit_skb(&pktinfo.rt6->dst, pktinfo.sk, skb, dev,
                                     &pktinfo.fl6.saddr, &pktinfo.fl6.daddr,
                                     pktinfo.tos,
                                     ip6_dst_hoplimit(&pktinfo.rt->dst),
                                     0,
                                     pktinfo.gtph_port, pktinfo.gtph_port,
                                     false, 0);
#else
                goto tx_err;
#endif
                break;
        }

        return NETDEV_TX_OK;
tx_err:
        dev->stats.tx_errors++;
        dev_kfree_skb(skb);
        return NETDEV_TX_OK;
}

static const struct net_device_ops gtp_netdev_ops = {
        .ndo_uninit                = gtp_dev_uninit,
        .ndo_start_xmit                = gtp_dev_xmit,
};

static const struct device_type gtp_type = {
        .name = "gtp",
};

#define GTP_TH_MAXLEN        (sizeof(struct udphdr) + sizeof(struct gtp0_header))
#define GTP_IPV4_MAXLEN        (sizeof(struct iphdr) + GTP_TH_MAXLEN)

static void gtp_link_setup(struct net_device *dev)
{
        struct gtp_dev *gtp = netdev_priv(dev);

        dev->netdev_ops                = &gtp_netdev_ops;
        dev->needs_free_netdev        = true;
        SET_NETDEV_DEVTYPE(dev, &gtp_type);

        dev->hard_header_len = 0;
        dev->addr_len = 0;
        dev->mtu = ETH_DATA_LEN - GTP_IPV4_MAXLEN;

        /* Zero header length. */
        dev->type = ARPHRD_NONE;
        dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;

        dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
        dev->priv_flags        |= IFF_NO_QUEUE;
        dev->lltx = true;
        netif_keep_dst(dev);

        dev->needed_headroom        = LL_MAX_HEADER + GTP_IPV4_MAXLEN;
        gtp->dev = dev;
}

static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);

static void gtp_destructor(struct net_device *dev)
{
        struct gtp_dev *gtp = netdev_priv(dev);

        kfree(gtp->addr_hash);
        kfree(gtp->tid_hash);
}

static int gtp_sock_udp_config(struct udp_port_cfg *udp_conf,
                               const struct nlattr *nla, int family)
{
        udp_conf->family = family;

        switch (udp_conf->family) {
        case AF_INET:
                udp_conf->local_ip.s_addr = nla_get_be32(nla);
                break;
#if IS_ENABLED(CONFIG_IPV6)
        case AF_INET6:
                udp_conf->local_ip6 = nla_get_in6_addr(nla);
                break;
#endif
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp,
                                    const struct nlattr *nla, int family)
{
        struct udp_tunnel_sock_cfg tuncfg = {};
        struct udp_port_cfg udp_conf = {};
        struct net *net = gtp->net;
        struct socket *sock;
        int err;

        if (nla) {
                err = gtp_sock_udp_config(&udp_conf, nla, family);
                if (err < 0)
                        return ERR_PTR(err);
        } else {
                udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
                udp_conf.family = AF_INET;
        }

        if (type == UDP_ENCAP_GTP0)
                udp_conf.local_udp_port = htons(GTP0_PORT);
        else if (type == UDP_ENCAP_GTP1U)
                udp_conf.local_udp_port = htons(GTP1U_PORT);
        else
                return ERR_PTR(-EINVAL);

        err = udp_sock_create(net, &udp_conf, &sock);
        if (err)
                return ERR_PTR(err);

        tuncfg.sk_user_data = gtp;
        tuncfg.encap_type = type;
        tuncfg.encap_rcv = gtp_encap_recv;
        tuncfg.encap_destroy = NULL;

        setup_udp_tunnel_sock(net, sock, &tuncfg);

        return sock->sk;
}

static int gtp_create_sockets(struct gtp_dev *gtp, const struct nlattr *nla,
                              int family)
{
        struct sock *sk1u;
        struct sock *sk0;

        sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp, nla, family);
        if (IS_ERR(sk0))
                return PTR_ERR(sk0);

        sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp, nla, family);
        if (IS_ERR(sk1u)) {
                udp_tunnel_sock_release(sk0->sk_socket);
                return PTR_ERR(sk1u);
        }

        gtp->sk_created = true;
        gtp->sk0 = sk0;
        gtp->sk1u = sk1u;

        return 0;
}

#define GTP_TH_MAXLEN        (sizeof(struct udphdr) + sizeof(struct gtp0_header))
#define GTP_IPV6_MAXLEN        (sizeof(struct ipv6hdr) + GTP_TH_MAXLEN)

static int gtp_newlink(struct net_device *dev,
                       struct rtnl_newlink_params *params,
                       struct netlink_ext_ack *extack)
{
        struct net *link_net = rtnl_newlink_link_net(params);
        struct nlattr **data = params->data;
        unsigned int role = GTP_ROLE_GGSN;
        struct gtp_dev *gtp;
        struct gtp_net *gn;
        int hashsize, err;

#if !IS_ENABLED(CONFIG_IPV6)
        if (data[IFLA_GTP_LOCAL6])
                return -EAFNOSUPPORT;
#endif

        gtp = netdev_priv(dev);

        if (!data[IFLA_GTP_PDP_HASHSIZE]) {
                hashsize = 1024;
        } else {
                hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
                if (!hashsize)
                        hashsize = 1024;
        }

        if (data[IFLA_GTP_ROLE]) {
                role = nla_get_u32(data[IFLA_GTP_ROLE]);
                if (role > GTP_ROLE_SGSN)
                        return -EINVAL;
        }
        gtp->role = role;

        gtp->restart_count = nla_get_u8_default(data[IFLA_GTP_RESTART_COUNT],
                                                0);

        gtp->net = link_net;

        err = gtp_hashtable_new(gtp, hashsize);
        if (err < 0)
                return err;

        if (data[IFLA_GTP_CREATE_SOCKETS]) {
                if (data[IFLA_GTP_LOCAL6])
                        err = gtp_create_sockets(gtp, data[IFLA_GTP_LOCAL6], AF_INET6);
                else
                        err = gtp_create_sockets(gtp, data[IFLA_GTP_LOCAL], AF_INET);
        } else {
                err = gtp_encap_enable(gtp, data);
        }

        if (err < 0)
                goto out_hashtable;

        if ((gtp->sk0 && gtp->sk0->sk_family == AF_INET6) ||
            (gtp->sk1u && gtp->sk1u->sk_family == AF_INET6)) {
                dev->mtu = ETH_DATA_LEN - GTP_IPV6_MAXLEN;
                dev->needed_headroom = LL_MAX_HEADER + GTP_IPV6_MAXLEN;
        }

        err = register_netdevice(dev);
        if (err < 0) {
                netdev_dbg(dev, "failed to register new netdev %d\n", err);
                goto out_encap;
        }

        gn = net_generic(link_net, gtp_net_id);
        list_add(&gtp->list, &gn->gtp_dev_list);
        dev->priv_destructor = gtp_destructor;

        netdev_dbg(dev, "registered new GTP interface\n");

        return 0;

out_encap:
        gtp_encap_disable(gtp);
out_hashtable:
        kfree(gtp->addr_hash);
        kfree(gtp->tid_hash);
        return err;
}

static void gtp_dellink(struct net_device *dev, struct list_head *head)
{
        struct gtp_dev *gtp = netdev_priv(dev);
        struct hlist_node *next;
        struct pdp_ctx *pctx;
        int i;

        for (i = 0; i < gtp->hash_size; i++)
                hlist_for_each_entry_safe(pctx, next, &gtp->tid_hash[i], hlist_tid)
                        pdp_context_delete(pctx);

        list_del(&gtp->list);
        unregister_netdevice_queue(dev, head);
}

static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
        [IFLA_GTP_FD0]                        = { .type = NLA_U32 },
        [IFLA_GTP_FD1]                        = { .type = NLA_U32 },
        [IFLA_GTP_PDP_HASHSIZE]                = { .type = NLA_U32 },
        [IFLA_GTP_ROLE]                        = { .type = NLA_U32 },
        [IFLA_GTP_CREATE_SOCKETS]        = { .type = NLA_U8 },
        [IFLA_GTP_RESTART_COUNT]        = { .type = NLA_U8 },
        [IFLA_GTP_LOCAL]                = { .type = NLA_U32 },
        [IFLA_GTP_LOCAL6]                = { .len = sizeof(struct in6_addr) },
};

static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
                        struct netlink_ext_ack *extack)
{
        if (!data)
                return -EINVAL;

        return 0;
}

static size_t gtp_get_size(const struct net_device *dev)
{
        return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
                nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */
                nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */
}

static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
        struct gtp_dev *gtp = netdev_priv(dev);

        if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
                goto nla_put_failure;
        if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
                goto nla_put_failure;
        if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count))
                goto nla_put_failure;

        return 0;

nla_put_failure:
        return -EMSGSIZE;
}

static struct rtnl_link_ops gtp_link_ops __read_mostly = {
        .kind                = "gtp",
        .maxtype        = IFLA_GTP_MAX,
        .policy                = gtp_policy,
        .priv_size        = sizeof(struct gtp_dev),
        .setup                = gtp_link_setup,
        .validate        = gtp_validate,
        .newlink        = gtp_newlink,
        .dellink        = gtp_dellink,
        .get_size        = gtp_get_size,
        .fill_info        = gtp_fill_info,
};

static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
{
        int i;

        gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
                                       GFP_KERNEL | __GFP_NOWARN);
        if (gtp->addr_hash == NULL)
                return -ENOMEM;

        gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
                                      GFP_KERNEL | __GFP_NOWARN);
        if (gtp->tid_hash == NULL)
                goto err1;

        gtp->hash_size = hsize;

        for (i = 0; i < hsize; i++) {
                INIT_HLIST_HEAD(&gtp->addr_hash[i]);
                INIT_HLIST_HEAD(&gtp->tid_hash[i]);
        }
        return 0;
err1:
        kfree(gtp->addr_hash);
        return -ENOMEM;
}

static struct sock *gtp_encap_enable_socket(int fd, int type,
                                            struct gtp_dev *gtp)
{
        struct udp_tunnel_sock_cfg tuncfg = {NULL};
        struct socket *sock;
        struct sock *sk;
        int err;

        pr_debug("enable gtp on %d, %d\n", fd, type);

        sock = sockfd_lookup(fd, &err);
        if (!sock) {
                pr_debug("gtp socket fd=%d not found\n", fd);
                return ERR_PTR(err);
        }

        sk = sock->sk;
        if (sk->sk_protocol != IPPROTO_UDP ||
            sk->sk_type != SOCK_DGRAM ||
            (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
                pr_debug("socket fd=%d not UDP\n", fd);
                sk = ERR_PTR(-EINVAL);
                goto out_sock;
        }

        if (sk->sk_family == AF_INET6 &&
            !sk->sk_ipv6only) {
                sk = ERR_PTR(-EADDRNOTAVAIL);
                goto out_sock;
        }

        lock_sock(sk);
        if (sk->sk_user_data) {
                sk = ERR_PTR(-EBUSY);
                goto out_rel_sock;
        }

        sock_hold(sk);

        tuncfg.sk_user_data = gtp;
        tuncfg.encap_type = type;
        tuncfg.encap_rcv = gtp_encap_recv;
        tuncfg.encap_destroy = gtp_encap_destroy;

        setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);

out_rel_sock:
        release_sock(sock->sk);
out_sock:
        sockfd_put(sock);
        return sk;
}

static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
{
        struct sock *sk1u = NULL;
        struct sock *sk0 = NULL;

        if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
                return -EINVAL;

        if (data[IFLA_GTP_FD0]) {
                int fd0 = nla_get_u32(data[IFLA_GTP_FD0]);

                if (fd0 >= 0) {
                        sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
                        if (IS_ERR(sk0))
                                return PTR_ERR(sk0);
                }
        }

        if (data[IFLA_GTP_FD1]) {
                int fd1 = nla_get_u32(data[IFLA_GTP_FD1]);

                if (fd1 >= 0) {
                        sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
                        if (IS_ERR(sk1u)) {
                                gtp_encap_disable_sock(sk0);
                                return PTR_ERR(sk1u);
                        }
                }
        }

        gtp->sk0 = sk0;
        gtp->sk1u = sk1u;

        if (sk0 && sk1u &&
            sk0->sk_family != sk1u->sk_family) {
                gtp_encap_disable_sock(sk0);
                gtp_encap_disable_sock(sk1u);
                return -EINVAL;
        }

        return 0;
}

static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
{
        struct gtp_dev *gtp = NULL;
        struct net_device *dev;
        struct net *net;

        /* Examine the link attributes and figure out which network namespace
         * we are talking about.
         */
        if (nla[GTPA_NET_NS_FD])
                net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
        else
                net = get_net(src_net);

        if (IS_ERR(net))
                return NULL;

        /* Check if there's an existing gtpX device to configure */
        dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
        if (dev && dev->netdev_ops == &gtp_netdev_ops)
                gtp = netdev_priv(dev);

        put_net(net);
        return gtp;
}

static void gtp_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
{
        pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);

        switch (pctx->gtp_version) {
        case GTP_V0:
                /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
                 * label needs to be the same for uplink and downlink packets,
                 * so let's annotate this.
                 */
                pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
                pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
                break;
        case GTP_V1:
                pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
                pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
                break;
        default:
                break;
        }
}

static void ip_pdp_peer_fill(struct pdp_ctx *pctx, struct genl_info *info)
{
        if (info->attrs[GTPA_PEER_ADDRESS]) {
                pctx->peer.addr.s_addr =
                        nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
        } else if (info->attrs[GTPA_PEER_ADDR6]) {
                pctx->peer.addr6 = nla_get_in6_addr(info->attrs[GTPA_PEER_ADDR6]);
        }
}

static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
{
        ip_pdp_peer_fill(pctx, info);
        pctx->ms.addr.s_addr =
                nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
        gtp_pdp_fill(pctx, info);
}

static bool ipv6_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
{
        ip_pdp_peer_fill(pctx, info);
        pctx->ms.addr6 = nla_get_in6_addr(info->attrs[GTPA_MS_ADDR6]);
        if (pctx->ms.addr6.s6_addr32[2] ||
            pctx->ms.addr6.s6_addr32[3])
                return false;

        gtp_pdp_fill(pctx, info);

        return true;
}

static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
                                   struct genl_info *info)
{
        struct pdp_ctx *pctx, *pctx_tid = NULL;
        struct net_device *dev = gtp->dev;
        u32 hash_ms, hash_tid = 0;
        struct in6_addr ms_addr6;
        unsigned int version;
        bool found = false;
        __be32 ms_addr;
        int family;

        version = nla_get_u32(info->attrs[GTPA_VERSION]);

        family = nla_get_u8_default(info->attrs[GTPA_FAMILY], AF_INET);

#if !IS_ENABLED(CONFIG_IPV6)
        if (family == AF_INET6)
                return ERR_PTR(-EAFNOSUPPORT);
#endif
        if (!info->attrs[GTPA_PEER_ADDRESS] &&
            !info->attrs[GTPA_PEER_ADDR6])
                return ERR_PTR(-EINVAL);

        if ((info->attrs[GTPA_PEER_ADDRESS] &&
             sk->sk_family == AF_INET6) ||
            (info->attrs[GTPA_PEER_ADDR6] &&
             sk->sk_family == AF_INET))
                return ERR_PTR(-EAFNOSUPPORT);

        switch (family) {
        case AF_INET:
                if (!info->attrs[GTPA_MS_ADDRESS] ||
                    info->attrs[GTPA_MS_ADDR6])
                        return ERR_PTR(-EINVAL);

                ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
                hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
                pctx = ipv4_pdp_find(gtp, ms_addr);
                break;
        case AF_INET6:
                if (!info->attrs[GTPA_MS_ADDR6] ||
                    info->attrs[GTPA_MS_ADDRESS])
                        return ERR_PTR(-EINVAL);

                ms_addr6 = nla_get_in6_addr(info->attrs[GTPA_MS_ADDR6]);
                hash_ms = ipv6_hashfn(&ms_addr6) % gtp->hash_size;
                pctx = ipv6_pdp_find(gtp, &ms_addr6);
                break;
        default:
                return ERR_PTR(-EAFNOSUPPORT);
        }
        if (pctx)
                found = true;
        if (version == GTP_V0)
                pctx_tid = gtp0_pdp_find(gtp,
                                         nla_get_u64(info->attrs[GTPA_TID]),
                                         family);
        else if (version == GTP_V1)
                pctx_tid = gtp1_pdp_find(gtp,
                                         nla_get_u32(info->attrs[GTPA_I_TEI]),
                                         family);
        if (pctx_tid)
                found = true;

        if (found) {
                if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
                        return ERR_PTR(-EEXIST);
                if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
                        return ERR_PTR(-EOPNOTSUPP);

                if (pctx && pctx_tid)
                        return ERR_PTR(-EEXIST);
                if (!pctx)
                        pctx = pctx_tid;

                switch (pctx->af) {
                case AF_INET:
                        ipv4_pdp_fill(pctx, info);
                        break;
                case AF_INET6:
                        if (!ipv6_pdp_fill(pctx, info))
                                return ERR_PTR(-EADDRNOTAVAIL);
                        break;
                }

                if (pctx->gtp_version == GTP_V0)
                        netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
                                   pctx->u.v0.tid, pctx);
                else if (pctx->gtp_version == GTP_V1)
                        netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
                                   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);

                return pctx;

        }

        pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
        if (pctx == NULL)
                return ERR_PTR(-ENOMEM);

        sock_hold(sk);
        pctx->sk = sk;
        pctx->dev = gtp->dev;
        pctx->af = family;

        switch (pctx->af) {
        case AF_INET:
                if (!info->attrs[GTPA_MS_ADDRESS]) {
                        sock_put(sk);
                        kfree(pctx);
                        return ERR_PTR(-EINVAL);
                }

                ipv4_pdp_fill(pctx, info);
                break;
        case AF_INET6:
                if (!info->attrs[GTPA_MS_ADDR6]) {
                        sock_put(sk);
                        kfree(pctx);
                        return ERR_PTR(-EINVAL);
                }

                if (!ipv6_pdp_fill(pctx, info)) {
                        sock_put(sk);
                        kfree(pctx);
                        return ERR_PTR(-EADDRNOTAVAIL);
                }
                break;
        }
        atomic_set(&pctx->tx_seq, 0);

        switch (pctx->gtp_version) {
        case GTP_V0:
                /* TS 09.60: "The flow label identifies unambiguously a GTP
                 * flow.". We use the tid for this instead, I cannot find a
                 * situation in which this doesn't unambiguosly identify the
                 * PDP context.
                 */
                hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
                break;
        case GTP_V1:
                hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
                break;
        }

        hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
        hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);

        switch (pctx->gtp_version) {
        case GTP_V0:
                netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
                           pctx->u.v0.tid, &pctx->peer.addr,
                           &pctx->ms.addr, pctx);
                break;
        case GTP_V1:
                netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
                           pctx->u.v1.i_tei, pctx->u.v1.o_tei,
                           &pctx->peer.addr, &pctx->ms.addr, pctx);
                break;
        }

        return pctx;
}

static void pdp_context_free(struct rcu_head *head)
{
        struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);

        sock_put(pctx->sk);
        kfree(pctx);
}

static void pdp_context_delete(struct pdp_ctx *pctx)
{
        hlist_del_rcu(&pctx->hlist_tid);
        hlist_del_rcu(&pctx->hlist_addr);
        call_rcu(&pctx->rcu_head, pdp_context_free);
}

static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);

static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
{
        unsigned int version;
        struct pdp_ctx *pctx;
        struct gtp_dev *gtp;
        struct sock *sk;
        int err;

        if (!info->attrs[GTPA_VERSION] ||
            !info->attrs[GTPA_LINK])
                return -EINVAL;

        version = nla_get_u32(info->attrs[GTPA_VERSION]);

        switch (version) {
        case GTP_V0:
                if (!info->attrs[GTPA_TID] ||
                    !info->attrs[GTPA_FLOW])
                        return -EINVAL;
                break;
        case GTP_V1:
                if (!info->attrs[GTPA_I_TEI] ||
                    !info->attrs[GTPA_O_TEI])
                        return -EINVAL;
                break;

        default:
                return -EINVAL;
        }

        rtnl_lock();

        gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
        if (!gtp) {
                err = -ENODEV;
                goto out_unlock;
        }

        if (version == GTP_V0)
                sk = gtp->sk0;
        else if (version == GTP_V1)
                sk = gtp->sk1u;
        else
                sk = NULL;

        if (!sk) {
                err = -ENODEV;
                goto out_unlock;
        }

        pctx = gtp_pdp_add(gtp, sk, info);
        if (IS_ERR(pctx)) {
                err = PTR_ERR(pctx);
        } else {
                gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
                err = 0;
        }

out_unlock:
        rtnl_unlock();
        return err;
}

static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
                                            struct nlattr *nla[])
{
        struct gtp_dev *gtp;
        int family;

        family = nla_get_u8_default(nla[GTPA_FAMILY], AF_INET);

        gtp = gtp_find_dev(net, nla);
        if (!gtp)
                return ERR_PTR(-ENODEV);

        if (nla[GTPA_MS_ADDRESS]) {
                __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);

                if (family != AF_INET)
                        return ERR_PTR(-EINVAL);

                return ipv4_pdp_find(gtp, ip);
        } else if (nla[GTPA_MS_ADDR6]) {
                struct in6_addr addr = nla_get_in6_addr(nla[GTPA_MS_ADDR6]);

                if (family != AF_INET6)
                        return ERR_PTR(-EINVAL);

                if (addr.s6_addr32[2] ||
                    addr.s6_addr32[3])
                        return ERR_PTR(-EADDRNOTAVAIL);

                return ipv6_pdp_find(gtp, &addr);
        } else if (nla[GTPA_VERSION]) {
                u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);

                if (gtp_version == GTP_V0 && nla[GTPA_TID]) {
                        return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]),
                                             family);
                } else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) {
                        return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]),
                                             family);
                }
        }

        return ERR_PTR(-EINVAL);
}

static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
{
        struct pdp_ctx *pctx;

        if (nla[GTPA_LINK])
                pctx = gtp_find_pdp_by_link(net, nla);
        else
                pctx = ERR_PTR(-EINVAL);

        if (!pctx)
                pctx = ERR_PTR(-ENOENT);

        return pctx;
}

static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
{
        struct pdp_ctx *pctx;
        int err = 0;

        if (!info->attrs[GTPA_VERSION])
                return -EINVAL;

        rcu_read_lock();

        pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
        if (IS_ERR(pctx)) {
                err = PTR_ERR(pctx);
                goto out_unlock;
        }

        if (pctx->gtp_version == GTP_V0)
                netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
                           pctx->u.v0.tid, pctx);
        else if (pctx->gtp_version == GTP_V1)
                netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
                           pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);

        gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
        pdp_context_delete(pctx);

out_unlock:
        rcu_read_unlock();
        return err;
}

static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
                              int flags, u32 type, struct pdp_ctx *pctx)
{
        void *genlh;

        genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
                            type);
        if (genlh == NULL)
                goto nlmsg_failure;

        if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
            nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
            nla_put_u8(skb, GTPA_FAMILY, pctx->af))
                goto nla_put_failure;

        switch (pctx->af) {
        case AF_INET:
                if (nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms.addr.s_addr))
                        goto nla_put_failure;
                break;
        case AF_INET6:
                if (nla_put_in6_addr(skb, GTPA_MS_ADDR6, &pctx->ms.addr6))
                        goto nla_put_failure;
                break;
        }

        switch (pctx->sk->sk_family) {
        case AF_INET:
                if (nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer.addr.s_addr))
                        goto nla_put_failure;
                break;
        case AF_INET6:
                if (nla_put_in6_addr(skb, GTPA_PEER_ADDR6, &pctx->peer.addr6))
                        goto nla_put_failure;
                break;
        }

        switch (pctx->gtp_version) {
        case GTP_V0:
                if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
                    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
                        goto nla_put_failure;
                break;
        case GTP_V1:
                if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
                    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
                        goto nla_put_failure;
                break;
        }
        genlmsg_end(skb, genlh);
        return 0;

nlmsg_failure:
nla_put_failure:
        genlmsg_cancel(skb, genlh);
        return -EMSGSIZE;
}

static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
{
        struct sk_buff *msg;
        int ret;

        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
        if (!msg)
                return -ENOMEM;

        ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
        if (ret < 0) {
                nlmsg_free(msg);
                return ret;
        }

        ret = genlmsg_multicast_netns(&gtp_genl_family, dev_net(pctx->dev), msg,
                                      0, GTP_GENL_MCGRP, GFP_ATOMIC);
        return ret;
}

static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
{
        struct pdp_ctx *pctx = NULL;
        struct sk_buff *skb2;
        int err;

        if (!info->attrs[GTPA_VERSION])
                return -EINVAL;

        rcu_read_lock();

        pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
        if (IS_ERR(pctx)) {
                err = PTR_ERR(pctx);
                goto err_unlock;
        }

        skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
        if (skb2 == NULL) {
                err = -ENOMEM;
                goto err_unlock;
        }

        err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
                                 0, info->nlhdr->nlmsg_type, pctx);
        if (err < 0)
                goto err_unlock_free;

        rcu_read_unlock();
        return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);

err_unlock_free:
        kfree_skb(skb2);
err_unlock:
        rcu_read_unlock();
        return err;
}

static int gtp_genl_dump_pdp(struct sk_buff *skb,
                                struct netlink_callback *cb)
{
        struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
        int i, j, bucket = cb->args[0], skip = cb->args[1];
        struct net *net = sock_net(skb->sk);
        struct net_device *dev;
        struct pdp_ctx *pctx;

        if (cb->args[4])
                return 0;

        rcu_read_lock();
        for_each_netdev_rcu(net, dev) {
                if (dev->rtnl_link_ops != &gtp_link_ops)
                        continue;

                gtp = netdev_priv(dev);

                if (last_gtp && last_gtp != gtp)
                        continue;
                else
                        last_gtp = NULL;

                for (i = bucket; i < gtp->hash_size; i++) {
                        j = 0;
                        hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
                                                 hlist_tid) {
                                if (j >= skip &&
                                    gtp_genl_fill_info(skb,
                                            NETLINK_CB(cb->skb).portid,
                                            cb->nlh->nlmsg_seq,
                                            NLM_F_MULTI,
                                            cb->nlh->nlmsg_type, pctx)) {
                                        cb->args[0] = i;
                                        cb->args[1] = j;
                                        cb->args[2] = (unsigned long)gtp;
                                        goto out;
                                }
                                j++;
                        }
                        skip = 0;
                }
                bucket = 0;
        }
        cb->args[4] = 1;
out:
        rcu_read_unlock();
        return skb->len;
}

static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
{
        struct sk_buff *skb_to_send;
        __be32 src_ip, dst_ip;
        unsigned int version;
        struct gtp_dev *gtp;
        struct flowi4 fl4;
        struct rtable *rt;
        struct sock *sk;
        __be16 port;
        int len;

        if (!info->attrs[GTPA_VERSION] ||
            !info->attrs[GTPA_LINK] ||
            !info->attrs[GTPA_PEER_ADDRESS] ||
            !info->attrs[GTPA_MS_ADDRESS])
                return -EINVAL;

        version = nla_get_u32(info->attrs[GTPA_VERSION]);
        dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
        src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);

        gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
        if (!gtp)
                return -ENODEV;

        if (!gtp->sk_created)
                return -EOPNOTSUPP;
        if (!(gtp->dev->flags & IFF_UP))
                return -ENETDOWN;

        if (version == GTP_V0) {
                struct gtp0_header *gtp0_h;

                len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
                        sizeof(struct iphdr) + sizeof(struct udphdr);

                skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
                if (!skb_to_send)
                        return -ENOMEM;

                sk = gtp->sk0;
                port = htons(GTP0_PORT);

                gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
                memset(gtp0_h, 0, sizeof(struct gtp0_header));
                gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
        } else if (version == GTP_V1) {
                struct gtp1_header_long *gtp1u_h;

                len = LL_RESERVED_SPACE(gtp->dev) +
                        sizeof(struct gtp1_header_long) +
                        sizeof(struct iphdr) + sizeof(struct udphdr);

                skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
                if (!skb_to_send)
                        return -ENOMEM;

                sk = gtp->sk1u;
                port = htons(GTP1U_PORT);

                gtp1u_h = skb_push(skb_to_send,
                                   sizeof(struct gtp1_header_long));
                memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
                gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
        } else {
                return -ENODEV;
        }

        rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
        if (IS_ERR(rt)) {
                netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
                           &dst_ip);
                kfree_skb(skb_to_send);
                return -ENODEV;
        }

        udp_tunnel_xmit_skb(rt, sk, skb_to_send,
                            fl4.saddr, fl4.daddr,
                            inet_dscp_to_dsfield(fl4.flowi4_dscp),
                            ip4_dst_hoplimit(&rt->dst),
                            0,
                            port, port,
                            !net_eq(sock_net(sk),
                                    dev_net(gtp->dev)),
                            false, 0);
        return 0;
}

static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
        [GTPA_LINK]                = { .type = NLA_U32, },
        [GTPA_VERSION]                = { .type = NLA_U32, },
        [GTPA_TID]                = { .type = NLA_U64, },
        [GTPA_PEER_ADDRESS]        = { .type = NLA_U32, },
        [GTPA_MS_ADDRESS]        = { .type = NLA_U32, },
        [GTPA_FLOW]                = { .type = NLA_U16, },
        [GTPA_NET_NS_FD]        = { .type = NLA_U32, },
        [GTPA_I_TEI]                = { .type = NLA_U32, },
        [GTPA_O_TEI]                = { .type = NLA_U32, },
        [GTPA_PEER_ADDR6]        = { .len = sizeof(struct in6_addr), },
        [GTPA_MS_ADDR6]                = { .len = sizeof(struct in6_addr), },
        [GTPA_FAMILY]                = { .type = NLA_U8, },
};

static const struct genl_small_ops gtp_genl_ops[] = {
        {
                .cmd = GTP_CMD_NEWPDP,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = gtp_genl_new_pdp,
                .flags = GENL_ADMIN_PERM,
        },
        {
                .cmd = GTP_CMD_DELPDP,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = gtp_genl_del_pdp,
                .flags = GENL_ADMIN_PERM,
        },
        {
                .cmd = GTP_CMD_GETPDP,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = gtp_genl_get_pdp,
                .dumpit = gtp_genl_dump_pdp,
                .flags = GENL_ADMIN_PERM,
        },
        {
                .cmd = GTP_CMD_ECHOREQ,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = gtp_genl_send_echo_req,
                .flags = GENL_ADMIN_PERM,
        },
};

static struct genl_family gtp_genl_family __ro_after_init = {
        .name                = "gtp",
        .version        = 0,
        .hdrsize        = 0,
        .maxattr        = GTPA_MAX,
        .policy = gtp_genl_policy,
        .netnsok        = true,
        .module                = THIS_MODULE,
        .small_ops        = gtp_genl_ops,
        .n_small_ops        = ARRAY_SIZE(gtp_genl_ops),
        .resv_start_op        = GTP_CMD_ECHOREQ + 1,
        .mcgrps                = gtp_genl_mcgrps,
        .n_mcgrps        = ARRAY_SIZE(gtp_genl_mcgrps),
};

static int __net_init gtp_net_init(struct net *net)
{
        struct gtp_net *gn = net_generic(net, gtp_net_id);

        INIT_LIST_HEAD(&gn->gtp_dev_list);
        return 0;
}

static void __net_exit gtp_net_exit_rtnl(struct net *net,
                                         struct list_head *dev_to_kill)
{
        struct gtp_net *gn = net_generic(net, gtp_net_id);
        struct gtp_dev *gtp, *gtp_next;

        list_for_each_entry_safe(gtp, gtp_next, &gn->gtp_dev_list, list)
                gtp_dellink(gtp->dev, dev_to_kill);
}

static struct pernet_operations gtp_net_ops = {
        .init        = gtp_net_init,
        .exit_rtnl = gtp_net_exit_rtnl,
        .id        = &gtp_net_id,
        .size        = sizeof(struct gtp_net),
};

static int __init gtp_init(void)
{
        int err;

        get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));

        err = register_pernet_subsys(&gtp_net_ops);
        if (err < 0)
                goto error_out;

        err = rtnl_link_register(&gtp_link_ops);
        if (err < 0)
                goto unreg_pernet_subsys;

        err = genl_register_family(&gtp_genl_family);
        if (err < 0)
                goto unreg_rtnl_link;

        pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
                sizeof(struct pdp_ctx));
        return 0;

unreg_rtnl_link:
        rtnl_link_unregister(&gtp_link_ops);
unreg_pernet_subsys:
        unregister_pernet_subsys(&gtp_net_ops);
error_out:
        pr_err("error loading GTP module loaded\n");
        return err;
}
late_initcall(gtp_init);

static void __exit gtp_fini(void)
{
        genl_unregister_family(&gtp_genl_family);
        rtnl_link_unregister(&gtp_link_ops);
        unregister_pernet_subsys(&gtp_net_ops);

        pr_info("GTP module unloaded\n");
}
module_exit(gtp_fini);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
MODULE_ALIAS_RTNL_LINK("gtp");
MODULE_ALIAS_GENL_FAMILY("gtp");





























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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_VIRTIO_RING_H
#define _LINUX_VIRTIO_RING_H

#include <asm/barrier.h>
#include <linux/virtio.h>
#include <linux/irqreturn.h>
#include <uapi/linux/virtio_ring.h>

/*
 * Barriers in virtio are tricky.  Non-SMP virtio guests can't assume
 * they're not on an SMP host system, so they need to assume real
 * barriers.  Non-SMP virtio hosts could skip the barriers, but does
 * anyone care?
 *
 * For virtio_pci on SMP, we don't need to order with respect to MMIO
 * accesses through relaxed memory I/O windows, so virt_mb() et al are
 * sufficient.
 *
 * For using virtio to talk to real devices (eg. other heterogeneous
 * CPUs) we do need real barriers.  In theory, we could be using both
 * kinds of virtio, so it's a runtime decision, and the branch is
 * actually quite cheap.
 */

static inline void virtio_mb(bool weak_barriers)
{
        if (weak_barriers)
                virt_mb();
        else
                mb();
}

static inline void virtio_rmb(bool weak_barriers)
{
        if (weak_barriers)
                virt_rmb();
        else
                dma_rmb();
}

static inline void virtio_wmb(bool weak_barriers)
{
        if (weak_barriers)
                virt_wmb();
        else
                dma_wmb();
}

#define virtio_store_mb(weak_barriers, p, v) \
do { \
        if (weak_barriers) { \
                virt_store_mb(*p, v); \
        } else { \
                WRITE_ONCE(*p, v); \
                mb(); \
        } \
} while (0) \

struct virtio_device;
struct virtqueue;
struct device;

/*
 * Creates a virtqueue and allocates the descriptor ring.  If
 * may_reduce_num is set, then this may allocate a smaller ring than
 * expected.  The caller should query virtqueue_get_vring_size to learn
 * the actual size of the ring.
 */
struct virtqueue *vring_create_virtqueue(unsigned int index,
                                         unsigned int num,
                                         unsigned int vring_align,
                                         struct virtio_device *vdev,
                                         bool weak_barriers,
                                         bool may_reduce_num,
                                         bool ctx,
                                         bool (*notify)(struct virtqueue *vq),
                                         void (*callback)(struct virtqueue *vq),
                                         const char *name);

/*
 * Creates a virtqueue and allocates the descriptor ring with per
 * virtqueue mapping operations.
 */
struct virtqueue *vring_create_virtqueue_map(unsigned int index,
                                             unsigned int num,
                                             unsigned int vring_align,
                                             struct virtio_device *vdev,
                                             bool weak_barriers,
                                             bool may_reduce_num,
                                             bool ctx,
                                             bool (*notify)(struct virtqueue *vq),
                                             void (*callback)(struct virtqueue *vq),
                                             const char *name,
                                             union virtio_map map);

/*
 * Creates a virtqueue with a standard layout but a caller-allocated
 * ring.
 */
struct virtqueue *vring_new_virtqueue(unsigned int index,
                                      unsigned int num,
                                      unsigned int vring_align,
                                      struct virtio_device *vdev,
                                      bool weak_barriers,
                                      bool ctx,
                                      void *pages,
                                      bool (*notify)(struct virtqueue *vq),
                                      void (*callback)(struct virtqueue *vq),
                                      const char *name);

/*
 * Destroys a virtqueue.  If created with vring_create_virtqueue, this
 * also frees the ring.
 */
void vring_del_virtqueue(struct virtqueue *vq);

/* Filter out transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev);

irqreturn_t vring_interrupt(int irq, void *_vq);

u32 vring_notification_data(struct virtqueue *_vq);
#endif /* _LINUX_VIRTIO_RING_H */























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// SPDX-License-Identifier: GPL-2.0+
/*
 *  HID driver for quirky Macally devices
 *
 *  Copyright (c) 2019 Alex Henrie <alexhenrie24@gmail.com>
 */

#include <linux/hid.h>
#include <linux/module.h>

#include "hid-ids.h"

MODULE_AUTHOR("Alex Henrie <alexhenrie24@gmail.com>");
MODULE_DESCRIPTION("Macally devices");
MODULE_LICENSE("GPL");

/*
 * The Macally ikey keyboard says that its logical and usage maximums are both
 * 101, but the power key is 102 and the equals key is 103
 */
static const __u8 *macally_report_fixup(struct hid_device *hdev, __u8 *rdesc,
                                        unsigned int *rsize)
{
        if (*rsize >= 60 && rdesc[53] == 0x65 && rdesc[59] == 0x65) {
                hid_info(hdev,
                        "fixing up Macally ikey keyboard report descriptor\n");
                rdesc[53] = rdesc[59] = 0x67;
        }
        return rdesc;
}

static const struct hid_device_id macally_id_table[] = {
        { HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
                         USB_DEVICE_ID_MACALLY_IKEY_KEYBOARD) },
        { }
};
MODULE_DEVICE_TABLE(hid, macally_id_table);

static struct hid_driver macally_driver = {
        .name                        = "macally",
        .id_table                = macally_id_table,
        .report_fixup                = macally_report_fixup,
};

module_hid_driver(macally_driver);































































































































































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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ASIX AX88172A based USB 2.0 Ethernet Devices
 * Copyright (C) 2012 OMICRON electronics GmbH
 *
 * Supports external PHYs via phylib. Based on the driver for the
 * AX88772. Original copyrights follow:
 *
 * Copyright (C) 2003-2006 David Hollis <dhollis@davehollis.com>
 * Copyright (C) 2005 Phil Chang <pchang23@sbcglobal.net>
 * Copyright (C) 2006 James Painter <jamie.painter@iname.com>
 * Copyright (c) 2002-2003 TiVo Inc.
 */

#include "asix.h"
#include <linux/phy.h>

struct ax88172a_private {
        struct mii_bus *mdio;
        struct phy_device *phydev;
        char phy_name[PHY_ID_SIZE];
        u8 phy_addr;
        u16 oldmode;
        int use_embdphy;
        struct asix_rx_fixup_info rx_fixup_info;
};

/* set MAC link settings according to information from phylib */
static void ax88172a_adjust_link(struct net_device *netdev)
{
        struct phy_device *phydev = netdev->phydev;
        struct usbnet *dev = netdev_priv(netdev);
        struct ax88172a_private *priv = dev->driver_priv;
        u16 mode = 0;

        if (phydev->link) {
                mode = AX88772_MEDIUM_DEFAULT;

                if (phydev->duplex == DUPLEX_HALF)
                        mode &= ~AX_MEDIUM_FD;

                if (phydev->speed != SPEED_100)
                        mode &= ~AX_MEDIUM_PS;
        }

        if (mode != priv->oldmode) {
                asix_write_medium_mode(dev, mode, 0);
                priv->oldmode = mode;
                netdev_dbg(netdev, "speed %u duplex %d, setting mode to 0x%04x\n",
                           phydev->speed, phydev->duplex, mode);
                phy_print_status(phydev);
        }
}

static void ax88172a_status(struct usbnet *dev, struct urb *urb)
{
        /* link changes are detected by polling the phy */
}

/* use phylib infrastructure */
static int ax88172a_init_mdio(struct usbnet *dev)
{
        struct ax88172a_private *priv = dev->driver_priv;
        int ret;

        priv->mdio = mdiobus_alloc();
        if (!priv->mdio) {
                netdev_err(dev->net, "Could not allocate MDIO bus\n");
                return -ENOMEM;
        }

        priv->mdio->priv = (void *)dev;
        priv->mdio->read = &asix_mdio_bus_read;
        priv->mdio->write = &asix_mdio_bus_write;
        priv->mdio->name = "Asix MDIO Bus";
        /* mii bus name is usb-<usb bus number>-<usb device number> */
        snprintf(priv->mdio->id, MII_BUS_ID_SIZE, "usb-%03d:%03d",
                 dev->udev->bus->busnum, dev->udev->devnum);

        ret = mdiobus_register(priv->mdio);
        if (ret) {
                netdev_err(dev->net, "Could not register MDIO bus\n");
                goto mfree;
        }

        netdev_info(dev->net, "registered mdio bus %s\n", priv->mdio->id);
        return 0;

mfree:
        mdiobus_free(priv->mdio);
        return ret;
}

static void ax88172a_remove_mdio(struct usbnet *dev)
{
        struct ax88172a_private *priv = dev->driver_priv;

        netdev_info(dev->net, "deregistering mdio bus %s\n", priv->mdio->id);
        mdiobus_unregister(priv->mdio);
        mdiobus_free(priv->mdio);
}

static const struct net_device_ops ax88172a_netdev_ops = {
        .ndo_open                = usbnet_open,
        .ndo_stop                = usbnet_stop,
        .ndo_start_xmit                = usbnet_start_xmit,
        .ndo_tx_timeout                = usbnet_tx_timeout,
        .ndo_change_mtu                = usbnet_change_mtu,
        .ndo_get_stats64        = dev_get_tstats64,
        .ndo_set_mac_address        = asix_set_mac_address,
        .ndo_validate_addr        = eth_validate_addr,
        .ndo_eth_ioctl                = phy_do_ioctl_running,
        .ndo_set_rx_mode        = asix_set_multicast,
};

static const struct ethtool_ops ax88172a_ethtool_ops = {
        .get_drvinfo                = asix_get_drvinfo,
        .get_link                = usbnet_get_link,
        .get_msglevel                = usbnet_get_msglevel,
        .set_msglevel                = usbnet_set_msglevel,
        .get_wol                = asix_get_wol,
        .set_wol                = asix_set_wol,
        .get_eeprom_len                = asix_get_eeprom_len,
        .get_eeprom                = asix_get_eeprom,
        .set_eeprom                = asix_set_eeprom,
        .nway_reset                = phy_ethtool_nway_reset,
        .get_link_ksettings        = phy_ethtool_get_link_ksettings,
        .set_link_ksettings        = phy_ethtool_set_link_ksettings,
};

static int ax88172a_reset_phy(struct usbnet *dev, int embd_phy)
{
        int ret;

        ret = asix_sw_reset(dev, AX_SWRESET_IPPD, 0);
        if (ret < 0)
                goto err;

        msleep(150);
        ret = asix_sw_reset(dev, AX_SWRESET_CLEAR, 0);
        if (ret < 0)
                goto err;

        msleep(150);

        ret = asix_sw_reset(dev, embd_phy ? AX_SWRESET_IPRL : AX_SWRESET_IPPD,
                            0);
        if (ret < 0)
                goto err;

        return 0;

err:
        return ret;
}


static int ax88172a_bind(struct usbnet *dev, struct usb_interface *intf)
{
        int ret;
        u8 buf[ETH_ALEN];
        struct ax88172a_private *priv;

        ret = usbnet_get_endpoints(dev, intf);
        if (ret)
                return ret;

        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        dev->driver_priv = priv;

        /* Get the MAC address */
        ret = asix_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, ETH_ALEN, buf, 0);
        if (ret < ETH_ALEN) {
                netdev_err(dev->net, "Failed to read MAC address: %d\n", ret);
                ret = -EIO;
                goto free;
        }
        eth_hw_addr_set(dev->net, buf);

        dev->net->netdev_ops = &ax88172a_netdev_ops;
        dev->net->ethtool_ops = &ax88172a_ethtool_ops;

        /* are we using the internal or the external phy? */
        ret = asix_read_cmd(dev, AX_CMD_SW_PHY_STATUS, 0, 0, 1, buf, 0);
        if (ret < 0) {
                netdev_err(dev->net, "Failed to read software interface selection register: %d\n",
                           ret);
                goto free;
        }

        netdev_dbg(dev->net, "AX_CMD_SW_PHY_STATUS = 0x%02x\n", buf[0]);
        switch (buf[0] & AX_PHY_SELECT_MASK) {
        case AX_PHY_SELECT_INTERNAL:
                netdev_dbg(dev->net, "use internal phy\n");
                priv->use_embdphy = 1;
                break;
        case AX_PHY_SELECT_EXTERNAL:
                netdev_dbg(dev->net, "use external phy\n");
                priv->use_embdphy = 0;
                break;
        default:
                netdev_err(dev->net, "Interface mode not supported by driver\n");
                ret = -ENOTSUPP;
                goto free;
        }

        ret = asix_read_phy_addr(dev, priv->use_embdphy);
        if (ret < 0)
                goto free;
        if (ret >= PHY_MAX_ADDR) {
                netdev_err(dev->net, "Invalid PHY address %#x\n", ret);
                ret = -ENODEV;
                goto free;
        }
        priv->phy_addr = ret;

        ax88172a_reset_phy(dev, priv->use_embdphy);

        /* Asix framing packs multiple eth frames into a 2K usb bulk transfer */
        if (dev->driver_info->flags & FLAG_FRAMING_AX) {
                /* hard_mtu  is still the default - the device does not support
                   jumbo eth frames */
                dev->rx_urb_size = 2048;
        }

        /* init MDIO bus */
        ret = ax88172a_init_mdio(dev);
        if (ret)
                goto free;

        return 0;

free:
        kfree(priv);
        return ret;
}

static int ax88172a_stop(struct usbnet *dev)
{
        struct ax88172a_private *priv = dev->driver_priv;

        netdev_dbg(dev->net, "Stopping interface\n");

        if (priv->phydev) {
                netdev_info(dev->net, "Disconnecting from phy %s\n",
                            priv->phy_name);
                phy_stop(priv->phydev);
                phy_disconnect(priv->phydev);
        }

        return 0;
}

static void ax88172a_unbind(struct usbnet *dev, struct usb_interface *intf)
{
        struct ax88172a_private *priv = dev->driver_priv;

        ax88172a_remove_mdio(dev);
        kfree(priv);
}

static int ax88172a_reset(struct usbnet *dev)
{
        struct asix_data *data = (struct asix_data *)&dev->data;
        struct ax88172a_private *priv = dev->driver_priv;
        int ret;
        u16 rx_ctl;

        ax88172a_reset_phy(dev, priv->use_embdphy);

        msleep(150);
        rx_ctl = asix_read_rx_ctl(dev, 0);
        netdev_dbg(dev->net, "RX_CTL is 0x%04x after software reset\n", rx_ctl);
        ret = asix_write_rx_ctl(dev, 0x0000, 0);
        if (ret < 0)
                goto out;

        rx_ctl = asix_read_rx_ctl(dev, 0);
        netdev_dbg(dev->net, "RX_CTL is 0x%04x setting to 0x0000\n", rx_ctl);

        msleep(150);

        ret = asix_write_cmd(dev, AX_CMD_WRITE_IPG0,
                             AX88772_IPG0_DEFAULT | AX88772_IPG1_DEFAULT,
                             AX88772_IPG2_DEFAULT, 0, NULL, 0);
        if (ret < 0) {
                netdev_err(dev->net, "Write IPG,IPG1,IPG2 failed: %d\n", ret);
                goto out;
        }

        /* Rewrite MAC address */
        memcpy(data->mac_addr, dev->net->dev_addr, ETH_ALEN);
        ret = asix_write_cmd(dev, AX_CMD_WRITE_NODE_ID, 0, 0, ETH_ALEN,
                             data->mac_addr, 0);
        if (ret < 0)
                goto out;

        /* Set RX_CTL to default values with 2k buffer, and enable cactus */
        ret = asix_write_rx_ctl(dev, AX_DEFAULT_RX_CTL, 0);
        if (ret < 0)
                goto out;

        rx_ctl = asix_read_rx_ctl(dev, 0);
        netdev_dbg(dev->net, "RX_CTL is 0x%04x after all initializations\n",
                   rx_ctl);

        rx_ctl = asix_read_medium_status(dev, 0);
        netdev_dbg(dev->net, "Medium Status is 0x%04x after all initializations\n",
                   rx_ctl);

        /* Connect to PHY */
        snprintf(priv->phy_name, sizeof(priv->phy_name), PHY_ID_FMT,
                 priv->mdio->id, priv->phy_addr);

        priv->phydev = phy_connect(dev->net, priv->phy_name,
                                   &ax88172a_adjust_link,
                                   PHY_INTERFACE_MODE_MII);
        if (IS_ERR(priv->phydev)) {
                netdev_err(dev->net, "Could not connect to PHY device %s\n",
                           priv->phy_name);
                ret = PTR_ERR(priv->phydev);
                goto out;
        }

        netdev_info(dev->net, "Connected to phy %s\n", priv->phy_name);

        /* During power-up, the AX88172A set the power down (BMCR_PDOWN)
         * bit of the PHY. Bring the PHY up again.
         */
        genphy_resume(priv->phydev);
        phy_start(priv->phydev);

        return 0;

out:
        return ret;

}

static int ax88172a_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
        struct ax88172a_private *dp = dev->driver_priv;
        struct asix_rx_fixup_info *rx = &dp->rx_fixup_info;

        return asix_rx_fixup_internal(dev, skb, rx);
}

const struct driver_info ax88172a_info = {
        .description = "ASIX AX88172A USB 2.0 Ethernet",
        .bind = ax88172a_bind,
        .reset = ax88172a_reset,
        .stop = ax88172a_stop,
        .unbind = ax88172a_unbind,
        .status = ax88172a_status,
        .flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR |
                 FLAG_MULTI_PACKET,
        .rx_fixup = ax88172a_rx_fixup,
        .tx_fixup = asix_tx_fixup,
};


































































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// SPDX-License-Identifier: GPL-2.0
#include <linux/slab.h>
#include <linux/lockdep.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/memory.h>
#include <linux/memory-tiers.h>
#include <linux/notifier.h>
#include <linux/sched/sysctl.h>

#include "internal.h"

struct memory_tier {
        /* hierarchy of memory tiers */
        struct list_head list;
        /* list of all memory types part of this tier */
        struct list_head memory_types;
        /*
         * start value of abstract distance. memory tier maps
         * an abstract distance  range,
         * adistance_start .. adistance_start + MEMTIER_CHUNK_SIZE
         */
        int adistance_start;
        struct device dev;
        /* All the nodes that are part of all the lower memory tiers. */
        nodemask_t lower_tier_mask;
};

struct demotion_nodes {
        nodemask_t preferred;
};

struct node_memory_type_map {
        struct memory_dev_type *memtype;
        int map_count;
};

static DEFINE_MUTEX(memory_tier_lock);
static LIST_HEAD(memory_tiers);
/*
 * The list is used to store all memory types that are not created
 * by a device driver.
 */
static LIST_HEAD(default_memory_types);
static struct node_memory_type_map node_memory_types[MAX_NUMNODES];
struct memory_dev_type *default_dram_type;
nodemask_t default_dram_nodes __initdata = NODE_MASK_NONE;

static const struct bus_type memory_tier_subsys = {
        .name = "memory_tiering",
        .dev_name = "memory_tier",
};

#ifdef CONFIG_NUMA_BALANCING
/**
 * folio_use_access_time - check if a folio reuses cpupid for page access time
 * @folio: folio to check
 *
 * folio's _last_cpupid field is repurposed by memory tiering. In memory
 * tiering mode, cpupid of slow memory folio (not toptier memory) is used to
 * record page access time.
 *
 * Return: the folio _last_cpupid is used to record page access time
 */
bool folio_use_access_time(struct folio *folio)
{
        return (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) &&
               !node_is_toptier(folio_nid(folio));
}
#endif

#ifdef CONFIG_MIGRATION
static int top_tier_adistance;
/*
 * node_demotion[] examples:
 *
 * Example 1:
 *
 * Node 0 & 1 are CPU + DRAM nodes, node 2 & 3 are PMEM nodes.
 *
 * node distances:
 * node   0    1    2    3
 *    0  10   20   30   40
 *    1  20   10   40   30
 *    2  30   40   10   40
 *    3  40   30   40   10
 *
 * memory_tiers0 = 0-1
 * memory_tiers1 = 2-3
 *
 * node_demotion[0].preferred = 2
 * node_demotion[1].preferred = 3
 * node_demotion[2].preferred = <empty>
 * node_demotion[3].preferred = <empty>
 *
 * Example 2:
 *
 * Node 0 & 1 are CPU + DRAM nodes, node 2 is memory-only DRAM node.
 *
 * node distances:
 * node   0    1    2
 *    0  10   20   30
 *    1  20   10   30
 *    2  30   30   10
 *
 * memory_tiers0 = 0-2
 *
 * node_demotion[0].preferred = <empty>
 * node_demotion[1].preferred = <empty>
 * node_demotion[2].preferred = <empty>
 *
 * Example 3:
 *
 * Node 0 is CPU + DRAM nodes, Node 1 is HBM node, node 2 is PMEM node.
 *
 * node distances:
 * node   0    1    2
 *    0  10   20   30
 *    1  20   10   40
 *    2  30   40   10
 *
 * memory_tiers0 = 1
 * memory_tiers1 = 0
 * memory_tiers2 = 2
 *
 * node_demotion[0].preferred = 2
 * node_demotion[1].preferred = 0
 * node_demotion[2].preferred = <empty>
 *
 */
static struct demotion_nodes *node_demotion __read_mostly;
#endif /* CONFIG_MIGRATION */

static BLOCKING_NOTIFIER_HEAD(mt_adistance_algorithms);

/* The lock is used to protect `default_dram_perf*` info and nid. */
static DEFINE_MUTEX(default_dram_perf_lock);
static bool default_dram_perf_error;
static struct access_coordinate default_dram_perf;
static int default_dram_perf_ref_nid = NUMA_NO_NODE;
static const char *default_dram_perf_ref_source;

static inline struct memory_tier *to_memory_tier(struct device *device)
{
        return container_of(device, struct memory_tier, dev);
}

static __always_inline nodemask_t get_memtier_nodemask(struct memory_tier *memtier)
{
        nodemask_t nodes = NODE_MASK_NONE;
        struct memory_dev_type *memtype;

        list_for_each_entry(memtype, &memtier->memory_types, tier_sibling)
                nodes_or(nodes, nodes, memtype->nodes);

        return nodes;
}

static void memory_tier_device_release(struct device *dev)
{
        struct memory_tier *tier = to_memory_tier(dev);
        /*
         * synchronize_rcu in clear_node_memory_tier makes sure
         * we don't have rcu access to this memory tier.
         */
        kfree(tier);
}

static ssize_t nodelist_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        int ret;
        nodemask_t nmask;

        mutex_lock(&memory_tier_lock);
        nmask = get_memtier_nodemask(to_memory_tier(dev));
        ret = sysfs_emit(buf, "%*pbl\n", nodemask_pr_args(&nmask));
        mutex_unlock(&memory_tier_lock);
        return ret;
}
static DEVICE_ATTR_RO(nodelist);

static struct attribute *memtier_dev_attrs[] = {
        &dev_attr_nodelist.attr,
        NULL
};

static const struct attribute_group memtier_dev_group = {
        .attrs = memtier_dev_attrs,
};

static const struct attribute_group *memtier_dev_groups[] = {
        &memtier_dev_group,
        NULL
};

static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memtype)
{
        int ret;
        bool found_slot = false;
        struct memory_tier *memtier, *new_memtier;
        int adistance = memtype->adistance;
        unsigned int memtier_adistance_chunk_size = MEMTIER_CHUNK_SIZE;

        lockdep_assert_held_once(&memory_tier_lock);

        adistance = round_down(adistance, memtier_adistance_chunk_size);
        /*
         * If the memtype is already part of a memory tier,
         * just return that.
         */
        if (!list_empty(&memtype->tier_sibling)) {
                list_for_each_entry(memtier, &memory_tiers, list) {
                        if (adistance == memtier->adistance_start)
                                return memtier;
                }
                WARN_ON(1);
                return ERR_PTR(-EINVAL);
        }

        list_for_each_entry(memtier, &memory_tiers, list) {
                if (adistance == memtier->adistance_start) {
                        goto link_memtype;
                } else if (adistance < memtier->adistance_start) {
                        found_slot = true;
                        break;
                }
        }

        new_memtier = kzalloc(sizeof(struct memory_tier), GFP_KERNEL);
        if (!new_memtier)
                return ERR_PTR(-ENOMEM);

        new_memtier->adistance_start = adistance;
        INIT_LIST_HEAD(&new_memtier->list);
        INIT_LIST_HEAD(&new_memtier->memory_types);
        if (found_slot)
                list_add_tail(&new_memtier->list, &memtier->list);
        else
                list_add_tail(&new_memtier->list, &memory_tiers);

        new_memtier->dev.id = adistance >> MEMTIER_CHUNK_BITS;
        new_memtier->dev.bus = &memory_tier_subsys;
        new_memtier->dev.release = memory_tier_device_release;
        new_memtier->dev.groups = memtier_dev_groups;

        ret = device_register(&new_memtier->dev);
        if (ret) {
                list_del(&new_memtier->list);
                put_device(&new_memtier->dev);
                return ERR_PTR(ret);
        }
        memtier = new_memtier;

link_memtype:
        list_add(&memtype->tier_sibling, &memtier->memory_types);
        return memtier;
}

static struct memory_tier *__node_get_memory_tier(int node)
{
        pg_data_t *pgdat;

        pgdat = NODE_DATA(node);
        if (!pgdat)
                return NULL;
        /*
         * Since we hold memory_tier_lock, we can avoid
         * RCU read locks when accessing the details. No
         * parallel updates are possible here.
         */
        return rcu_dereference_check(pgdat->memtier,
                                     lockdep_is_held(&memory_tier_lock));
}

#ifdef CONFIG_MIGRATION
bool node_is_toptier(int node)
{
        bool toptier;
        pg_data_t *pgdat;
        struct memory_tier *memtier;

        pgdat = NODE_DATA(node);
        if (!pgdat)
                return false;

        rcu_read_lock();
        memtier = rcu_dereference(pgdat->memtier);
        if (!memtier) {
                toptier = true;
                goto out;
        }
        if (memtier->adistance_start <= top_tier_adistance)
                toptier = true;
        else
                toptier = false;
out:
        rcu_read_unlock();
        return toptier;
}

void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
{
        struct memory_tier *memtier;

        /*
         * pg_data_t.memtier updates includes a synchronize_rcu()
         * which ensures that we either find NULL or a valid memtier
         * in NODE_DATA. protect the access via rcu_read_lock();
         */
        rcu_read_lock();
        memtier = rcu_dereference(pgdat->memtier);
        if (memtier)
                *targets = memtier->lower_tier_mask;
        else
                *targets = NODE_MASK_NONE;
        rcu_read_unlock();
}

/**
 * next_demotion_node() - Get the next node in the demotion path
 * @node: The starting node to lookup the next node
 *
 * Return: node id for next memory node in the demotion path hierarchy
 * from @node; NUMA_NO_NODE if @node is terminal.  This does not keep
 * @node online or guarantee that it *continues* to be the next demotion
 * target.
 */
int next_demotion_node(int node)
{
        struct demotion_nodes *nd;
        int target;

        if (!node_demotion)
                return NUMA_NO_NODE;

        nd = &node_demotion[node];

        /*
         * node_demotion[] is updated without excluding this
         * function from running.
         *
         * Make sure to use RCU over entire code blocks if
         * node_demotion[] reads need to be consistent.
         */
        rcu_read_lock();
        /*
         * If there are multiple target nodes, just select one
         * target node randomly.
         *
         * In addition, we can also use round-robin to select
         * target node, but we should introduce another variable
         * for node_demotion[] to record last selected target node,
         * that may cause cache ping-pong due to the changing of
         * last target node. Or introducing per-cpu data to avoid
         * caching issue, which seems more complicated. So selecting
         * target node randomly seems better until now.
         */
        target = node_random(&nd->preferred);
        rcu_read_unlock();

        return target;
}

static void disable_all_demotion_targets(void)
{
        struct memory_tier *memtier;
        int node;

        for_each_node_state(node, N_MEMORY) {
                node_demotion[node].preferred = NODE_MASK_NONE;
                /*
                 * We are holding memory_tier_lock, it is safe
                 * to access pgda->memtier.
                 */
                memtier = __node_get_memory_tier(node);
                if (memtier)
                        memtier->lower_tier_mask = NODE_MASK_NONE;
        }
        /*
         * Ensure that the "disable" is visible across the system.
         * Readers will see either a combination of before+disable
         * state or disable+after.  They will never see before and
         * after state together.
         */
        synchronize_rcu();
}

static void dump_demotion_targets(void)
{
        int node;

        for_each_node_state(node, N_MEMORY) {
                struct memory_tier *memtier = __node_get_memory_tier(node);
                nodemask_t preferred = node_demotion[node].preferred;

                if (!memtier)
                        continue;

                if (nodes_empty(preferred))
                        pr_info("Demotion targets for Node %d: null\n", node);
                else
                        pr_info("Demotion targets for Node %d: preferred: %*pbl, fallback: %*pbl\n",
                                node, nodemask_pr_args(&preferred),
                                nodemask_pr_args(&memtier->lower_tier_mask));
        }
}

/*
 * Find an automatic demotion target for all memory
 * nodes. Failing here is OK.  It might just indicate
 * being at the end of a chain.
 */
static void establish_demotion_targets(void)
{
        struct memory_tier *memtier;
        struct demotion_nodes *nd;
        int target = NUMA_NO_NODE, node;
        int distance, best_distance;
        nodemask_t tier_nodes, lower_tier;

        lockdep_assert_held_once(&memory_tier_lock);

        if (!node_demotion)
                return;

        disable_all_demotion_targets();

        for_each_node_state(node, N_MEMORY) {
                best_distance = -1;
                nd = &node_demotion[node];

                memtier = __node_get_memory_tier(node);
                if (!memtier || list_is_last(&memtier->list, &memory_tiers))
                        continue;
                /*
                 * Get the lower memtier to find the  demotion node list.
                 */
                memtier = list_next_entry(memtier, list);
                tier_nodes = get_memtier_nodemask(memtier);
                /*
                 * find_next_best_node, use 'used' nodemask as a skip list.
                 * Add all memory nodes except the selected memory tier
                 * nodelist to skip list so that we find the best node from the
                 * memtier nodelist.
                 */
                nodes_andnot(tier_nodes, node_states[N_MEMORY], tier_nodes);

                /*
                 * Find all the nodes in the memory tier node list of same best distance.
                 * add them to the preferred mask. We randomly select between nodes
                 * in the preferred mask when allocating pages during demotion.
                 */
                do {
                        target = find_next_best_node(node, &tier_nodes);
                        if (target == NUMA_NO_NODE)
                                break;

                        distance = node_distance(node, target);
                        if (distance == best_distance || best_distance == -1) {
                                best_distance = distance;
                                node_set(target, nd->preferred);
                        } else {
                                break;
                        }
                } while (1);
        }
        /*
         * Promotion is allowed from a memory tier to higher
         * memory tier only if the memory tier doesn't include
         * compute. We want to skip promotion from a memory tier,
         * if any node that is part of the memory tier have CPUs.
         * Once we detect such a memory tier, we consider that tier
         * as top tiper from which promotion is not allowed.
         */
        list_for_each_entry_reverse(memtier, &memory_tiers, list) {
                tier_nodes = get_memtier_nodemask(memtier);
                nodes_and(tier_nodes, node_states[N_CPU], tier_nodes);
                if (!nodes_empty(tier_nodes)) {
                        /*
                         * abstract distance below the max value of this memtier
                         * is considered toptier.
                         */
                        top_tier_adistance = memtier->adistance_start +
                                                MEMTIER_CHUNK_SIZE - 1;
                        break;
                }
        }
        /*
         * Now build the lower_tier mask for each node collecting node mask from
         * all memory tier below it. This allows us to fallback demotion page
         * allocation to a set of nodes that is closer the above selected
         * preferred node.
         */
        lower_tier = node_states[N_MEMORY];
        list_for_each_entry(memtier, &memory_tiers, list) {
                /*
                 * Keep removing current tier from lower_tier nodes,
                 * This will remove all nodes in current and above
                 * memory tier from the lower_tier mask.
                 */
                tier_nodes = get_memtier_nodemask(memtier);
                nodes_andnot(lower_tier, lower_tier, tier_nodes);
                memtier->lower_tier_mask = lower_tier;
        }

        dump_demotion_targets();
}

#else
static inline void establish_demotion_targets(void) {}
#endif /* CONFIG_MIGRATION */

static inline void __init_node_memory_type(int node, struct memory_dev_type *memtype)
{
        if (!node_memory_types[node].memtype)
                node_memory_types[node].memtype = memtype;
        /*
         * for each device getting added in the same NUMA node
         * with this specific memtype, bump the map count. We
         * Only take memtype device reference once, so that
         * changing a node memtype can be done by droping the
         * only reference count taken here.
         */

        if (node_memory_types[node].memtype == memtype) {
                if (!node_memory_types[node].map_count++)
                        kref_get(&memtype->kref);
        }
}

static struct memory_tier *set_node_memory_tier(int node)
{
        struct memory_tier *memtier;
        struct memory_dev_type *memtype = default_dram_type;
        int adist = MEMTIER_ADISTANCE_DRAM;
        pg_data_t *pgdat = NODE_DATA(node);


        lockdep_assert_held_once(&memory_tier_lock);

        if (!node_state(node, N_MEMORY))
                return ERR_PTR(-EINVAL);

        mt_calc_adistance(node, &adist);
        if (!node_memory_types[node].memtype) {
                memtype = mt_find_alloc_memory_type(adist, &default_memory_types);
                if (IS_ERR(memtype)) {
                        memtype = default_dram_type;
                        pr_info("Failed to allocate a memory type. Fall back.\n");
                }
        }

        __init_node_memory_type(node, memtype);

        memtype = node_memory_types[node].memtype;
        node_set(node, memtype->nodes);
        memtier = find_create_memory_tier(memtype);
        if (!IS_ERR(memtier))
                rcu_assign_pointer(pgdat->memtier, memtier);
        return memtier;
}

static void destroy_memory_tier(struct memory_tier *memtier)
{
        list_del(&memtier->list);
        device_unregister(&memtier->dev);
}

static bool clear_node_memory_tier(int node)
{
        bool cleared = false;
        pg_data_t *pgdat;
        struct memory_tier *memtier;

        pgdat = NODE_DATA(node);
        if (!pgdat)
                return false;

        /*
         * Make sure that anybody looking at NODE_DATA who finds
         * a valid memtier finds memory_dev_types with nodes still
         * linked to the memtier. We achieve this by waiting for
         * rcu read section to finish using synchronize_rcu.
         * This also enables us to free the destroyed memory tier
         * with kfree instead of kfree_rcu
         */
        memtier = __node_get_memory_tier(node);
        if (memtier) {
                struct memory_dev_type *memtype;

                rcu_assign_pointer(pgdat->memtier, NULL);
                synchronize_rcu();
                memtype = node_memory_types[node].memtype;
                node_clear(node, memtype->nodes);
                if (nodes_empty(memtype->nodes)) {
                        list_del_init(&memtype->tier_sibling);
                        if (list_empty(&memtier->memory_types))
                                destroy_memory_tier(memtier);
                }
                cleared = true;
        }
        return cleared;
}

static void release_memtype(struct kref *kref)
{
        struct memory_dev_type *memtype;

        memtype = container_of(kref, struct memory_dev_type, kref);
        kfree(memtype);
}

struct memory_dev_type *alloc_memory_type(int adistance)
{
        struct memory_dev_type *memtype;

        memtype = kmalloc(sizeof(*memtype), GFP_KERNEL);
        if (!memtype)
                return ERR_PTR(-ENOMEM);

        memtype->adistance = adistance;
        INIT_LIST_HEAD(&memtype->tier_sibling);
        memtype->nodes  = NODE_MASK_NONE;
        kref_init(&memtype->kref);
        return memtype;
}
EXPORT_SYMBOL_GPL(alloc_memory_type);

void put_memory_type(struct memory_dev_type *memtype)
{
        kref_put(&memtype->kref, release_memtype);
}
EXPORT_SYMBOL_GPL(put_memory_type);

void init_node_memory_type(int node, struct memory_dev_type *memtype)
{

        mutex_lock(&memory_tier_lock);
        __init_node_memory_type(node, memtype);
        mutex_unlock(&memory_tier_lock);
}
EXPORT_SYMBOL_GPL(init_node_memory_type);

void clear_node_memory_type(int node, struct memory_dev_type *memtype)
{
        mutex_lock(&memory_tier_lock);
        if (node_memory_types[node].memtype == memtype || !memtype)
                node_memory_types[node].map_count--;
        /*
         * If we umapped all the attached devices to this node,
         * clear the node memory type.
         */
        if (!node_memory_types[node].map_count) {
                memtype = node_memory_types[node].memtype;
                node_memory_types[node].memtype = NULL;
                put_memory_type(memtype);
        }
        mutex_unlock(&memory_tier_lock);
}
EXPORT_SYMBOL_GPL(clear_node_memory_type);

struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
{
        struct memory_dev_type *mtype;

        list_for_each_entry(mtype, memory_types, list)
                if (mtype->adistance == adist)
                        return mtype;

        mtype = alloc_memory_type(adist);
        if (IS_ERR(mtype))
                return mtype;

        list_add(&mtype->list, memory_types);

        return mtype;
}
EXPORT_SYMBOL_GPL(mt_find_alloc_memory_type);

void mt_put_memory_types(struct list_head *memory_types)
{
        struct memory_dev_type *mtype, *mtn;

        list_for_each_entry_safe(mtype, mtn, memory_types, list) {
                list_del(&mtype->list);
                put_memory_type(mtype);
        }
}
EXPORT_SYMBOL_GPL(mt_put_memory_types);

/*
 * This is invoked via `late_initcall()` to initialize memory tiers for
 * memory nodes, both with and without CPUs. After the initialization of
 * firmware and devices, adistance algorithms are expected to be provided.
 */
static int __init memory_tier_late_init(void)
{
        int nid;
        struct memory_tier *memtier;

        get_online_mems();
        guard(mutex)(&memory_tier_lock);

        /* Assign each uninitialized N_MEMORY node to a memory tier. */
        for_each_node_state(nid, N_MEMORY) {
                /*
                 * Some device drivers may have initialized
                 * memory tiers, potentially bringing memory nodes
                 * online and configuring memory tiers.
                 * Exclude them here.
                 */
                if (node_memory_types[nid].memtype)
                        continue;

                memtier = set_node_memory_tier(nid);
                if (IS_ERR(memtier))
                        continue;
        }

        establish_demotion_targets();
        put_online_mems();

        return 0;
}
late_initcall(memory_tier_late_init);

static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix)
{
        pr_info(
"%sread_latency: %u, write_latency: %u, read_bandwidth: %u, write_bandwidth: %u\n",
                prefix, coord->read_latency, coord->write_latency,
                coord->read_bandwidth, coord->write_bandwidth);
}

int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
                             const char *source)
{
        guard(mutex)(&default_dram_perf_lock);
        if (default_dram_perf_error)
                return -EIO;

        if (perf->read_latency + perf->write_latency == 0 ||
            perf->read_bandwidth + perf->write_bandwidth == 0)
                return -EINVAL;

        if (default_dram_perf_ref_nid == NUMA_NO_NODE) {
                default_dram_perf = *perf;
                default_dram_perf_ref_nid = nid;
                default_dram_perf_ref_source = kstrdup(source, GFP_KERNEL);
                return 0;
        }

        /*
         * The performance of all default DRAM nodes is expected to be
         * same (that is, the variation is less than 10%).  And it
         * will be used as base to calculate the abstract distance of
         * other memory nodes.
         */
        if (abs(perf->read_latency - default_dram_perf.read_latency) * 10 >
            default_dram_perf.read_latency ||
            abs(perf->write_latency - default_dram_perf.write_latency) * 10 >
            default_dram_perf.write_latency ||
            abs(perf->read_bandwidth - default_dram_perf.read_bandwidth) * 10 >
            default_dram_perf.read_bandwidth ||
            abs(perf->write_bandwidth - default_dram_perf.write_bandwidth) * 10 >
            default_dram_perf.write_bandwidth) {
                pr_info(
"memory-tiers: the performance of DRAM node %d mismatches that of the reference\n"
"DRAM node %d.\n", nid, default_dram_perf_ref_nid);
                pr_info("  performance of reference DRAM node %d from %s:\n",
                        default_dram_perf_ref_nid, default_dram_perf_ref_source);
                dump_hmem_attrs(&default_dram_perf, "    ");
                pr_info("  performance of DRAM node %d from %s:\n", nid, source);
                dump_hmem_attrs(perf, "    ");
                pr_info(
"  disable default DRAM node performance based abstract distance algorithm.\n");
                default_dram_perf_error = true;
                return -EINVAL;
        }

        return 0;
}

int mt_perf_to_adistance(struct access_coordinate *perf, int *adist)
{
        guard(mutex)(&default_dram_perf_lock);
        if (default_dram_perf_error)
                return -EIO;

        if (perf->read_latency + perf->write_latency == 0 ||
            perf->read_bandwidth + perf->write_bandwidth == 0)
                return -EINVAL;

        if (default_dram_perf_ref_nid == NUMA_NO_NODE)
                return -ENOENT;

        /*
         * The abstract distance of a memory node is in direct proportion to
         * its memory latency (read + write) and inversely proportional to its
         * memory bandwidth (read + write).  The abstract distance, memory
         * latency, and memory bandwidth of the default DRAM nodes are used as
         * the base.
         */
        *adist = MEMTIER_ADISTANCE_DRAM *
                (perf->read_latency + perf->write_latency) /
                (default_dram_perf.read_latency + default_dram_perf.write_latency) *
                (default_dram_perf.read_bandwidth + default_dram_perf.write_bandwidth) /
                (perf->read_bandwidth + perf->write_bandwidth);

        return 0;
}
EXPORT_SYMBOL_GPL(mt_perf_to_adistance);

/**
 * register_mt_adistance_algorithm() - Register memory tiering abstract distance algorithm
 * @nb: The notifier block which describe the algorithm
 *
 * Return: 0 on success, errno on error.
 *
 * Every memory tiering abstract distance algorithm provider needs to
 * register the algorithm with register_mt_adistance_algorithm().  To
 * calculate the abstract distance for a specified memory node, the
 * notifier function will be called unless some high priority
 * algorithm has provided result.  The prototype of the notifier
 * function is as follows,
 *
 *   int (*algorithm_notifier)(struct notifier_block *nb,
 *                             unsigned long nid, void *data);
 *
 * Where "nid" specifies the memory node, "data" is the pointer to the
 * returned abstract distance (that is, "int *adist").  If the
 * algorithm provides the result, NOTIFY_STOP should be returned.
 * Otherwise, return_value & %NOTIFY_STOP_MASK == 0 to allow the next
 * algorithm in the chain to provide the result.
 */
int register_mt_adistance_algorithm(struct notifier_block *nb)
{
        return blocking_notifier_chain_register(&mt_adistance_algorithms, nb);
}
EXPORT_SYMBOL_GPL(register_mt_adistance_algorithm);

/**
 * unregister_mt_adistance_algorithm() - Unregister memory tiering abstract distance algorithm
 * @nb: the notifier block which describe the algorithm
 *
 * Return: 0 on success, errno on error.
 */
int unregister_mt_adistance_algorithm(struct notifier_block *nb)
{
        return blocking_notifier_chain_unregister(&mt_adistance_algorithms, nb);
}
EXPORT_SYMBOL_GPL(unregister_mt_adistance_algorithm);

/**
 * mt_calc_adistance() - Calculate abstract distance with registered algorithms
 * @node: the node to calculate abstract distance for
 * @adist: the returned abstract distance
 *
 * Return: if return_value & %NOTIFY_STOP_MASK != 0, then some
 * abstract distance algorithm provides the result, and return it via
 * @adist.  Otherwise, no algorithm can provide the result and @adist
 * will be kept as it is.
 */
int mt_calc_adistance(int node, int *adist)
{
        return blocking_notifier_call_chain(&mt_adistance_algorithms, node, adist);
}
EXPORT_SYMBOL_GPL(mt_calc_adistance);

static int __meminit memtier_hotplug_callback(struct notifier_block *self,
                                              unsigned long action, void *_arg)
{
        struct memory_tier *memtier;
        struct node_notify *nn = _arg;

        switch (action) {
        case NODE_REMOVED_LAST_MEMORY:
                mutex_lock(&memory_tier_lock);
                if (clear_node_memory_tier(nn->nid))
                        establish_demotion_targets();
                mutex_unlock(&memory_tier_lock);
                break;
        case NODE_ADDED_FIRST_MEMORY:
                mutex_lock(&memory_tier_lock);
                memtier = set_node_memory_tier(nn->nid);
                if (!IS_ERR(memtier))
                        establish_demotion_targets();
                mutex_unlock(&memory_tier_lock);
                break;
        }

        return notifier_from_errno(0);
}

static int __init memory_tier_init(void)
{
        int ret;

        ret = subsys_virtual_register(&memory_tier_subsys, NULL);
        if (ret)
                panic("%s() failed to register memory tier subsystem\n", __func__);

#ifdef CONFIG_MIGRATION
        node_demotion = kcalloc(nr_node_ids, sizeof(struct demotion_nodes),
                                GFP_KERNEL);
        WARN_ON(!node_demotion);
#endif

        mutex_lock(&memory_tier_lock);
        /*
         * For now we can have 4 faster memory tiers with smaller adistance
         * than default DRAM tier.
         */
        default_dram_type = mt_find_alloc_memory_type(MEMTIER_ADISTANCE_DRAM,
                                                      &default_memory_types);
        mutex_unlock(&memory_tier_lock);
        if (IS_ERR(default_dram_type))
                panic("%s() failed to allocate default DRAM tier\n", __func__);

        /* Record nodes with memory and CPU to set default DRAM performance. */
        nodes_and(default_dram_nodes, node_states[N_MEMORY],
                  node_states[N_CPU]);

        hotplug_node_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRI);
        return 0;
}
subsys_initcall(memory_tier_init);

bool numa_demotion_enabled = false;

#ifdef CONFIG_MIGRATION
#ifdef CONFIG_SYSFS
static ssize_t demotion_enabled_show(struct kobject *kobj,
                                     struct kobj_attribute *attr, char *buf)
{
        return sysfs_emit(buf, "%s\n", str_true_false(numa_demotion_enabled));
}

static ssize_t demotion_enabled_store(struct kobject *kobj,
                                      struct kobj_attribute *attr,
                                      const char *buf, size_t count)
{
        ssize_t ret;
        bool before = numa_demotion_enabled;

        ret = kstrtobool(buf, &numa_demotion_enabled);
        if (ret)
                return ret;

        /*
         * Reset kswapd_failures statistics. They may no longer be
         * valid since the policy for kswapd has changed.
         */
        if (before == false && numa_demotion_enabled == true) {
                struct pglist_data *pgdat;

                for_each_online_pgdat(pgdat)
                        atomic_set(&pgdat->kswapd_failures, 0);
        }

        return count;
}

static struct kobj_attribute numa_demotion_enabled_attr =
        __ATTR_RW(demotion_enabled);

static struct attribute *numa_attrs[] = {
        &numa_demotion_enabled_attr.attr,
        NULL,
};

static const struct attribute_group numa_attr_group = {
        .attrs = numa_attrs,
};

static int __init numa_init_sysfs(void)
{
        int err;
        struct kobject *numa_kobj;

        numa_kobj = kobject_create_and_add("numa", mm_kobj);
        if (!numa_kobj) {
                pr_err("failed to create numa kobject\n");
                return -ENOMEM;
        }
        err = sysfs_create_group(numa_kobj, &numa_attr_group);
        if (err) {
                pr_err("failed to register numa group\n");
                goto delete_obj;
        }
        return 0;

delete_obj:
        kobject_put(numa_kobj);
        return err;
}
subsys_initcall(numa_init_sysfs);
#endif /* CONFIG_SYSFS */
#endif






























































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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
 * Copyright (c) 2016 Facebook
 */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bpf.h>
#include <linux/bpf_verifier.h>
#include <linux/bpf_perf_event.h>
#include <linux/btf.h>
#include <linux/filter.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>
#include <linux/kprobes.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
#include <linux/error-injection.h>
#include <linux/btf_ids.h>
#include <linux/bpf_lsm.h>
#include <linux/fprobe.h>
#include <linux/bsearch.h>
#include <linux/sort.h>
#include <linux/key.h>
#include <linux/namei.h>

#include <net/bpf_sk_storage.h>

#include <uapi/linux/bpf.h>
#include <uapi/linux/btf.h>

#include <asm/tlb.h>

#include "trace_probe.h"
#include "trace.h"

#define CREATE_TRACE_POINTS
#include "bpf_trace.h"

#define bpf_event_rcu_dereference(p)                                        \
        rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))

#define MAX_UPROBE_MULTI_CNT (1U << 20)
#define MAX_KPROBE_MULTI_CNT (1U << 20)

#ifdef CONFIG_MODULES
struct bpf_trace_module {
        struct module *module;
        struct list_head list;
};

static LIST_HEAD(bpf_trace_modules);
static DEFINE_MUTEX(bpf_module_mutex);

static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
{
        struct bpf_raw_event_map *btp, *ret = NULL;
        struct bpf_trace_module *btm;
        unsigned int i;

        mutex_lock(&bpf_module_mutex);
        list_for_each_entry(btm, &bpf_trace_modules, list) {
                for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
                        btp = &btm->module->bpf_raw_events[i];
                        if (!strcmp(btp->tp->name, name)) {
                                if (try_module_get(btm->module))
                                        ret = btp;
                                goto out;
                        }
                }
        }
out:
        mutex_unlock(&bpf_module_mutex);
        return ret;
}
#else
static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
{
        return NULL;
}
#endif /* CONFIG_MODULES */

u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);

static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
                                  u64 flags, const struct btf **btf,
                                  s32 *btf_id);
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);

static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);

/**
 * trace_call_bpf - invoke BPF program
 * @call: tracepoint event
 * @ctx: opaque context pointer
 *
 * kprobe handlers execute BPF programs via this helper.
 * Can be used from static tracepoints in the future.
 *
 * Return: BPF programs always return an integer which is interpreted by
 * kprobe handler as:
 * 0 - return from kprobe (event is filtered out)
 * 1 - store kprobe event into ring buffer
 * Other values are reserved and currently alias to 1
 */
unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
{
        unsigned int ret;

        cant_sleep();

        if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
                /*
                 * since some bpf program is already running on this cpu,
                 * don't call into another bpf program (same or different)
                 * and don't send kprobe event into ring-buffer,
                 * so return zero here
                 */
                rcu_read_lock();
                bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array));
                rcu_read_unlock();
                ret = 0;
                goto out;
        }

        /*
         * Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
         * to all call sites, we did a bpf_prog_array_valid() there to check
         * whether call->prog_array is empty or not, which is
         * a heuristic to speed up execution.
         *
         * If bpf_prog_array_valid() fetched prog_array was
         * non-NULL, we go into trace_call_bpf() and do the actual
         * proper rcu_dereference() under RCU lock.
         * If it turns out that prog_array is NULL then, we bail out.
         * For the opposite, if the bpf_prog_array_valid() fetched pointer
         * was NULL, you'll skip the prog_array with the risk of missing
         * out of events when it was updated in between this and the
         * rcu_dereference() which is accepted risk.
         */
        rcu_read_lock();
        ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
                                 ctx, bpf_prog_run);
        rcu_read_unlock();

 out:
        __this_cpu_dec(bpf_prog_active);

        return ret;
}

#ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
{
        regs_set_return_value(regs, rc);
        override_function_with_return(regs);
        return 0;
}

static const struct bpf_func_proto bpf_override_return_proto = {
        .func                = bpf_override_return,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_ANYTHING,
};
#endif

static __always_inline int
bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
{
        int ret;

        ret = copy_from_user_nofault(dst, unsafe_ptr, size);
        if (unlikely(ret < 0))
                memset(dst, 0, size);
        return ret;
}

BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
           const void __user *, unsafe_ptr)
{
        return bpf_probe_read_user_common(dst, size, unsafe_ptr);
}

const struct bpf_func_proto bpf_probe_read_user_proto = {
        .func                = bpf_probe_read_user,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type        = ARG_ANYTHING,
};

static __always_inline int
bpf_probe_read_user_str_common(void *dst, u32 size,
                               const void __user *unsafe_ptr)
{
        int ret;

        /*
         * NB: We rely on strncpy_from_user() not copying junk past the NUL
         * terminator into `dst`.
         *
         * strncpy_from_user() does long-sized strides in the fast path. If the
         * strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
         * then there could be junk after the NUL in `dst`. If user takes `dst`
         * and keys a hash map with it, then semantically identical strings can
         * occupy multiple entries in the map.
         */
        ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
        if (unlikely(ret < 0))
                memset(dst, 0, size);
        return ret;
}

BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
           const void __user *, unsafe_ptr)
{
        return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
}

const struct bpf_func_proto bpf_probe_read_user_str_proto = {
        .func                = bpf_probe_read_user_str,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type        = ARG_ANYTHING,
};

BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
           const void *, unsafe_ptr)
{
        return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
}

const struct bpf_func_proto bpf_probe_read_kernel_proto = {
        .func                = bpf_probe_read_kernel,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type        = ARG_ANYTHING,
};

static __always_inline int
bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
{
        int ret;

        /*
         * The strncpy_from_kernel_nofault() call will likely not fill the
         * entire buffer, but that's okay in this circumstance as we're probing
         * arbitrary memory anyway similar to bpf_probe_read_*() and might
         * as well probe the stack. Thus, memory is explicitly cleared
         * only in error case, so that improper users ignoring return
         * code altogether don't copy garbage; otherwise length of string
         * is returned that can be used for bpf_perf_event_output() et al.
         */
        ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
        if (unlikely(ret < 0))
                memset(dst, 0, size);
        return ret;
}

BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
           const void *, unsafe_ptr)
{
        return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
}

const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
        .func                = bpf_probe_read_kernel_str,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type        = ARG_ANYTHING,
};

#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
           const void *, unsafe_ptr)
{
        if ((unsigned long)unsafe_ptr < TASK_SIZE) {
                return bpf_probe_read_user_common(dst, size,
                                (__force void __user *)unsafe_ptr);
        }
        return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
}

static const struct bpf_func_proto bpf_probe_read_compat_proto = {
        .func                = bpf_probe_read_compat,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type        = ARG_ANYTHING,
};

BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
           const void *, unsafe_ptr)
{
        if ((unsigned long)unsafe_ptr < TASK_SIZE) {
                return bpf_probe_read_user_str_common(dst, size,
                                (__force void __user *)unsafe_ptr);
        }
        return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
}

static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
        .func                = bpf_probe_read_compat_str,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type        = ARG_ANYTHING,
};
#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */

BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
           u32, size)
{
        /*
         * Ensure we're in user context which is safe for the helper to
         * run. This helper has no business in a kthread.
         *
         * access_ok() should prevent writing to non-user memory, but in
         * some situations (nommu, temporary switch, etc) access_ok() does
         * not provide enough validation, hence the check on KERNEL_DS.
         *
         * nmi_uaccess_okay() ensures the probe is not run in an interim
         * state, when the task or mm are switched. This is specifically
         * required to prevent the use of temporary mm.
         */

        if (unlikely(in_interrupt() ||
                     current->flags & (PF_KTHREAD | PF_EXITING)))
                return -EPERM;
        if (unlikely(!nmi_uaccess_okay()))
                return -EPERM;

        return copy_to_user_nofault(unsafe_ptr, src, size);
}

static const struct bpf_func_proto bpf_probe_write_user_proto = {
        .func                = bpf_probe_write_user,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_ANYTHING,
        .arg2_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg3_type        = ARG_CONST_SIZE,
};

#define MAX_TRACE_PRINTK_VARARGS        3
#define BPF_TRACE_PRINTK_SIZE                1024

BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
           u64, arg2, u64, arg3)
{
        u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
        struct bpf_bprintf_data data = {
                .get_bin_args        = true,
                .get_buf        = true,
        };
        int ret;

        ret = bpf_bprintf_prepare(fmt, fmt_size, args,
                                  MAX_TRACE_PRINTK_VARARGS, &data);
        if (ret < 0)
                return ret;

        ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);

        trace_bpf_trace_printk(data.buf);

        bpf_bprintf_cleanup(&data);

        return ret;
}

static const struct bpf_func_proto bpf_trace_printk_proto = {
        .func                = bpf_trace_printk,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg2_type        = ARG_CONST_SIZE,
};

static void __set_printk_clr_event(struct work_struct *work)
{
        /*
         * This program might be calling bpf_trace_printk,
         * so enable the associated bpf_trace/bpf_trace_printk event.
         * Repeat this each time as it is possible a user has
         * disabled bpf_trace_printk events.  By loading a program
         * calling bpf_trace_printk() however the user has expressed
         * the intent to see such events.
         */
        if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
                pr_warn_ratelimited("could not enable bpf_trace_printk events");
}
static DECLARE_WORK(set_printk_work, __set_printk_clr_event);

const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
{
        schedule_work(&set_printk_work);
        return &bpf_trace_printk_proto;
}

BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args,
           u32, data_len)
{
        struct bpf_bprintf_data data = {
                .get_bin_args        = true,
                .get_buf        = true,
        };
        int ret, num_args;

        if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
            (data_len && !args))
                return -EINVAL;
        num_args = data_len / 8;

        ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
        if (ret < 0)
                return ret;

        ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args);

        trace_bpf_trace_printk(data.buf);

        bpf_bprintf_cleanup(&data);

        return ret;
}

static const struct bpf_func_proto bpf_trace_vprintk_proto = {
        .func                = bpf_trace_vprintk,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg2_type        = ARG_CONST_SIZE,
        .arg3_type        = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
        .arg4_type        = ARG_CONST_SIZE_OR_ZERO,
};

const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
{
        schedule_work(&set_printk_work);
        return &bpf_trace_vprintk_proto;
}

BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
           const void *, args, u32, data_len)
{
        struct bpf_bprintf_data data = {
                .get_bin_args        = true,
        };
        int err, num_args;

        if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
            (data_len && !args))
                return -EINVAL;
        num_args = data_len / 8;

        err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data);
        if (err < 0)
                return err;

        seq_bprintf(m, fmt, data.bin_args);

        bpf_bprintf_cleanup(&data);

        return seq_has_overflowed(m) ? -EOVERFLOW : 0;
}

BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)

static const struct bpf_func_proto bpf_seq_printf_proto = {
        .func                = bpf_seq_printf,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_BTF_ID,
        .arg1_btf_id        = &btf_seq_file_ids[0],
        .arg2_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg3_type        = ARG_CONST_SIZE,
        .arg4_type      = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
        .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
};

BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
{
        return seq_write(m, data, len) ? -EOVERFLOW : 0;
}

static const struct bpf_func_proto bpf_seq_write_proto = {
        .func                = bpf_seq_write,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_BTF_ID,
        .arg1_btf_id        = &btf_seq_file_ids[0],
        .arg2_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg3_type        = ARG_CONST_SIZE_OR_ZERO,
};

BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
           u32, btf_ptr_size, u64, flags)
{
        const struct btf *btf;
        s32 btf_id;
        int ret;

        ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
        if (ret)
                return ret;

        return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
}

static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
        .func                = bpf_seq_printf_btf,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_BTF_ID,
        .arg1_btf_id        = &btf_seq_file_ids[0],
        .arg2_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg3_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type        = ARG_ANYTHING,
};

static __always_inline int
get_map_perf_counter(struct bpf_map *map, u64 flags,
                     u64 *value, u64 *enabled, u64 *running)
{
        struct bpf_array *array = container_of(map, struct bpf_array, map);
        unsigned int cpu = smp_processor_id();
        u64 index = flags & BPF_F_INDEX_MASK;
        struct bpf_event_entry *ee;

        if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
                return -EINVAL;
        if (index == BPF_F_CURRENT_CPU)
                index = cpu;
        if (unlikely(index >= array->map.max_entries))
                return -E2BIG;

        ee = READ_ONCE(array->ptrs[index]);
        if (!ee)
                return -ENOENT;

        return perf_event_read_local(ee->event, value, enabled, running);
}

BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
{
        u64 value = 0;
        int err;

        err = get_map_perf_counter(map, flags, &value, NULL, NULL);
        /*
         * this api is ugly since we miss [-22..-2] range of valid
         * counter values, but that's uapi
         */
        if (err)
                return err;
        return value;
}

const struct bpf_func_proto bpf_perf_event_read_proto = {
        .func                = bpf_perf_event_read,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_CONST_MAP_PTR,
        .arg2_type        = ARG_ANYTHING,
};

BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
           struct bpf_perf_event_value *, buf, u32, size)
{
        int err = -EINVAL;

        if (unlikely(size != sizeof(struct bpf_perf_event_value)))
                goto clear;
        err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
                                   &buf->running);
        if (unlikely(err))
                goto clear;
        return 0;
clear:
        memset(buf, 0, size);
        return err;
}

static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
        .func                = bpf_perf_event_read_value,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_CONST_MAP_PTR,
        .arg2_type        = ARG_ANYTHING,
        .arg3_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg4_type        = ARG_CONST_SIZE,
};

const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void)
{
        return &bpf_perf_event_read_value_proto;
}

static __always_inline u64
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
                        u64 flags, struct perf_raw_record *raw,
                        struct perf_sample_data *sd)
{
        struct bpf_array *array = container_of(map, struct bpf_array, map);
        unsigned int cpu = smp_processor_id();
        u64 index = flags & BPF_F_INDEX_MASK;
        struct bpf_event_entry *ee;
        struct perf_event *event;

        if (index == BPF_F_CURRENT_CPU)
                index = cpu;
        if (unlikely(index >= array->map.max_entries))
                return -E2BIG;

        ee = READ_ONCE(array->ptrs[index]);
        if (!ee)
                return -ENOENT;

        event = ee->event;
        if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
                     event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
                return -EINVAL;

        if (unlikely(event->oncpu != cpu))
                return -EOPNOTSUPP;

        perf_sample_save_raw_data(sd, event, raw);

        return perf_event_output(event, sd, regs);
}

/*
 * Support executing tracepoints in normal, irq, and nmi context that each call
 * bpf_perf_event_output
 */
struct bpf_trace_sample_data {
        struct perf_sample_data sds[3];
};

static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
static DEFINE_PER_CPU(int, bpf_trace_nest_level);
BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
           u64, flags, void *, data, u64, size)
{
        struct bpf_trace_sample_data *sds;
        struct perf_raw_record raw = {
                .frag = {
                        .size = size,
                        .data = data,
                },
        };
        struct perf_sample_data *sd;
        int nest_level, err;

        preempt_disable();
        sds = this_cpu_ptr(&bpf_trace_sds);
        nest_level = this_cpu_inc_return(bpf_trace_nest_level);

        if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
                err = -EBUSY;
                goto out;
        }

        sd = &sds->sds[nest_level - 1];

        if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
                err = -EINVAL;
                goto out;
        }

        perf_sample_data_init(sd, 0, 0);

        err = __bpf_perf_event_output(regs, map, flags, &raw, sd);
out:
        this_cpu_dec(bpf_trace_nest_level);
        preempt_enable();
        return err;
}

static const struct bpf_func_proto bpf_perf_event_output_proto = {
        .func                = bpf_perf_event_output,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_CONST_MAP_PTR,
        .arg3_type        = ARG_ANYTHING,
        .arg4_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg5_type        = ARG_CONST_SIZE_OR_ZERO,
};

static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
struct bpf_nested_pt_regs {
        struct pt_regs regs[3];
};
static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);

u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
                     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
{
        struct perf_raw_frag frag = {
                .copy                = ctx_copy,
                .size                = ctx_size,
                .data                = ctx,
        };
        struct perf_raw_record raw = {
                .frag = {
                        {
                                .next        = ctx_size ? &frag : NULL,
                        },
                        .size        = meta_size,
                        .data        = meta,
                },
        };
        struct perf_sample_data *sd;
        struct pt_regs *regs;
        int nest_level;
        u64 ret;

        preempt_disable();
        nest_level = this_cpu_inc_return(bpf_event_output_nest_level);

        if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
                ret = -EBUSY;
                goto out;
        }
        sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
        regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);

        perf_fetch_caller_regs(regs);
        perf_sample_data_init(sd, 0, 0);

        ret = __bpf_perf_event_output(regs, map, flags, &raw, sd);
out:
        this_cpu_dec(bpf_event_output_nest_level);
        preempt_enable();
        return ret;
}

BPF_CALL_0(bpf_get_current_task)
{
        return (long) current;
}

const struct bpf_func_proto bpf_get_current_task_proto = {
        .func                = bpf_get_current_task,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
};

BPF_CALL_0(bpf_get_current_task_btf)
{
        return (unsigned long) current;
}

const struct bpf_func_proto bpf_get_current_task_btf_proto = {
        .func                = bpf_get_current_task_btf,
        .gpl_only        = true,
        .ret_type        = RET_PTR_TO_BTF_ID_TRUSTED,
        .ret_btf_id        = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};

BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
{
        return (unsigned long) task_pt_regs(task);
}

BTF_ID_LIST_SINGLE(bpf_task_pt_regs_ids, struct, pt_regs)

const struct bpf_func_proto bpf_task_pt_regs_proto = {
        .func                = bpf_task_pt_regs,
        .gpl_only        = true,
        .arg1_type        = ARG_PTR_TO_BTF_ID,
        .arg1_btf_id        = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
        .ret_type        = RET_PTR_TO_BTF_ID,
        .ret_btf_id        = &bpf_task_pt_regs_ids[0],
};

struct send_signal_irq_work {
        struct irq_work irq_work;
        struct task_struct *task;
        u32 sig;
        enum pid_type type;
        bool has_siginfo;
        struct kernel_siginfo info;
};

static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);

static void do_bpf_send_signal(struct irq_work *entry)
{
        struct send_signal_irq_work *work;
        struct kernel_siginfo *siginfo;

        work = container_of(entry, struct send_signal_irq_work, irq_work);
        siginfo = work->has_siginfo ? &work->info : SEND_SIG_PRIV;

        group_send_sig_info(work->sig, siginfo, work->task, work->type);
        put_task_struct(work->task);
}

static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struct *task, u64 value)
{
        struct send_signal_irq_work *work = NULL;
        struct kernel_siginfo info;
        struct kernel_siginfo *siginfo;

        if (!task) {
                task = current;
                siginfo = SEND_SIG_PRIV;
        } else {
                clear_siginfo(&info);
                info.si_signo = sig;
                info.si_errno = 0;
                info.si_code = SI_KERNEL;
                info.si_pid = 0;
                info.si_uid = 0;
                info.si_value.sival_ptr = (void *)(unsigned long)value;
                siginfo = &info;
        }

        /* Similar to bpf_probe_write_user, task needs to be
         * in a sound condition and kernel memory access be
         * permitted in order to send signal to the current
         * task.
         */
        if (unlikely(task->flags & (PF_KTHREAD | PF_EXITING)))
                return -EPERM;
        if (unlikely(!nmi_uaccess_okay()))
                return -EPERM;
        /* Task should not be pid=1 to avoid kernel panic. */
        if (unlikely(is_global_init(task)))
                return -EPERM;

        if (preempt_count() != 0 || irqs_disabled()) {
                /* Do an early check on signal validity. Otherwise,
                 * the error is lost in deferred irq_work.
                 */
                if (unlikely(!valid_signal(sig)))
                        return -EINVAL;

                work = this_cpu_ptr(&send_signal_work);
                if (irq_work_is_busy(&work->irq_work))
                        return -EBUSY;

                /* Add the current task, which is the target of sending signal,
                 * to the irq_work. The current task may change when queued
                 * irq works get executed.
                 */
                work->task = get_task_struct(task);
                work->has_siginfo = siginfo == &info;
                if (work->has_siginfo)
                        copy_siginfo(&work->info, &info);
                work->sig = sig;
                work->type = type;
                irq_work_queue(&work->irq_work);
                return 0;
        }

        return group_send_sig_info(sig, siginfo, task, type);
}

BPF_CALL_1(bpf_send_signal, u32, sig)
{
        return bpf_send_signal_common(sig, PIDTYPE_TGID, NULL, 0);
}

const struct bpf_func_proto bpf_send_signal_proto = {
        .func                = bpf_send_signal,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_ANYTHING,
};

BPF_CALL_1(bpf_send_signal_thread, u32, sig)
{
        return bpf_send_signal_common(sig, PIDTYPE_PID, NULL, 0);
}

const struct bpf_func_proto bpf_send_signal_thread_proto = {
        .func                = bpf_send_signal_thread,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_ANYTHING,
};

BPF_CALL_3(bpf_d_path, const struct path *, path, char *, buf, u32, sz)
{
        struct path copy;
        long len;
        char *p;

        if (!sz)
                return 0;

        /*
         * The path pointer is verified as trusted and safe to use,
         * but let's double check it's valid anyway to workaround
         * potentially broken verifier.
         */
        len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
        if (len < 0)
                return len;

        p = d_path(&copy, buf, sz);
        if (IS_ERR(p)) {
                len = PTR_ERR(p);
        } else {
                len = buf + sz - p;
                memmove(buf, p, len);
        }

        return len;
}

BTF_SET_START(btf_allowlist_d_path)
#ifdef CONFIG_SECURITY
BTF_ID(func, security_file_permission)
BTF_ID(func, security_inode_getattr)
BTF_ID(func, security_file_open)
#endif
#ifdef CONFIG_SECURITY_PATH
BTF_ID(func, security_path_truncate)
#endif
BTF_ID(func, vfs_truncate)
BTF_ID(func, vfs_fallocate)
BTF_ID(func, dentry_open)
BTF_ID(func, vfs_getattr)
BTF_ID(func, filp_close)
BTF_SET_END(btf_allowlist_d_path)

static bool bpf_d_path_allowed(const struct bpf_prog *prog)
{
        if (prog->type == BPF_PROG_TYPE_TRACING &&
            prog->expected_attach_type == BPF_TRACE_ITER)
                return true;

        if (prog->type == BPF_PROG_TYPE_LSM)
                return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);

        return btf_id_set_contains(&btf_allowlist_d_path,
                                   prog->aux->attach_btf_id);
}

BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)

static const struct bpf_func_proto bpf_d_path_proto = {
        .func                = bpf_d_path,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_BTF_ID,
        .arg1_btf_id        = &bpf_d_path_btf_ids[0],
        .arg2_type        = ARG_PTR_TO_MEM,
        .arg3_type        = ARG_CONST_SIZE_OR_ZERO,
        .allowed        = bpf_d_path_allowed,
};

#define BTF_F_ALL        (BTF_F_COMPACT  | BTF_F_NONAME | \
                         BTF_F_PTR_RAW | BTF_F_ZERO)

static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
                                  u64 flags, const struct btf **btf,
                                  s32 *btf_id)
{
        const struct btf_type *t;

        if (unlikely(flags & ~(BTF_F_ALL)))
                return -EINVAL;

        if (btf_ptr_size != sizeof(struct btf_ptr))
                return -EINVAL;

        *btf = bpf_get_btf_vmlinux();

        if (IS_ERR_OR_NULL(*btf))
                return IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;

        if (ptr->type_id > 0)
                *btf_id = ptr->type_id;
        else
                return -EINVAL;

        if (*btf_id > 0)
                t = btf_type_by_id(*btf, *btf_id);
        if (*btf_id <= 0 || !t)
                return -ENOENT;

        return 0;
}

BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
           u32, btf_ptr_size, u64, flags)
{
        const struct btf *btf;
        s32 btf_id;
        int ret;

        ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
        if (ret)
                return ret;

        return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
                                      flags);
}

const struct bpf_func_proto bpf_snprintf_btf_proto = {
        .func                = bpf_snprintf_btf,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_MEM,
        .arg2_type        = ARG_CONST_SIZE,
        .arg3_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg4_type        = ARG_CONST_SIZE,
        .arg5_type        = ARG_ANYTHING,
};

BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
{
        /* This helper call is inlined by verifier. */
        return ((u64 *)ctx)[-2];
}

static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
        .func                = bpf_get_func_ip_tracing,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

static inline unsigned long get_entry_ip(unsigned long fentry_ip)
{
#ifdef CONFIG_X86_KERNEL_IBT
        if (is_endbr((void *)(fentry_ip - ENDBR_INSN_SIZE)))
                fentry_ip -= ENDBR_INSN_SIZE;
#endif
        return fentry_ip;
}

BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
{
        struct bpf_trace_run_ctx *run_ctx __maybe_unused;
        struct kprobe *kp;

#ifdef CONFIG_UPROBES
        run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
        if (run_ctx->is_uprobe)
                return ((struct uprobe_dispatch_data *)current->utask->vaddr)->bp_addr;
#endif

        kp = kprobe_running();

        if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
                return 0;

        return get_entry_ip((uintptr_t)kp->addr);
}

static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
        .func                = bpf_get_func_ip_kprobe,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
{
        return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
}

static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
        .func                = bpf_get_func_ip_kprobe_multi,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
{
        return bpf_kprobe_multi_cookie(current->bpf_ctx);
}

static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
        .func                = bpf_get_attach_cookie_kprobe_multi,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
{
        return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
}

static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
        .func                = bpf_get_func_ip_uprobe_multi,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
{
        return bpf_uprobe_multi_cookie(current->bpf_ctx);
}

static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
        .func                = bpf_get_attach_cookie_uprobe_multi,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
{
        struct bpf_trace_run_ctx *run_ctx;

        run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
        return run_ctx->bpf_cookie;
}

static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
        .func                = bpf_get_attach_cookie_trace,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
{
        return ctx->event->bpf_cookie;
}

static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
        .func                = bpf_get_attach_cookie_pe,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
{
        struct bpf_trace_run_ctx *run_ctx;

        run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
        return run_ctx->bpf_cookie;
}

static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
        .func                = bpf_get_attach_cookie_tracing,
        .gpl_only        = false,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
{
        static const u32 br_entry_size = sizeof(struct perf_branch_entry);
        u32 entry_cnt = size / br_entry_size;

        entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);

        if (unlikely(flags))
                return -EINVAL;

        if (!entry_cnt)
                return -ENOENT;

        return entry_cnt * br_entry_size;
}

const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
        .func                = bpf_get_branch_snapshot,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg2_type        = ARG_CONST_SIZE_OR_ZERO,
};

BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
{
        /* This helper call is inlined by verifier. */
        u64 nr_args = ((u64 *)ctx)[-1];

        if ((u64) n >= nr_args)
                return -EINVAL;
        *value = ((u64 *)ctx)[n];
        return 0;
}

static const struct bpf_func_proto bpf_get_func_arg_proto = {
        .func                = get_func_arg,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_ANYTHING,
        .arg3_type        = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
        .arg3_size        = sizeof(u64),
};

BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
{
        /* This helper call is inlined by verifier. */
        u64 nr_args = ((u64 *)ctx)[-1];

        *value = ((u64 *)ctx)[nr_args];
        return 0;
}

static const struct bpf_func_proto bpf_get_func_ret_proto = {
        .func                = get_func_ret,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
        .arg2_size        = sizeof(u64),
};

BPF_CALL_1(get_func_arg_cnt, void *, ctx)
{
        /* This helper call is inlined by verifier. */
        return ((u64 *)ctx)[-1];
}

static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
        .func                = get_func_arg_cnt,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
};

static const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        const struct bpf_func_proto *func_proto;

        switch (func_id) {
        case BPF_FUNC_get_smp_processor_id:
                return &bpf_get_smp_processor_id_proto;
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
        case BPF_FUNC_probe_read:
                return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
                       NULL : &bpf_probe_read_compat_proto;
        case BPF_FUNC_probe_read_str:
                return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
                       NULL : &bpf_probe_read_compat_str_proto;
#endif
        case BPF_FUNC_get_func_ip:
                return &bpf_get_func_ip_proto_tracing;
        default:
                break;
        }

        func_proto = bpf_base_func_proto(func_id, prog);
        if (func_proto)
                return func_proto;

        if (!bpf_token_capable(prog->aux->token, CAP_SYS_ADMIN))
                return NULL;

        switch (func_id) {
        case BPF_FUNC_probe_write_user:
                return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
                       NULL : &bpf_probe_write_user_proto;
        default:
                return NULL;
        }
}

static bool is_kprobe_multi(const struct bpf_prog *prog)
{
        return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ||
               prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
}

static inline bool is_kprobe_session(const struct bpf_prog *prog)
{
        return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION;
}

static inline bool is_uprobe_multi(const struct bpf_prog *prog)
{
        return prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI ||
               prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
}

static inline bool is_uprobe_session(const struct bpf_prog *prog)
{
        return prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION;
}

static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        switch (func_id) {
        case BPF_FUNC_perf_event_output:
                return &bpf_perf_event_output_proto;
        case BPF_FUNC_get_stackid:
                return &bpf_get_stackid_proto;
        case BPF_FUNC_get_stack:
                return prog->sleepable ? &bpf_get_stack_sleepable_proto : &bpf_get_stack_proto;
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
        case BPF_FUNC_override_return:
                return &bpf_override_return_proto;
#endif
        case BPF_FUNC_get_func_ip:
                if (is_kprobe_multi(prog))
                        return &bpf_get_func_ip_proto_kprobe_multi;
                if (is_uprobe_multi(prog))
                        return &bpf_get_func_ip_proto_uprobe_multi;
                return &bpf_get_func_ip_proto_kprobe;
        case BPF_FUNC_get_attach_cookie:
                if (is_kprobe_multi(prog))
                        return &bpf_get_attach_cookie_proto_kmulti;
                if (is_uprobe_multi(prog))
                        return &bpf_get_attach_cookie_proto_umulti;
                return &bpf_get_attach_cookie_proto_trace;
        default:
                return bpf_tracing_func_proto(func_id, prog);
        }
}

/* bpf+kprobe programs can access fields of 'struct pt_regs' */
static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
                                        const struct bpf_prog *prog,
                                        struct bpf_insn_access_aux *info)
{
        if (off < 0 || off >= sizeof(struct pt_regs))
                return false;
        if (off % size != 0)
                return false;
        /*
         * Assertion for 32 bit to make sure last 8 byte access
         * (BPF_DW) to the last 4 byte member is disallowed.
         */
        if (off + size > sizeof(struct pt_regs))
                return false;

        if (type == BPF_WRITE)
                prog->aux->kprobe_write_ctx = true;

        return true;
}

const struct bpf_verifier_ops kprobe_verifier_ops = {
        .get_func_proto  = kprobe_prog_func_proto,
        .is_valid_access = kprobe_prog_is_valid_access,
};

const struct bpf_prog_ops kprobe_prog_ops = {
};

BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
           u64, flags, void *, data, u64, size)
{
        struct pt_regs *regs = *(struct pt_regs **)tp_buff;

        /*
         * r1 points to perf tracepoint buffer where first 8 bytes are hidden
         * from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
         * from there and call the same bpf_perf_event_output() helper inline.
         */
        return ____bpf_perf_event_output(regs, map, flags, data, size);
}

static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
        .func                = bpf_perf_event_output_tp,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_CONST_MAP_PTR,
        .arg3_type        = ARG_ANYTHING,
        .arg4_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg5_type        = ARG_CONST_SIZE_OR_ZERO,
};

BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
           u64, flags)
{
        struct pt_regs *regs = *(struct pt_regs **)tp_buff;

        /*
         * Same comment as in bpf_perf_event_output_tp(), only that this time
         * the other helper's function body cannot be inlined due to being
         * external, thus we need to call raw helper function.
         */
        return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
                               flags, 0, 0);
}

static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
        .func                = bpf_get_stackid_tp,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_CONST_MAP_PTR,
        .arg3_type        = ARG_ANYTHING,
};

BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
           u64, flags)
{
        struct pt_regs *regs = *(struct pt_regs **)tp_buff;

        return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
                             (unsigned long) size, flags, 0);
}

static const struct bpf_func_proto bpf_get_stack_proto_tp = {
        .func                = bpf_get_stack_tp,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_PTR_TO_UNINIT_MEM,
        .arg3_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type        = ARG_ANYTHING,
};

static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        switch (func_id) {
        case BPF_FUNC_perf_event_output:
                return &bpf_perf_event_output_proto_tp;
        case BPF_FUNC_get_stackid:
                return &bpf_get_stackid_proto_tp;
        case BPF_FUNC_get_stack:
                return &bpf_get_stack_proto_tp;
        case BPF_FUNC_get_attach_cookie:
                return &bpf_get_attach_cookie_proto_trace;
        default:
                return bpf_tracing_func_proto(func_id, prog);
        }
}

static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
                                    const struct bpf_prog *prog,
                                    struct bpf_insn_access_aux *info)
{
        if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
                return false;
        if (type != BPF_READ)
                return false;
        if (off % size != 0)
                return false;

        BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
        return true;
}

const struct bpf_verifier_ops tracepoint_verifier_ops = {
        .get_func_proto  = tp_prog_func_proto,
        .is_valid_access = tp_prog_is_valid_access,
};

const struct bpf_prog_ops tracepoint_prog_ops = {
};

BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
           struct bpf_perf_event_value *, buf, u32, size)
{
        int err = -EINVAL;

        if (unlikely(size != sizeof(struct bpf_perf_event_value)))
                goto clear;
        err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
                                    &buf->running);
        if (unlikely(err))
                goto clear;
        return 0;
clear:
        memset(buf, 0, size);
        return err;
}

static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
         .func           = bpf_perf_prog_read_value,
         .gpl_only       = true,
         .ret_type       = RET_INTEGER,
         .arg1_type      = ARG_PTR_TO_CTX,
         .arg2_type      = ARG_PTR_TO_UNINIT_MEM,
         .arg3_type      = ARG_CONST_SIZE,
};

BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
           void *, buf, u32, size, u64, flags)
{
        static const u32 br_entry_size = sizeof(struct perf_branch_entry);
        struct perf_branch_stack *br_stack = ctx->data->br_stack;
        u32 to_copy;

        if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
                return -EINVAL;

        if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
                return -ENOENT;

        if (unlikely(!br_stack))
                return -ENOENT;

        if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
                return br_stack->nr * br_entry_size;

        if (!buf || (size % br_entry_size != 0))
                return -EINVAL;

        to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
        memcpy(buf, br_stack->entries, to_copy);

        return to_copy;
}

static const struct bpf_func_proto bpf_read_branch_records_proto = {
        .func           = bpf_read_branch_records,
        .gpl_only       = true,
        .ret_type       = RET_INTEGER,
        .arg1_type      = ARG_PTR_TO_CTX,
        .arg2_type      = ARG_PTR_TO_MEM_OR_NULL,
        .arg3_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type      = ARG_ANYTHING,
};

static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        switch (func_id) {
        case BPF_FUNC_perf_event_output:
                return &bpf_perf_event_output_proto_tp;
        case BPF_FUNC_get_stackid:
                return &bpf_get_stackid_proto_pe;
        case BPF_FUNC_get_stack:
                return &bpf_get_stack_proto_pe;
        case BPF_FUNC_perf_prog_read_value:
                return &bpf_perf_prog_read_value_proto;
        case BPF_FUNC_read_branch_records:
                return &bpf_read_branch_records_proto;
        case BPF_FUNC_get_attach_cookie:
                return &bpf_get_attach_cookie_proto_pe;
        default:
                return bpf_tracing_func_proto(func_id, prog);
        }
}

/*
 * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
 * to avoid potential recursive reuse issue when/if tracepoints are added
 * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
 *
 * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
 * in normal, irq, and nmi context.
 */
struct bpf_raw_tp_regs {
        struct pt_regs regs[3];
};
static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
static struct pt_regs *get_bpf_raw_tp_regs(void)
{
        struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
        int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);

        if (nest_level > ARRAY_SIZE(tp_regs->regs)) {
                this_cpu_dec(bpf_raw_tp_nest_level);
                return ERR_PTR(-EBUSY);
        }

        return &tp_regs->regs[nest_level - 1];
}

static void put_bpf_raw_tp_regs(void)
{
        this_cpu_dec(bpf_raw_tp_nest_level);
}

BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
           struct bpf_map *, map, u64, flags, void *, data, u64, size)
{
        struct pt_regs *regs = get_bpf_raw_tp_regs();
        int ret;

        if (IS_ERR(regs))
                return PTR_ERR(regs);

        perf_fetch_caller_regs(regs);
        ret = ____bpf_perf_event_output(regs, map, flags, data, size);

        put_bpf_raw_tp_regs();
        return ret;
}

static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
        .func                = bpf_perf_event_output_raw_tp,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_CONST_MAP_PTR,
        .arg3_type        = ARG_ANYTHING,
        .arg4_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg5_type        = ARG_CONST_SIZE_OR_ZERO,
};

extern const struct bpf_func_proto bpf_skb_output_proto;
extern const struct bpf_func_proto bpf_xdp_output_proto;
extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_proto;

BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
           struct bpf_map *, map, u64, flags)
{
        struct pt_regs *regs = get_bpf_raw_tp_regs();
        int ret;

        if (IS_ERR(regs))
                return PTR_ERR(regs);

        perf_fetch_caller_regs(regs);
        /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
        ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
                              flags, 0, 0);
        put_bpf_raw_tp_regs();
        return ret;
}

static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
        .func                = bpf_get_stackid_raw_tp,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_CONST_MAP_PTR,
        .arg3_type        = ARG_ANYTHING,
};

BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
           void *, buf, u32, size, u64, flags)
{
        struct pt_regs *regs = get_bpf_raw_tp_regs();
        int ret;

        if (IS_ERR(regs))
                return PTR_ERR(regs);

        perf_fetch_caller_regs(regs);
        ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
                            (unsigned long) size, flags, 0);
        put_bpf_raw_tp_regs();
        return ret;
}

static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
        .func                = bpf_get_stack_raw_tp,
        .gpl_only        = true,
        .ret_type        = RET_INTEGER,
        .arg1_type        = ARG_PTR_TO_CTX,
        .arg2_type        = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg3_type        = ARG_CONST_SIZE_OR_ZERO,
        .arg4_type        = ARG_ANYTHING,
};

static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        switch (func_id) {
        case BPF_FUNC_perf_event_output:
                return &bpf_perf_event_output_proto_raw_tp;
        case BPF_FUNC_get_stackid:
                return &bpf_get_stackid_proto_raw_tp;
        case BPF_FUNC_get_stack:
                return &bpf_get_stack_proto_raw_tp;
        case BPF_FUNC_get_attach_cookie:
                return &bpf_get_attach_cookie_proto_tracing;
        default:
                return bpf_tracing_func_proto(func_id, prog);
        }
}

const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        const struct bpf_func_proto *fn;

        switch (func_id) {
#ifdef CONFIG_NET
        case BPF_FUNC_skb_output:
                return &bpf_skb_output_proto;
        case BPF_FUNC_xdp_output:
                return &bpf_xdp_output_proto;
        case BPF_FUNC_skc_to_tcp6_sock:
                return &bpf_skc_to_tcp6_sock_proto;
        case BPF_FUNC_skc_to_tcp_sock:
                return &bpf_skc_to_tcp_sock_proto;
        case BPF_FUNC_skc_to_tcp_timewait_sock:
                return &bpf_skc_to_tcp_timewait_sock_proto;
        case BPF_FUNC_skc_to_tcp_request_sock:
                return &bpf_skc_to_tcp_request_sock_proto;
        case BPF_FUNC_skc_to_udp6_sock:
                return &bpf_skc_to_udp6_sock_proto;
        case BPF_FUNC_skc_to_unix_sock:
                return &bpf_skc_to_unix_sock_proto;
        case BPF_FUNC_skc_to_mptcp_sock:
                return &bpf_skc_to_mptcp_sock_proto;
        case BPF_FUNC_sk_storage_get:
                return &bpf_sk_storage_get_tracing_proto;
        case BPF_FUNC_sk_storage_delete:
                return &bpf_sk_storage_delete_tracing_proto;
        case BPF_FUNC_sock_from_file:
                return &bpf_sock_from_file_proto;
        case BPF_FUNC_get_socket_cookie:
                return &bpf_get_socket_ptr_cookie_proto;
        case BPF_FUNC_xdp_get_buff_len:
                return &bpf_xdp_get_buff_len_trace_proto;
#endif
        case BPF_FUNC_seq_printf:
                return prog->expected_attach_type == BPF_TRACE_ITER ?
                       &bpf_seq_printf_proto :
                       NULL;
        case BPF_FUNC_seq_write:
                return prog->expected_attach_type == BPF_TRACE_ITER ?
                       &bpf_seq_write_proto :
                       NULL;
        case BPF_FUNC_seq_printf_btf:
                return prog->expected_attach_type == BPF_TRACE_ITER ?
                       &bpf_seq_printf_btf_proto :
                       NULL;
        case BPF_FUNC_d_path:
                return &bpf_d_path_proto;
        case BPF_FUNC_get_func_arg:
                return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
        case BPF_FUNC_get_func_ret:
                return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
        case BPF_FUNC_get_func_arg_cnt:
                return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
        case BPF_FUNC_get_attach_cookie:
                if (prog->type == BPF_PROG_TYPE_TRACING &&
                    prog->expected_attach_type == BPF_TRACE_RAW_TP)
                        return &bpf_get_attach_cookie_proto_tracing;
                return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
        default:
                fn = raw_tp_prog_func_proto(func_id, prog);
                if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
                        fn = bpf_iter_get_func_proto(func_id, prog);
                return fn;
        }
}

static bool raw_tp_prog_is_valid_access(int off, int size,
                                        enum bpf_access_type type,
                                        const struct bpf_prog *prog,
                                        struct bpf_insn_access_aux *info)
{
        return bpf_tracing_ctx_access(off, size, type);
}

static bool tracing_prog_is_valid_access(int off, int size,
                                         enum bpf_access_type type,
                                         const struct bpf_prog *prog,
                                         struct bpf_insn_access_aux *info)
{
        return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
}

int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
                                     const union bpf_attr *kattr,
                                     union bpf_attr __user *uattr)
{
        return -ENOTSUPP;
}

const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
        .get_func_proto  = raw_tp_prog_func_proto,
        .is_valid_access = raw_tp_prog_is_valid_access,
};

const struct bpf_prog_ops raw_tracepoint_prog_ops = {
#ifdef CONFIG_NET
        .test_run = bpf_prog_test_run_raw_tp,
#endif
};

const struct bpf_verifier_ops tracing_verifier_ops = {
        .get_func_proto  = tracing_prog_func_proto,
        .is_valid_access = tracing_prog_is_valid_access,
};

const struct bpf_prog_ops tracing_prog_ops = {
        .test_run = bpf_prog_test_run_tracing,
};

static bool raw_tp_writable_prog_is_valid_access(int off, int size,
                                                 enum bpf_access_type type,
                                                 const struct bpf_prog *prog,
                                                 struct bpf_insn_access_aux *info)
{
        if (off == 0) {
                if (size != sizeof(u64) || type != BPF_READ)
                        return false;
                info->reg_type = PTR_TO_TP_BUFFER;
        }
        return raw_tp_prog_is_valid_access(off, size, type, prog, info);
}

const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
        .get_func_proto  = raw_tp_prog_func_proto,
        .is_valid_access = raw_tp_writable_prog_is_valid_access,
};

const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
};

static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
                                    const struct bpf_prog *prog,
                                    struct bpf_insn_access_aux *info)
{
        const int size_u64 = sizeof(u64);

        if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
                return false;
        if (type != BPF_READ)
                return false;
        if (off % size != 0) {
                if (sizeof(unsigned long) != 4)
                        return false;
                if (size != 8)
                        return false;
                if (off % size != 4)
                        return false;
        }

        switch (off) {
        case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
                bpf_ctx_record_field_size(info, size_u64);
                if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
                        return false;
                break;
        case bpf_ctx_range(struct bpf_perf_event_data, addr):
                bpf_ctx_record_field_size(info, size_u64);
                if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
                        return false;
                break;
        default:
                if (size != sizeof(long))
                        return false;
        }

        return true;
}

static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
                                      const struct bpf_insn *si,
                                      struct bpf_insn *insn_buf,
                                      struct bpf_prog *prog, u32 *target_size)
{
        struct bpf_insn *insn = insn_buf;

        switch (si->off) {
        case offsetof(struct bpf_perf_event_data, sample_period):
                *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
                                                       data), si->dst_reg, si->src_reg,
                                      offsetof(struct bpf_perf_event_data_kern, data));
                *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
                                      bpf_target_off(struct perf_sample_data, period, 8,
                                                     target_size));
                break;
        case offsetof(struct bpf_perf_event_data, addr):
                *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
                                                       data), si->dst_reg, si->src_reg,
                                      offsetof(struct bpf_perf_event_data_kern, data));
                *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
                                      bpf_target_off(struct perf_sample_data, addr, 8,
                                                     target_size));
                break;
        default:
                *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
                                                       regs), si->dst_reg, si->src_reg,
                                      offsetof(struct bpf_perf_event_data_kern, regs));
                *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
                                      si->off);
                break;
        }

        return insn - insn_buf;
}

const struct bpf_verifier_ops perf_event_verifier_ops = {
        .get_func_proto                = pe_prog_func_proto,
        .is_valid_access        = pe_prog_is_valid_access,
        .convert_ctx_access        = pe_prog_convert_ctx_access,
};

const struct bpf_prog_ops perf_event_prog_ops = {
};

static DEFINE_MUTEX(bpf_event_mutex);

#define BPF_TRACE_MAX_PROGS 64

int perf_event_attach_bpf_prog(struct perf_event *event,
                               struct bpf_prog *prog,
                               u64 bpf_cookie)
{
        struct bpf_prog_array *old_array;
        struct bpf_prog_array *new_array;
        int ret = -EEXIST;

        /*
         * Kprobe override only works if they are on the function entry,
         * and only if they are on the opt-in list.
         */
        if (prog->kprobe_override &&
            (!trace_kprobe_on_func_entry(event->tp_event) ||
             !trace_kprobe_error_injectable(event->tp_event)))
                return -EINVAL;

        mutex_lock(&bpf_event_mutex);

        if (event->prog)
                goto unlock;

        old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
        if (old_array &&
            bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
                ret = -E2BIG;
                goto unlock;
        }

        ret = bpf_prog_array_copy(old_array, NULL, prog, bpf_cookie, &new_array);
        if (ret < 0)
                goto unlock;

        /* set the new array to event->tp_event and set event->prog */
        event->prog = prog;
        event->bpf_cookie = bpf_cookie;
        rcu_assign_pointer(event->tp_event->prog_array, new_array);
        bpf_prog_array_free_sleepable(old_array);

unlock:
        mutex_unlock(&bpf_event_mutex);
        return ret;
}

void perf_event_detach_bpf_prog(struct perf_event *event)
{
        struct bpf_prog_array *old_array;
        struct bpf_prog_array *new_array;
        struct bpf_prog *prog = NULL;
        int ret;

        mutex_lock(&bpf_event_mutex);

        if (!event->prog)
                goto unlock;

        old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
        if (!old_array)
                goto put;

        ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);
        if (ret < 0) {
                bpf_prog_array_delete_safe(old_array, event->prog);
        } else {
                rcu_assign_pointer(event->tp_event->prog_array, new_array);
                bpf_prog_array_free_sleepable(old_array);
        }

put:
        prog = event->prog;
        event->prog = NULL;

unlock:
        mutex_unlock(&bpf_event_mutex);

        if (prog) {
                /*
                 * It could be that the bpf_prog is not sleepable (and will be freed
                 * via normal RCU), but is called from a point that supports sleepable
                 * programs and uses tasks-trace-RCU.
                 */
                synchronize_rcu_tasks_trace();

                bpf_prog_put(prog);
        }
}

int perf_event_query_prog_array(struct perf_event *event, void __user *info)
{
        struct perf_event_query_bpf __user *uquery = info;
        struct perf_event_query_bpf query = {};
        struct bpf_prog_array *progs;
        u32 *ids, prog_cnt, ids_len;
        int ret;

        if (!perfmon_capable())
                return -EPERM;
        if (event->attr.type != PERF_TYPE_TRACEPOINT)
                return -EINVAL;
        if (copy_from_user(&query, uquery, sizeof(query)))
                return -EFAULT;

        ids_len = query.ids_len;
        if (ids_len > BPF_TRACE_MAX_PROGS)
                return -E2BIG;
        ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
        if (!ids)
                return -ENOMEM;
        /*
         * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
         * is required when user only wants to check for uquery->prog_cnt.
         * There is no need to check for it since the case is handled
         * gracefully in bpf_prog_array_copy_info.
         */

        mutex_lock(&bpf_event_mutex);
        progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
        ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
        mutex_unlock(&bpf_event_mutex);

        if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
            copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
                ret = -EFAULT;

        kfree(ids);
        return ret;
}

extern struct bpf_raw_event_map __start__bpf_raw_tp[];
extern struct bpf_raw_event_map __stop__bpf_raw_tp[];

struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
{
        struct bpf_raw_event_map *btp = __start__bpf_raw_tp;

        for (; btp < __stop__bpf_raw_tp; btp++) {
                if (!strcmp(btp->tp->name, name))
                        return btp;
        }

        return bpf_get_raw_tracepoint_module(name);
}

void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
{
        struct module *mod;

        guard(rcu)();
        mod = __module_address((unsigned long)btp);
        module_put(mod);
}

static __always_inline
void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
{
        struct bpf_prog *prog = link->link.prog;
        struct bpf_run_ctx *old_run_ctx;
        struct bpf_trace_run_ctx run_ctx;

        cant_sleep();
        if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
                bpf_prog_inc_misses_counter(prog);
                goto out;
        }

        run_ctx.bpf_cookie = link->cookie;
        old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);

        rcu_read_lock();
        (void) bpf_prog_run(prog, args);
        rcu_read_unlock();

        bpf_reset_run_ctx(old_run_ctx);
out:
        this_cpu_dec(*(prog->active));
}

#define UNPACK(...)                        __VA_ARGS__
#define REPEAT_1(FN, DL, X, ...)        FN(X)
#define REPEAT_2(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
#define REPEAT_3(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
#define REPEAT_4(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
#define REPEAT_5(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
#define REPEAT_6(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
#define REPEAT_7(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
#define REPEAT_8(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
#define REPEAT_9(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
#define REPEAT_10(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
#define REPEAT_11(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
#define REPEAT_12(FN, DL, X, ...)        FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
#define REPEAT(X, FN, DL, ...)                REPEAT_##X(FN, DL, __VA_ARGS__)

#define SARG(X)                u64 arg##X
#define COPY(X)                args[X] = arg##X

#define __DL_COM        (,)
#define __DL_SEM        (;)

#define __SEQ_0_11        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11

#define BPF_TRACE_DEFN_x(x)                                                \
        void bpf_trace_run##x(struct bpf_raw_tp_link *link,                \
                              REPEAT(x, SARG, __DL_COM, __SEQ_0_11))        \
        {                                                                \
                u64 args[x];                                                \
                REPEAT(x, COPY, __DL_SEM, __SEQ_0_11);                        \
                __bpf_trace_run(link, args);                                \
        }                                                                \
        EXPORT_SYMBOL_GPL(bpf_trace_run##x)
BPF_TRACE_DEFN_x(1);
BPF_TRACE_DEFN_x(2);
BPF_TRACE_DEFN_x(3);
BPF_TRACE_DEFN_x(4);
BPF_TRACE_DEFN_x(5);
BPF_TRACE_DEFN_x(6);
BPF_TRACE_DEFN_x(7);
BPF_TRACE_DEFN_x(8);
BPF_TRACE_DEFN_x(9);
BPF_TRACE_DEFN_x(10);
BPF_TRACE_DEFN_x(11);
BPF_TRACE_DEFN_x(12);

int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
{
        struct tracepoint *tp = btp->tp;
        struct bpf_prog *prog = link->link.prog;

        /*
         * check that program doesn't access arguments beyond what's
         * available in this tracepoint
         */
        if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
                return -EINVAL;

        if (prog->aux->max_tp_access > btp->writable_size)
                return -EINVAL;

        return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, link);
}

int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
{
        return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, link);
}

int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
                            u32 *fd_type, const char **buf,
                            u64 *probe_offset, u64 *probe_addr,
                            unsigned long *missed)
{
        bool is_tracepoint, is_syscall_tp;
        struct bpf_prog *prog;
        int flags, err = 0;

        prog = event->prog;
        if (!prog)
                return -ENOENT;

        /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
        if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
                return -EOPNOTSUPP;

        *prog_id = prog->aux->id;
        flags = event->tp_event->flags;
        is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
        is_syscall_tp = is_syscall_trace_event(event->tp_event);

        if (is_tracepoint || is_syscall_tp) {
                *buf = is_tracepoint ? event->tp_event->tp->name
                                     : event->tp_event->name;
                /* We allow NULL pointer for tracepoint */
                if (fd_type)
                        *fd_type = BPF_FD_TYPE_TRACEPOINT;
                if (probe_offset)
                        *probe_offset = 0x0;
                if (probe_addr)
                        *probe_addr = 0x0;
        } else {
                /* kprobe/uprobe */
                err = -EOPNOTSUPP;
#ifdef CONFIG_KPROBE_EVENTS
                if (flags & TRACE_EVENT_FL_KPROBE)
                        err = bpf_get_kprobe_info(event, fd_type, buf,
                                                  probe_offset, probe_addr, missed,
                                                  event->attr.type == PERF_TYPE_TRACEPOINT);
#endif
#ifdef CONFIG_UPROBE_EVENTS
                if (flags & TRACE_EVENT_FL_UPROBE)
                        err = bpf_get_uprobe_info(event, fd_type, buf,
                                                  probe_offset, probe_addr,
                                                  event->attr.type == PERF_TYPE_TRACEPOINT);
#endif
        }

        return err;
}

static int __init send_signal_irq_work_init(void)
{
        int cpu;
        struct send_signal_irq_work *work;

        for_each_possible_cpu(cpu) {
                work = per_cpu_ptr(&send_signal_work, cpu);
                init_irq_work(&work->irq_work, do_bpf_send_signal);
        }
        return 0;
}

subsys_initcall(send_signal_irq_work_init);

#ifdef CONFIG_MODULES
static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
                            void *module)
{
        struct bpf_trace_module *btm, *tmp;
        struct module *mod = module;
        int ret = 0;

        if (mod->num_bpf_raw_events == 0 ||
            (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
                goto out;

        mutex_lock(&bpf_module_mutex);

        switch (op) {
        case MODULE_STATE_COMING:
                btm = kzalloc(sizeof(*btm), GFP_KERNEL);
                if (btm) {
                        btm->module = module;
                        list_add(&btm->list, &bpf_trace_modules);
                } else {
                        ret = -ENOMEM;
                }
                break;
        case MODULE_STATE_GOING:
                list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
                        if (btm->module == module) {
                                list_del(&btm->list);
                                kfree(btm);
                                break;
                        }
                }
                break;
        }

        mutex_unlock(&bpf_module_mutex);

out:
        return notifier_from_errno(ret);
}

static struct notifier_block bpf_module_nb = {
        .notifier_call = bpf_event_notify,
};

static int __init bpf_event_init(void)
{
        register_module_notifier(&bpf_module_nb);
        return 0;
}

fs_initcall(bpf_event_init);
#endif /* CONFIG_MODULES */

struct bpf_session_run_ctx {
        struct bpf_run_ctx run_ctx;
        bool is_return;
        void *data;
};

#ifdef CONFIG_FPROBE
struct bpf_kprobe_multi_link {
        struct bpf_link link;
        struct fprobe fp;
        unsigned long *addrs;
        u64 *cookies;
        u32 cnt;
        u32 mods_cnt;
        struct module **mods;
};

struct bpf_kprobe_multi_run_ctx {
        struct bpf_session_run_ctx session_ctx;
        struct bpf_kprobe_multi_link *link;
        unsigned long entry_ip;
};

struct user_syms {
        const char **syms;
        char *buf;
};

#ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS
static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs);
#define bpf_kprobe_multi_pt_regs_ptr()        this_cpu_ptr(&bpf_kprobe_multi_pt_regs)
#else
#define bpf_kprobe_multi_pt_regs_ptr()        (NULL)
#endif

static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
{
        unsigned long ip = ftrace_get_symaddr(fentry_ip);

        return ip ? : fentry_ip;
}

static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
{
        unsigned long __user usymbol;
        const char **syms = NULL;
        char *buf = NULL, *p;
        int err = -ENOMEM;
        unsigned int i;

        syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
        if (!syms)
                goto error;

        buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
        if (!buf)
                goto error;

        for (p = buf, i = 0; i < cnt; i++) {
                if (__get_user(usymbol, usyms + i)) {
                        err = -EFAULT;
                        goto error;
                }
                err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
                if (err == KSYM_NAME_LEN)
                        err = -E2BIG;
                if (err < 0)
                        goto error;
                syms[i] = p;
                p += err + 1;
        }

        us->syms = syms;
        us->buf = buf;
        return 0;

error:
        if (err) {
                kvfree(syms);
                kvfree(buf);
        }
        return err;
}

static void kprobe_multi_put_modules(struct module **mods, u32 cnt)
{
        u32 i;

        for (i = 0; i < cnt; i++)
                module_put(mods[i]);
}

static void free_user_syms(struct user_syms *us)
{
        kvfree(us->syms);
        kvfree(us->buf);
}

static void bpf_kprobe_multi_link_release(struct bpf_link *link)
{
        struct bpf_kprobe_multi_link *kmulti_link;

        kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
        unregister_fprobe(&kmulti_link->fp);
        kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt);
}

static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
{
        struct bpf_kprobe_multi_link *kmulti_link;

        kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
        kvfree(kmulti_link->addrs);
        kvfree(kmulti_link->cookies);
        kfree(kmulti_link->mods);
        kfree(kmulti_link);
}

static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
                                                struct bpf_link_info *info)
{
        u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);
        u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
        struct bpf_kprobe_multi_link *kmulti_link;
        u32 ucount = info->kprobe_multi.count;
        int err = 0, i;

        if (!uaddrs ^ !ucount)
                return -EINVAL;
        if (ucookies && !ucount)
                return -EINVAL;

        kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
        info->kprobe_multi.count = kmulti_link->cnt;
        info->kprobe_multi.flags = kmulti_link->link.flags;
        info->kprobe_multi.missed = kmulti_link->fp.nmissed;

        if (!uaddrs)
                return 0;
        if (ucount < kmulti_link->cnt)
                err = -ENOSPC;
        else
                ucount = kmulti_link->cnt;

        if (ucookies) {
                if (kmulti_link->cookies) {
                        if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))
                                return -EFAULT;
                } else {
                        for (i = 0; i < ucount; i++) {
                                if (put_user(0, ucookies + i))
                                        return -EFAULT;
                        }
                }
        }

        if (kallsyms_show_value(current_cred())) {
                if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
                        return -EFAULT;
        } else {
                for (i = 0; i < ucount; i++) {
                        if (put_user(0, uaddrs + i))
                                return -EFAULT;
                }
        }
        return err;
}

#ifdef CONFIG_PROC_FS
static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link,
                                         struct seq_file *seq)
{
        struct bpf_kprobe_multi_link *kmulti_link;

        kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);

        seq_printf(seq,
                   "kprobe_cnt:\t%u\n"
                   "missed:\t%lu\n",
                   kmulti_link->cnt,
                   kmulti_link->fp.nmissed);

        seq_printf(seq, "%s\t %s\n", "cookie", "func");
        for (int i = 0; i < kmulti_link->cnt; i++) {
                seq_printf(seq,
                           "%llu\t %pS\n",
                           kmulti_link->cookies[i],
                           (void *)kmulti_link->addrs[i]);
        }
}
#endif

static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
        .release = bpf_kprobe_multi_link_release,
        .dealloc_deferred = bpf_kprobe_multi_link_dealloc,
        .fill_link_info = bpf_kprobe_multi_link_fill_link_info,
#ifdef CONFIG_PROC_FS
        .show_fdinfo = bpf_kprobe_multi_show_fdinfo,
#endif
};

static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
{
        const struct bpf_kprobe_multi_link *link = priv;
        unsigned long *addr_a = a, *addr_b = b;
        u64 *cookie_a, *cookie_b;

        cookie_a = link->cookies + (addr_a - link->addrs);
        cookie_b = link->cookies + (addr_b - link->addrs);

        /* swap addr_a/addr_b and cookie_a/cookie_b values */
        swap(*addr_a, *addr_b);
        swap(*cookie_a, *cookie_b);
}

static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b)
{
        const unsigned long *addr_a = a, *addr_b = b;

        if (*addr_a == *addr_b)
                return 0;
        return *addr_a < *addr_b ? -1 : 1;
}

static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
{
        return bpf_kprobe_multi_addrs_cmp(a, b);
}

static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
{
        struct bpf_kprobe_multi_run_ctx *run_ctx;
        struct bpf_kprobe_multi_link *link;
        u64 *cookie, entry_ip;
        unsigned long *addr;

        if (WARN_ON_ONCE(!ctx))
                return 0;
        run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
                               session_ctx.run_ctx);
        link = run_ctx->link;
        if (!link->cookies)
                return 0;
        entry_ip = run_ctx->entry_ip;
        addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
                       bpf_kprobe_multi_addrs_cmp);
        if (!addr)
                return 0;
        cookie = link->cookies + (addr - link->addrs);
        return *cookie;
}

static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
{
        struct bpf_kprobe_multi_run_ctx *run_ctx;

        run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx,
                               session_ctx.run_ctx);
        return run_ctx->entry_ip;
}

static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
                           unsigned long entry_ip, struct ftrace_regs *fregs,
                           bool is_return, void *data)
{
        struct bpf_kprobe_multi_run_ctx run_ctx = {
                .session_ctx = {
                        .is_return = is_return,
                        .data = data,
                },
                .link = link,
                .entry_ip = entry_ip,
        };
        struct bpf_run_ctx *old_run_ctx;
        struct pt_regs *regs;
        int err;

        /*
         * graph tracer framework ensures we won't migrate, so there is no need
         * to use migrate_disable for bpf_prog_run again. The check here just for
         * __this_cpu_inc_return.
         */
        cant_sleep();

        if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
                bpf_prog_inc_misses_counter(link->link.prog);
                err = 1;
                goto out;
        }

        rcu_read_lock();
        regs = ftrace_partial_regs(fregs, bpf_kprobe_multi_pt_regs_ptr());
        old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
        err = bpf_prog_run(link->link.prog, regs);
        bpf_reset_run_ctx(old_run_ctx);
        rcu_read_unlock();

 out:
        __this_cpu_dec(bpf_prog_active);
        return err;
}

static int
kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
                          unsigned long ret_ip, struct ftrace_regs *fregs,
                          void *data)
{
        struct bpf_kprobe_multi_link *link;
        int err;

        link = container_of(fp, struct bpf_kprobe_multi_link, fp);
        err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
                                         fregs, false, data);
        return is_kprobe_session(link->link.prog) ? err : 0;
}

static void
kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
                               unsigned long ret_ip, struct ftrace_regs *fregs,
                               void *data)
{
        struct bpf_kprobe_multi_link *link;

        link = container_of(fp, struct bpf_kprobe_multi_link, fp);
        kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
                                   fregs, true, data);
}

static int symbols_cmp_r(const void *a, const void *b, const void *priv)
{
        const char **str_a = (const char **) a;
        const char **str_b = (const char **) b;

        return strcmp(*str_a, *str_b);
}

struct multi_symbols_sort {
        const char **funcs;
        u64 *cookies;
};

static void symbols_swap_r(void *a, void *b, int size, const void *priv)
{
        const struct multi_symbols_sort *data = priv;
        const char **name_a = a, **name_b = b;

        swap(*name_a, *name_b);

        /* If defined, swap also related cookies. */
        if (data->cookies) {
                u64 *cookie_a, *cookie_b;

                cookie_a = data->cookies + (name_a - data->funcs);
                cookie_b = data->cookies + (name_b - data->funcs);
                swap(*cookie_a, *cookie_b);
        }
}

struct modules_array {
        struct module **mods;
        int mods_cnt;
        int mods_cap;
};

static int add_module(struct modules_array *arr, struct module *mod)
{
        struct module **mods;

        if (arr->mods_cnt == arr->mods_cap) {
                arr->mods_cap = max(16, arr->mods_cap * 3 / 2);
                mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL);
                if (!mods)
                        return -ENOMEM;
                arr->mods = mods;
        }

        arr->mods[arr->mods_cnt] = mod;
        arr->mods_cnt++;
        return 0;
}

static bool has_module(struct modules_array *arr, struct module *mod)
{
        int i;

        for (i = arr->mods_cnt - 1; i >= 0; i--) {
                if (arr->mods[i] == mod)
                        return true;
        }
        return false;
}

static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt)
{
        struct modules_array arr = {};
        u32 i, err = 0;

        for (i = 0; i < addrs_cnt; i++) {
                bool skip_add = false;
                struct module *mod;

                scoped_guard(rcu) {
                        mod = __module_address(addrs[i]);
                        /* Either no module or it's already stored  */
                        if (!mod || has_module(&arr, mod)) {
                                skip_add = true;
                                break; /* scoped_guard */
                        }
                        if (!try_module_get(mod))
                                err = -EINVAL;
                }
                if (skip_add)
                        continue;
                if (err)
                        break;
                err = add_module(&arr, mod);
                if (err) {
                        module_put(mod);
                        break;
                }
        }

        /* We return either err < 0 in case of error, ... */
        if (err) {
                kprobe_multi_put_modules(arr.mods, arr.mods_cnt);
                kfree(arr.mods);
                return err;
        }

        /* or number of modules found if everything is ok. */
        *mods = arr.mods;
        return arr.mods_cnt;
}

static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)
{
        u32 i;

        for (i = 0; i < cnt; i++) {
                if (!within_error_injection_list(addrs[i]))
                        return -EINVAL;
        }
        return 0;
}

int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
        struct bpf_kprobe_multi_link *link = NULL;
        struct bpf_link_primer link_primer;
        void __user *ucookies;
        unsigned long *addrs;
        u32 flags, cnt, size;
        void __user *uaddrs;
        u64 *cookies = NULL;
        void __user *usyms;
        int err;

        /* no support for 32bit archs yet */
        if (sizeof(u64) != sizeof(void *))
                return -EOPNOTSUPP;

        if (attr->link_create.flags)
                return -EINVAL;

        if (!is_kprobe_multi(prog))
                return -EINVAL;

        /* Writing to context is not allowed for kprobes. */
        if (prog->aux->kprobe_write_ctx)
                return -EINVAL;

        flags = attr->link_create.kprobe_multi.flags;
        if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
                return -EINVAL;

        uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
        usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
        if (!!uaddrs == !!usyms)
                return -EINVAL;

        cnt = attr->link_create.kprobe_multi.cnt;
        if (!cnt)
                return -EINVAL;
        if (cnt > MAX_KPROBE_MULTI_CNT)
                return -E2BIG;

        size = cnt * sizeof(*addrs);
        addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
        if (!addrs)
                return -ENOMEM;

        ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
        if (ucookies) {
                cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
                if (!cookies) {
                        err = -ENOMEM;
                        goto error;
                }
                if (copy_from_user(cookies, ucookies, size)) {
                        err = -EFAULT;
                        goto error;
                }
        }

        if (uaddrs) {
                if (copy_from_user(addrs, uaddrs, size)) {
                        err = -EFAULT;
                        goto error;
                }
        } else {
                struct multi_symbols_sort data = {
                        .cookies = cookies,
                };
                struct user_syms us;

                err = copy_user_syms(&us, usyms, cnt);
                if (err)
                        goto error;

                if (cookies)
                        data.funcs = us.syms;

                sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
                       symbols_swap_r, &data);

                err = ftrace_lookup_symbols(us.syms, cnt, addrs);
                free_user_syms(&us);
                if (err)
                        goto error;
        }

        if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {
                err = -EINVAL;
                goto error;
        }

        link = kzalloc(sizeof(*link), GFP_KERNEL);
        if (!link) {
                err = -ENOMEM;
                goto error;
        }

        bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
                      &bpf_kprobe_multi_link_lops, prog, attr->link_create.attach_type);

        err = bpf_link_prime(&link->link, &link_primer);
        if (err)
                goto error;

        if (!(flags & BPF_F_KPROBE_MULTI_RETURN))
                link->fp.entry_handler = kprobe_multi_link_handler;
        if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog))
                link->fp.exit_handler = kprobe_multi_link_exit_handler;
        if (is_kprobe_session(prog))
                link->fp.entry_data_size = sizeof(u64);

        link->addrs = addrs;
        link->cookies = cookies;
        link->cnt = cnt;
        link->link.flags = flags;

        if (cookies) {
                /*
                 * Sorting addresses will trigger sorting cookies as well
                 * (check bpf_kprobe_multi_cookie_swap). This way we can
                 * find cookie based on the address in bpf_get_attach_cookie
                 * helper.
                 */
                sort_r(addrs, cnt, sizeof(*addrs),
                       bpf_kprobe_multi_cookie_cmp,
                       bpf_kprobe_multi_cookie_swap,
                       link);
        }

        err = get_modules_for_addrs(&link->mods, addrs, cnt);
        if (err < 0) {
                bpf_link_cleanup(&link_primer);
                return err;
        }
        link->mods_cnt = err;

        err = register_fprobe_ips(&link->fp, addrs, cnt);
        if (err) {
                kprobe_multi_put_modules(link->mods, link->mods_cnt);
                bpf_link_cleanup(&link_primer);
                return err;
        }

        return bpf_link_settle(&link_primer);

error:
        kfree(link);
        kvfree(addrs);
        kvfree(cookies);
        return err;
}
#else /* !CONFIG_FPROBE */
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
        return -EOPNOTSUPP;
}
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
{
        return 0;
}
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
{
        return 0;
}
#endif

#ifdef CONFIG_UPROBES
struct bpf_uprobe_multi_link;

struct bpf_uprobe {
        struct bpf_uprobe_multi_link *link;
        loff_t offset;
        unsigned long ref_ctr_offset;
        u64 cookie;
        struct uprobe *uprobe;
        struct uprobe_consumer consumer;
        bool session;
};

struct bpf_uprobe_multi_link {
        struct path path;
        struct bpf_link link;
        u32 cnt;
        struct bpf_uprobe *uprobes;
        struct task_struct *task;
};

struct bpf_uprobe_multi_run_ctx {
        struct bpf_session_run_ctx session_ctx;
        unsigned long entry_ip;
        struct bpf_uprobe *uprobe;
};

static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
{
        u32 i;

        for (i = 0; i < cnt; i++)
                uprobe_unregister_nosync(uprobes[i].uprobe, &uprobes[i].consumer);

        if (cnt)
                uprobe_unregister_sync();
}

static void bpf_uprobe_multi_link_release(struct bpf_link *link)
{
        struct bpf_uprobe_multi_link *umulti_link;

        umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
        bpf_uprobe_unregister(umulti_link->uprobes, umulti_link->cnt);
        if (umulti_link->task)
                put_task_struct(umulti_link->task);
        path_put(&umulti_link->path);
}

static void bpf_uprobe_multi_link_dealloc(struct bpf_link *link)
{
        struct bpf_uprobe_multi_link *umulti_link;

        umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
        kvfree(umulti_link->uprobes);
        kfree(umulti_link);
}

static int bpf_uprobe_multi_link_fill_link_info(const struct bpf_link *link,
                                                struct bpf_link_info *info)
{
        u64 __user *uref_ctr_offsets = u64_to_user_ptr(info->uprobe_multi.ref_ctr_offsets);
        u64 __user *ucookies = u64_to_user_ptr(info->uprobe_multi.cookies);
        u64 __user *uoffsets = u64_to_user_ptr(info->uprobe_multi.offsets);
        u64 __user *upath = u64_to_user_ptr(info->uprobe_multi.path);
        u32 upath_size = info->uprobe_multi.path_size;
        struct bpf_uprobe_multi_link *umulti_link;
        u32 ucount = info->uprobe_multi.count;
        int err = 0, i;
        char *p, *buf;
        long left = 0;

        if (!upath ^ !upath_size)
                return -EINVAL;

        if ((uoffsets || uref_ctr_offsets || ucookies) && !ucount)
                return -EINVAL;

        umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);
        info->uprobe_multi.count = umulti_link->cnt;
        info->uprobe_multi.flags = umulti_link->link.flags;
        info->uprobe_multi.pid = umulti_link->task ?
                                 task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;

        upath_size = upath_size ? min_t(u32, upath_size, PATH_MAX) : PATH_MAX;
        buf = kmalloc(upath_size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;
        p = d_path(&umulti_link->path, buf, upath_size);
        if (IS_ERR(p)) {
                kfree(buf);
                return PTR_ERR(p);
        }
        upath_size = buf + upath_size - p;

        if (upath)
                left = copy_to_user(upath, p, upath_size);
        kfree(buf);
        if (left)
                return -EFAULT;
        info->uprobe_multi.path_size = upath_size;

        if (!uoffsets && !ucookies && !uref_ctr_offsets)
                return 0;

        if (ucount < umulti_link->cnt)
                err = -ENOSPC;
        else
                ucount = umulti_link->cnt;

        for (i = 0; i < ucount; i++) {
                if (uoffsets &&
                    put_user(umulti_link->uprobes[i].offset, uoffsets + i))
                        return -EFAULT;
                if (uref_ctr_offsets &&
                    put_user(umulti_link->uprobes[i].ref_ctr_offset, uref_ctr_offsets + i))
                        return -EFAULT;
                if (ucookies &&
                    put_user(umulti_link->uprobes[i].cookie, ucookies + i))
                        return -EFAULT;
        }

        return err;
}

#ifdef CONFIG_PROC_FS
static void bpf_uprobe_multi_show_fdinfo(const struct bpf_link *link,
                                         struct seq_file *seq)
{
        struct bpf_uprobe_multi_link *umulti_link;
        char *p, *buf;
        pid_t pid;

        umulti_link = container_of(link, struct bpf_uprobe_multi_link, link);

        buf = kmalloc(PATH_MAX, GFP_KERNEL);
        if (!buf)
                return;

        p = d_path(&umulti_link->path, buf, PATH_MAX);
        if (IS_ERR(p)) {
                kfree(buf);
                return;
        }

        pid = umulti_link->task ?
              task_pid_nr_ns(umulti_link->task, task_active_pid_ns(current)) : 0;
        seq_printf(seq,
                   "uprobe_cnt:\t%u\n"
                   "pid:\t%u\n"
                   "path:\t%s\n",
                   umulti_link->cnt, pid, p);

        seq_printf(seq, "%s\t %s\t %s\n", "cookie", "offset", "ref_ctr_offset");
        for (int i = 0; i < umulti_link->cnt; i++) {
                seq_printf(seq,
                           "%llu\t %#llx\t %#lx\n",
                           umulti_link->uprobes[i].cookie,
                           umulti_link->uprobes[i].offset,
                           umulti_link->uprobes[i].ref_ctr_offset);
        }

        kfree(buf);
}
#endif

static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
        .release = bpf_uprobe_multi_link_release,
        .dealloc_deferred = bpf_uprobe_multi_link_dealloc,
        .fill_link_info = bpf_uprobe_multi_link_fill_link_info,
#ifdef CONFIG_PROC_FS
        .show_fdinfo = bpf_uprobe_multi_show_fdinfo,
#endif
};

static int uprobe_prog_run(struct bpf_uprobe *uprobe,
                           unsigned long entry_ip,
                           struct pt_regs *regs,
                           bool is_return, void *data)
{
        struct bpf_uprobe_multi_link *link = uprobe->link;
        struct bpf_uprobe_multi_run_ctx run_ctx = {
                .session_ctx = {
                        .is_return = is_return,
                        .data = data,
                },
                .entry_ip = entry_ip,
                .uprobe = uprobe,
        };
        struct bpf_prog *prog = link->link.prog;
        bool sleepable = prog->sleepable;
        struct bpf_run_ctx *old_run_ctx;
        int err;

        if (link->task && !same_thread_group(current, link->task))
                return 0;

        if (sleepable)
                rcu_read_lock_trace();
        else
                rcu_read_lock();

        migrate_disable();

        old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
        err = bpf_prog_run(link->link.prog, regs);
        bpf_reset_run_ctx(old_run_ctx);

        migrate_enable();

        if (sleepable)
                rcu_read_unlock_trace();
        else
                rcu_read_unlock();
        return err;
}

static bool
uprobe_multi_link_filter(struct uprobe_consumer *con, struct mm_struct *mm)
{
        struct bpf_uprobe *uprobe;

        uprobe = container_of(con, struct bpf_uprobe, consumer);
        return uprobe->link->task->mm == mm;
}

static int
uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
                          __u64 *data)
{
        struct bpf_uprobe *uprobe;
        int ret;

        uprobe = container_of(con, struct bpf_uprobe, consumer);
        ret = uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
        if (uprobe->session)
                return ret ? UPROBE_HANDLER_IGNORE : 0;
        return 0;
}

static int
uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs,
                              __u64 *data)
{
        struct bpf_uprobe *uprobe;

        uprobe = container_of(con, struct bpf_uprobe, consumer);
        uprobe_prog_run(uprobe, func, regs, true, data);
        return 0;
}

static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
{
        struct bpf_uprobe_multi_run_ctx *run_ctx;

        run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
                               session_ctx.run_ctx);
        return run_ctx->entry_ip;
}

static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
{
        struct bpf_uprobe_multi_run_ctx *run_ctx;

        run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
                               session_ctx.run_ctx);
        return run_ctx->uprobe->cookie;
}

int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
        struct bpf_uprobe_multi_link *link = NULL;
        unsigned long __user *uref_ctr_offsets;
        struct bpf_link_primer link_primer;
        struct bpf_uprobe *uprobes = NULL;
        struct task_struct *task = NULL;
        unsigned long __user *uoffsets;
        u64 __user *ucookies;
        void __user *upath;
        u32 flags, cnt, i;
        struct path path;
        char *name;
        pid_t pid;
        int err;

        /* no support for 32bit archs yet */
        if (sizeof(u64) != sizeof(void *))
                return -EOPNOTSUPP;

        if (attr->link_create.flags)
                return -EINVAL;

        if (!is_uprobe_multi(prog))
                return -EINVAL;

        flags = attr->link_create.uprobe_multi.flags;
        if (flags & ~BPF_F_UPROBE_MULTI_RETURN)
                return -EINVAL;

        /*
         * path, offsets and cnt are mandatory,
         * ref_ctr_offsets and cookies are optional
         */
        upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
        uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
        cnt = attr->link_create.uprobe_multi.cnt;
        pid = attr->link_create.uprobe_multi.pid;

        if (!upath || !uoffsets || !cnt || pid < 0)
                return -EINVAL;
        if (cnt > MAX_UPROBE_MULTI_CNT)
                return -E2BIG;

        uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
        ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);

        name = strndup_user(upath, PATH_MAX);
        if (IS_ERR(name)) {
                err = PTR_ERR(name);
                return err;
        }

        err = kern_path(name, LOOKUP_FOLLOW, &path);
        kfree(name);
        if (err)
                return err;

        if (!d_is_reg(path.dentry)) {
                err = -EBADF;
                goto error_path_put;
        }

        if (pid) {
                rcu_read_lock();
                task = get_pid_task(find_vpid(pid), PIDTYPE_TGID);
                rcu_read_unlock();
                if (!task) {
                        err = -ESRCH;
                        goto error_path_put;
                }
        }

        err = -ENOMEM;

        link = kzalloc(sizeof(*link), GFP_KERNEL);
        uprobes = kvcalloc(cnt, sizeof(*uprobes), GFP_KERNEL);

        if (!uprobes || !link)
                goto error_free;

        for (i = 0; i < cnt; i++) {
                if (__get_user(uprobes[i].offset, uoffsets + i)) {
                        err = -EFAULT;
                        goto error_free;
                }
                if (uprobes[i].offset < 0) {
                        err = -EINVAL;
                        goto error_free;
                }
                if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
                        err = -EFAULT;
                        goto error_free;
                }
                if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
                        err = -EFAULT;
                        goto error_free;
                }

                uprobes[i].link = link;

                if (!(flags & BPF_F_UPROBE_MULTI_RETURN))
                        uprobes[i].consumer.handler = uprobe_multi_link_handler;
                if (flags & BPF_F_UPROBE_MULTI_RETURN || is_uprobe_session(prog))
                        uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
                if (is_uprobe_session(prog))
                        uprobes[i].session = true;
                if (pid)
                        uprobes[i].consumer.filter = uprobe_multi_link_filter;
        }

        link->cnt = cnt;
        link->uprobes = uprobes;
        link->path = path;
        link->task = task;
        link->link.flags = flags;

        bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
                      &bpf_uprobe_multi_link_lops, prog, attr->link_create.attach_type);

        for (i = 0; i < cnt; i++) {
                uprobes[i].uprobe = uprobe_register(d_real_inode(link->path.dentry),
                                                    uprobes[i].offset,
                                                    uprobes[i].ref_ctr_offset,
                                                    &uprobes[i].consumer);
                if (IS_ERR(uprobes[i].uprobe)) {
                        err = PTR_ERR(uprobes[i].uprobe);
                        link->cnt = i;
                        goto error_unregister;
                }
        }

        err = bpf_link_prime(&link->link, &link_primer);
        if (err)
                goto error_unregister;

        return bpf_link_settle(&link_primer);

error_unregister:
        bpf_uprobe_unregister(uprobes, link->cnt);

error_free:
        kvfree(uprobes);
        kfree(link);
        if (task)
                put_task_struct(task);
error_path_put:
        path_put(&path);
        return err;
}
#else /* !CONFIG_UPROBES */
int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
        return -EOPNOTSUPP;
}
static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
{
        return 0;
}
static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
{
        return 0;
}
#endif /* CONFIG_UPROBES */

__bpf_kfunc_start_defs();

__bpf_kfunc bool bpf_session_is_return(void)
{
        struct bpf_session_run_ctx *session_ctx;

        session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
        return session_ctx->is_return;
}

__bpf_kfunc __u64 *bpf_session_cookie(void)
{
        struct bpf_session_run_ctx *session_ctx;

        session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx);
        return session_ctx->data;
}

__bpf_kfunc_end_defs();

BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids)
BTF_ID_FLAGS(func, bpf_session_is_return)
BTF_ID_FLAGS(func, bpf_session_cookie)
BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids)

static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
{
        if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
                return 0;

        if (!is_kprobe_session(prog) && !is_uprobe_session(prog))
                return -EACCES;

        return 0;
}

static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = {
        .owner = THIS_MODULE,
        .set = &kprobe_multi_kfunc_set_ids,
        .filter = bpf_kprobe_multi_filter,
};

static int __init bpf_kprobe_multi_kfuncs_init(void)
{
        return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set);
}

late_initcall(bpf_kprobe_multi_kfuncs_init);

typedef int (*copy_fn_t)(void *dst, const void *src, u32 size, struct task_struct *tsk);

/*
 * The __always_inline is to make sure the compiler doesn't
 * generate indirect calls into callbacks, which is expensive,
 * on some kernel configurations. This allows compiler to put
 * direct calls into all the specific callback implementations
 * (copy_user_data_sleepable, copy_user_data_nofault, and so on)
 */
static __always_inline int __bpf_dynptr_copy_str(struct bpf_dynptr *dptr, u32 doff, u32 size,
                                                 const void *unsafe_src,
                                                 copy_fn_t str_copy_fn,
                                                 struct task_struct *tsk)
{
        struct bpf_dynptr_kern *dst;
        u32 chunk_sz, off;
        void *dst_slice;
        int cnt, err;
        char buf[256];

        dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size);
        if (likely(dst_slice))
                return str_copy_fn(dst_slice, unsafe_src, size, tsk);

        dst = (struct bpf_dynptr_kern *)dptr;
        if (bpf_dynptr_check_off_len(dst, doff, size))
                return -E2BIG;

        for (off = 0; off < size; off += chunk_sz - 1) {
                chunk_sz = min_t(u32, sizeof(buf), size - off);
                /* Expect str_copy_fn to return count of copied bytes, including
                 * zero terminator. Next iteration increment off by chunk_sz - 1 to
                 * overwrite NUL.
                 */
                cnt = str_copy_fn(buf, unsafe_src + off, chunk_sz, tsk);
                if (cnt < 0)
                        return cnt;
                err = __bpf_dynptr_write(dst, doff + off, buf, cnt, 0);
                if (err)
                        return err;
                if (cnt < chunk_sz || chunk_sz == 1) /* we are done */
                        return off + cnt;
        }
        return off;
}

static __always_inline int __bpf_dynptr_copy(const struct bpf_dynptr *dptr, u32 doff,
                                             u32 size, const void *unsafe_src,
                                             copy_fn_t copy_fn, struct task_struct *tsk)
{
        struct bpf_dynptr_kern *dst;
        void *dst_slice;
        char buf[256];
        u32 off, chunk_sz;
        int err;

        dst_slice = bpf_dynptr_slice_rdwr(dptr, doff, NULL, size);
        if (likely(dst_slice))
                return copy_fn(dst_slice, unsafe_src, size, tsk);

        dst = (struct bpf_dynptr_kern *)dptr;
        if (bpf_dynptr_check_off_len(dst, doff, size))
                return -E2BIG;

        for (off = 0; off < size; off += chunk_sz) {
                chunk_sz = min_t(u32, sizeof(buf), size - off);
                err = copy_fn(buf, unsafe_src + off, chunk_sz, tsk);
                if (err)
                        return err;
                err = __bpf_dynptr_write(dst, doff + off, buf, chunk_sz, 0);
                if (err)
                        return err;
        }
        return 0;
}

static __always_inline int copy_user_data_nofault(void *dst, const void *unsafe_src,
                                                  u32 size, struct task_struct *tsk)
{
        return copy_from_user_nofault(dst, (const void __user *)unsafe_src, size);
}

static __always_inline int copy_user_data_sleepable(void *dst, const void *unsafe_src,
                                                    u32 size, struct task_struct *tsk)
{
        int ret;

        if (!tsk) { /* Read from the current task */
                ret = copy_from_user(dst, (const void __user *)unsafe_src, size);
                if (ret)
                        return -EFAULT;
                return 0;
        }

        ret = access_process_vm(tsk, (unsigned long)unsafe_src, dst, size, 0);
        if (ret != size)
                return -EFAULT;
        return 0;
}

static __always_inline int copy_kernel_data_nofault(void *dst, const void *unsafe_src,
                                                    u32 size, struct task_struct *tsk)
{
        return copy_from_kernel_nofault(dst, unsafe_src, size);
}

static __always_inline int copy_user_str_nofault(void *dst, const void *unsafe_src,
                                                 u32 size, struct task_struct *tsk)
{
        return strncpy_from_user_nofault(dst, (const void __user *)unsafe_src, size);
}

static __always_inline int copy_user_str_sleepable(void *dst, const void *unsafe_src,
                                                   u32 size, struct task_struct *tsk)
{
        int ret;

        if (unlikely(size == 0))
                return 0;

        if (tsk) {
                ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_src, dst, size, 0);
        } else {
                ret = strncpy_from_user(dst, (const void __user *)unsafe_src, size - 1);
                /* strncpy_from_user does not guarantee NUL termination */
                if (ret >= 0)
                        ((char *)dst)[ret] = '\0';
        }

        if (ret < 0)
                return ret;
        return ret + 1;
}

static __always_inline int copy_kernel_str_nofault(void *dst, const void *unsafe_src,
                                                   u32 size, struct task_struct *tsk)
{
        return strncpy_from_kernel_nofault(dst, unsafe_src, size);
}

__bpf_kfunc_start_defs();

__bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid_type type,
                                     u64 value)
{
        if (type != PIDTYPE_PID && type != PIDTYPE_TGID)
                return -EINVAL;

        return bpf_send_signal_common(sig, type, task, value);
}

__bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u32 off,
                                           u32 size, const void __user *unsafe_ptr__ign)
{
        return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign,
                                 copy_user_data_nofault, NULL);
}

__bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u32 off,
                                             u32 size, const void *unsafe_ptr__ign)
{
        return __bpf_dynptr_copy(dptr, off, size, unsafe_ptr__ign,
                                 copy_kernel_data_nofault, NULL);
}

__bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u32 off,
                                               u32 size, const void __user *unsafe_ptr__ign)
{
        return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign,
                                     copy_user_str_nofault, NULL);
}

__bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u32 off,
                                                 u32 size, const void *unsafe_ptr__ign)
{
        return __bpf_dynptr_copy_str(dptr, off, size, unsafe_ptr__ign,
                                     copy_kernel_str_nofault, NULL);
}

__bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u32 off,
                                          u32 size, const void __user *unsafe_ptr__ign)
{
        return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign,
                                 copy_user_data_sleepable, NULL);
}

__bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u32 off,
                                              u32 size, const void __user *unsafe_ptr__ign)
{
        return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign,
                                     copy_user_str_sleepable, NULL);
}

__bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u32 off,
                                               u32 size, const void __user *unsafe_ptr__ign,
                                               struct task_struct *tsk)
{
        return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign,
                                 copy_user_data_sleepable, tsk);
}

__bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u32 off,
                                                   u32 size, const void __user *unsafe_ptr__ign,
                                                   struct task_struct *tsk)
{
        return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign,
                                     copy_user_str_sleepable, tsk);
}

__bpf_kfunc_end_defs();






































































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// SPDX-License-Identifier: GPL-2.0-or-later
/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * This file is part of the SCTP kernel implementation
 *
 * This module provides the abstraction for an SCTP association.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Hui Huang             <hui.huang@nokia.com>
 *    Sridhar Samudrala            <sri@us.ibm.com>
 *    Daisy Chang            <daisyc@us.ibm.com>
 *    Ryan Layer            <rmlayer@us.ibm.com>
 *    Kevin Gao             <kevin.gao@intel.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>

#include <linux/slab.h>
#include <linux/in.h>
#include <net/ipv6.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* Forward declarations for internal functions. */
static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
static void sctp_assoc_bh_rcv(struct work_struct *work);
static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);

/* 1st Level Abstractions. */

/* Initialize a new association from provided memory. */
static struct sctp_association *sctp_association_init(
                                        struct sctp_association *asoc,
                                        const struct sctp_endpoint *ep,
                                        const struct sock *sk,
                                        enum sctp_scope scope, gfp_t gfp)
{
        struct sctp_sock *sp;
        struct sctp_paramhdr *p;
        int i;

        /* Retrieve the SCTP per socket area.  */
        sp = sctp_sk((struct sock *)sk);

        /* Discarding const is appropriate here.  */
        asoc->ep = (struct sctp_endpoint *)ep;
        asoc->base.sk = (struct sock *)sk;
        asoc->base.net = sock_net(sk);

        sctp_endpoint_hold(asoc->ep);
        sock_hold(asoc->base.sk);

        /* Initialize the common base substructure.  */
        asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;

        /* Initialize the object handling fields.  */
        refcount_set(&asoc->base.refcnt, 1);

        /* Initialize the bind addr area.  */
        sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);

        asoc->state = SCTP_STATE_CLOSED;
        asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
        asoc->user_frag = sp->user_frag;

        /* Set the association max_retrans and RTO values from the
         * socket values.
         */
        asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
        asoc->pf_retrans  = sp->pf_retrans;
        asoc->ps_retrans  = sp->ps_retrans;
        asoc->pf_expose   = sp->pf_expose;

        asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
        asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
        asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);

        /* Initialize the association's heartbeat interval based on the
         * sock configured value.
         */
        asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
        asoc->probe_interval = msecs_to_jiffies(sp->probe_interval);

        asoc->encap_port = sp->encap_port;

        /* Initialize path max retrans value. */
        asoc->pathmaxrxt = sp->pathmaxrxt;

        asoc->flowlabel = sp->flowlabel;
        asoc->dscp = sp->dscp;

        /* Set association default SACK delay */
        asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
        asoc->sackfreq = sp->sackfreq;

        /* Set the association default flags controlling
         * Heartbeat, SACK delay, and Path MTU Discovery.
         */
        asoc->param_flags = sp->param_flags;

        /* Initialize the maximum number of new data packets that can be sent
         * in a burst.
         */
        asoc->max_burst = sp->max_burst;

        asoc->subscribe = sp->subscribe;

        /* initialize association timers */
        asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
        asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
        asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;

        /* sctpimpguide Section 2.12.2
         * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
         * recommended value of 5 times 'RTO.Max'.
         */
        asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
                = 5 * asoc->rto_max;

        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
        asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
                (unsigned long)sp->autoclose * HZ;

        /* Initializes the timers */
        for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
                timer_setup(&asoc->timers[i], sctp_timer_events[i], 0);

        /* Pull default initialization values from the sock options.
         * Note: This assumes that the values have already been
         * validated in the sock.
         */
        asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
        asoc->c.sinit_num_ostreams  = sp->initmsg.sinit_num_ostreams;
        asoc->max_init_attempts        = sp->initmsg.sinit_max_attempts;

        asoc->max_init_timeo =
                 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);

        /* Set the local window size for receive.
         * This is also the rcvbuf space per association.
         * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
         * 1500 bytes in one SCTP packet.
         */
        if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
                asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
        else
                asoc->rwnd = sk->sk_rcvbuf/2;

        asoc->a_rwnd = asoc->rwnd;

        /* Use my own max window until I learn something better.  */
        asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;

        /* Initialize the receive memory counter */
        atomic_set(&asoc->rmem_alloc, 0);

        init_waitqueue_head(&asoc->wait);

        asoc->c.my_vtag = sctp_generate_tag(ep);
        asoc->c.my_port = ep->base.bind_addr.port;

        asoc->c.initial_tsn = sctp_generate_tsn(ep);

        asoc->next_tsn = asoc->c.initial_tsn;

        asoc->ctsn_ack_point = asoc->next_tsn - 1;
        asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
        asoc->highest_sacked = asoc->ctsn_ack_point;
        asoc->last_cwr_tsn = asoc->ctsn_ack_point;

        /* ADDIP Section 4.1 Asconf Chunk Procedures
         *
         * When an endpoint has an ASCONF signaled change to be sent to the
         * remote endpoint it should do the following:
         * ...
         * A2) a serial number should be assigned to the chunk. The serial
         * number SHOULD be a monotonically increasing number. The serial
         * numbers SHOULD be initialized at the start of the
         * association to the same value as the initial TSN.
         */
        asoc->addip_serial = asoc->c.initial_tsn;
        asoc->strreset_outseq = asoc->c.initial_tsn;

        INIT_LIST_HEAD(&asoc->addip_chunk_list);
        INIT_LIST_HEAD(&asoc->asconf_ack_list);

        /* Make an empty list of remote transport addresses.  */
        INIT_LIST_HEAD(&asoc->peer.transport_addr_list);

        /* RFC 2960 5.1 Normal Establishment of an Association
         *
         * After the reception of the first data chunk in an
         * association the endpoint must immediately respond with a
         * sack to acknowledge the data chunk.  Subsequent
         * acknowledgements should be done as described in Section
         * 6.2.
         *
         * [We implement this by telling a new association that it
         * already received one packet.]
         */
        asoc->peer.sack_needed = 1;
        asoc->peer.sack_generation = 1;

        /* Create an input queue.  */
        sctp_inq_init(&asoc->base.inqueue);
        sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);

        /* Create an output queue.  */
        sctp_outq_init(asoc, &asoc->outqueue);

        sctp_ulpq_init(&asoc->ulpq, asoc);

        if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 0, gfp))
                goto stream_free;

        /* Initialize default path MTU. */
        asoc->pathmtu = sp->pathmtu;
        sctp_assoc_update_frag_point(asoc);

        /* Assume that peer would support both address types unless we are
         * told otherwise.
         */
        asoc->peer.ipv4_address = 1;
        if (asoc->base.sk->sk_family == PF_INET6)
                asoc->peer.ipv6_address = 1;
        INIT_LIST_HEAD(&asoc->asocs);

        asoc->default_stream = sp->default_stream;
        asoc->default_ppid = sp->default_ppid;
        asoc->default_flags = sp->default_flags;
        asoc->default_context = sp->default_context;
        asoc->default_timetolive = sp->default_timetolive;
        asoc->default_rcv_context = sp->default_rcv_context;

        /* AUTH related initializations */
        INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
        if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
                goto stream_free;

        asoc->active_key_id = ep->active_key_id;
        asoc->strreset_enable = ep->strreset_enable;

        /* Save the hmacs and chunks list into this association */
        if (ep->auth_hmacs_list)
                memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
                        ntohs(ep->auth_hmacs_list->param_hdr.length));
        if (ep->auth_chunk_list)
                memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
                        ntohs(ep->auth_chunk_list->param_hdr.length));

        /* Get the AUTH random number for this association */
        p = (struct sctp_paramhdr *)asoc->c.auth_random;
        p->type = SCTP_PARAM_RANDOM;
        p->length = htons(sizeof(*p) + SCTP_AUTH_RANDOM_LENGTH);
        get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);

        return asoc;

stream_free:
        sctp_stream_free(&asoc->stream);
        sock_put(asoc->base.sk);
        sctp_endpoint_put(asoc->ep);
        return NULL;
}

/* Allocate and initialize a new association */
struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
                                              const struct sock *sk,
                                              enum sctp_scope scope, gfp_t gfp)
{
        struct sctp_association *asoc;

        asoc = kzalloc(sizeof(*asoc), gfp);
        if (!asoc)
                goto fail;

        if (!sctp_association_init(asoc, ep, sk, scope, gfp))
                goto fail_init;

        SCTP_DBG_OBJCNT_INC(assoc);

        pr_debug("Created asoc %p\n", asoc);

        return asoc;

fail_init:
        kfree(asoc);
fail:
        return NULL;
}

/* Free this association if possible.  There may still be users, so
 * the actual deallocation may be delayed.
 */
void sctp_association_free(struct sctp_association *asoc)
{
        struct sock *sk = asoc->base.sk;
        struct sctp_transport *transport;
        struct list_head *pos, *temp;
        int i;

        /* Only real associations count against the endpoint, so
         * don't bother for if this is a temporary association.
         */
        if (!list_empty(&asoc->asocs)) {
                list_del(&asoc->asocs);

                /* Decrement the backlog value for a TCP-style listening
                 * socket.
                 */
                if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
                        sk_acceptq_removed(sk);
        }

        /* Mark as dead, so other users can know this structure is
         * going away.
         */
        asoc->base.dead = true;

        /* Dispose of any data lying around in the outqueue. */
        sctp_outq_free(&asoc->outqueue);

        /* Dispose of any pending messages for the upper layer. */
        sctp_ulpq_free(&asoc->ulpq);

        /* Dispose of any pending chunks on the inqueue. */
        sctp_inq_free(&asoc->base.inqueue);

        sctp_tsnmap_free(&asoc->peer.tsn_map);

        /* Free stream information. */
        sctp_stream_free(&asoc->stream);

        if (asoc->strreset_chunk)
                sctp_chunk_free(asoc->strreset_chunk);

        /* Clean up the bound address list. */
        sctp_bind_addr_free(&asoc->base.bind_addr);

        /* Do we need to go through all of our timers and
         * delete them?   To be safe we will try to delete all, but we
         * should be able to go through and make a guess based
         * on our state.
         */
        for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
                if (timer_delete(&asoc->timers[i]))
                        sctp_association_put(asoc);
        }

        /* Free peer's cached cookie. */
        kfree(asoc->peer.cookie);
        kfree(asoc->peer.peer_random);
        kfree(asoc->peer.peer_chunks);
        kfree(asoc->peer.peer_hmacs);

        /* Release the transport structures. */
        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
                transport = list_entry(pos, struct sctp_transport, transports);
                list_del_rcu(pos);
                sctp_unhash_transport(transport);
                sctp_transport_free(transport);
        }

        asoc->peer.transport_count = 0;

        sctp_asconf_queue_teardown(asoc);

        /* Free pending address space being deleted */
        kfree(asoc->asconf_addr_del_pending);

        /* AUTH - Free the endpoint shared keys */
        sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);

        /* AUTH - Free the association shared key */
        sctp_auth_key_put(asoc->asoc_shared_key);

        sctp_association_put(asoc);
}

/* Cleanup and free up an association. */
static void sctp_association_destroy(struct sctp_association *asoc)
{
        if (unlikely(!asoc->base.dead)) {
                WARN(1, "Attempt to destroy undead association %p!\n", asoc);
                return;
        }

        sctp_endpoint_put(asoc->ep);
        sock_put(asoc->base.sk);

        if (asoc->assoc_id != 0) {
                spin_lock_bh(&sctp_assocs_id_lock);
                idr_remove(&sctp_assocs_id, asoc->assoc_id);
                spin_unlock_bh(&sctp_assocs_id_lock);
        }

        WARN_ON(atomic_read(&asoc->rmem_alloc));

        kfree_rcu(asoc, rcu);
        SCTP_DBG_OBJCNT_DEC(assoc);
}

/* Change the primary destination address for the peer. */
void sctp_assoc_set_primary(struct sctp_association *asoc,
                            struct sctp_transport *transport)
{
        int changeover = 0;

        /* it's a changeover only if we already have a primary path
         * that we are changing
         */
        if (asoc->peer.primary_path != NULL &&
            asoc->peer.primary_path != transport)
                changeover = 1 ;

        asoc->peer.primary_path = transport;
        sctp_ulpevent_notify_peer_addr_change(transport,
                                              SCTP_ADDR_MADE_PRIM, 0);

        /* Set a default msg_name for events. */
        memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
               sizeof(union sctp_addr));

        /* If the primary path is changing, assume that the
         * user wants to use this new path.
         */
        if ((transport->state == SCTP_ACTIVE) ||
            (transport->state == SCTP_UNKNOWN))
                asoc->peer.active_path = transport;

        /*
         * SFR-CACC algorithm:
         * Upon the receipt of a request to change the primary
         * destination address, on the data structure for the new
         * primary destination, the sender MUST do the following:
         *
         * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
         * to this destination address earlier. The sender MUST set
         * CYCLING_CHANGEOVER to indicate that this switch is a
         * double switch to the same destination address.
         *
         * Really, only bother is we have data queued or outstanding on
         * the association.
         */
        if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
                return;

        if (transport->cacc.changeover_active)
                transport->cacc.cycling_changeover = changeover;

        /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
         * a changeover has occurred.
         */
        transport->cacc.changeover_active = changeover;

        /* 3) The sender MUST store the next TSN to be sent in
         * next_tsn_at_change.
         */
        transport->cacc.next_tsn_at_change = asoc->next_tsn;
}

/* Remove a transport from an association.  */
void sctp_assoc_rm_peer(struct sctp_association *asoc,
                        struct sctp_transport *peer)
{
        struct sctp_transport *transport;
        struct list_head *pos;
        struct sctp_chunk *ch;

        pr_debug("%s: association:%p addr:%pISpc\n",
                 __func__, asoc, &peer->ipaddr.sa);

        /* If we are to remove the current retran_path, update it
         * to the next peer before removing this peer from the list.
         */
        if (asoc->peer.retran_path == peer)
                sctp_assoc_update_retran_path(asoc);

        /* Remove this peer from the list. */
        list_del_rcu(&peer->transports);
        /* Remove this peer from the transport hashtable */
        sctp_unhash_transport(peer);

        /* Get the first transport of asoc. */
        pos = asoc->peer.transport_addr_list.next;
        transport = list_entry(pos, struct sctp_transport, transports);

        /* Update any entries that match the peer to be deleted. */
        if (asoc->peer.primary_path == peer)
                sctp_assoc_set_primary(asoc, transport);
        if (asoc->peer.active_path == peer)
                asoc->peer.active_path = transport;
        if (asoc->peer.retran_path == peer)
                asoc->peer.retran_path = transport;
        if (asoc->peer.last_data_from == peer)
                asoc->peer.last_data_from = transport;

        if (asoc->strreset_chunk &&
            asoc->strreset_chunk->transport == peer) {
                asoc->strreset_chunk->transport = transport;
                sctp_transport_reset_reconf_timer(transport);
        }

        /* If we remove the transport an INIT was last sent to, set it to
         * NULL. Combined with the update of the retran path above, this
         * will cause the next INIT to be sent to the next available
         * transport, maintaining the cycle.
         */
        if (asoc->init_last_sent_to == peer)
                asoc->init_last_sent_to = NULL;

        /* If we remove the transport an SHUTDOWN was last sent to, set it
         * to NULL. Combined with the update of the retran path above, this
         * will cause the next SHUTDOWN to be sent to the next available
         * transport, maintaining the cycle.
         */
        if (asoc->shutdown_last_sent_to == peer)
                asoc->shutdown_last_sent_to = NULL;

        /* If we remove the transport an ASCONF was last sent to, set it to
         * NULL.
         */
        if (asoc->addip_last_asconf &&
            asoc->addip_last_asconf->transport == peer)
                asoc->addip_last_asconf->transport = NULL;

        /* If we have something on the transmitted list, we have to
         * save it off.  The best place is the active path.
         */
        if (!list_empty(&peer->transmitted)) {
                struct sctp_transport *active = asoc->peer.active_path;

                /* Reset the transport of each chunk on this list */
                list_for_each_entry(ch, &peer->transmitted,
                                        transmitted_list) {
                        ch->transport = NULL;
                        ch->rtt_in_progress = 0;
                }

                list_splice_tail_init(&peer->transmitted,
                                        &active->transmitted);

                /* Start a T3 timer here in case it wasn't running so
                 * that these migrated packets have a chance to get
                 * retransmitted.
                 */
                if (!timer_pending(&active->T3_rtx_timer))
                        if (!mod_timer(&active->T3_rtx_timer,
                                        jiffies + active->rto))
                                sctp_transport_hold(active);
        }

        list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list)
                if (ch->transport == peer)
                        ch->transport = NULL;

        asoc->peer.transport_count--;

        sctp_ulpevent_notify_peer_addr_change(peer, SCTP_ADDR_REMOVED, 0);
        sctp_transport_free(peer);
}

/* Add a transport address to an association.  */
struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
                                           const union sctp_addr *addr,
                                           const gfp_t gfp,
                                           const int peer_state)
{
        struct sctp_transport *peer;
        struct sctp_sock *sp;
        unsigned short port;

        sp = sctp_sk(asoc->base.sk);

        /* AF_INET and AF_INET6 share common port field. */
        port = ntohs(addr->v4.sin_port);

        pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
                 asoc, &addr->sa, peer_state);

        /* Set the port if it has not been set yet.  */
        if (0 == asoc->peer.port)
                asoc->peer.port = port;

        /* Check to see if this is a duplicate. */
        peer = sctp_assoc_lookup_paddr(asoc, addr);
        if (peer) {
                /* An UNKNOWN state is only set on transports added by
                 * user in sctp_connectx() call.  Such transports should be
                 * considered CONFIRMED per RFC 4960, Section 5.4.
                 */
                if (peer->state == SCTP_UNKNOWN) {
                        peer->state = SCTP_ACTIVE;
                }
                return peer;
        }

        peer = sctp_transport_new(asoc->base.net, addr, gfp);
        if (!peer)
                return NULL;

        sctp_transport_set_owner(peer, asoc);

        /* Initialize the peer's heartbeat interval based on the
         * association configured value.
         */
        peer->hbinterval = asoc->hbinterval;
        peer->probe_interval = asoc->probe_interval;

        peer->encap_port = asoc->encap_port;

        /* Set the path max_retrans.  */
        peer->pathmaxrxt = asoc->pathmaxrxt;

        /* And the partial failure retrans threshold */
        peer->pf_retrans = asoc->pf_retrans;
        /* And the primary path switchover retrans threshold */
        peer->ps_retrans = asoc->ps_retrans;

        /* Initialize the peer's SACK delay timeout based on the
         * association configured value.
         */
        peer->sackdelay = asoc->sackdelay;
        peer->sackfreq = asoc->sackfreq;

        if (addr->sa.sa_family == AF_INET6) {
                __be32 info = addr->v6.sin6_flowinfo;

                if (info) {
                        peer->flowlabel = ntohl(info & IPV6_FLOWLABEL_MASK);
                        peer->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
                } else {
                        peer->flowlabel = asoc->flowlabel;
                }
        }
        peer->dscp = asoc->dscp;

        /* Enable/disable heartbeat, SACK delay, and path MTU discovery
         * based on association setting.
         */
        peer->param_flags = asoc->param_flags;

        /* Initialize the pmtu of the transport. */
        sctp_transport_route(peer, NULL, sp);

        /* If this is the first transport addr on this association,
         * initialize the association PMTU to the peer's PMTU.
         * If not and the current association PMTU is higher than the new
         * peer's PMTU, reset the association PMTU to the new peer's PMTU.
         */
        sctp_assoc_set_pmtu(asoc, asoc->pathmtu ?
                                  min_t(int, peer->pathmtu, asoc->pathmtu) :
                                  peer->pathmtu);

        peer->pmtu_pending = 0;

        /* The asoc->peer.port might not be meaningful yet, but
         * initialize the packet structure anyway.
         */
        sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
                         asoc->peer.port);

        /* 7.2.1 Slow-Start
         *
         * o The initial cwnd before DATA transmission or after a sufficiently
         *   long idle period MUST be set to
         *      min(4*MTU, max(2*MTU, 4380 bytes))
         *
         * o The initial value of ssthresh MAY be arbitrarily high
         *   (for example, implementations MAY use the size of the
         *   receiver advertised window).
         */
        peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));

        /* At this point, we may not have the receiver's advertised window,
         * so initialize ssthresh to the default value and it will be set
         * later when we process the INIT.
         */
        peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;

        peer->partial_bytes_acked = 0;
        peer->flight_size = 0;
        peer->burst_limited = 0;

        /* Set the transport's RTO.initial value */
        peer->rto = asoc->rto_initial;
        sctp_max_rto(asoc, peer);

        /* Set the peer's active state. */
        peer->state = peer_state;

        /* Add this peer into the transport hashtable */
        if (sctp_hash_transport(peer)) {
                sctp_transport_free(peer);
                return NULL;
        }

        sctp_transport_pl_reset(peer);

        /* Attach the remote transport to our asoc.  */
        list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
        asoc->peer.transport_count++;

        sctp_ulpevent_notify_peer_addr_change(peer, SCTP_ADDR_ADDED, 0);

        /* If we do not yet have a primary path, set one.  */
        if (!asoc->peer.primary_path) {
                sctp_assoc_set_primary(asoc, peer);
                asoc->peer.retran_path = peer;
        }

        if (asoc->peer.active_path == asoc->peer.retran_path &&
            peer->state != SCTP_UNCONFIRMED) {
                asoc->peer.retran_path = peer;
        }

        return peer;
}

/* Lookup a transport by address. */
struct sctp_transport *sctp_assoc_lookup_paddr(
                                        const struct sctp_association *asoc,
                                        const union sctp_addr *address)
{
        struct sctp_transport *t;

        /* Cycle through all transports searching for a peer address. */

        list_for_each_entry(t, &asoc->peer.transport_addr_list,
                        transports) {
                if (sctp_cmp_addr_exact(address, &t->ipaddr))
                        return t;
        }

        return NULL;
}

/* Remove all transports except a give one */
void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
                                     struct sctp_transport *primary)
{
        struct sctp_transport        *temp;
        struct sctp_transport        *t;

        list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
                                 transports) {
                /* if the current transport is not the primary one, delete it */
                if (t != primary)
                        sctp_assoc_rm_peer(asoc, t);
        }
}

/* Engage in transport control operations.
 * Mark the transport up or down and send a notification to the user.
 * Select and update the new active and retran paths.
 */
void sctp_assoc_control_transport(struct sctp_association *asoc,
                                  struct sctp_transport *transport,
                                  enum sctp_transport_cmd command,
                                  sctp_sn_error_t error)
{
        int spc_state = SCTP_ADDR_AVAILABLE;
        bool ulp_notify = true;

        /* Record the transition on the transport.  */
        switch (command) {
        case SCTP_TRANSPORT_UP:
                /* If we are moving from UNCONFIRMED state due
                 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
                 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
                 */
                if (transport->state == SCTP_PF &&
                    asoc->pf_expose != SCTP_PF_EXPOSE_ENABLE)
                        ulp_notify = false;
                else if (transport->state == SCTP_UNCONFIRMED &&
                         error == SCTP_HEARTBEAT_SUCCESS)
                        spc_state = SCTP_ADDR_CONFIRMED;

                transport->state = SCTP_ACTIVE;
                sctp_transport_pl_reset(transport);
                break;

        case SCTP_TRANSPORT_DOWN:
                /* If the transport was never confirmed, do not transition it
                 * to inactive state.  Also, release the cached route since
                 * there may be a better route next time.
                 */
                if (transport->state != SCTP_UNCONFIRMED) {
                        transport->state = SCTP_INACTIVE;
                        sctp_transport_pl_reset(transport);
                        spc_state = SCTP_ADDR_UNREACHABLE;
                } else {
                        sctp_transport_dst_release(transport);
                        ulp_notify = false;
                }
                break;

        case SCTP_TRANSPORT_PF:
                transport->state = SCTP_PF;
                if (asoc->pf_expose != SCTP_PF_EXPOSE_ENABLE)
                        ulp_notify = false;
                else
                        spc_state = SCTP_ADDR_POTENTIALLY_FAILED;
                break;

        default:
                return;
        }

        /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
         * to the user.
         */
        if (ulp_notify)
                sctp_ulpevent_notify_peer_addr_change(transport,
                                                      spc_state, error);

        /* Select new active and retran paths. */
        sctp_select_active_and_retran_path(asoc);
}

/* Hold a reference to an association. */
void sctp_association_hold(struct sctp_association *asoc)
{
        refcount_inc(&asoc->base.refcnt);
}

/* Release a reference to an association and cleanup
 * if there are no more references.
 */
void sctp_association_put(struct sctp_association *asoc)
{
        if (refcount_dec_and_test(&asoc->base.refcnt))
                sctp_association_destroy(asoc);
}

/* Allocate the next TSN, Transmission Sequence Number, for the given
 * association.
 */
__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
{
        /* From Section 1.6 Serial Number Arithmetic:
         * Transmission Sequence Numbers wrap around when they reach
         * 2**32 - 1.  That is, the next TSN a DATA chunk MUST use
         * after transmitting TSN = 2*32 - 1 is TSN = 0.
         */
        __u32 retval = asoc->next_tsn;
        asoc->next_tsn++;
        asoc->unack_data++;

        return retval;
}

/* Compare two addresses to see if they match.  Wildcard addresses
 * only match themselves.
 */
int sctp_cmp_addr_exact(const union sctp_addr *ss1,
                        const union sctp_addr *ss2)
{
        struct sctp_af *af;

        af = sctp_get_af_specific(ss1->sa.sa_family);
        if (unlikely(!af))
                return 0;

        return af->cmp_addr(ss1, ss2);
}

/* Return an ecne chunk to get prepended to a packet.
 * Note:  We are sly and return a shared, prealloced chunk.  FIXME:
 * No we don't, but we could/should.
 */
struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
{
        if (!asoc->need_ecne)
                return NULL;

        /* Send ECNE if needed.
         * Not being able to allocate a chunk here is not deadly.
         */
        return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
}

/*
 * Find which transport this TSN was sent on.
 */
struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
                                             __u32 tsn)
{
        struct sctp_transport *active;
        struct sctp_transport *match;
        struct sctp_transport *transport;
        struct sctp_chunk *chunk;
        __be32 key = htonl(tsn);

        match = NULL;

        /*
         * FIXME: In general, find a more efficient data structure for
         * searching.
         */

        /*
         * The general strategy is to search each transport's transmitted
         * list.   Return which transport this TSN lives on.
         *
         * Let's be hopeful and check the active_path first.
         * Another optimization would be to know if there is only one
         * outbound path and not have to look for the TSN at all.
         *
         */

        active = asoc->peer.active_path;

        list_for_each_entry(chunk, &active->transmitted,
                        transmitted_list) {

                if (key == chunk->subh.data_hdr->tsn) {
                        match = active;
                        goto out;
                }
        }

        /* If not found, go search all the other transports. */
        list_for_each_entry(transport, &asoc->peer.transport_addr_list,
                        transports) {

                if (transport == active)
                        continue;
                list_for_each_entry(chunk, &transport->transmitted,
                                transmitted_list) {
                        if (key == chunk->subh.data_hdr->tsn) {
                                match = transport;
                                goto out;
                        }
                }
        }
out:
        return match;
}

/* Do delayed input processing.  This is scheduled by sctp_rcv(). */
static void sctp_assoc_bh_rcv(struct work_struct *work)
{
        struct sctp_association *asoc =
                container_of(work, struct sctp_association,
                             base.inqueue.immediate);
        struct net *net = asoc->base.net;
        union sctp_subtype subtype;
        struct sctp_endpoint *ep;
        struct sctp_chunk *chunk;
        struct sctp_inq *inqueue;
        int first_time = 1;        /* is this the first time through the loop */
        int error = 0;
        int state;

        /* The association should be held so we should be safe. */
        ep = asoc->ep;

        inqueue = &asoc->base.inqueue;
        sctp_association_hold(asoc);
        while (NULL != (chunk = sctp_inq_pop(inqueue))) {
                state = asoc->state;
                subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);

                /* If the first chunk in the packet is AUTH, do special
                 * processing specified in Section 6.3 of SCTP-AUTH spec
                 */
                if (first_time && subtype.chunk == SCTP_CID_AUTH) {
                        struct sctp_chunkhdr *next_hdr;

                        next_hdr = sctp_inq_peek(inqueue);
                        if (!next_hdr)
                                goto normal;

                        /* If the next chunk is COOKIE-ECHO, skip the AUTH
                         * chunk while saving a pointer to it so we can do
                         * Authentication later (during cookie-echo
                         * processing).
                         */
                        if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
                                chunk->auth_chunk = skb_clone(chunk->skb,
                                                              GFP_ATOMIC);
                                chunk->auth = 1;
                                continue;
                        }
                }

normal:
                /* SCTP-AUTH, Section 6.3:
                 *    The receiver has a list of chunk types which it expects
                 *    to be received only after an AUTH-chunk.  This list has
                 *    been sent to the peer during the association setup.  It
                 *    MUST silently discard these chunks if they are not placed
                 *    after an AUTH chunk in the packet.
                 */
                if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
                        continue;

                /* Remember where the last DATA chunk came from so we
                 * know where to send the SACK.
                 */
                if (sctp_chunk_is_data(chunk))
                        asoc->peer.last_data_from = chunk->transport;
                else {
                        SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
                        asoc->stats.ictrlchunks++;
                        if (chunk->chunk_hdr->type == SCTP_CID_SACK)
                                asoc->stats.isacks++;
                }

                if (chunk->transport)
                        chunk->transport->last_time_heard = ktime_get();

                /* Run through the state machine. */
                error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
                                   state, ep, asoc, chunk, GFP_ATOMIC);

                /* Check to see if the association is freed in response to
                 * the incoming chunk.  If so, get out of the while loop.
                 */
                if (asoc->base.dead)
                        break;

                /* If there is an error on chunk, discard this packet. */
                if (error && chunk)
                        chunk->pdiscard = 1;

                if (first_time)
                        first_time = 0;
        }
        sctp_association_put(asoc);
}

/* This routine moves an association from its old sk to a new sk.  */
void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
{
        struct sctp_sock *newsp = sctp_sk(newsk);
        struct sock *oldsk = assoc->base.sk;

        /* Delete the association from the old endpoint's list of
         * associations.
         */
        list_del_init(&assoc->asocs);

        /* Decrement the backlog value for a TCP-style socket. */
        if (sctp_style(oldsk, TCP))
                sk_acceptq_removed(oldsk);

        /* Release references to the old endpoint and the sock.  */
        sctp_endpoint_put(assoc->ep);
        sock_put(assoc->base.sk);

        /* Get a reference to the new endpoint.  */
        assoc->ep = newsp->ep;
        sctp_endpoint_hold(assoc->ep);

        /* Get a reference to the new sock.  */
        assoc->base.sk = newsk;
        sock_hold(assoc->base.sk);

        /* Add the association to the new endpoint's list of associations.  */
        sctp_endpoint_add_asoc(newsp->ep, assoc);
}

/* Update an association (possibly from unexpected COOKIE-ECHO processing).  */
int sctp_assoc_update(struct sctp_association *asoc,
                      struct sctp_association *new)
{
        struct sctp_transport *trans;
        struct list_head *pos, *temp;

        /* Copy in new parameters of peer. */
        asoc->c = new->c;
        asoc->peer.rwnd = new->peer.rwnd;
        asoc->peer.sack_needed = new->peer.sack_needed;
        asoc->peer.auth_capable = new->peer.auth_capable;
        asoc->peer.i = new->peer.i;

        if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
                              asoc->peer.i.initial_tsn, GFP_ATOMIC))
                return -ENOMEM;

        /* Remove any peer addresses not present in the new association. */
        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
                trans = list_entry(pos, struct sctp_transport, transports);
                if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
                        sctp_assoc_rm_peer(asoc, trans);
                        continue;
                }

                if (asoc->state >= SCTP_STATE_ESTABLISHED)
                        sctp_transport_reset(trans);
        }

        /* If the case is A (association restart), use
         * initial_tsn as next_tsn. If the case is B, use
         * current next_tsn in case data sent to peer
         * has been discarded and needs retransmission.
         */
        if (asoc->state >= SCTP_STATE_ESTABLISHED) {
                asoc->next_tsn = new->next_tsn;
                asoc->ctsn_ack_point = new->ctsn_ack_point;
                asoc->adv_peer_ack_point = new->adv_peer_ack_point;

                /* Reinitialize SSN for both local streams
                 * and peer's streams.
                 */
                sctp_stream_clear(&asoc->stream);

                /* Flush the ULP reassembly and ordered queue.
                 * Any data there will now be stale and will
                 * cause problems.
                 */
                sctp_ulpq_flush(&asoc->ulpq);

                /* reset the overall association error count so
                 * that the restarted association doesn't get torn
                 * down on the next retransmission timer.
                 */
                asoc->overall_error_count = 0;

        } else {
                /* Add any peer addresses from the new association. */
                list_for_each_entry(trans, &new->peer.transport_addr_list,
                                    transports)
                        if (!sctp_assoc_add_peer(asoc, &trans->ipaddr,
                                                 GFP_ATOMIC, trans->state))
                                return -ENOMEM;

                asoc->ctsn_ack_point = asoc->next_tsn - 1;
                asoc->adv_peer_ack_point = asoc->ctsn_ack_point;

                if (sctp_state(asoc, COOKIE_WAIT))
                        sctp_stream_update(&asoc->stream, &new->stream);

                /* get a new assoc id if we don't have one yet. */
                if (sctp_assoc_set_id(asoc, GFP_ATOMIC))
                        return -ENOMEM;
        }

        /* SCTP-AUTH: Save the peer parameters from the new associations
         * and also move the association shared keys over
         */
        kfree(asoc->peer.peer_random);
        asoc->peer.peer_random = new->peer.peer_random;
        new->peer.peer_random = NULL;

        kfree(asoc->peer.peer_chunks);
        asoc->peer.peer_chunks = new->peer.peer_chunks;
        new->peer.peer_chunks = NULL;

        kfree(asoc->peer.peer_hmacs);
        asoc->peer.peer_hmacs = new->peer.peer_hmacs;
        new->peer.peer_hmacs = NULL;

        return sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
}

/* Update the retran path for sending a retransmitted packet.
 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
 *
 *   When there is outbound data to send and the primary path
 *   becomes inactive (e.g., due to failures), or where the
 *   SCTP user explicitly requests to send data to an
 *   inactive destination transport address, before reporting
 *   an error to its ULP, the SCTP endpoint should try to send
 *   the data to an alternate active destination transport
 *   address if one exists.
 *
 *   When retransmitting data that timed out, if the endpoint
 *   is multihomed, it should consider each source-destination
 *   address pair in its retransmission selection policy.
 *   When retransmitting timed-out data, the endpoint should
 *   attempt to pick the most divergent source-destination
 *   pair from the original source-destination pair to which
 *   the packet was transmitted.
 *
 *   Note: Rules for picking the most divergent source-destination
 *   pair are an implementation decision and are not specified
 *   within this document.
 *
 * Our basic strategy is to round-robin transports in priorities
 * according to sctp_trans_score() e.g., if no such
 * transport with state SCTP_ACTIVE exists, round-robin through
 * SCTP_UNKNOWN, etc. You get the picture.
 */
static u8 sctp_trans_score(const struct sctp_transport *trans)
{
        switch (trans->state) {
        case SCTP_ACTIVE:
                return 3;        /* best case */
        case SCTP_UNKNOWN:
                return 2;
        case SCTP_PF:
                return 1;
        default: /* case SCTP_INACTIVE */
                return 0;        /* worst case */
        }
}

static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
                                                   struct sctp_transport *trans2)
{
        if (trans1->error_count > trans2->error_count) {
                return trans2;
        } else if (trans1->error_count == trans2->error_count &&
                   ktime_after(trans2->last_time_heard,
                               trans1->last_time_heard)) {
                return trans2;
        } else {
                return trans1;
        }
}

static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
                                                    struct sctp_transport *best)
{
        u8 score_curr, score_best;

        if (best == NULL || curr == best)
                return curr;

        score_curr = sctp_trans_score(curr);
        score_best = sctp_trans_score(best);

        /* First, try a score-based selection if both transport states
         * differ. If we're in a tie, lets try to make a more clever
         * decision here based on error counts and last time heard.
         */
        if (score_curr > score_best)
                return curr;
        else if (score_curr == score_best)
                return sctp_trans_elect_tie(best, curr);
        else
                return best;
}

void sctp_assoc_update_retran_path(struct sctp_association *asoc)
{
        struct sctp_transport *trans = asoc->peer.retran_path;
        struct sctp_transport *trans_next = NULL;

        /* We're done as we only have the one and only path. */
        if (asoc->peer.transport_count == 1)
                return;
        /* If active_path and retran_path are the same and active,
         * then this is the only active path. Use it.
         */
        if (asoc->peer.active_path == asoc->peer.retran_path &&
            asoc->peer.active_path->state == SCTP_ACTIVE)
                return;

        /* Iterate from retran_path's successor back to retran_path. */
        for (trans = list_next_entry(trans, transports); 1;
             trans = list_next_entry(trans, transports)) {
                /* Manually skip the head element. */
                if (&trans->transports == &asoc->peer.transport_addr_list)
                        continue;
                if (trans->state == SCTP_UNCONFIRMED)
                        continue;
                trans_next = sctp_trans_elect_best(trans, trans_next);
                /* Active is good enough for immediate return. */
                if (trans_next->state == SCTP_ACTIVE)
                        break;
                /* We've reached the end, time to update path. */
                if (trans == asoc->peer.retran_path)
                        break;
        }

        asoc->peer.retran_path = trans_next;

        pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
                 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
}

static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
{
        struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
        struct sctp_transport *trans_pf = NULL;

        /* Look for the two most recently used active transports. */
        list_for_each_entry(trans, &asoc->peer.transport_addr_list,
                            transports) {
                /* Skip uninteresting transports. */
                if (trans->state == SCTP_INACTIVE ||
                    trans->state == SCTP_UNCONFIRMED)
                        continue;
                /* Keep track of the best PF transport from our
                 * list in case we don't find an active one.
                 */
                if (trans->state == SCTP_PF) {
                        trans_pf = sctp_trans_elect_best(trans, trans_pf);
                        continue;
                }
                /* For active transports, pick the most recent ones. */
                if (trans_pri == NULL ||
                    ktime_after(trans->last_time_heard,
                                trans_pri->last_time_heard)) {
                        trans_sec = trans_pri;
                        trans_pri = trans;
                } else if (trans_sec == NULL ||
                           ktime_after(trans->last_time_heard,
                                       trans_sec->last_time_heard)) {
                        trans_sec = trans;
                }
        }

        /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
         *
         * By default, an endpoint should always transmit to the primary
         * path, unless the SCTP user explicitly specifies the
         * destination transport address (and possibly source transport
         * address) to use. [If the primary is active but not most recent,
         * bump the most recently used transport.]
         */
        if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
             asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
             asoc->peer.primary_path != trans_pri) {
                trans_sec = trans_pri;
                trans_pri = asoc->peer.primary_path;
        }

        /* We did not find anything useful for a possible retransmission
         * path; either primary path that we found is the same as
         * the current one, or we didn't generally find an active one.
         */
        if (trans_sec == NULL)
                trans_sec = trans_pri;

        /* If we failed to find a usable transport, just camp on the
         * active or pick a PF iff it's the better choice.
         */
        if (trans_pri == NULL) {
                trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
                trans_sec = trans_pri;
        }

        /* Set the active and retran transports. */
        asoc->peer.active_path = trans_pri;
        asoc->peer.retran_path = trans_sec;
}

struct sctp_transport *
sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
                                  struct sctp_transport *last_sent_to)
{
        /* If this is the first time packet is sent, use the active path,
         * else use the retran path. If the last packet was sent over the
         * retran path, update the retran path and use it.
         */
        if (last_sent_to == NULL) {
                return asoc->peer.active_path;
        } else {
                if (last_sent_to == asoc->peer.retran_path)
                        sctp_assoc_update_retran_path(asoc);

                return asoc->peer.retran_path;
        }
}

void sctp_assoc_update_frag_point(struct sctp_association *asoc)
{
        int frag = sctp_mtu_payload(sctp_sk(asoc->base.sk), asoc->pathmtu,
                                    sctp_datachk_len(&asoc->stream));

        if (asoc->user_frag)
                frag = min_t(int, frag, asoc->user_frag);

        frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN -
                                sctp_datachk_len(&asoc->stream));

        asoc->frag_point = SCTP_TRUNC4(frag);
}

void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu)
{
        if (asoc->pathmtu != pmtu) {
                asoc->pathmtu = pmtu;
                sctp_assoc_update_frag_point(asoc);
        }

        pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
                 asoc->pathmtu, asoc->frag_point);
}

/* Update the association's pmtu and frag_point by going through all the
 * transports. This routine is called when a transport's PMTU has changed.
 */
void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
{
        struct sctp_transport *t;
        __u32 pmtu = 0;

        if (!asoc)
                return;

        /* Get the lowest pmtu of all the transports. */
        list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
                if (t->pmtu_pending && t->dst) {
                        sctp_transport_update_pmtu(t,
                                                   atomic_read(&t->mtu_info));
                        t->pmtu_pending = 0;
                }
                if (!pmtu || (t->pathmtu < pmtu))
                        pmtu = t->pathmtu;
        }

        sctp_assoc_set_pmtu(asoc, pmtu);
}

/* Should we send a SACK to update our peer? */
static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
{
        struct net *net = asoc->base.net;

        switch (asoc->state) {
        case SCTP_STATE_ESTABLISHED:
        case SCTP_STATE_SHUTDOWN_PENDING:
        case SCTP_STATE_SHUTDOWN_RECEIVED:
        case SCTP_STATE_SHUTDOWN_SENT:
                if ((asoc->rwnd > asoc->a_rwnd) &&
                    ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
                           (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
                           asoc->pathmtu)))
                        return true;
                break;
        default:
                break;
        }
        return false;
}

/* Increase asoc's rwnd by len and send any window update SACK if needed. */
void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
{
        struct sctp_chunk *sack;
        struct timer_list *timer;

        if (asoc->rwnd_over) {
                if (asoc->rwnd_over >= len) {
                        asoc->rwnd_over -= len;
                } else {
                        asoc->rwnd += (len - asoc->rwnd_over);
                        asoc->rwnd_over = 0;
                }
        } else {
                asoc->rwnd += len;
        }

        /* If we had window pressure, start recovering it
         * once our rwnd had reached the accumulated pressure
         * threshold.  The idea is to recover slowly, but up
         * to the initial advertised window.
         */
        if (asoc->rwnd_press) {
                int change = min(asoc->pathmtu, asoc->rwnd_press);
                asoc->rwnd += change;
                asoc->rwnd_press -= change;
        }

        pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
                 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
                 asoc->a_rwnd);

        /* Send a window update SACK if the rwnd has increased by at least the
         * minimum of the association's PMTU and half of the receive buffer.
         * The algorithm used is similar to the one described in
         * Section 4.2.3.3 of RFC 1122.
         */
        if (sctp_peer_needs_update(asoc)) {
                asoc->a_rwnd = asoc->rwnd;

                pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
                         "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
                         asoc->a_rwnd);

                sack = sctp_make_sack(asoc);
                if (!sack)
                        return;

                asoc->peer.sack_needed = 0;

                sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);

                /* Stop the SACK timer.  */
                timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
                if (timer_delete(timer))
                        sctp_association_put(asoc);
        }
}

/* Decrease asoc's rwnd by len. */
void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
{
        int rx_count;
        int over = 0;

        if (unlikely(!asoc->rwnd || asoc->rwnd_over))
                pr_debug("%s: association:%p has asoc->rwnd:%u, "
                         "asoc->rwnd_over:%u!\n", __func__, asoc,
                         asoc->rwnd, asoc->rwnd_over);

        if (asoc->ep->rcvbuf_policy)
                rx_count = atomic_read(&asoc->rmem_alloc);
        else
                rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);

        /* If we've reached or overflowed our receive buffer, announce
         * a 0 rwnd if rwnd would still be positive.  Store the
         * potential pressure overflow so that the window can be restored
         * back to original value.
         */
        if (rx_count >= asoc->base.sk->sk_rcvbuf)
                over = 1;

        if (asoc->rwnd >= len) {
                asoc->rwnd -= len;
                if (over) {
                        asoc->rwnd_press += asoc->rwnd;
                        asoc->rwnd = 0;
                }
        } else {
                asoc->rwnd_over += len - asoc->rwnd;
                asoc->rwnd = 0;
        }

        pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
                 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
                 asoc->rwnd_press);
}

/* Build the bind address list for the association based on info from the
 * local endpoint and the remote peer.
 */
int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
                                     enum sctp_scope scope, gfp_t gfp)
{
        struct sock *sk = asoc->base.sk;
        int flags;

        /* Use scoping rules to determine the subset of addresses from
         * the endpoint.
         */
        flags = (PF_INET6 == sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
        if (!inet_v6_ipv6only(sk))
                flags |= SCTP_ADDR4_ALLOWED;
        if (asoc->peer.ipv4_address)
                flags |= SCTP_ADDR4_PEERSUPP;
        if (asoc->peer.ipv6_address)
                flags |= SCTP_ADDR6_PEERSUPP;

        return sctp_bind_addr_copy(asoc->base.net,
                                   &asoc->base.bind_addr,
                                   &asoc->ep->base.bind_addr,
                                   scope, gfp, flags);
}

/* Build the association's bind address list from the cookie.  */
int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
                                         struct sctp_cookie *cookie,
                                         gfp_t gfp)
{
        struct sctp_init_chunk *peer_init = (struct sctp_init_chunk *)(cookie + 1);
        int var_size2 = ntohs(peer_init->chunk_hdr.length);
        int var_size3 = cookie->raw_addr_list_len;
        __u8 *raw = (__u8 *)peer_init + var_size2;

        return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
                                      asoc->ep->base.bind_addr.port, gfp);
}

/* Lookup laddr in the bind address list of an association. */
int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
                            const union sctp_addr *laddr)
{
        int found = 0;

        if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
            sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
                                 sctp_sk(asoc->base.sk)))
                found = 1;

        return found;
}

/* Set an association id for a given association */
int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
{
        bool preload = gfpflags_allow_blocking(gfp);
        int ret;

        /* If the id is already assigned, keep it. */
        if (asoc->assoc_id)
                return 0;

        if (preload)
                idr_preload(gfp);
        spin_lock_bh(&sctp_assocs_id_lock);
        /* 0, 1, 2 are used as SCTP_FUTURE_ASSOC, SCTP_CURRENT_ASSOC and
         * SCTP_ALL_ASSOC, so an available id must be > SCTP_ALL_ASSOC.
         */
        ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, SCTP_ALL_ASSOC + 1, 0,
                               GFP_NOWAIT);
        spin_unlock_bh(&sctp_assocs_id_lock);
        if (preload)
                idr_preload_end();
        if (ret < 0)
                return ret;

        asoc->assoc_id = (sctp_assoc_t)ret;
        return 0;
}

/* Free the ASCONF queue */
static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
{
        struct sctp_chunk *asconf;
        struct sctp_chunk *tmp;

        list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
                list_del_init(&asconf->list);
                sctp_chunk_free(asconf);
        }
}

/* Free asconf_ack cache */
static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
{
        struct sctp_chunk *ack;
        struct sctp_chunk *tmp;

        list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
                                transmitted_list) {
                list_del_init(&ack->transmitted_list);
                sctp_chunk_free(ack);
        }
}

/* Clean up the ASCONF_ACK queue */
void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
{
        struct sctp_chunk *ack;
        struct sctp_chunk *tmp;

        /* We can remove all the entries from the queue up to
         * the "Peer-Sequence-Number".
         */
        list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
                                transmitted_list) {
                if (ack->subh.addip_hdr->serial ==
                                htonl(asoc->peer.addip_serial))
                        break;

                list_del_init(&ack->transmitted_list);
                sctp_chunk_free(ack);
        }
}

/* Find the ASCONF_ACK whose serial number matches ASCONF */
struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
                                        const struct sctp_association *asoc,
                                        __be32 serial)
{
        struct sctp_chunk *ack;

        /* Walk through the list of cached ASCONF-ACKs and find the
         * ack chunk whose serial number matches that of the request.
         */
        list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
                if (sctp_chunk_pending(ack))
                        continue;
                if (ack->subh.addip_hdr->serial == serial) {
                        sctp_chunk_hold(ack);
                        return ack;
                }
        }

        return NULL;
}

void sctp_asconf_queue_teardown(struct sctp_association *asoc)
{
        /* Free any cached ASCONF_ACK chunk. */
        sctp_assoc_free_asconf_acks(asoc);

        /* Free the ASCONF queue. */
        sctp_assoc_free_asconf_queue(asoc);

        /* Free any cached ASCONF chunk. */
        if (asoc->addip_last_asconf)
                sctp_chunk_free(asoc->addip_last_asconf);
}










































































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   11 


































































































































































































































































































































































  736 


  734 

































































































































































































































































































































































































  894 





  893 






  893 











































































  719 



  717 




















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































    4 












    4 












    4 





    4 





    4 





    4 















































    4 











    4 













    4 




    4 




















    4 



















    4 

























    4 







    4 

    4 

    4 

    4 

    4 

    4 

    4 

    4 







    4 

    4 

    4 








    4 




    2 
















    4 












    4 









    4 
















































    4 




    4 









    4 



    4 















    4 
















    4 











    4 



    4 

    4 









    4 


















    4 


    4 





    4 









    4 

























    4 


















    4 
















































































































































































































































































































































































































































































































































































































































































































































    4 






























    4 










    4 













    4 



















    3 
















    4 






































































































































































































   86 



   86 



























































































































   86 









    4 

    3 



    1 







    1 
    1 






















































































































































































































































  537 
























































































  536 








  537 





























































































































































































































































































   11 







   11 
















   11 
   11 




    8 




    8 





    8 



    8 
    8 


















1
2
3
4
5
6
7
8
9
10
11
12
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// SPDX-License-Identifier: GPL-2.0
/*
 * Performance events core code:
 *
 *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
 *  Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
 *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
 *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
 */

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/idr.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/hash.h>
#include <linux/tick.h>
#include <linux/sysfs.h>
#include <linux/dcache.h>
#include <linux/percpu.h>
#include <linux/ptrace.h>
#include <linux/reboot.h>
#include <linux/vmstat.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/vmalloc.h>
#include <linux/hardirq.h>
#include <linux/hugetlb.h>
#include <linux/rculist.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <linux/anon_inodes.h>
#include <linux/kernel_stat.h>
#include <linux/cgroup.h>
#include <linux/perf_event.h>
#include <linux/trace_events.h>
#include <linux/hw_breakpoint.h>
#include <linux/mm_types.h>
#include <linux/module.h>
#include <linux/mman.h>
#include <linux/compat.h>
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/namei.h>
#include <linux/parser.h>
#include <linux/sched/clock.h>
#include <linux/sched/mm.h>
#include <linux/proc_ns.h>
#include <linux/mount.h>
#include <linux/min_heap.h>
#include <linux/highmem.h>
#include <linux/pgtable.h>
#include <linux/buildid.h>
#include <linux/task_work.h>
#include <linux/percpu-rwsem.h>

#include "internal.h"

#include <asm/irq_regs.h>

typedef int (*remote_function_f)(void *);

struct remote_function_call {
        struct task_struct        *p;
        remote_function_f        func;
        void                        *info;
        int                        ret;
};

static void remote_function(void *data)
{
        struct remote_function_call *tfc = data;
        struct task_struct *p = tfc->p;

        if (p) {
                /* -EAGAIN */
                if (task_cpu(p) != smp_processor_id())
                        return;

                /*
                 * Now that we're on right CPU with IRQs disabled, we can test
                 * if we hit the right task without races.
                 */

                tfc->ret = -ESRCH; /* No such (running) process */
                if (p != current)
                        return;
        }

        tfc->ret = tfc->func(tfc->info);
}

/**
 * task_function_call - call a function on the cpu on which a task runs
 * @p:                the task to evaluate
 * @func:        the function to be called
 * @info:        the function call argument
 *
 * Calls the function @func when the task is currently running. This might
 * be on the current CPU, which just calls the function directly.  This will
 * retry due to any failures in smp_call_function_single(), such as if the
 * task_cpu() goes offline concurrently.
 *
 * returns @func return value or -ESRCH or -ENXIO when the process isn't running
 */
static int
task_function_call(struct task_struct *p, remote_function_f func, void *info)
{
        struct remote_function_call data = {
                .p        = p,
                .func        = func,
                .info        = info,
                .ret        = -EAGAIN,
        };
        int ret;

        for (;;) {
                ret = smp_call_function_single(task_cpu(p), remote_function,
                                               &data, 1);
                if (!ret)
                        ret = data.ret;

                if (ret != -EAGAIN)
                        break;

                cond_resched();
        }

        return ret;
}

/**
 * cpu_function_call - call a function on the cpu
 * @cpu:        target cpu to queue this function
 * @func:        the function to be called
 * @info:        the function call argument
 *
 * Calls the function @func on the remote cpu.
 *
 * returns: @func return value or -ENXIO when the cpu is offline
 */
static int cpu_function_call(int cpu, remote_function_f func, void *info)
{
        struct remote_function_call data = {
                .p        = NULL,
                .func        = func,
                .info        = info,
                .ret        = -ENXIO, /* No such CPU */
        };

        smp_call_function_single(cpu, remote_function, &data, 1);

        return data.ret;
}

enum event_type_t {
        EVENT_FLEXIBLE        = 0x01,
        EVENT_PINNED        = 0x02,
        EVENT_TIME        = 0x04,
        EVENT_FROZEN        = 0x08,
        /* see ctx_resched() for details */
        EVENT_CPU        = 0x10,
        EVENT_CGROUP        = 0x20,

        /* compound helpers */
        EVENT_ALL         = EVENT_FLEXIBLE | EVENT_PINNED,
        EVENT_TIME_FROZEN = EVENT_TIME | EVENT_FROZEN,
};

static inline void __perf_ctx_lock(struct perf_event_context *ctx)
{
        raw_spin_lock(&ctx->lock);
        WARN_ON_ONCE(ctx->is_active & EVENT_FROZEN);
}

static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
                          struct perf_event_context *ctx)
{
        __perf_ctx_lock(&cpuctx->ctx);
        if (ctx)
                __perf_ctx_lock(ctx);
}

static inline void __perf_ctx_unlock(struct perf_event_context *ctx)
{
        /*
         * If ctx_sched_in() didn't again set any ALL flags, clean up
         * after ctx_sched_out() by clearing is_active.
         */
        if (ctx->is_active & EVENT_FROZEN) {
                if (!(ctx->is_active & EVENT_ALL))
                        ctx->is_active = 0;
                else
                        ctx->is_active &= ~EVENT_FROZEN;
        }
        raw_spin_unlock(&ctx->lock);
}

static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
                            struct perf_event_context *ctx)
{
        if (ctx)
                __perf_ctx_unlock(ctx);
        __perf_ctx_unlock(&cpuctx->ctx);
}

typedef struct {
        struct perf_cpu_context *cpuctx;
        struct perf_event_context *ctx;
} class_perf_ctx_lock_t;

static inline void class_perf_ctx_lock_destructor(class_perf_ctx_lock_t *_T)
{ perf_ctx_unlock(_T->cpuctx, _T->ctx); }

static inline class_perf_ctx_lock_t
class_perf_ctx_lock_constructor(struct perf_cpu_context *cpuctx,
                                struct perf_event_context *ctx)
{ perf_ctx_lock(cpuctx, ctx); return (class_perf_ctx_lock_t){ cpuctx, ctx }; }

#define TASK_TOMBSTONE ((void *)-1L)

static bool is_kernel_event(struct perf_event *event)
{
        return READ_ONCE(event->owner) == TASK_TOMBSTONE;
}

static DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);

struct perf_event_context *perf_cpu_task_ctx(void)
{
        lockdep_assert_irqs_disabled();
        return this_cpu_ptr(&perf_cpu_context)->task_ctx;
}

/*
 * On task ctx scheduling...
 *
 * When !ctx->nr_events a task context will not be scheduled. This means
 * we can disable the scheduler hooks (for performance) without leaving
 * pending task ctx state.
 *
 * This however results in two special cases:
 *
 *  - removing the last event from a task ctx; this is relatively straight
 *    forward and is done in __perf_remove_from_context.
 *
 *  - adding the first event to a task ctx; this is tricky because we cannot
 *    rely on ctx->is_active and therefore cannot use event_function_call().
 *    See perf_install_in_context().
 *
 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
 */

typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *,
                        struct perf_event_context *, void *);

struct event_function_struct {
        struct perf_event *event;
        event_f func;
        void *data;
};

static int event_function(void *info)
{
        struct event_function_struct *efs = info;
        struct perf_event *event = efs->event;
        struct perf_event_context *ctx = event->ctx;
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_context *task_ctx = cpuctx->task_ctx;
        int ret = 0;

        lockdep_assert_irqs_disabled();

        perf_ctx_lock(cpuctx, task_ctx);
        /*
         * Since we do the IPI call without holding ctx->lock things can have
         * changed, double check we hit the task we set out to hit.
         */
        if (ctx->task) {
                if (ctx->task != current) {
                        ret = -ESRCH;
                        goto unlock;
                }

                /*
                 * We only use event_function_call() on established contexts,
                 * and event_function() is only ever called when active (or
                 * rather, we'll have bailed in task_function_call() or the
                 * above ctx->task != current test), therefore we must have
                 * ctx->is_active here.
                 */
                WARN_ON_ONCE(!ctx->is_active);
                /*
                 * And since we have ctx->is_active, cpuctx->task_ctx must
                 * match.
                 */
                WARN_ON_ONCE(task_ctx != ctx);
        } else {
                WARN_ON_ONCE(&cpuctx->ctx != ctx);
        }

        efs->func(event, cpuctx, ctx, efs->data);
unlock:
        perf_ctx_unlock(cpuctx, task_ctx);

        return ret;
}

static void event_function_call(struct perf_event *event, event_f func, void *data)
{
        struct perf_event_context *ctx = event->ctx;
        struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
        struct perf_cpu_context *cpuctx;
        struct event_function_struct efs = {
                .event = event,
                .func = func,
                .data = data,
        };

        if (!event->parent) {
                /*
                 * If this is a !child event, we must hold ctx::mutex to
                 * stabilize the event->ctx relation. See
                 * perf_event_ctx_lock().
                 */
                lockdep_assert_held(&ctx->mutex);
        }

        if (!task) {
                cpu_function_call(event->cpu, event_function, &efs);
                return;
        }

        if (task == TASK_TOMBSTONE)
                return;

again:
        if (!task_function_call(task, event_function, &efs))
                return;

        local_irq_disable();
        cpuctx = this_cpu_ptr(&perf_cpu_context);
        perf_ctx_lock(cpuctx, ctx);
        /*
         * Reload the task pointer, it might have been changed by
         * a concurrent perf_event_context_sched_out().
         */
        task = ctx->task;
        if (task == TASK_TOMBSTONE)
                goto unlock;
        if (ctx->is_active) {
                perf_ctx_unlock(cpuctx, ctx);
                local_irq_enable();
                goto again;
        }
        func(event, NULL, ctx, data);
unlock:
        perf_ctx_unlock(cpuctx, ctx);
        local_irq_enable();
}

/*
 * Similar to event_function_call() + event_function(), but hard assumes IRQs
 * are already disabled and we're on the right CPU.
 */
static void event_function_local(struct perf_event *event, event_f func, void *data)
{
        struct perf_event_context *ctx = event->ctx;
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct task_struct *task = READ_ONCE(ctx->task);
        struct perf_event_context *task_ctx = NULL;

        lockdep_assert_irqs_disabled();

        if (task) {
                if (task == TASK_TOMBSTONE)
                        return;

                task_ctx = ctx;
        }

        perf_ctx_lock(cpuctx, task_ctx);

        task = ctx->task;
        if (task == TASK_TOMBSTONE)
                goto unlock;

        if (task) {
                /*
                 * We must be either inactive or active and the right task,
                 * otherwise we're screwed, since we cannot IPI to somewhere
                 * else.
                 */
                if (ctx->is_active) {
                        if (WARN_ON_ONCE(task != current))
                                goto unlock;

                        if (WARN_ON_ONCE(cpuctx->task_ctx != ctx))
                                goto unlock;
                }
        } else {
                WARN_ON_ONCE(&cpuctx->ctx != ctx);
        }

        func(event, cpuctx, ctx, data);
unlock:
        perf_ctx_unlock(cpuctx, task_ctx);
}

#define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
                       PERF_FLAG_FD_OUTPUT  |\
                       PERF_FLAG_PID_CGROUP |\
                       PERF_FLAG_FD_CLOEXEC)

/*
 * branch priv levels that need permission checks
 */
#define PERF_SAMPLE_BRANCH_PERM_PLM \
        (PERF_SAMPLE_BRANCH_KERNEL |\
         PERF_SAMPLE_BRANCH_HV)

/*
 * perf_sched_events : >0 events exist
 */

static void perf_sched_delayed(struct work_struct *work);
DEFINE_STATIC_KEY_FALSE(perf_sched_events);
static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);
static DEFINE_MUTEX(perf_sched_mutex);
static atomic_t perf_sched_count;

static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);

static atomic_t nr_mmap_events __read_mostly;
static atomic_t nr_comm_events __read_mostly;
static atomic_t nr_namespaces_events __read_mostly;
static atomic_t nr_task_events __read_mostly;
static atomic_t nr_freq_events __read_mostly;
static atomic_t nr_switch_events __read_mostly;
static atomic_t nr_ksymbol_events __read_mostly;
static atomic_t nr_bpf_events __read_mostly;
static atomic_t nr_cgroup_events __read_mostly;
static atomic_t nr_text_poke_events __read_mostly;
static atomic_t nr_build_id_events __read_mostly;

static LIST_HEAD(pmus);
static DEFINE_MUTEX(pmus_lock);
static struct srcu_struct pmus_srcu;
static cpumask_var_t perf_online_mask;
static cpumask_var_t perf_online_core_mask;
static cpumask_var_t perf_online_die_mask;
static cpumask_var_t perf_online_cluster_mask;
static cpumask_var_t perf_online_pkg_mask;
static cpumask_var_t perf_online_sys_mask;
static struct kmem_cache *perf_event_cache;

/*
 * perf event paranoia level:
 *  -1 - not paranoid at all
 *   0 - disallow raw tracepoint access for unpriv
 *   1 - disallow cpu events for unpriv
 *   2 - disallow kernel profiling for unpriv
 */
int sysctl_perf_event_paranoid __read_mostly = 2;

/* Minimum for 512 kiB + 1 user control page. 'free' kiB per user. */
static int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024);

/*
 * max perf event sample rate
 */
#define DEFAULT_MAX_SAMPLE_RATE                100000
#define DEFAULT_SAMPLE_PERIOD_NS        (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
#define DEFAULT_CPU_TIME_MAX_PERCENT        25

int sysctl_perf_event_sample_rate __read_mostly        = DEFAULT_MAX_SAMPLE_RATE;
static int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;

static int max_samples_per_tick __read_mostly        = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
static int perf_sample_period_ns __read_mostly        = DEFAULT_SAMPLE_PERIOD_NS;

static int perf_sample_allowed_ns __read_mostly =
        DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;

static void update_perf_cpu_limits(void)
{
        u64 tmp = perf_sample_period_ns;

        tmp *= sysctl_perf_cpu_time_max_percent;
        tmp = div_u64(tmp, 100);
        if (!tmp)
                tmp = 1;

        WRITE_ONCE(perf_sample_allowed_ns, tmp);
}

static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc);

static int perf_event_max_sample_rate_handler(const struct ctl_table *table, int write,
                                       void *buffer, size_t *lenp, loff_t *ppos)
{
        int ret;
        int perf_cpu = sysctl_perf_cpu_time_max_percent;
        /*
         * If throttling is disabled don't allow the write:
         */
        if (write && (perf_cpu == 100 || perf_cpu == 0))
                return -EINVAL;

        ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
        if (ret || !write)
                return ret;

        max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
        perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
        update_perf_cpu_limits();

        return 0;
}

static int perf_cpu_time_max_percent_handler(const struct ctl_table *table, int write,
                void *buffer, size_t *lenp, loff_t *ppos)
{
        int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);

        if (ret || !write)
                return ret;

        if (sysctl_perf_cpu_time_max_percent == 100 ||
            sysctl_perf_cpu_time_max_percent == 0) {
                printk(KERN_WARNING
                       "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
                WRITE_ONCE(perf_sample_allowed_ns, 0);
        } else {
                update_perf_cpu_limits();
        }

        return 0;
}

static const struct ctl_table events_core_sysctl_table[] = {
        /*
         * User-space relies on this file as a feature check for
         * perf_events being enabled. It's an ABI, do not remove!
         */
        {
                .procname        = "perf_event_paranoid",
                .data                = &sysctl_perf_event_paranoid,
                .maxlen                = sizeof(sysctl_perf_event_paranoid),
                .mode                = 0644,
                .proc_handler        = proc_dointvec,
        },
        {
                .procname        = "perf_event_mlock_kb",
                .data                = &sysctl_perf_event_mlock,
                .maxlen                = sizeof(sysctl_perf_event_mlock),
                .mode                = 0644,
                .proc_handler        = proc_dointvec,
        },
        {
                .procname        = "perf_event_max_sample_rate",
                .data                = &sysctl_perf_event_sample_rate,
                .maxlen                = sizeof(sysctl_perf_event_sample_rate),
                .mode                = 0644,
                .proc_handler        = perf_event_max_sample_rate_handler,
                .extra1                = SYSCTL_ONE,
        },
        {
                .procname        = "perf_cpu_time_max_percent",
                .data                = &sysctl_perf_cpu_time_max_percent,
                .maxlen                = sizeof(sysctl_perf_cpu_time_max_percent),
                .mode                = 0644,
                .proc_handler        = perf_cpu_time_max_percent_handler,
                .extra1                = SYSCTL_ZERO,
                .extra2                = SYSCTL_ONE_HUNDRED,
        },
};

static int __init init_events_core_sysctls(void)
{
        register_sysctl_init("kernel", events_core_sysctl_table);
        return 0;
}
core_initcall(init_events_core_sysctls);


/*
 * perf samples are done in some very critical code paths (NMIs).
 * If they take too much CPU time, the system can lock up and not
 * get any real work done.  This will drop the sample rate when
 * we detect that events are taking too long.
 */
#define NR_ACCUMULATED_SAMPLES 128
static DEFINE_PER_CPU(u64, running_sample_length);

static u64 __report_avg;
static u64 __report_allowed;

static void perf_duration_warn(struct irq_work *w)
{
        printk_ratelimited(KERN_INFO
                "perf: interrupt took too long (%lld > %lld), lowering "
                "kernel.perf_event_max_sample_rate to %d\n",
                __report_avg, __report_allowed,
                sysctl_perf_event_sample_rate);
}

static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);

void perf_sample_event_took(u64 sample_len_ns)
{
        u64 max_len = READ_ONCE(perf_sample_allowed_ns);
        u64 running_len;
        u64 avg_len;
        u32 max;

        if (max_len == 0)
                return;

        /* Decay the counter by 1 average sample. */
        running_len = __this_cpu_read(running_sample_length);
        running_len -= running_len/NR_ACCUMULATED_SAMPLES;
        running_len += sample_len_ns;
        __this_cpu_write(running_sample_length, running_len);

        /*
         * Note: this will be biased artificially low until we have
         * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
         * from having to maintain a count.
         */
        avg_len = running_len/NR_ACCUMULATED_SAMPLES;
        if (avg_len <= max_len)
                return;

        __report_avg = avg_len;
        __report_allowed = max_len;

        /*
         * Compute a throttle threshold 25% below the current duration.
         */
        avg_len += avg_len / 4;
        max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent;
        if (avg_len < max)
                max /= (u32)avg_len;
        else
                max = 1;

        WRITE_ONCE(perf_sample_allowed_ns, avg_len);
        WRITE_ONCE(max_samples_per_tick, max);

        sysctl_perf_event_sample_rate = max * HZ;
        perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;

        if (!irq_work_queue(&perf_duration_work)) {
                early_printk("perf: interrupt took too long (%lld > %lld), lowering "
                             "kernel.perf_event_max_sample_rate to %d\n",
                             __report_avg, __report_allowed,
                             sysctl_perf_event_sample_rate);
        }
}

static atomic64_t perf_event_id;

static void update_context_time(struct perf_event_context *ctx);
static u64 perf_event_time(struct perf_event *event);

void __weak perf_event_print_debug(void)        { }

static inline u64 perf_clock(void)
{
        return local_clock();
}

static inline u64 perf_event_clock(struct perf_event *event)
{
        return event->clock();
}

/*
 * State based event timekeeping...
 *
 * The basic idea is to use event->state to determine which (if any) time
 * fields to increment with the current delta. This means we only need to
 * update timestamps when we change state or when they are explicitly requested
 * (read).
 *
 * Event groups make things a little more complicated, but not terribly so. The
 * rules for a group are that if the group leader is OFF the entire group is
 * OFF, irrespective of what the group member states are. This results in
 * __perf_effective_state().
 *
 * A further ramification is that when a group leader flips between OFF and
 * !OFF, we need to update all group member times.
 *
 *
 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
 * need to make sure the relevant context time is updated before we try and
 * update our timestamps.
 */

static __always_inline enum perf_event_state
__perf_effective_state(struct perf_event *event)
{
        struct perf_event *leader = event->group_leader;

        if (leader->state <= PERF_EVENT_STATE_OFF)
                return leader->state;

        return event->state;
}

static __always_inline void
__perf_update_times(struct perf_event *event, u64 now, u64 *enabled, u64 *running)
{
        enum perf_event_state state = __perf_effective_state(event);
        u64 delta = now - event->tstamp;

        *enabled = event->total_time_enabled;
        if (state >= PERF_EVENT_STATE_INACTIVE)
                *enabled += delta;

        *running = event->total_time_running;
        if (state >= PERF_EVENT_STATE_ACTIVE)
                *running += delta;
}

static void perf_event_update_time(struct perf_event *event)
{
        u64 now = perf_event_time(event);

        __perf_update_times(event, now, &event->total_time_enabled,
                                        &event->total_time_running);
        event->tstamp = now;
}

static void perf_event_update_sibling_time(struct perf_event *leader)
{
        struct perf_event *sibling;

        for_each_sibling_event(sibling, leader)
                perf_event_update_time(sibling);
}

static void
perf_event_set_state(struct perf_event *event, enum perf_event_state state)
{
        if (event->state == state)
                return;

        perf_event_update_time(event);
        /*
         * If a group leader gets enabled/disabled all its siblings
         * are affected too.
         */
        if ((event->state < 0) ^ (state < 0))
                perf_event_update_sibling_time(event);

        WRITE_ONCE(event->state, state);
}

/*
 * UP store-release, load-acquire
 */

#define __store_release(ptr, val)                                        \
do {                                                                        \
        barrier();                                                        \
        WRITE_ONCE(*(ptr), (val));                                        \
} while (0)

#define __load_acquire(ptr)                                                \
({                                                                        \
        __unqual_scalar_typeof(*(ptr)) ___p = READ_ONCE(*(ptr));        \
        barrier();                                                        \
        ___p;                                                                \
})

#define for_each_epc(_epc, _ctx, _pmu, _cgroup)                                \
        list_for_each_entry(_epc, &((_ctx)->pmu_ctx_list), pmu_ctx_entry) \
                if (_cgroup && !_epc->nr_cgroups)                        \
                        continue;                                        \
                else if (_pmu && _epc->pmu != _pmu)                        \
                        continue;                                        \
                else

static void perf_ctx_disable(struct perf_event_context *ctx, bool cgroup)
{
        struct perf_event_pmu_context *pmu_ctx;

        for_each_epc(pmu_ctx, ctx, NULL, cgroup)
                perf_pmu_disable(pmu_ctx->pmu);
}

static void perf_ctx_enable(struct perf_event_context *ctx, bool cgroup)
{
        struct perf_event_pmu_context *pmu_ctx;

        for_each_epc(pmu_ctx, ctx, NULL, cgroup)
                perf_pmu_enable(pmu_ctx->pmu);
}

static void ctx_sched_out(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type);
static void ctx_sched_in(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type);

#ifdef CONFIG_CGROUP_PERF

static inline bool
perf_cgroup_match(struct perf_event *event)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);

        /* @event doesn't care about cgroup */
        if (!event->cgrp)
                return true;

        /* wants specific cgroup scope but @cpuctx isn't associated with any */
        if (!cpuctx->cgrp)
                return false;

        /*
         * Cgroup scoping is recursive.  An event enabled for a cgroup is
         * also enabled for all its descendant cgroups.  If @cpuctx's
         * cgroup is a descendant of @event's (the test covers identity
         * case), it's a match.
         */
        return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
                                    event->cgrp->css.cgroup);
}

static inline void perf_detach_cgroup(struct perf_event *event)
{
        css_put(&event->cgrp->css);
        event->cgrp = NULL;
}

static inline int is_cgroup_event(struct perf_event *event)
{
        return event->cgrp != NULL;
}

static inline u64 perf_cgroup_event_time(struct perf_event *event)
{
        struct perf_cgroup_info *t;

        t = per_cpu_ptr(event->cgrp->info, event->cpu);
        return t->time;
}

static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now)
{
        struct perf_cgroup_info *t;

        t = per_cpu_ptr(event->cgrp->info, event->cpu);
        if (!__load_acquire(&t->active))
                return t->time;
        now += READ_ONCE(t->timeoffset);
        return now;
}

static inline void __update_cgrp_time(struct perf_cgroup_info *info, u64 now, bool adv)
{
        if (adv)
                info->time += now - info->timestamp;
        info->timestamp = now;
        /*
         * see update_context_time()
         */
        WRITE_ONCE(info->timeoffset, info->time - info->timestamp);
}

static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx, bool final)
{
        struct perf_cgroup *cgrp = cpuctx->cgrp;
        struct cgroup_subsys_state *css;
        struct perf_cgroup_info *info;

        if (cgrp) {
                u64 now = perf_clock();

                for (css = &cgrp->css; css; css = css->parent) {
                        cgrp = container_of(css, struct perf_cgroup, css);
                        info = this_cpu_ptr(cgrp->info);

                        __update_cgrp_time(info, now, true);
                        if (final)
                                __store_release(&info->active, 0);
                }
        }
}

static inline void update_cgrp_time_from_event(struct perf_event *event)
{
        struct perf_cgroup_info *info;

        /*
         * ensure we access cgroup data only when needed and
         * when we know the cgroup is pinned (css_get)
         */
        if (!is_cgroup_event(event))
                return;

        info = this_cpu_ptr(event->cgrp->info);
        /*
         * Do not update time when cgroup is not active
         */
        if (info->active)
                __update_cgrp_time(info, perf_clock(), true);
}

static inline void
perf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx)
{
        struct perf_event_context *ctx = &cpuctx->ctx;
        struct perf_cgroup *cgrp = cpuctx->cgrp;
        struct perf_cgroup_info *info;
        struct cgroup_subsys_state *css;

        /*
         * ctx->lock held by caller
         * ensure we do not access cgroup data
         * unless we have the cgroup pinned (css_get)
         */
        if (!cgrp)
                return;

        WARN_ON_ONCE(!ctx->nr_cgroups);

        for (css = &cgrp->css; css; css = css->parent) {
                cgrp = container_of(css, struct perf_cgroup, css);
                info = this_cpu_ptr(cgrp->info);
                __update_cgrp_time(info, ctx->timestamp, false);
                __store_release(&info->active, 1);
        }
}

/*
 * reschedule events based on the cgroup constraint of task.
 */
static void perf_cgroup_switch(struct task_struct *task)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_cgroup *cgrp;

        /*
         * cpuctx->cgrp is set when the first cgroup event enabled,
         * and is cleared when the last cgroup event disabled.
         */
        if (READ_ONCE(cpuctx->cgrp) == NULL)
                return;

        cgrp = perf_cgroup_from_task(task, NULL);
        if (READ_ONCE(cpuctx->cgrp) == cgrp)
                return;

        guard(perf_ctx_lock)(cpuctx, cpuctx->task_ctx);
        /*
         * Re-check, could've raced vs perf_remove_from_context().
         */
        if (READ_ONCE(cpuctx->cgrp) == NULL)
                return;

        WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0);

        perf_ctx_disable(&cpuctx->ctx, true);

        ctx_sched_out(&cpuctx->ctx, NULL, EVENT_ALL|EVENT_CGROUP);
        /*
         * must not be done before ctxswout due
         * to update_cgrp_time_from_cpuctx() in
         * ctx_sched_out()
         */
        cpuctx->cgrp = cgrp;
        /*
         * set cgrp before ctxsw in to allow
         * perf_cgroup_set_timestamp() in ctx_sched_in()
         * to not have to pass task around
         */
        ctx_sched_in(&cpuctx->ctx, NULL, EVENT_ALL|EVENT_CGROUP);

        perf_ctx_enable(&cpuctx->ctx, true);
}

static int perf_cgroup_ensure_storage(struct perf_event *event,
                                struct cgroup_subsys_state *css)
{
        struct perf_cpu_context *cpuctx;
        struct perf_event **storage;
        int cpu, heap_size, ret = 0;

        /*
         * Allow storage to have sufficient space for an iterator for each
         * possibly nested cgroup plus an iterator for events with no cgroup.
         */
        for (heap_size = 1; css; css = css->parent)
                heap_size++;

        for_each_possible_cpu(cpu) {
                cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
                if (heap_size <= cpuctx->heap_size)
                        continue;

                storage = kmalloc_node(heap_size * sizeof(struct perf_event *),
                                       GFP_KERNEL, cpu_to_node(cpu));
                if (!storage) {
                        ret = -ENOMEM;
                        break;
                }

                raw_spin_lock_irq(&cpuctx->ctx.lock);
                if (cpuctx->heap_size < heap_size) {
                        swap(cpuctx->heap, storage);
                        if (storage == cpuctx->heap_default)
                                storage = NULL;
                        cpuctx->heap_size = heap_size;
                }
                raw_spin_unlock_irq(&cpuctx->ctx.lock);

                kfree(storage);
        }

        return ret;
}

static inline int perf_cgroup_connect(int fd, struct perf_event *event,
                                      struct perf_event_attr *attr,
                                      struct perf_event *group_leader)
{
        struct perf_cgroup *cgrp;
        struct cgroup_subsys_state *css;
        CLASS(fd, f)(fd);
        int ret = 0;

        if (fd_empty(f))
                return -EBADF;

        css = css_tryget_online_from_dir(fd_file(f)->f_path.dentry,
                                         &perf_event_cgrp_subsys);
        if (IS_ERR(css))
                return PTR_ERR(css);

        ret = perf_cgroup_ensure_storage(event, css);
        if (ret)
                return ret;

        cgrp = container_of(css, struct perf_cgroup, css);
        event->cgrp = cgrp;

        /*
         * all events in a group must monitor
         * the same cgroup because a task belongs
         * to only one perf cgroup at a time
         */
        if (group_leader && group_leader->cgrp != cgrp) {
                perf_detach_cgroup(event);
                ret = -EINVAL;
        }
        return ret;
}

static inline void
perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
{
        struct perf_cpu_context *cpuctx;

        if (!is_cgroup_event(event))
                return;

        event->pmu_ctx->nr_cgroups++;

        /*
         * Because cgroup events are always per-cpu events,
         * @ctx == &cpuctx->ctx.
         */
        cpuctx = container_of(ctx, struct perf_cpu_context, ctx);

        if (ctx->nr_cgroups++)
                return;

        cpuctx->cgrp = perf_cgroup_from_task(current, ctx);
}

static inline void
perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
{
        struct perf_cpu_context *cpuctx;

        if (!is_cgroup_event(event))
                return;

        event->pmu_ctx->nr_cgroups--;

        /*
         * Because cgroup events are always per-cpu events,
         * @ctx == &cpuctx->ctx.
         */
        cpuctx = container_of(ctx, struct perf_cpu_context, ctx);

        if (--ctx->nr_cgroups)
                return;

        cpuctx->cgrp = NULL;
}

#else /* !CONFIG_CGROUP_PERF */

static inline bool
perf_cgroup_match(struct perf_event *event)
{
        return true;
}

static inline void perf_detach_cgroup(struct perf_event *event)
{}

static inline int is_cgroup_event(struct perf_event *event)
{
        return 0;
}

static inline void update_cgrp_time_from_event(struct perf_event *event)
{
}

static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx,
                                                bool final)
{
}

static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
                                      struct perf_event_attr *attr,
                                      struct perf_event *group_leader)
{
        return -EINVAL;
}

static inline void
perf_cgroup_set_timestamp(struct perf_cpu_context *cpuctx)
{
}

static inline u64 perf_cgroup_event_time(struct perf_event *event)
{
        return 0;
}

static inline u64 perf_cgroup_event_time_now(struct perf_event *event, u64 now)
{
        return 0;
}

static inline void
perf_cgroup_event_enable(struct perf_event *event, struct perf_event_context *ctx)
{
}

static inline void
perf_cgroup_event_disable(struct perf_event *event, struct perf_event_context *ctx)
{
}

static void perf_cgroup_switch(struct task_struct *task)
{
}
#endif

/*
 * set default to be dependent on timer tick just
 * like original code
 */
#define PERF_CPU_HRTIMER (1000 / HZ)
/*
 * function must be called with interrupts disabled
 */
static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
{
        struct perf_cpu_pmu_context *cpc;
        bool rotations;

        lockdep_assert_irqs_disabled();

        cpc = container_of(hr, struct perf_cpu_pmu_context, hrtimer);
        rotations = perf_rotate_context(cpc);

        raw_spin_lock(&cpc->hrtimer_lock);
        if (rotations)
                hrtimer_forward_now(hr, cpc->hrtimer_interval);
        else
                cpc->hrtimer_active = 0;
        raw_spin_unlock(&cpc->hrtimer_lock);

        return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
}

static void __perf_mux_hrtimer_init(struct perf_cpu_pmu_context *cpc, int cpu)
{
        struct hrtimer *timer = &cpc->hrtimer;
        struct pmu *pmu = cpc->epc.pmu;
        u64 interval;

        /*
         * check default is sane, if not set then force to
         * default interval (1/tick)
         */
        interval = pmu->hrtimer_interval_ms;
        if (interval < 1)
                interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;

        cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);

        raw_spin_lock_init(&cpc->hrtimer_lock);
        hrtimer_setup(timer, perf_mux_hrtimer_handler, CLOCK_MONOTONIC,
                      HRTIMER_MODE_ABS_PINNED_HARD);
}

static int perf_mux_hrtimer_restart(struct perf_cpu_pmu_context *cpc)
{
        struct hrtimer *timer = &cpc->hrtimer;
        unsigned long flags;

        raw_spin_lock_irqsave(&cpc->hrtimer_lock, flags);
        if (!cpc->hrtimer_active) {
                cpc->hrtimer_active = 1;
                hrtimer_forward_now(timer, cpc->hrtimer_interval);
                hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD);
        }
        raw_spin_unlock_irqrestore(&cpc->hrtimer_lock, flags);

        return 0;
}

static int perf_mux_hrtimer_restart_ipi(void *arg)
{
        return perf_mux_hrtimer_restart(arg);
}

static __always_inline struct perf_cpu_pmu_context *this_cpc(struct pmu *pmu)
{
        return *this_cpu_ptr(pmu->cpu_pmu_context);
}

void perf_pmu_disable(struct pmu *pmu)
{
        int *count = &this_cpc(pmu)->pmu_disable_count;
        if (!(*count)++)
                pmu->pmu_disable(pmu);
}

void perf_pmu_enable(struct pmu *pmu)
{
        int *count = &this_cpc(pmu)->pmu_disable_count;
        if (!--(*count))
                pmu->pmu_enable(pmu);
}

static void perf_assert_pmu_disabled(struct pmu *pmu)
{
        int *count = &this_cpc(pmu)->pmu_disable_count;
        WARN_ON_ONCE(*count == 0);
}

static inline void perf_pmu_read(struct perf_event *event)
{
        if (event->state == PERF_EVENT_STATE_ACTIVE)
                event->pmu->read(event);
}

static void get_ctx(struct perf_event_context *ctx)
{
        refcount_inc(&ctx->refcount);
}

static void free_ctx(struct rcu_head *head)
{
        struct perf_event_context *ctx;

        ctx = container_of(head, struct perf_event_context, rcu_head);
        kfree(ctx);
}

static void put_ctx(struct perf_event_context *ctx)
{
        if (refcount_dec_and_test(&ctx->refcount)) {
                if (ctx->parent_ctx)
                        put_ctx(ctx->parent_ctx);
                if (ctx->task && ctx->task != TASK_TOMBSTONE)
                        put_task_struct(ctx->task);
                call_rcu(&ctx->rcu_head, free_ctx);
        } else {
                smp_mb__after_atomic(); /* pairs with wait_var_event() */
                if (ctx->task == TASK_TOMBSTONE)
                        wake_up_var(&ctx->refcount);
        }
}

/*
 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
 * perf_pmu_migrate_context() we need some magic.
 *
 * Those places that change perf_event::ctx will hold both
 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
 *
 * Lock ordering is by mutex address. There are two other sites where
 * perf_event_context::mutex nests and those are:
 *
 *  - perf_event_exit_task_context()        [ child , 0 ]
 *      perf_event_exit_event()
 *        put_event()                        [ parent, 1 ]
 *
 *  - perf_event_init_context()                [ parent, 0 ]
 *      inherit_task_group()
 *        inherit_group()
 *          inherit_event()
 *            perf_event_alloc()
 *              perf_init_event()
 *                perf_try_init_event()        [ child , 1 ]
 *
 * While it appears there is an obvious deadlock here -- the parent and child
 * nesting levels are inverted between the two. This is in fact safe because
 * life-time rules separate them. That is an exiting task cannot fork, and a
 * spawning task cannot (yet) exit.
 *
 * But remember that these are parent<->child context relations, and
 * migration does not affect children, therefore these two orderings should not
 * interact.
 *
 * The change in perf_event::ctx does not affect children (as claimed above)
 * because the sys_perf_event_open() case will install a new event and break
 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
 * concerned with cpuctx and that doesn't have children.
 *
 * The places that change perf_event::ctx will issue:
 *
 *   perf_remove_from_context();
 *   synchronize_rcu();
 *   perf_install_in_context();
 *
 * to affect the change. The remove_from_context() + synchronize_rcu() should
 * quiesce the event, after which we can install it in the new location. This
 * means that only external vectors (perf_fops, prctl) can perturb the event
 * while in transit. Therefore all such accessors should also acquire
 * perf_event_context::mutex to serialize against this.
 *
 * However; because event->ctx can change while we're waiting to acquire
 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
 * function.
 *
 * Lock order:
 *    exec_update_lock
 *        task_struct::perf_event_mutex
 *          perf_event_context::mutex
 *            perf_event::child_mutex;
 *              perf_event_context::lock
 *            mmap_lock
 *              perf_event::mmap_mutex
 *                perf_buffer::aux_mutex
 *              perf_addr_filters_head::lock
 *
 *    cpu_hotplug_lock
 *      pmus_lock
 *          cpuctx->mutex / perf_event_context::mutex
 */
static struct perf_event_context *
perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
{
        struct perf_event_context *ctx;

again:
        rcu_read_lock();
        ctx = READ_ONCE(event->ctx);
        if (!refcount_inc_not_zero(&ctx->refcount)) {
                rcu_read_unlock();
                goto again;
        }
        rcu_read_unlock();

        mutex_lock_nested(&ctx->mutex, nesting);
        if (event->ctx != ctx) {
                mutex_unlock(&ctx->mutex);
                put_ctx(ctx);
                goto again;
        }

        return ctx;
}

static inline struct perf_event_context *
perf_event_ctx_lock(struct perf_event *event)
{
        return perf_event_ctx_lock_nested(event, 0);
}

static void perf_event_ctx_unlock(struct perf_event *event,
                                  struct perf_event_context *ctx)
{
        mutex_unlock(&ctx->mutex);
        put_ctx(ctx);
}

/*
 * This must be done under the ctx->lock, such as to serialize against
 * context_equiv(), therefore we cannot call put_ctx() since that might end up
 * calling scheduler related locks and ctx->lock nests inside those.
 */
static __must_check struct perf_event_context *
unclone_ctx(struct perf_event_context *ctx)
{
        struct perf_event_context *parent_ctx = ctx->parent_ctx;

        lockdep_assert_held(&ctx->lock);

        if (parent_ctx)
                ctx->parent_ctx = NULL;
        ctx->generation++;

        return parent_ctx;
}

static u32 perf_event_pid_type(struct perf_event *event, struct task_struct *p,
                                enum pid_type type)
{
        u32 nr;
        /*
         * only top level events have the pid namespace they were created in
         */
        if (event->parent)
                event = event->parent;

        nr = __task_pid_nr_ns(p, type, event->ns);
        /* avoid -1 if it is idle thread or runs in another ns */
        if (!nr && !pid_alive(p))
                nr = -1;
        return nr;
}

static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
{
        return perf_event_pid_type(event, p, PIDTYPE_TGID);
}

static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
{
        return perf_event_pid_type(event, p, PIDTYPE_PID);
}

/*
 * If we inherit events we want to return the parent event id
 * to userspace.
 */
static u64 primary_event_id(struct perf_event *event)
{
        u64 id = event->id;

        if (event->parent)
                id = event->parent->id;

        return id;
}

/*
 * Get the perf_event_context for a task and lock it.
 *
 * This has to cope with the fact that until it is locked,
 * the context could get moved to another task.
 */
static struct perf_event_context *
perf_lock_task_context(struct task_struct *task, unsigned long *flags)
{
        struct perf_event_context *ctx;

retry:
        /*
         * One of the few rules of preemptible RCU is that one cannot do
         * rcu_read_unlock() while holding a scheduler (or nested) lock when
         * part of the read side critical section was irqs-enabled -- see
         * rcu_read_unlock_special().
         *
         * Since ctx->lock nests under rq->lock we must ensure the entire read
         * side critical section has interrupts disabled.
         */
        local_irq_save(*flags);
        rcu_read_lock();
        ctx = rcu_dereference(task->perf_event_ctxp);
        if (ctx) {
                /*
                 * If this context is a clone of another, it might
                 * get swapped for another underneath us by
                 * perf_event_task_sched_out, though the
                 * rcu_read_lock() protects us from any context
                 * getting freed.  Lock the context and check if it
                 * got swapped before we could get the lock, and retry
                 * if so.  If we locked the right context, then it
                 * can't get swapped on us any more.
                 */
                raw_spin_lock(&ctx->lock);
                if (ctx != rcu_dereference(task->perf_event_ctxp)) {
                        raw_spin_unlock(&ctx->lock);
                        rcu_read_unlock();
                        local_irq_restore(*flags);
                        goto retry;
                }

                if (ctx->task == TASK_TOMBSTONE ||
                    !refcount_inc_not_zero(&ctx->refcount)) {
                        raw_spin_unlock(&ctx->lock);
                        ctx = NULL;
                } else {
                        WARN_ON_ONCE(ctx->task != task);
                }
        }
        rcu_read_unlock();
        if (!ctx)
                local_irq_restore(*flags);
        return ctx;
}

/*
 * Get the context for a task and increment its pin_count so it
 * can't get swapped to another task.  This also increments its
 * reference count so that the context can't get freed.
 */
static struct perf_event_context *
perf_pin_task_context(struct task_struct *task)
{
        struct perf_event_context *ctx;
        unsigned long flags;

        ctx = perf_lock_task_context(task, &flags);
        if (ctx) {
                ++ctx->pin_count;
                raw_spin_unlock_irqrestore(&ctx->lock, flags);
        }
        return ctx;
}

static void perf_unpin_context(struct perf_event_context *ctx)
{
        unsigned long flags;

        raw_spin_lock_irqsave(&ctx->lock, flags);
        --ctx->pin_count;
        raw_spin_unlock_irqrestore(&ctx->lock, flags);
}

/*
 * Update the record of the current time in a context.
 */
static void __update_context_time(struct perf_event_context *ctx, bool adv)
{
        u64 now = perf_clock();

        lockdep_assert_held(&ctx->lock);

        if (adv)
                ctx->time += now - ctx->timestamp;
        ctx->timestamp = now;

        /*
         * The above: time' = time + (now - timestamp), can be re-arranged
         * into: time` = now + (time - timestamp), which gives a single value
         * offset to compute future time without locks on.
         *
         * See perf_event_time_now(), which can be used from NMI context where
         * it's (obviously) not possible to acquire ctx->lock in order to read
         * both the above values in a consistent manner.
         */
        WRITE_ONCE(ctx->timeoffset, ctx->time - ctx->timestamp);
}

static void update_context_time(struct perf_event_context *ctx)
{
        __update_context_time(ctx, true);
}

static u64 perf_event_time(struct perf_event *event)
{
        struct perf_event_context *ctx = event->ctx;

        if (unlikely(!ctx))
                return 0;

        if (is_cgroup_event(event))
                return perf_cgroup_event_time(event);

        return ctx->time;
}

static u64 perf_event_time_now(struct perf_event *event, u64 now)
{
        struct perf_event_context *ctx = event->ctx;

        if (unlikely(!ctx))
                return 0;

        if (is_cgroup_event(event))
                return perf_cgroup_event_time_now(event, now);

        if (!(__load_acquire(&ctx->is_active) & EVENT_TIME))
                return ctx->time;

        now += READ_ONCE(ctx->timeoffset);
        return now;
}

static enum event_type_t get_event_type(struct perf_event *event)
{
        struct perf_event_context *ctx = event->ctx;
        enum event_type_t event_type;

        lockdep_assert_held(&ctx->lock);

        /*
         * It's 'group type', really, because if our group leader is
         * pinned, so are we.
         */
        if (event->group_leader != event)
                event = event->group_leader;

        event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE;
        if (!ctx->task)
                event_type |= EVENT_CPU;

        return event_type;
}

/*
 * Helper function to initialize event group nodes.
 */
static void init_event_group(struct perf_event *event)
{
        RB_CLEAR_NODE(&event->group_node);
        event->group_index = 0;
}

/*
 * Extract pinned or flexible groups from the context
 * based on event attrs bits.
 */
static struct perf_event_groups *
get_event_groups(struct perf_event *event, struct perf_event_context *ctx)
{
        if (event->attr.pinned)
                return &ctx->pinned_groups;
        else
                return &ctx->flexible_groups;
}

/*
 * Helper function to initializes perf_event_group trees.
 */
static void perf_event_groups_init(struct perf_event_groups *groups)
{
        groups->tree = RB_ROOT;
        groups->index = 0;
}

static inline struct cgroup *event_cgroup(const struct perf_event *event)
{
        struct cgroup *cgroup = NULL;

#ifdef CONFIG_CGROUP_PERF
        if (event->cgrp)
                cgroup = event->cgrp->css.cgroup;
#endif

        return cgroup;
}

/*
 * Compare function for event groups;
 *
 * Implements complex key that first sorts by CPU and then by virtual index
 * which provides ordering when rotating groups for the same CPU.
 */
static __always_inline int
perf_event_groups_cmp(const int left_cpu, const struct pmu *left_pmu,
                      const struct cgroup *left_cgroup, const u64 left_group_index,
                      const struct perf_event *right)
{
        if (left_cpu < right->cpu)
                return -1;
        if (left_cpu > right->cpu)
                return 1;

        if (left_pmu) {
                if (left_pmu < right->pmu_ctx->pmu)
                        return -1;
                if (left_pmu > right->pmu_ctx->pmu)
                        return 1;
        }

#ifdef CONFIG_CGROUP_PERF
        {
                const struct cgroup *right_cgroup = event_cgroup(right);

                if (left_cgroup != right_cgroup) {
                        if (!left_cgroup) {
                                /*
                                 * Left has no cgroup but right does, no
                                 * cgroups come first.
                                 */
                                return -1;
                        }
                        if (!right_cgroup) {
                                /*
                                 * Right has no cgroup but left does, no
                                 * cgroups come first.
                                 */
                                return 1;
                        }
                        /* Two dissimilar cgroups, order by id. */
                        if (cgroup_id(left_cgroup) < cgroup_id(right_cgroup))
                                return -1;

                        return 1;
                }
        }
#endif

        if (left_group_index < right->group_index)
                return -1;
        if (left_group_index > right->group_index)
                return 1;

        return 0;
}

#define __node_2_pe(node) \
        rb_entry((node), struct perf_event, group_node)

static inline bool __group_less(struct rb_node *a, const struct rb_node *b)
{
        struct perf_event *e = __node_2_pe(a);
        return perf_event_groups_cmp(e->cpu, e->pmu_ctx->pmu, event_cgroup(e),
                                     e->group_index, __node_2_pe(b)) < 0;
}

struct __group_key {
        int cpu;
        struct pmu *pmu;
        struct cgroup *cgroup;
};

static inline int __group_cmp(const void *key, const struct rb_node *node)
{
        const struct __group_key *a = key;
        const struct perf_event *b = __node_2_pe(node);

        /* partial/subtree match: @cpu, @pmu, @cgroup; ignore: @group_index */
        return perf_event_groups_cmp(a->cpu, a->pmu, a->cgroup, b->group_index, b);
}

static inline int
__group_cmp_ignore_cgroup(const void *key, const struct rb_node *node)
{
        const struct __group_key *a = key;
        const struct perf_event *b = __node_2_pe(node);

        /* partial/subtree match: @cpu, @pmu, ignore: @cgroup, @group_index */
        return perf_event_groups_cmp(a->cpu, a->pmu, event_cgroup(b),
                                     b->group_index, b);
}

/*
 * Insert @event into @groups' tree; using
 *   {@event->cpu, @event->pmu_ctx->pmu, event_cgroup(@event), ++@groups->index}
 * as key. This places it last inside the {cpu,pmu,cgroup} subtree.
 */
static void
perf_event_groups_insert(struct perf_event_groups *groups,
                         struct perf_event *event)
{
        event->group_index = ++groups->index;

        rb_add(&event->group_node, &groups->tree, __group_less);
}

/*
 * Helper function to insert event into the pinned or flexible groups.
 */
static void
add_event_to_groups(struct perf_event *event, struct perf_event_context *ctx)
{
        struct perf_event_groups *groups;

        groups = get_event_groups(event, ctx);
        perf_event_groups_insert(groups, event);
}

/*
 * Delete a group from a tree.
 */
static void
perf_event_groups_delete(struct perf_event_groups *groups,
                         struct perf_event *event)
{
        WARN_ON_ONCE(RB_EMPTY_NODE(&event->group_node) ||
                     RB_EMPTY_ROOT(&groups->tree));

        rb_erase(&event->group_node, &groups->tree);
        init_event_group(event);
}

/*
 * Helper function to delete event from its groups.
 */
static void
del_event_from_groups(struct perf_event *event, struct perf_event_context *ctx)
{
        struct perf_event_groups *groups;

        groups = get_event_groups(event, ctx);
        perf_event_groups_delete(groups, event);
}

/*
 * Get the leftmost event in the {cpu,pmu,cgroup} subtree.
 */
static struct perf_event *
perf_event_groups_first(struct perf_event_groups *groups, int cpu,
                        struct pmu *pmu, struct cgroup *cgrp)
{
        struct __group_key key = {
                .cpu = cpu,
                .pmu = pmu,
                .cgroup = cgrp,
        };
        struct rb_node *node;

        node = rb_find_first(&key, &groups->tree, __group_cmp);
        if (node)
                return __node_2_pe(node);

        return NULL;
}

static struct perf_event *
perf_event_groups_next(struct perf_event *event, struct pmu *pmu)
{
        struct __group_key key = {
                .cpu = event->cpu,
                .pmu = pmu,
                .cgroup = event_cgroup(event),
        };
        struct rb_node *next;

        next = rb_next_match(&key, &event->group_node, __group_cmp);
        if (next)
                return __node_2_pe(next);

        return NULL;
}

#define perf_event_groups_for_cpu_pmu(event, groups, cpu, pmu)                \
        for (event = perf_event_groups_first(groups, cpu, pmu, NULL);        \
             event; event = perf_event_groups_next(event, pmu))

/*
 * Iterate through the whole groups tree.
 */
#define perf_event_groups_for_each(event, groups)                        \
        for (event = rb_entry_safe(rb_first(&((groups)->tree)),                \
                                typeof(*event), group_node); event;        \
                event = rb_entry_safe(rb_next(&event->group_node),        \
                                typeof(*event), group_node))

/*
 * Does the event attribute request inherit with PERF_SAMPLE_READ
 */
static inline bool has_inherit_and_sample_read(struct perf_event_attr *attr)
{
        return attr->inherit && (attr->sample_type & PERF_SAMPLE_READ);
}

/*
 * Add an event from the lists for its context.
 * Must be called with ctx->mutex and ctx->lock held.
 */
static void
list_add_event(struct perf_event *event, struct perf_event_context *ctx)
{
        lockdep_assert_held(&ctx->lock);

        WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
        event->attach_state |= PERF_ATTACH_CONTEXT;

        event->tstamp = perf_event_time(event);

        /*
         * If we're a stand alone event or group leader, we go to the context
         * list, group events are kept attached to the group so that
         * perf_group_detach can, at all times, locate all siblings.
         */
        if (event->group_leader == event) {
                event->group_caps = event->event_caps;
                add_event_to_groups(event, ctx);
        }

        list_add_rcu(&event->event_entry, &ctx->event_list);
        ctx->nr_events++;
        if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)
                ctx->nr_user++;
        if (event->attr.inherit_stat)
                ctx->nr_stat++;
        if (has_inherit_and_sample_read(&event->attr))
                local_inc(&ctx->nr_no_switch_fast);

        if (event->state > PERF_EVENT_STATE_OFF)
                perf_cgroup_event_enable(event, ctx);

        ctx->generation++;
        event->pmu_ctx->nr_events++;
}

/*
 * Initialize event state based on the perf_event_attr::disabled.
 */
static inline void perf_event__state_init(struct perf_event *event)
{
        event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
                                              PERF_EVENT_STATE_INACTIVE;
}

static int __perf_event_read_size(u64 read_format, int nr_siblings)
{
        int entry = sizeof(u64); /* value */
        int size = 0;
        int nr = 1;

        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
                size += sizeof(u64);

        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
                size += sizeof(u64);

        if (read_format & PERF_FORMAT_ID)
                entry += sizeof(u64);

        if (read_format & PERF_FORMAT_LOST)
                entry += sizeof(u64);

        if (read_format & PERF_FORMAT_GROUP) {
                nr += nr_siblings;
                size += sizeof(u64);
        }

        /*
         * Since perf_event_validate_size() limits this to 16k and inhibits
         * adding more siblings, this will never overflow.
         */
        return size + nr * entry;
}

static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
{
        struct perf_sample_data *data;
        u16 size = 0;

        if (sample_type & PERF_SAMPLE_IP)
                size += sizeof(data->ip);

        if (sample_type & PERF_SAMPLE_ADDR)
                size += sizeof(data->addr);

        if (sample_type & PERF_SAMPLE_PERIOD)
                size += sizeof(data->period);

        if (sample_type & PERF_SAMPLE_WEIGHT_TYPE)
                size += sizeof(data->weight.full);

        if (sample_type & PERF_SAMPLE_READ)
                size += event->read_size;

        if (sample_type & PERF_SAMPLE_DATA_SRC)
                size += sizeof(data->data_src.val);

        if (sample_type & PERF_SAMPLE_TRANSACTION)
                size += sizeof(data->txn);

        if (sample_type & PERF_SAMPLE_PHYS_ADDR)
                size += sizeof(data->phys_addr);

        if (sample_type & PERF_SAMPLE_CGROUP)
                size += sizeof(data->cgroup);

        if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
                size += sizeof(data->data_page_size);

        if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
                size += sizeof(data->code_page_size);

        event->header_size = size;
}

/*
 * Called at perf_event creation and when events are attached/detached from a
 * group.
 */
static void perf_event__header_size(struct perf_event *event)
{
        event->read_size =
                __perf_event_read_size(event->attr.read_format,
                                       event->group_leader->nr_siblings);
        __perf_event_header_size(event, event->attr.sample_type);
}

static void perf_event__id_header_size(struct perf_event *event)
{
        struct perf_sample_data *data;
        u64 sample_type = event->attr.sample_type;
        u16 size = 0;

        if (sample_type & PERF_SAMPLE_TID)
                size += sizeof(data->tid_entry);

        if (sample_type & PERF_SAMPLE_TIME)
                size += sizeof(data->time);

        if (sample_type & PERF_SAMPLE_IDENTIFIER)
                size += sizeof(data->id);

        if (sample_type & PERF_SAMPLE_ID)
                size += sizeof(data->id);

        if (sample_type & PERF_SAMPLE_STREAM_ID)
                size += sizeof(data->stream_id);

        if (sample_type & PERF_SAMPLE_CPU)
                size += sizeof(data->cpu_entry);

        event->id_header_size = size;
}

/*
 * Check that adding an event to the group does not result in anybody
 * overflowing the 64k event limit imposed by the output buffer.
 *
 * Specifically, check that the read_size for the event does not exceed 16k,
 * read_size being the one term that grows with groups size. Since read_size
 * depends on per-event read_format, also (re)check the existing events.
 *
 * This leaves 48k for the constant size fields and things like callchains,
 * branch stacks and register sets.
 */
static bool perf_event_validate_size(struct perf_event *event)
{
        struct perf_event *sibling, *group_leader = event->group_leader;

        if (__perf_event_read_size(event->attr.read_format,
                                   group_leader->nr_siblings + 1) > 16*1024)
                return false;

        if (__perf_event_read_size(group_leader->attr.read_format,
                                   group_leader->nr_siblings + 1) > 16*1024)
                return false;

        /*
         * When creating a new group leader, group_leader->ctx is initialized
         * after the size has been validated, but we cannot safely use
         * for_each_sibling_event() until group_leader->ctx is set. A new group
         * leader cannot have any siblings yet, so we can safely skip checking
         * the non-existent siblings.
         */
        if (event == group_leader)
                return true;

        for_each_sibling_event(sibling, group_leader) {
                if (__perf_event_read_size(sibling->attr.read_format,
                                           group_leader->nr_siblings + 1) > 16*1024)
                        return false;
        }

        return true;
}

static void perf_group_attach(struct perf_event *event)
{
        struct perf_event *group_leader = event->group_leader, *pos;

        lockdep_assert_held(&event->ctx->lock);

        /*
         * We can have double attach due to group movement (move_group) in
         * perf_event_open().
         */
        if (event->attach_state & PERF_ATTACH_GROUP)
                return;

        event->attach_state |= PERF_ATTACH_GROUP;

        if (group_leader == event)
                return;

        WARN_ON_ONCE(group_leader->ctx != event->ctx);

        group_leader->group_caps &= event->event_caps;

        list_add_tail(&event->sibling_list, &group_leader->sibling_list);
        group_leader->nr_siblings++;
        group_leader->group_generation++;

        perf_event__header_size(group_leader);

        for_each_sibling_event(pos, group_leader)
                perf_event__header_size(pos);
}

/*
 * Remove an event from the lists for its context.
 * Must be called with ctx->mutex and ctx->lock held.
 */
static void
list_del_event(struct perf_event *event, struct perf_event_context *ctx)
{
        WARN_ON_ONCE(event->ctx != ctx);
        lockdep_assert_held(&ctx->lock);

        /*
         * We can have double detach due to exit/hot-unplug + close.
         */
        if (!(event->attach_state & PERF_ATTACH_CONTEXT))
                return;

        event->attach_state &= ~PERF_ATTACH_CONTEXT;

        ctx->nr_events--;
        if (event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT)
                ctx->nr_user--;
        if (event->attr.inherit_stat)
                ctx->nr_stat--;
        if (has_inherit_and_sample_read(&event->attr))
                local_dec(&ctx->nr_no_switch_fast);

        list_del_rcu(&event->event_entry);

        if (event->group_leader == event)
                del_event_from_groups(event, ctx);

        ctx->generation++;
        event->pmu_ctx->nr_events--;
}

static int
perf_aux_output_match(struct perf_event *event, struct perf_event *aux_event)
{
        if (!has_aux(aux_event))
                return 0;

        if (!event->pmu->aux_output_match)
                return 0;

        return event->pmu->aux_output_match(aux_event);
}

static void put_event(struct perf_event *event);
static void __event_disable(struct perf_event *event,
                            struct perf_event_context *ctx,
                            enum perf_event_state state);

static void perf_put_aux_event(struct perf_event *event)
{
        struct perf_event_context *ctx = event->ctx;
        struct perf_event *iter;

        /*
         * If event uses aux_event tear down the link
         */
        if (event->aux_event) {
                iter = event->aux_event;
                event->aux_event = NULL;
                put_event(iter);
                return;
        }

        /*
         * If the event is an aux_event, tear down all links to
         * it from other events.
         */
        for_each_sibling_event(iter, event) {
                if (iter->aux_event != event)
                        continue;

                iter->aux_event = NULL;
                put_event(event);

                /*
                 * If it's ACTIVE, schedule it out and put it into ERROR
                 * state so that we don't try to schedule it again. Note
                 * that perf_event_enable() will clear the ERROR status.
                 */
                __event_disable(iter, ctx, PERF_EVENT_STATE_ERROR);
        }
}

static bool perf_need_aux_event(struct perf_event *event)
{
        return event->attr.aux_output || has_aux_action(event);
}

static int perf_get_aux_event(struct perf_event *event,
                              struct perf_event *group_leader)
{
        /*
         * Our group leader must be an aux event if we want to be
         * an aux_output. This way, the aux event will precede its
         * aux_output events in the group, and therefore will always
         * schedule first.
         */
        if (!group_leader)
                return 0;

        /*
         * aux_output and aux_sample_size are mutually exclusive.
         */
        if (event->attr.aux_output && event->attr.aux_sample_size)
                return 0;

        if (event->attr.aux_output &&
            !perf_aux_output_match(event, group_leader))
                return 0;

        if ((event->attr.aux_pause || event->attr.aux_resume) &&
            !(group_leader->pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE))
                return 0;

        if (event->attr.aux_sample_size && !group_leader->pmu->snapshot_aux)
                return 0;

        if (!atomic_long_inc_not_zero(&group_leader->refcount))
                return 0;

        /*
         * Link aux_outputs to their aux event; this is undone in
         * perf_group_detach() by perf_put_aux_event(). When the
         * group in torn down, the aux_output events loose their
         * link to the aux_event and can't schedule any more.
         */
        event->aux_event = group_leader;

        return 1;
}

static inline struct list_head *get_event_list(struct perf_event *event)
{
        return event->attr.pinned ? &event->pmu_ctx->pinned_active :
                                    &event->pmu_ctx->flexible_active;
}

static void perf_group_detach(struct perf_event *event)
{
        struct perf_event *leader = event->group_leader;
        struct perf_event *sibling, *tmp;
        struct perf_event_context *ctx = event->ctx;

        lockdep_assert_held(&ctx->lock);

        /*
         * We can have double detach due to exit/hot-unplug + close.
         */
        if (!(event->attach_state & PERF_ATTACH_GROUP))
                return;

        event->attach_state &= ~PERF_ATTACH_GROUP;

        perf_put_aux_event(event);

        /*
         * If this is a sibling, remove it from its group.
         */
        if (leader != event) {
                list_del_init(&event->sibling_list);
                event->group_leader->nr_siblings--;
                event->group_leader->group_generation++;
                goto out;
        }

        /*
         * If this was a group event with sibling events then
         * upgrade the siblings to singleton events by adding them
         * to whatever list we are on.
         */
        list_for_each_entry_safe(sibling, tmp, &event->sibling_list, sibling_list) {

                /*
                 * Events that have PERF_EV_CAP_SIBLING require being part of
                 * a group and cannot exist on their own, schedule them out
                 * and move them into the ERROR state. Also see
                 * _perf_event_enable(), it will not be able to recover this
                 * ERROR state.
                 */
                if (sibling->event_caps & PERF_EV_CAP_SIBLING)
                        __event_disable(sibling, ctx, PERF_EVENT_STATE_ERROR);

                sibling->group_leader = sibling;
                list_del_init(&sibling->sibling_list);

                /* Inherit group flags from the previous leader */
                sibling->group_caps = event->group_caps;

                if (sibling->attach_state & PERF_ATTACH_CONTEXT) {
                        add_event_to_groups(sibling, event->ctx);

                        if (sibling->state == PERF_EVENT_STATE_ACTIVE)
                                list_add_tail(&sibling->active_list, get_event_list(sibling));
                }

                WARN_ON_ONCE(sibling->ctx != event->ctx);
        }

out:
        for_each_sibling_event(tmp, leader)
                perf_event__header_size(tmp);

        perf_event__header_size(leader);
}

static void sync_child_event(struct perf_event *child_event);

static void perf_child_detach(struct perf_event *event)
{
        struct perf_event *parent_event = event->parent;

        if (!(event->attach_state & PERF_ATTACH_CHILD))
                return;

        event->attach_state &= ~PERF_ATTACH_CHILD;

        if (WARN_ON_ONCE(!parent_event))
                return;

        /*
         * Can't check this from an IPI, the holder is likey another CPU.
         *
        lockdep_assert_held(&parent_event->child_mutex);
         */

        sync_child_event(event);
        list_del_init(&event->child_list);
}

static bool is_orphaned_event(struct perf_event *event)
{
        return event->state == PERF_EVENT_STATE_DEAD;
}

static inline int
event_filter_match(struct perf_event *event)
{
        return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
               perf_cgroup_match(event);
}

static inline bool is_event_in_freq_mode(struct perf_event *event)
{
        return event->attr.freq && event->attr.sample_freq;
}

static void
event_sched_out(struct perf_event *event, struct perf_event_context *ctx)
{
        struct perf_event_pmu_context *epc = event->pmu_ctx;
        struct perf_cpu_pmu_context *cpc = this_cpc(epc->pmu);
        enum perf_event_state state = PERF_EVENT_STATE_INACTIVE;

        // XXX cpc serialization, probably per-cpu IRQ disabled

        WARN_ON_ONCE(event->ctx != ctx);
        lockdep_assert_held(&ctx->lock);

        if (event->state != PERF_EVENT_STATE_ACTIVE)
                return;

        /*
         * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
         * we can schedule events _OUT_ individually through things like
         * __perf_remove_from_context().
         */
        list_del_init(&event->active_list);

        perf_pmu_disable(event->pmu);

        event->pmu->del(event, 0);
        event->oncpu = -1;

        if (event->pending_disable) {
                event->pending_disable = 0;
                perf_cgroup_event_disable(event, ctx);
                state = PERF_EVENT_STATE_OFF;
        }

        perf_event_set_state(event, state);

        if (!is_software_event(event))
                cpc->active_oncpu--;
        if (is_event_in_freq_mode(event)) {
                ctx->nr_freq--;
                epc->nr_freq--;
        }
        if (event->attr.exclusive || !cpc->active_oncpu)
                cpc->exclusive = 0;

        perf_pmu_enable(event->pmu);
}

static void
group_sched_out(struct perf_event *group_event, struct perf_event_context *ctx)
{
        struct perf_event *event;

        if (group_event->state != PERF_EVENT_STATE_ACTIVE)
                return;

        perf_assert_pmu_disabled(group_event->pmu_ctx->pmu);

        event_sched_out(group_event, ctx);

        /*
         * Schedule out siblings (if any):
         */
        for_each_sibling_event(event, group_event)
                event_sched_out(event, ctx);
}

static inline void
__ctx_time_update(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx, bool final)
{
        if (ctx->is_active & EVENT_TIME) {
                if (ctx->is_active & EVENT_FROZEN)
                        return;
                update_context_time(ctx);
                update_cgrp_time_from_cpuctx(cpuctx, final);
        }
}

static inline void
ctx_time_update(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx)
{
        __ctx_time_update(cpuctx, ctx, false);
}

/*
 * To be used inside perf_ctx_lock() / perf_ctx_unlock(). Lasts until perf_ctx_unlock().
 */
static inline void
ctx_time_freeze(struct perf_cpu_context *cpuctx, struct perf_event_context *ctx)
{
        ctx_time_update(cpuctx, ctx);
        if (ctx->is_active & EVENT_TIME)
                ctx->is_active |= EVENT_FROZEN;
}

static inline void
ctx_time_update_event(struct perf_event_context *ctx, struct perf_event *event)
{
        if (ctx->is_active & EVENT_TIME) {
                if (ctx->is_active & EVENT_FROZEN)
                        return;
                update_context_time(ctx);
                update_cgrp_time_from_event(event);
        }
}

#define DETACH_GROUP        0x01UL
#define DETACH_CHILD        0x02UL
#define DETACH_EXIT        0x04UL
#define DETACH_REVOKE        0x08UL
#define DETACH_DEAD        0x10UL

/*
 * Cross CPU call to remove a performance event
 *
 * We disable the event on the hardware level first. After that we
 * remove it from the context list.
 */
static void
__perf_remove_from_context(struct perf_event *event,
                           struct perf_cpu_context *cpuctx,
                           struct perf_event_context *ctx,
                           void *info)
{
        struct perf_event_pmu_context *pmu_ctx = event->pmu_ctx;
        enum perf_event_state state = PERF_EVENT_STATE_OFF;
        unsigned long flags = (unsigned long)info;

        ctx_time_update(cpuctx, ctx);

        /*
         * Ensure event_sched_out() switches to OFF, at the very least
         * this avoids raising perf_pending_task() at this time.
         */
        if (flags & DETACH_EXIT)
                state = PERF_EVENT_STATE_EXIT;
        if (flags & DETACH_REVOKE)
                state = PERF_EVENT_STATE_REVOKED;
        if (flags & DETACH_DEAD)
                state = PERF_EVENT_STATE_DEAD;

        event_sched_out(event, ctx);

        if (event->state > PERF_EVENT_STATE_OFF)
                perf_cgroup_event_disable(event, ctx);

        perf_event_set_state(event, min(event->state, state));

        if (flags & DETACH_GROUP)
                perf_group_detach(event);
        if (flags & DETACH_CHILD)
                perf_child_detach(event);
        list_del_event(event, ctx);

        if (!pmu_ctx->nr_events) {
                pmu_ctx->rotate_necessary = 0;

                if (ctx->task && ctx->is_active) {
                        struct perf_cpu_pmu_context *cpc = this_cpc(pmu_ctx->pmu);

                        WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
                        cpc->task_epc = NULL;
                }
        }

        if (!ctx->nr_events && ctx->is_active) {
                if (ctx == &cpuctx->ctx)
                        update_cgrp_time_from_cpuctx(cpuctx, true);

                ctx->is_active = 0;
                if (ctx->task) {
                        WARN_ON_ONCE(cpuctx->task_ctx != ctx);
                        cpuctx->task_ctx = NULL;
                }
        }
}

/*
 * Remove the event from a task's (or a CPU's) list of events.
 *
 * If event->ctx is a cloned context, callers must make sure that
 * every task struct that event->ctx->task could possibly point to
 * remains valid.  This is OK when called from perf_release since
 * that only calls us on the top-level context, which can't be a clone.
 * When called from perf_event_exit_task, it's OK because the
 * context has been detached from its task.
 */
static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
{
        struct perf_event_context *ctx = event->ctx;

        lockdep_assert_held(&ctx->mutex);

        /*
         * Because of perf_event_exit_task(), perf_remove_from_context() ought
         * to work in the face of TASK_TOMBSTONE, unlike every other
         * event_function_call() user.
         */
        raw_spin_lock_irq(&ctx->lock);
        if (!ctx->is_active) {
                __perf_remove_from_context(event, this_cpu_ptr(&perf_cpu_context),
                                           ctx, (void *)flags);
                raw_spin_unlock_irq(&ctx->lock);
                return;
        }
        raw_spin_unlock_irq(&ctx->lock);

        event_function_call(event, __perf_remove_from_context, (void *)flags);
}

static void __event_disable(struct perf_event *event,
                            struct perf_event_context *ctx,
                            enum perf_event_state state)
{
        event_sched_out(event, ctx);
        perf_cgroup_event_disable(event, ctx);
        perf_event_set_state(event, state);
}

/*
 * Cross CPU call to disable a performance event
 */
static void __perf_event_disable(struct perf_event *event,
                                 struct perf_cpu_context *cpuctx,
                                 struct perf_event_context *ctx,
                                 void *info)
{
        if (event->state < PERF_EVENT_STATE_INACTIVE)
                return;

        perf_pmu_disable(event->pmu_ctx->pmu);
        ctx_time_update_event(ctx, event);

        /*
         * When disabling a group leader, the whole group becomes ineligible
         * to run, so schedule out the full group.
         */
        if (event == event->group_leader)
                group_sched_out(event, ctx);

        /*
         * But only mark the leader OFF; the siblings will remain
         * INACTIVE.
         */
        __event_disable(event, ctx, PERF_EVENT_STATE_OFF);

        perf_pmu_enable(event->pmu_ctx->pmu);
}

/*
 * Disable an event.
 *
 * If event->ctx is a cloned context, callers must make sure that
 * every task struct that event->ctx->task could possibly point to
 * remains valid.  This condition is satisfied when called through
 * perf_event_for_each_child or perf_event_for_each because they
 * hold the top-level event's child_mutex, so any descendant that
 * goes to exit will block in perf_event_exit_event().
 *
 * When called from perf_pending_disable it's OK because event->ctx
 * is the current context on this CPU and preemption is disabled,
 * hence we can't get into perf_event_task_sched_out for this context.
 */
static void _perf_event_disable(struct perf_event *event)
{
        struct perf_event_context *ctx = event->ctx;

        raw_spin_lock_irq(&ctx->lock);
        if (event->state <= PERF_EVENT_STATE_OFF) {
                raw_spin_unlock_irq(&ctx->lock);
                return;
        }
        raw_spin_unlock_irq(&ctx->lock);

        event_function_call(event, __perf_event_disable, NULL);
}

void perf_event_disable_local(struct perf_event *event)
{
        event_function_local(event, __perf_event_disable, NULL);
}

/*
 * Strictly speaking kernel users cannot create groups and therefore this
 * interface does not need the perf_event_ctx_lock() magic.
 */
void perf_event_disable(struct perf_event *event)
{
        struct perf_event_context *ctx;

        ctx = perf_event_ctx_lock(event);
        _perf_event_disable(event);
        perf_event_ctx_unlock(event, ctx);
}
EXPORT_SYMBOL_GPL(perf_event_disable);

void perf_event_disable_inatomic(struct perf_event *event)
{
        event->pending_disable = 1;
        irq_work_queue(&event->pending_disable_irq);
}

#define MAX_INTERRUPTS (~0ULL)

static void perf_log_throttle(struct perf_event *event, int enable);
static void perf_log_itrace_start(struct perf_event *event);

static void perf_event_unthrottle(struct perf_event *event, bool start)
{
        if (event->state != PERF_EVENT_STATE_ACTIVE)
                return;

        event->hw.interrupts = 0;
        if (start)
                event->pmu->start(event, 0);
        if (event == event->group_leader)
                perf_log_throttle(event, 1);
}

static void perf_event_throttle(struct perf_event *event)
{
        if (event->state != PERF_EVENT_STATE_ACTIVE)
                return;

        event->hw.interrupts = MAX_INTERRUPTS;
        event->pmu->stop(event, 0);
        if (event == event->group_leader)
                perf_log_throttle(event, 0);
}

static void perf_event_unthrottle_group(struct perf_event *event, bool skip_start_event)
{
        struct perf_event *sibling, *leader = event->group_leader;

        perf_event_unthrottle(leader, skip_start_event ? leader != event : true);
        for_each_sibling_event(sibling, leader)
                perf_event_unthrottle(sibling, skip_start_event ? sibling != event : true);
}

static void perf_event_throttle_group(struct perf_event *event)
{
        struct perf_event *sibling, *leader = event->group_leader;

        perf_event_throttle(leader);
        for_each_sibling_event(sibling, leader)
                perf_event_throttle(sibling);
}

static int
event_sched_in(struct perf_event *event, struct perf_event_context *ctx)
{
        struct perf_event_pmu_context *epc = event->pmu_ctx;
        struct perf_cpu_pmu_context *cpc = this_cpc(epc->pmu);
        int ret = 0;

        WARN_ON_ONCE(event->ctx != ctx);

        lockdep_assert_held(&ctx->lock);

        if (event->state <= PERF_EVENT_STATE_OFF)
                return 0;

        WRITE_ONCE(event->oncpu, smp_processor_id());
        /*
         * Order event::oncpu write to happen before the ACTIVE state is
         * visible. This allows perf_event_{stop,read}() to observe the correct
         * ->oncpu if it sees ACTIVE.
         */
        smp_wmb();
        perf_event_set_state(event, PERF_EVENT_STATE_ACTIVE);

        /*
         * Unthrottle events, since we scheduled we might have missed several
         * ticks already, also for a heavily scheduling task there is little
         * guarantee it'll get a tick in a timely manner.
         */
        if (unlikely(event->hw.interrupts == MAX_INTERRUPTS))
                perf_event_unthrottle(event, false);

        perf_pmu_disable(event->pmu);

        perf_log_itrace_start(event);

        if (event->pmu->add(event, PERF_EF_START)) {
                perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
                event->oncpu = -1;
                ret = -EAGAIN;
                goto out;
        }

        if (!is_software_event(event))
                cpc->active_oncpu++;
        if (is_event_in_freq_mode(event)) {
                ctx->nr_freq++;
                epc->nr_freq++;
        }
        if (event->attr.exclusive)
                cpc->exclusive = 1;

out:
        perf_pmu_enable(event->pmu);

        return ret;
}

static int
group_sched_in(struct perf_event *group_event, struct perf_event_context *ctx)
{
        struct perf_event *event, *partial_group = NULL;
        struct pmu *pmu = group_event->pmu_ctx->pmu;

        if (group_event->state == PERF_EVENT_STATE_OFF)
                return 0;

        pmu->start_txn(pmu, PERF_PMU_TXN_ADD);

        if (event_sched_in(group_event, ctx))
                goto error;

        /*
         * Schedule in siblings as one group (if any):
         */
        for_each_sibling_event(event, group_event) {
                if (event_sched_in(event, ctx)) {
                        partial_group = event;
                        goto group_error;
                }
        }

        if (!pmu->commit_txn(pmu))
                return 0;

group_error:
        /*
         * Groups can be scheduled in as one unit only, so undo any
         * partial group before returning:
         * The events up to the failed event are scheduled out normally.
         */
        for_each_sibling_event(event, group_event) {
                if (event == partial_group)
                        break;

                event_sched_out(event, ctx);
        }
        event_sched_out(group_event, ctx);

error:
        pmu->cancel_txn(pmu);
        return -EAGAIN;
}

/*
 * Work out whether we can put this event group on the CPU now.
 */
static int group_can_go_on(struct perf_event *event, int can_add_hw)
{
        struct perf_event_pmu_context *epc = event->pmu_ctx;
        struct perf_cpu_pmu_context *cpc = this_cpc(epc->pmu);

        /*
         * Groups consisting entirely of software events can always go on.
         */
        if (event->group_caps & PERF_EV_CAP_SOFTWARE)
                return 1;
        /*
         * If an exclusive group is already on, no other hardware
         * events can go on.
         */
        if (cpc->exclusive)
                return 0;
        /*
         * If this group is exclusive and there are already
         * events on the CPU, it can't go on.
         */
        if (event->attr.exclusive && !list_empty(get_event_list(event)))
                return 0;
        /*
         * Otherwise, try to add it if all previous groups were able
         * to go on.
         */
        return can_add_hw;
}

static void add_event_to_ctx(struct perf_event *event,
                               struct perf_event_context *ctx)
{
        list_add_event(event, ctx);
        perf_group_attach(event);
}

static void task_ctx_sched_out(struct perf_event_context *ctx,
                               struct pmu *pmu,
                               enum event_type_t event_type)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);

        if (!cpuctx->task_ctx)
                return;

        if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
                return;

        ctx_sched_out(ctx, pmu, event_type);
}

static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
                                struct perf_event_context *ctx,
                                struct pmu *pmu)
{
        ctx_sched_in(&cpuctx->ctx, pmu, EVENT_PINNED);
        if (ctx)
                 ctx_sched_in(ctx, pmu, EVENT_PINNED);
        ctx_sched_in(&cpuctx->ctx, pmu, EVENT_FLEXIBLE);
        if (ctx)
                 ctx_sched_in(ctx, pmu, EVENT_FLEXIBLE);
}

/*
 * We want to maintain the following priority of scheduling:
 *  - CPU pinned (EVENT_CPU | EVENT_PINNED)
 *  - task pinned (EVENT_PINNED)
 *  - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
 *  - task flexible (EVENT_FLEXIBLE).
 *
 * In order to avoid unscheduling and scheduling back in everything every
 * time an event is added, only do it for the groups of equal priority and
 * below.
 *
 * This can be called after a batch operation on task events, in which case
 * event_type is a bit mask of the types of events involved. For CPU events,
 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
 */
static void ctx_resched(struct perf_cpu_context *cpuctx,
                        struct perf_event_context *task_ctx,
                        struct pmu *pmu, enum event_type_t event_type)
{
        bool cpu_event = !!(event_type & EVENT_CPU);
        struct perf_event_pmu_context *epc;

        /*
         * If pinned groups are involved, flexible groups also need to be
         * scheduled out.
         */
        if (event_type & EVENT_PINNED)
                event_type |= EVENT_FLEXIBLE;

        event_type &= EVENT_ALL;

        for_each_epc(epc, &cpuctx->ctx, pmu, false)
                perf_pmu_disable(epc->pmu);

        if (task_ctx) {
                for_each_epc(epc, task_ctx, pmu, false)
                        perf_pmu_disable(epc->pmu);

                task_ctx_sched_out(task_ctx, pmu, event_type);
        }

        /*
         * Decide which cpu ctx groups to schedule out based on the types
         * of events that caused rescheduling:
         *  - EVENT_CPU: schedule out corresponding groups;
         *  - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
         *  - otherwise, do nothing more.
         */
        if (cpu_event)
                ctx_sched_out(&cpuctx->ctx, pmu, event_type);
        else if (event_type & EVENT_PINNED)
                ctx_sched_out(&cpuctx->ctx, pmu, EVENT_FLEXIBLE);

        perf_event_sched_in(cpuctx, task_ctx, pmu);

        for_each_epc(epc, &cpuctx->ctx, pmu, false)
                perf_pmu_enable(epc->pmu);

        if (task_ctx) {
                for_each_epc(epc, task_ctx, pmu, false)
                        perf_pmu_enable(epc->pmu);
        }
}

void perf_pmu_resched(struct pmu *pmu)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_context *task_ctx = cpuctx->task_ctx;

        perf_ctx_lock(cpuctx, task_ctx);
        ctx_resched(cpuctx, task_ctx, pmu, EVENT_ALL|EVENT_CPU);
        perf_ctx_unlock(cpuctx, task_ctx);
}

/*
 * Cross CPU call to install and enable a performance event
 *
 * Very similar to remote_function() + event_function() but cannot assume that
 * things like ctx->is_active and cpuctx->task_ctx are set.
 */
static int  __perf_install_in_context(void *info)
{
        struct perf_event *event = info;
        struct perf_event_context *ctx = event->ctx;
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_context *task_ctx = cpuctx->task_ctx;
        bool reprogram = true;
        int ret = 0;

        raw_spin_lock(&cpuctx->ctx.lock);
        if (ctx->task) {
                raw_spin_lock(&ctx->lock);
                task_ctx = ctx;

                reprogram = (ctx->task == current);

                /*
                 * If the task is running, it must be running on this CPU,
                 * otherwise we cannot reprogram things.
                 *
                 * If its not running, we don't care, ctx->lock will
                 * serialize against it becoming runnable.
                 */
                if (task_curr(ctx->task) && !reprogram) {
                        ret = -ESRCH;
                        goto unlock;
                }

                WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx);
        } else if (task_ctx) {
                raw_spin_lock(&task_ctx->lock);
        }

#ifdef CONFIG_CGROUP_PERF
        if (event->state > PERF_EVENT_STATE_OFF && is_cgroup_event(event)) {
                /*
                 * If the current cgroup doesn't match the event's
                 * cgroup, we should not try to schedule it.
                 */
                struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
                reprogram = cgroup_is_descendant(cgrp->css.cgroup,
                                        event->cgrp->css.cgroup);
        }
#endif

        if (reprogram) {
                ctx_time_freeze(cpuctx, ctx);
                add_event_to_ctx(event, ctx);
                ctx_resched(cpuctx, task_ctx, event->pmu_ctx->pmu,
                            get_event_type(event));
        } else {
                add_event_to_ctx(event, ctx);
        }

unlock:
        perf_ctx_unlock(cpuctx, task_ctx);

        return ret;
}

static bool exclusive_event_installable(struct perf_event *event,
                                        struct perf_event_context *ctx);

/*
 * Attach a performance event to a context.
 *
 * Very similar to event_function_call, see comment there.
 */
static void
perf_install_in_context(struct perf_event_context *ctx,
                        struct perf_event *event,
                        int cpu)
{
        struct task_struct *task = READ_ONCE(ctx->task);

        lockdep_assert_held(&ctx->mutex);

        WARN_ON_ONCE(!exclusive_event_installable(event, ctx));

        if (event->cpu != -1)
                WARN_ON_ONCE(event->cpu != cpu);

        /*
         * Ensures that if we can observe event->ctx, both the event and ctx
         * will be 'complete'. See perf_iterate_sb_cpu().
         */
        smp_store_release(&event->ctx, ctx);

        /*
         * perf_event_attr::disabled events will not run and can be initialized
         * without IPI. Except when this is the first event for the context, in
         * that case we need the magic of the IPI to set ctx->is_active.
         *
         * The IOC_ENABLE that is sure to follow the creation of a disabled
         * event will issue the IPI and reprogram the hardware.
         */
        if (__perf_effective_state(event) == PERF_EVENT_STATE_OFF &&
            ctx->nr_events && !is_cgroup_event(event)) {
                raw_spin_lock_irq(&ctx->lock);
                if (ctx->task == TASK_TOMBSTONE) {
                        raw_spin_unlock_irq(&ctx->lock);
                        return;
                }
                add_event_to_ctx(event, ctx);
                raw_spin_unlock_irq(&ctx->lock);
                return;
        }

        if (!task) {
                cpu_function_call(cpu, __perf_install_in_context, event);
                return;
        }

        /*
         * Should not happen, we validate the ctx is still alive before calling.
         */
        if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
                return;

        /*
         * Installing events is tricky because we cannot rely on ctx->is_active
         * to be set in case this is the nr_events 0 -> 1 transition.
         *
         * Instead we use task_curr(), which tells us if the task is running.
         * However, since we use task_curr() outside of rq::lock, we can race
         * against the actual state. This means the result can be wrong.
         *
         * If we get a false positive, we retry, this is harmless.
         *
         * If we get a false negative, things are complicated. If we are after
         * perf_event_context_sched_in() ctx::lock will serialize us, and the
         * value must be correct. If we're before, it doesn't matter since
         * perf_event_context_sched_in() will program the counter.
         *
         * However, this hinges on the remote context switch having observed
         * our task->perf_event_ctxp[] store, such that it will in fact take
         * ctx::lock in perf_event_context_sched_in().
         *
         * We do this by task_function_call(), if the IPI fails to hit the task
         * we know any future context switch of task must see the
         * perf_event_ctpx[] store.
         */

        /*
         * This smp_mb() orders the task->perf_event_ctxp[] store with the
         * task_cpu() load, such that if the IPI then does not find the task
         * running, a future context switch of that task must observe the
         * store.
         */
        smp_mb();
again:
        if (!task_function_call(task, __perf_install_in_context, event))
                return;

        raw_spin_lock_irq(&ctx->lock);
        task = ctx->task;
        if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
                /*
                 * Cannot happen because we already checked above (which also
                 * cannot happen), and we hold ctx->mutex, which serializes us
                 * against perf_event_exit_task_context().
                 */
                raw_spin_unlock_irq(&ctx->lock);
                return;
        }
        /*
         * If the task is not running, ctx->lock will avoid it becoming so,
         * thus we can safely install the event.
         */
        if (task_curr(task)) {
                raw_spin_unlock_irq(&ctx->lock);
                goto again;
        }
        add_event_to_ctx(event, ctx);
        raw_spin_unlock_irq(&ctx->lock);
}

/*
 * Cross CPU call to enable a performance event
 */
static void __perf_event_enable(struct perf_event *event,
                                struct perf_cpu_context *cpuctx,
                                struct perf_event_context *ctx,
                                void *info)
{
        struct perf_event *leader = event->group_leader;
        struct perf_event_context *task_ctx;

        if (event->state >= PERF_EVENT_STATE_INACTIVE ||
            event->state <= PERF_EVENT_STATE_ERROR)
                return;

        ctx_time_freeze(cpuctx, ctx);

        perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
        perf_cgroup_event_enable(event, ctx);

        if (!ctx->is_active)
                return;

        if (!event_filter_match(event))
                return;

        /*
         * If the event is in a group and isn't the group leader,
         * then don't put it on unless the group is on.
         */
        if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
                return;

        task_ctx = cpuctx->task_ctx;
        if (ctx->task)
                WARN_ON_ONCE(task_ctx != ctx);

        ctx_resched(cpuctx, task_ctx, event->pmu_ctx->pmu, get_event_type(event));
}

/*
 * Enable an event.
 *
 * If event->ctx is a cloned context, callers must make sure that
 * every task struct that event->ctx->task could possibly point to
 * remains valid.  This condition is satisfied when called through
 * perf_event_for_each_child or perf_event_for_each as described
 * for perf_event_disable.
 */
static void _perf_event_enable(struct perf_event *event)
{
        struct perf_event_context *ctx = event->ctx;

        raw_spin_lock_irq(&ctx->lock);
        if (event->state >= PERF_EVENT_STATE_INACTIVE ||
            event->state <  PERF_EVENT_STATE_ERROR) {
out:
                raw_spin_unlock_irq(&ctx->lock);
                return;
        }

        /*
         * If the event is in error state, clear that first.
         *
         * That way, if we see the event in error state below, we know that it
         * has gone back into error state, as distinct from the task having
         * been scheduled away before the cross-call arrived.
         */
        if (event->state == PERF_EVENT_STATE_ERROR) {
                /*
                 * Detached SIBLING events cannot leave ERROR state.
                 */
                if (event->event_caps & PERF_EV_CAP_SIBLING &&
                    event->group_leader == event)
                        goto out;

                event->state = PERF_EVENT_STATE_OFF;
        }
        raw_spin_unlock_irq(&ctx->lock);

        event_function_call(event, __perf_event_enable, NULL);
}

/*
 * See perf_event_disable();
 */
void perf_event_enable(struct perf_event *event)
{
        struct perf_event_context *ctx;

        ctx = perf_event_ctx_lock(event);
        _perf_event_enable(event);
        perf_event_ctx_unlock(event, ctx);
}
EXPORT_SYMBOL_GPL(perf_event_enable);

struct stop_event_data {
        struct perf_event        *event;
        unsigned int                restart;
};

static int __perf_event_stop(void *info)
{
        struct stop_event_data *sd = info;
        struct perf_event *event = sd->event;

        /* if it's already INACTIVE, do nothing */
        if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
                return 0;

        /* matches smp_wmb() in event_sched_in() */
        smp_rmb();

        /*
         * There is a window with interrupts enabled before we get here,
         * so we need to check again lest we try to stop another CPU's event.
         */
        if (READ_ONCE(event->oncpu) != smp_processor_id())
                return -EAGAIN;

        event->pmu->stop(event, PERF_EF_UPDATE);

        /*
         * May race with the actual stop (through perf_pmu_output_stop()),
         * but it is only used for events with AUX ring buffer, and such
         * events will refuse to restart because of rb::aux_mmap_count==0,
         * see comments in perf_aux_output_begin().
         *
         * Since this is happening on an event-local CPU, no trace is lost
         * while restarting.
         */
        if (sd->restart)
                event->pmu->start(event, 0);

        return 0;
}

static int perf_event_stop(struct perf_event *event, int restart)
{
        struct stop_event_data sd = {
                .event                = event,
                .restart        = restart,
        };
        int ret = 0;

        do {
                if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
                        return 0;

                /* matches smp_wmb() in event_sched_in() */
                smp_rmb();

                /*
                 * We only want to restart ACTIVE events, so if the event goes
                 * inactive here (event->oncpu==-1), there's nothing more to do;
                 * fall through with ret==-ENXIO.
                 */
                ret = cpu_function_call(READ_ONCE(event->oncpu),
                                        __perf_event_stop, &sd);
        } while (ret == -EAGAIN);

        return ret;
}

/*
 * In order to contain the amount of racy and tricky in the address filter
 * configuration management, it is a two part process:
 *
 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
 *      we update the addresses of corresponding vmas in
 *        event::addr_filter_ranges array and bump the event::addr_filters_gen;
 * (p2) when an event is scheduled in (pmu::add), it calls
 *      perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
 *      if the generation has changed since the previous call.
 *
 * If (p1) happens while the event is active, we restart it to force (p2).
 *
 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
 *     pre-existing mappings, called once when new filters arrive via SET_FILTER
 *     ioctl;
 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
 *     registered mapping, called for every new mmap(), with mm::mmap_lock down
 *     for reading;
 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
 *     of exec.
 */
void perf_event_addr_filters_sync(struct perf_event *event)
{
        struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);

        if (!has_addr_filter(event))
                return;

        raw_spin_lock(&ifh->lock);
        if (event->addr_filters_gen != event->hw.addr_filters_gen) {
                event->pmu->addr_filters_sync(event);
                event->hw.addr_filters_gen = event->addr_filters_gen;
        }
        raw_spin_unlock(&ifh->lock);
}
EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);

static int _perf_event_refresh(struct perf_event *event, int refresh)
{
        /*
         * not supported on inherited events
         */
        if (event->attr.inherit || !is_sampling_event(event))
                return -EINVAL;

        atomic_add(refresh, &event->event_limit);
        _perf_event_enable(event);

        return 0;
}

/*
 * See perf_event_disable()
 */
int perf_event_refresh(struct perf_event *event, int refresh)
{
        struct perf_event_context *ctx;
        int ret;

        ctx = perf_event_ctx_lock(event);
        ret = _perf_event_refresh(event, refresh);
        perf_event_ctx_unlock(event, ctx);

        return ret;
}
EXPORT_SYMBOL_GPL(perf_event_refresh);

static int perf_event_modify_breakpoint(struct perf_event *bp,
                                         struct perf_event_attr *attr)
{
        int err;

        _perf_event_disable(bp);

        err = modify_user_hw_breakpoint_check(bp, attr, true);

        if (!bp->attr.disabled)
                _perf_event_enable(bp);

        return err;
}

/*
 * Copy event-type-independent attributes that may be modified.
 */
static void perf_event_modify_copy_attr(struct perf_event_attr *to,
                                        const struct perf_event_attr *from)
{
        to->sig_data = from->sig_data;
}

static int perf_event_modify_attr(struct perf_event *event,
                                  struct perf_event_attr *attr)
{
        int (*func)(struct perf_event *, struct perf_event_attr *);
        struct perf_event *child;
        int err;

        if (event->attr.type != attr->type)
                return -EINVAL;

        switch (event->attr.type) {
        case PERF_TYPE_BREAKPOINT:
                func = perf_event_modify_breakpoint;
                break;
        default:
                /* Place holder for future additions. */
                return -EOPNOTSUPP;
        }

        WARN_ON_ONCE(event->ctx->parent_ctx);

        mutex_lock(&event->child_mutex);
        /*
         * Event-type-independent attributes must be copied before event-type
         * modification, which will validate that final attributes match the
         * source attributes after all relevant attributes have been copied.
         */
        perf_event_modify_copy_attr(&event->attr, attr);
        err = func(event, attr);
        if (err)
                goto out;
        list_for_each_entry(child, &event->child_list, child_list) {
                perf_event_modify_copy_attr(&child->attr, attr);
                err = func(child, attr);
                if (err)
                        goto out;
        }
out:
        mutex_unlock(&event->child_mutex);
        return err;
}

static void __pmu_ctx_sched_out(struct perf_event_pmu_context *pmu_ctx,
                                enum event_type_t event_type)
{
        struct perf_event_context *ctx = pmu_ctx->ctx;
        struct perf_event *event, *tmp;
        struct pmu *pmu = pmu_ctx->pmu;

        if (ctx->task && !(ctx->is_active & EVENT_ALL)) {
                struct perf_cpu_pmu_context *cpc = this_cpc(pmu);

                WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
                cpc->task_epc = NULL;
        }

        if (!(event_type & EVENT_ALL))
                return;

        perf_pmu_disable(pmu);
        if (event_type & EVENT_PINNED) {
                list_for_each_entry_safe(event, tmp,
                                         &pmu_ctx->pinned_active,
                                         active_list)
                        group_sched_out(event, ctx);
        }

        if (event_type & EVENT_FLEXIBLE) {
                list_for_each_entry_safe(event, tmp,
                                         &pmu_ctx->flexible_active,
                                         active_list)
                        group_sched_out(event, ctx);
                /*
                 * Since we cleared EVENT_FLEXIBLE, also clear
                 * rotate_necessary, is will be reset by
                 * ctx_flexible_sched_in() when needed.
                 */
                pmu_ctx->rotate_necessary = 0;
        }
        perf_pmu_enable(pmu);
}

/*
 * Be very careful with the @pmu argument since this will change ctx state.
 * The @pmu argument works for ctx_resched(), because that is symmetric in
 * ctx_sched_out() / ctx_sched_in() usage and the ctx state ends up invariant.
 *
 * However, if you were to be asymmetrical, you could end up with messed up
 * state, eg. ctx->is_active cleared even though most EPCs would still actually
 * be active.
 */
static void
ctx_sched_out(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_pmu_context *pmu_ctx;
        int is_active = ctx->is_active;
        bool cgroup = event_type & EVENT_CGROUP;

        event_type &= ~EVENT_CGROUP;

        lockdep_assert_held(&ctx->lock);

        if (likely(!ctx->nr_events)) {
                /*
                 * See __perf_remove_from_context().
                 */
                WARN_ON_ONCE(ctx->is_active);
                if (ctx->task)
                        WARN_ON_ONCE(cpuctx->task_ctx);
                return;
        }

        /*
         * Always update time if it was set; not only when it changes.
         * Otherwise we can 'forget' to update time for any but the last
         * context we sched out. For example:
         *
         *   ctx_sched_out(.event_type = EVENT_FLEXIBLE)
         *   ctx_sched_out(.event_type = EVENT_PINNED)
         *
         * would only update time for the pinned events.
         */
        __ctx_time_update(cpuctx, ctx, ctx == &cpuctx->ctx);

        /*
         * CPU-release for the below ->is_active store,
         * see __load_acquire() in perf_event_time_now()
         */
        barrier();
        ctx->is_active &= ~event_type;

        if (!(ctx->is_active & EVENT_ALL)) {
                /*
                 * For FROZEN, preserve TIME|FROZEN such that perf_event_time_now()
                 * does not observe a hole. perf_ctx_unlock() will clean up.
                 */
                if (ctx->is_active & EVENT_FROZEN)
                        ctx->is_active &= EVENT_TIME_FROZEN;
                else
                        ctx->is_active = 0;
        }

        if (ctx->task) {
                WARN_ON_ONCE(cpuctx->task_ctx != ctx);
                if (!(ctx->is_active & EVENT_ALL))
                        cpuctx->task_ctx = NULL;
        }

        is_active ^= ctx->is_active; /* changed bits */

        for_each_epc(pmu_ctx, ctx, pmu, cgroup)
                __pmu_ctx_sched_out(pmu_ctx, is_active);
}

/*
 * Test whether two contexts are equivalent, i.e. whether they have both been
 * cloned from the same version of the same context.
 *
 * Equivalence is measured using a generation number in the context that is
 * incremented on each modification to it; see unclone_ctx(), list_add_event()
 * and list_del_event().
 */
static int context_equiv(struct perf_event_context *ctx1,
                         struct perf_event_context *ctx2)
{
        lockdep_assert_held(&ctx1->lock);
        lockdep_assert_held(&ctx2->lock);

        /* Pinning disables the swap optimization */
        if (ctx1->pin_count || ctx2->pin_count)
                return 0;

        /* If ctx1 is the parent of ctx2 */
        if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
                return 1;

        /* If ctx2 is the parent of ctx1 */
        if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
                return 1;

        /*
         * If ctx1 and ctx2 have the same parent; we flatten the parent
         * hierarchy, see perf_event_init_context().
         */
        if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
                        ctx1->parent_gen == ctx2->parent_gen)
                return 1;

        /* Unmatched */
        return 0;
}

static void __perf_event_sync_stat(struct perf_event *event,
                                     struct perf_event *next_event)
{
        u64 value;

        if (!event->attr.inherit_stat)
                return;

        /*
         * Update the event value, we cannot use perf_event_read()
         * because we're in the middle of a context switch and have IRQs
         * disabled, which upsets smp_call_function_single(), however
         * we know the event must be on the current CPU, therefore we
         * don't need to use it.
         */
        perf_pmu_read(event);

        perf_event_update_time(event);

        /*
         * In order to keep per-task stats reliable we need to flip the event
         * values when we flip the contexts.
         */
        value = local64_read(&next_event->count);
        value = local64_xchg(&event->count, value);
        local64_set(&next_event->count, value);

        swap(event->total_time_enabled, next_event->total_time_enabled);
        swap(event->total_time_running, next_event->total_time_running);

        /*
         * Since we swizzled the values, update the user visible data too.
         */
        perf_event_update_userpage(event);
        perf_event_update_userpage(next_event);
}

static void perf_event_sync_stat(struct perf_event_context *ctx,
                                   struct perf_event_context *next_ctx)
{
        struct perf_event *event, *next_event;

        if (!ctx->nr_stat)
                return;

        update_context_time(ctx);

        event = list_first_entry(&ctx->event_list,
                                   struct perf_event, event_entry);

        next_event = list_first_entry(&next_ctx->event_list,
                                        struct perf_event, event_entry);

        while (&event->event_entry != &ctx->event_list &&
               &next_event->event_entry != &next_ctx->event_list) {

                __perf_event_sync_stat(event, next_event);

                event = list_next_entry(event, event_entry);
                next_event = list_next_entry(next_event, event_entry);
        }
}

static void perf_ctx_sched_task_cb(struct perf_event_context *ctx,
                                   struct task_struct *task, bool sched_in)
{
        struct perf_event_pmu_context *pmu_ctx;
        struct perf_cpu_pmu_context *cpc;

        list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
                cpc = this_cpc(pmu_ctx->pmu);

                if (cpc->sched_cb_usage && pmu_ctx->pmu->sched_task)
                        pmu_ctx->pmu->sched_task(pmu_ctx, task, sched_in);
        }
}

static void
perf_event_context_sched_out(struct task_struct *task, struct task_struct *next)
{
        struct perf_event_context *ctx = task->perf_event_ctxp;
        struct perf_event_context *next_ctx;
        struct perf_event_context *parent, *next_parent;
        int do_switch = 1;

        if (likely(!ctx))
                return;

        rcu_read_lock();
        next_ctx = rcu_dereference(next->perf_event_ctxp);
        if (!next_ctx)
                goto unlock;

        parent = rcu_dereference(ctx->parent_ctx);
        next_parent = rcu_dereference(next_ctx->parent_ctx);

        /* If neither context have a parent context; they cannot be clones. */
        if (!parent && !next_parent)
                goto unlock;

        if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
                /*
                 * Looks like the two contexts are clones, so we might be
                 * able to optimize the context switch.  We lock both
                 * contexts and check that they are clones under the
                 * lock (including re-checking that neither has been
                 * uncloned in the meantime).  It doesn't matter which
                 * order we take the locks because no other cpu could
                 * be trying to lock both of these tasks.
                 */
                raw_spin_lock(&ctx->lock);
                raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
                if (context_equiv(ctx, next_ctx)) {

                        perf_ctx_disable(ctx, false);

                        /* PMIs are disabled; ctx->nr_no_switch_fast is stable. */
                        if (local_read(&ctx->nr_no_switch_fast) ||
                            local_read(&next_ctx->nr_no_switch_fast)) {
                                /*
                                 * Must not swap out ctx when there's pending
                                 * events that rely on the ctx->task relation.
                                 *
                                 * Likewise, when a context contains inherit +
                                 * SAMPLE_READ events they should be switched
                                 * out using the slow path so that they are
                                 * treated as if they were distinct contexts.
                                 */
                                raw_spin_unlock(&next_ctx->lock);
                                rcu_read_unlock();
                                goto inside_switch;
                        }

                        WRITE_ONCE(ctx->task, next);
                        WRITE_ONCE(next_ctx->task, task);

                        perf_ctx_sched_task_cb(ctx, task, false);

                        perf_ctx_enable(ctx, false);

                        /*
                         * RCU_INIT_POINTER here is safe because we've not
                         * modified the ctx and the above modification of
                         * ctx->task is immaterial since this value is
                         * always verified under ctx->lock which we're now
                         * holding.
                         */
                        RCU_INIT_POINTER(task->perf_event_ctxp, next_ctx);
                        RCU_INIT_POINTER(next->perf_event_ctxp, ctx);

                        do_switch = 0;

                        perf_event_sync_stat(ctx, next_ctx);
                }
                raw_spin_unlock(&next_ctx->lock);
                raw_spin_unlock(&ctx->lock);
        }
unlock:
        rcu_read_unlock();

        if (do_switch) {
                raw_spin_lock(&ctx->lock);
                perf_ctx_disable(ctx, false);

inside_switch:
                perf_ctx_sched_task_cb(ctx, task, false);
                task_ctx_sched_out(ctx, NULL, EVENT_ALL);

                perf_ctx_enable(ctx, false);
                raw_spin_unlock(&ctx->lock);
        }
}

static DEFINE_PER_CPU(struct list_head, sched_cb_list);
static DEFINE_PER_CPU(int, perf_sched_cb_usages);

void perf_sched_cb_dec(struct pmu *pmu)
{
        struct perf_cpu_pmu_context *cpc = this_cpc(pmu);

        this_cpu_dec(perf_sched_cb_usages);
        barrier();

        if (!--cpc->sched_cb_usage)
                list_del(&cpc->sched_cb_entry);
}


void perf_sched_cb_inc(struct pmu *pmu)
{
        struct perf_cpu_pmu_context *cpc = this_cpc(pmu);

        if (!cpc->sched_cb_usage++)
                list_add(&cpc->sched_cb_entry, this_cpu_ptr(&sched_cb_list));

        barrier();
        this_cpu_inc(perf_sched_cb_usages);
}

/*
 * This function provides the context switch callback to the lower code
 * layer. It is invoked ONLY when the context switch callback is enabled.
 *
 * This callback is relevant even to per-cpu events; for example multi event
 * PEBS requires this to provide PID/TID information. This requires we flush
 * all queued PEBS records before we context switch to a new task.
 */
static void __perf_pmu_sched_task(struct perf_cpu_pmu_context *cpc,
                                  struct task_struct *task, bool sched_in)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct pmu *pmu;

        pmu = cpc->epc.pmu;

        /* software PMUs will not have sched_task */
        if (WARN_ON_ONCE(!pmu->sched_task))
                return;

        perf_ctx_lock(cpuctx, cpuctx->task_ctx);
        perf_pmu_disable(pmu);

        pmu->sched_task(cpc->task_epc, task, sched_in);

        perf_pmu_enable(pmu);
        perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
}

static void perf_pmu_sched_task(struct task_struct *prev,
                                struct task_struct *next,
                                bool sched_in)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_cpu_pmu_context *cpc;

        /* cpuctx->task_ctx will be handled in perf_event_context_sched_in/out */
        if (prev == next || cpuctx->task_ctx)
                return;

        list_for_each_entry(cpc, this_cpu_ptr(&sched_cb_list), sched_cb_entry)
                __perf_pmu_sched_task(cpc, sched_in ? next : prev, sched_in);
}

static void perf_event_switch(struct task_struct *task,
                              struct task_struct *next_prev, bool sched_in);

/*
 * Called from scheduler to remove the events of the current task,
 * with interrupts disabled.
 *
 * We stop each event and update the event value in event->count.
 *
 * This does not protect us against NMI, but disable()
 * sets the disabled bit in the control field of event _before_
 * accessing the event control register. If a NMI hits, then it will
 * not restart the event.
 */
void __perf_event_task_sched_out(struct task_struct *task,
                                 struct task_struct *next)
{
        if (__this_cpu_read(perf_sched_cb_usages))
                perf_pmu_sched_task(task, next, false);

        if (atomic_read(&nr_switch_events))
                perf_event_switch(task, next, false);

        perf_event_context_sched_out(task, next);

        /*
         * if cgroup events exist on this CPU, then we need
         * to check if we have to switch out PMU state.
         * cgroup event are system-wide mode only
         */
        perf_cgroup_switch(next);
}

static bool perf_less_group_idx(const void *l, const void *r, void __always_unused *args)
{
        const struct perf_event *le = *(const struct perf_event **)l;
        const struct perf_event *re = *(const struct perf_event **)r;

        return le->group_index < re->group_index;
}

DEFINE_MIN_HEAP(struct perf_event *, perf_event_min_heap);

static const struct min_heap_callbacks perf_min_heap = {
        .less = perf_less_group_idx,
        .swp = NULL,
};

static void __heap_add(struct perf_event_min_heap *heap, struct perf_event *event)
{
        struct perf_event **itrs = heap->data;

        if (event) {
                itrs[heap->nr] = event;
                heap->nr++;
        }
}

static void __link_epc(struct perf_event_pmu_context *pmu_ctx)
{
        struct perf_cpu_pmu_context *cpc;

        if (!pmu_ctx->ctx->task)
                return;

        cpc = this_cpc(pmu_ctx->pmu);
        WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
        cpc->task_epc = pmu_ctx;
}

static noinline int visit_groups_merge(struct perf_event_context *ctx,
                                struct perf_event_groups *groups, int cpu,
                                struct pmu *pmu,
                                int (*func)(struct perf_event *, void *),
                                void *data)
{
#ifdef CONFIG_CGROUP_PERF
        struct cgroup_subsys_state *css = NULL;
#endif
        struct perf_cpu_context *cpuctx = NULL;
        /* Space for per CPU and/or any CPU event iterators. */
        struct perf_event *itrs[2];
        struct perf_event_min_heap event_heap;
        struct perf_event **evt;
        int ret;

        if (pmu->filter && pmu->filter(pmu, cpu))
                return 0;

        if (!ctx->task) {
                cpuctx = this_cpu_ptr(&perf_cpu_context);
                event_heap = (struct perf_event_min_heap){
                        .data = cpuctx->heap,
                        .nr = 0,
                        .size = cpuctx->heap_size,
                };

                lockdep_assert_held(&cpuctx->ctx.lock);

#ifdef CONFIG_CGROUP_PERF
                if (cpuctx->cgrp)
                        css = &cpuctx->cgrp->css;
#endif
        } else {
                event_heap = (struct perf_event_min_heap){
                        .data = itrs,
                        .nr = 0,
                        .size = ARRAY_SIZE(itrs),
                };
                /* Events not within a CPU context may be on any CPU. */
                __heap_add(&event_heap, perf_event_groups_first(groups, -1, pmu, NULL));
        }
        evt = event_heap.data;

        __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, NULL));

#ifdef CONFIG_CGROUP_PERF
        for (; css; css = css->parent)
                __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, css->cgroup));
#endif

        if (event_heap.nr) {
                __link_epc((*evt)->pmu_ctx);
                perf_assert_pmu_disabled((*evt)->pmu_ctx->pmu);
        }

        min_heapify_all_inline(&event_heap, &perf_min_heap, NULL);

        while (event_heap.nr) {
                ret = func(*evt, data);
                if (ret)
                        return ret;

                *evt = perf_event_groups_next(*evt, pmu);
                if (*evt)
                        min_heap_sift_down_inline(&event_heap, 0, &perf_min_heap, NULL);
                else
                        min_heap_pop_inline(&event_heap, &perf_min_heap, NULL);
        }

        return 0;
}

/*
 * Because the userpage is strictly per-event (there is no concept of context,
 * so there cannot be a context indirection), every userpage must be updated
 * when context time starts :-(
 *
 * IOW, we must not miss EVENT_TIME edges.
 */
static inline bool event_update_userpage(struct perf_event *event)
{
        if (likely(!refcount_read(&event->mmap_count)))
                return false;

        perf_event_update_time(event);
        perf_event_update_userpage(event);

        return true;
}

static inline void group_update_userpage(struct perf_event *group_event)
{
        struct perf_event *event;

        if (!event_update_userpage(group_event))
                return;

        for_each_sibling_event(event, group_event)
                event_update_userpage(event);
}

static int merge_sched_in(struct perf_event *event, void *data)
{
        struct perf_event_context *ctx = event->ctx;
        int *can_add_hw = data;

        if (event->state <= PERF_EVENT_STATE_OFF)
                return 0;

        if (!event_filter_match(event))
                return 0;

        if (group_can_go_on(event, *can_add_hw)) {
                if (!group_sched_in(event, ctx))
                        list_add_tail(&event->active_list, get_event_list(event));
        }

        if (event->state == PERF_EVENT_STATE_INACTIVE) {
                *can_add_hw = 0;
                if (event->attr.pinned) {
                        perf_cgroup_event_disable(event, ctx);
                        perf_event_set_state(event, PERF_EVENT_STATE_ERROR);

                        if (*perf_event_fasync(event))
                                event->pending_kill = POLL_ERR;

                        perf_event_wakeup(event);
                } else {
                        struct perf_cpu_pmu_context *cpc = this_cpc(event->pmu_ctx->pmu);

                        event->pmu_ctx->rotate_necessary = 1;
                        perf_mux_hrtimer_restart(cpc);
                        group_update_userpage(event);
                }
        }

        return 0;
}

static void pmu_groups_sched_in(struct perf_event_context *ctx,
                                struct perf_event_groups *groups,
                                struct pmu *pmu)
{
        int can_add_hw = 1;
        visit_groups_merge(ctx, groups, smp_processor_id(), pmu,
                           merge_sched_in, &can_add_hw);
}

static void __pmu_ctx_sched_in(struct perf_event_pmu_context *pmu_ctx,
                               enum event_type_t event_type)
{
        struct perf_event_context *ctx = pmu_ctx->ctx;

        if (event_type & EVENT_PINNED)
                pmu_groups_sched_in(ctx, &ctx->pinned_groups, pmu_ctx->pmu);
        if (event_type & EVENT_FLEXIBLE)
                pmu_groups_sched_in(ctx, &ctx->flexible_groups, pmu_ctx->pmu);
}

static void
ctx_sched_in(struct perf_event_context *ctx, struct pmu *pmu, enum event_type_t event_type)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_pmu_context *pmu_ctx;
        int is_active = ctx->is_active;
        bool cgroup = event_type & EVENT_CGROUP;

        event_type &= ~EVENT_CGROUP;

        lockdep_assert_held(&ctx->lock);

        if (likely(!ctx->nr_events))
                return;

        if (!(is_active & EVENT_TIME)) {
                /* start ctx time */
                __update_context_time(ctx, false);
                perf_cgroup_set_timestamp(cpuctx);
                /*
                 * CPU-release for the below ->is_active store,
                 * see __load_acquire() in perf_event_time_now()
                 */
                barrier();
        }

        ctx->is_active |= (event_type | EVENT_TIME);
        if (ctx->task) {
                if (!(is_active & EVENT_ALL))
                        cpuctx->task_ctx = ctx;
                else
                        WARN_ON_ONCE(cpuctx->task_ctx != ctx);
        }

        is_active ^= ctx->is_active; /* changed bits */

        /*
         * First go through the list and put on any pinned groups
         * in order to give them the best chance of going on.
         */
        if (is_active & EVENT_PINNED) {
                for_each_epc(pmu_ctx, ctx, pmu, cgroup)
                        __pmu_ctx_sched_in(pmu_ctx, EVENT_PINNED);
        }

        /* Then walk through the lower prio flexible groups */
        if (is_active & EVENT_FLEXIBLE) {
                for_each_epc(pmu_ctx, ctx, pmu, cgroup)
                        __pmu_ctx_sched_in(pmu_ctx, EVENT_FLEXIBLE);
        }
}

static void perf_event_context_sched_in(struct task_struct *task)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_context *ctx;

        rcu_read_lock();
        ctx = rcu_dereference(task->perf_event_ctxp);
        if (!ctx)
                goto rcu_unlock;

        if (cpuctx->task_ctx == ctx) {
                perf_ctx_lock(cpuctx, ctx);
                perf_ctx_disable(ctx, false);

                perf_ctx_sched_task_cb(ctx, task, true);

                perf_ctx_enable(ctx, false);
                perf_ctx_unlock(cpuctx, ctx);
                goto rcu_unlock;
        }

        perf_ctx_lock(cpuctx, ctx);
        /*
         * We must check ctx->nr_events while holding ctx->lock, such
         * that we serialize against perf_install_in_context().
         */
        if (!ctx->nr_events)
                goto unlock;

        perf_ctx_disable(ctx, false);
        /*
         * We want to keep the following priority order:
         * cpu pinned (that don't need to move), task pinned,
         * cpu flexible, task flexible.
         *
         * However, if task's ctx is not carrying any pinned
         * events, no need to flip the cpuctx's events around.
         */
        if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree)) {
                perf_ctx_disable(&cpuctx->ctx, false);
                ctx_sched_out(&cpuctx->ctx, NULL, EVENT_FLEXIBLE);
        }

        perf_event_sched_in(cpuctx, ctx, NULL);

        perf_ctx_sched_task_cb(cpuctx->task_ctx, task, true);

        if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree))
                perf_ctx_enable(&cpuctx->ctx, false);

        perf_ctx_enable(ctx, false);

unlock:
        perf_ctx_unlock(cpuctx, ctx);
rcu_unlock:
        rcu_read_unlock();
}

/*
 * Called from scheduler to add the events of the current task
 * with interrupts disabled.
 *
 * We restore the event value and then enable it.
 *
 * This does not protect us against NMI, but enable()
 * sets the enabled bit in the control field of event _before_
 * accessing the event control register. If a NMI hits, then it will
 * keep the event running.
 */
void __perf_event_task_sched_in(struct task_struct *prev,
                                struct task_struct *task)
{
        perf_event_context_sched_in(task);

        if (atomic_read(&nr_switch_events))
                perf_event_switch(task, prev, true);

        if (__this_cpu_read(perf_sched_cb_usages))
                perf_pmu_sched_task(prev, task, true);
}

static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
{
        u64 frequency = event->attr.sample_freq;
        u64 sec = NSEC_PER_SEC;
        u64 divisor, dividend;

        int count_fls, nsec_fls, frequency_fls, sec_fls;

        count_fls = fls64(count);
        nsec_fls = fls64(nsec);
        frequency_fls = fls64(frequency);
        sec_fls = 30;

        /*
         * We got @count in @nsec, with a target of sample_freq HZ
         * the target period becomes:
         *
         *             @count * 10^9
         * period = -------------------
         *          @nsec * sample_freq
         *
         */

        /*
         * Reduce accuracy by one bit such that @a and @b converge
         * to a similar magnitude.
         */
#define REDUCE_FLS(a, b)                \
do {                                        \
        if (a##_fls > b##_fls) {        \
                a >>= 1;                \
                a##_fls--;                \
        } else {                        \
                b >>= 1;                \
                b##_fls--;                \
        }                                \
} while (0)

        /*
         * Reduce accuracy until either term fits in a u64, then proceed with
         * the other, so that finally we can do a u64/u64 division.
         */
        while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
                REDUCE_FLS(nsec, frequency);
                REDUCE_FLS(sec, count);
        }

        if (count_fls + sec_fls > 64) {
                divisor = nsec * frequency;

                while (count_fls + sec_fls > 64) {
                        REDUCE_FLS(count, sec);
                        divisor >>= 1;
                }

                dividend = count * sec;
        } else {
                dividend = count * sec;

                while (nsec_fls + frequency_fls > 64) {
                        REDUCE_FLS(nsec, frequency);
                        dividend >>= 1;
                }

                divisor = nsec * frequency;
        }

        if (!divisor)
                return dividend;

        return div64_u64(dividend, divisor);
}

static DEFINE_PER_CPU(int, perf_throttled_count);
static DEFINE_PER_CPU(u64, perf_throttled_seq);

static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
{
        struct hw_perf_event *hwc = &event->hw;
        s64 period, sample_period;
        s64 delta;

        period = perf_calculate_period(event, nsec, count);

        delta = (s64)(period - hwc->sample_period);
        if (delta >= 0)
                delta += 7;
        else
                delta -= 7;
        delta /= 8; /* low pass filter */

        sample_period = hwc->sample_period + delta;

        if (!sample_period)
                sample_period = 1;

        hwc->sample_period = sample_period;

        if (local64_read(&hwc->period_left) > 8*sample_period) {
                if (disable)
                        event->pmu->stop(event, PERF_EF_UPDATE);

                local64_set(&hwc->period_left, 0);

                if (disable)
                        event->pmu->start(event, PERF_EF_RELOAD);
        }
}

static void perf_adjust_freq_unthr_events(struct list_head *event_list)
{
        struct perf_event *event;
        struct hw_perf_event *hwc;
        u64 now, period = TICK_NSEC;
        s64 delta;

        list_for_each_entry(event, event_list, active_list) {
                if (event->state != PERF_EVENT_STATE_ACTIVE)
                        continue;

                // XXX use visit thingy to avoid the -1,cpu match
                if (!event_filter_match(event))
                        continue;

                hwc = &event->hw;

                if (hwc->interrupts == MAX_INTERRUPTS)
                        perf_event_unthrottle_group(event, is_event_in_freq_mode(event));

                if (!is_event_in_freq_mode(event))
                        continue;

                /*
                 * stop the event and update event->count
                 */
                event->pmu->stop(event, PERF_EF_UPDATE);

                now = local64_read(&event->count);
                delta = now - hwc->freq_count_stamp;
                hwc->freq_count_stamp = now;

                /*
                 * restart the event
                 * reload only if value has changed
                 * we have stopped the event so tell that
                 * to perf_adjust_period() to avoid stopping it
                 * twice.
                 */
                if (delta > 0)
                        perf_adjust_period(event, period, delta, false);

                event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
        }
}

/*
 * combine freq adjustment with unthrottling to avoid two passes over the
 * events. At the same time, make sure, having freq events does not change
 * the rate of unthrottling as that would introduce bias.
 */
static void
perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
{
        struct perf_event_pmu_context *pmu_ctx;

        /*
         * only need to iterate over all events iff:
         * - context have events in frequency mode (needs freq adjust)
         * - there are events to unthrottle on this cpu
         */
        if (!(ctx->nr_freq || unthrottle))
                return;

        raw_spin_lock(&ctx->lock);

        list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
                if (!(pmu_ctx->nr_freq || unthrottle))
                        continue;
                if (!perf_pmu_ctx_is_active(pmu_ctx))
                        continue;
                if (pmu_ctx->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT)
                        continue;

                perf_pmu_disable(pmu_ctx->pmu);
                perf_adjust_freq_unthr_events(&pmu_ctx->pinned_active);
                perf_adjust_freq_unthr_events(&pmu_ctx->flexible_active);
                perf_pmu_enable(pmu_ctx->pmu);
        }

        raw_spin_unlock(&ctx->lock);
}

/*
 * Move @event to the tail of the @ctx's elegible events.
 */
static void rotate_ctx(struct perf_event_context *ctx, struct perf_event *event)
{
        /*
         * Rotate the first entry last of non-pinned groups. Rotation might be
         * disabled by the inheritance code.
         */
        if (ctx->rotate_disable)
                return;

        perf_event_groups_delete(&ctx->flexible_groups, event);
        perf_event_groups_insert(&ctx->flexible_groups, event);
}

/* pick an event from the flexible_groups to rotate */
static inline struct perf_event *
ctx_event_to_rotate(struct perf_event_pmu_context *pmu_ctx)
{
        struct perf_event *event;
        struct rb_node *node;
        struct rb_root *tree;
        struct __group_key key = {
                .pmu = pmu_ctx->pmu,
        };

        /* pick the first active flexible event */
        event = list_first_entry_or_null(&pmu_ctx->flexible_active,
                                         struct perf_event, active_list);
        if (event)
                goto out;

        /* if no active flexible event, pick the first event */
        tree = &pmu_ctx->ctx->flexible_groups.tree;

        if (!pmu_ctx->ctx->task) {
                key.cpu = smp_processor_id();

                node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
                if (node)
                        event = __node_2_pe(node);
                goto out;
        }

        key.cpu = -1;
        node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
        if (node) {
                event = __node_2_pe(node);
                goto out;
        }

        key.cpu = smp_processor_id();
        node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
        if (node)
                event = __node_2_pe(node);

out:
        /*
         * Unconditionally clear rotate_necessary; if ctx_flexible_sched_in()
         * finds there are unschedulable events, it will set it again.
         */
        pmu_ctx->rotate_necessary = 0;

        return event;
}

static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_pmu_context *cpu_epc, *task_epc = NULL;
        struct perf_event *cpu_event = NULL, *task_event = NULL;
        int cpu_rotate, task_rotate;
        struct pmu *pmu;

        /*
         * Since we run this from IRQ context, nobody can install new
         * events, thus the event count values are stable.
         */

        cpu_epc = &cpc->epc;
        pmu = cpu_epc->pmu;
        task_epc = cpc->task_epc;

        cpu_rotate = cpu_epc->rotate_necessary;
        task_rotate = task_epc ? task_epc->rotate_necessary : 0;

        if (!(cpu_rotate || task_rotate))
                return false;

        perf_ctx_lock(cpuctx, cpuctx->task_ctx);
        perf_pmu_disable(pmu);

        if (task_rotate)
                task_event = ctx_event_to_rotate(task_epc);
        if (cpu_rotate)
                cpu_event = ctx_event_to_rotate(cpu_epc);

        /*
         * As per the order given at ctx_resched() first 'pop' task flexible
         * and then, if needed CPU flexible.
         */
        if (task_event || (task_epc && cpu_event)) {
                update_context_time(task_epc->ctx);
                __pmu_ctx_sched_out(task_epc, EVENT_FLEXIBLE);
        }

        if (cpu_event) {
                update_context_time(&cpuctx->ctx);
                __pmu_ctx_sched_out(cpu_epc, EVENT_FLEXIBLE);
                rotate_ctx(&cpuctx->ctx, cpu_event);
                __pmu_ctx_sched_in(cpu_epc, EVENT_FLEXIBLE);
        }

        if (task_event)
                rotate_ctx(task_epc->ctx, task_event);

        if (task_event || (task_epc && cpu_event))
                __pmu_ctx_sched_in(task_epc, EVENT_FLEXIBLE);

        perf_pmu_enable(pmu);
        perf_ctx_unlock(cpuctx, cpuctx->task_ctx);

        return true;
}

void perf_event_task_tick(void)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_context *ctx;
        int throttled;

        lockdep_assert_irqs_disabled();

        __this_cpu_inc(perf_throttled_seq);
        throttled = __this_cpu_xchg(perf_throttled_count, 0);
        tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);

        perf_adjust_freq_unthr_context(&cpuctx->ctx, !!throttled);

        rcu_read_lock();
        ctx = rcu_dereference(current->perf_event_ctxp);
        if (ctx)
                perf_adjust_freq_unthr_context(ctx, !!throttled);
        rcu_read_unlock();
}

static int event_enable_on_exec(struct perf_event *event,
                                struct perf_event_context *ctx)
{
        if (!event->attr.enable_on_exec)
                return 0;

        event->attr.enable_on_exec = 0;
        if (event->state >= PERF_EVENT_STATE_INACTIVE)
                return 0;

        perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);

        return 1;
}

/*
 * Enable all of a task's events that have been marked enable-on-exec.
 * This expects task == current.
 */
static void perf_event_enable_on_exec(struct perf_event_context *ctx)
{
        struct perf_event_context *clone_ctx = NULL;
        enum event_type_t event_type = 0;
        struct perf_cpu_context *cpuctx;
        struct perf_event *event;
        unsigned long flags;
        int enabled = 0;

        local_irq_save(flags);
        if (WARN_ON_ONCE(current->perf_event_ctxp != ctx))
                goto out;

        if (!ctx->nr_events)
                goto out;

        cpuctx = this_cpu_ptr(&perf_cpu_context);
        perf_ctx_lock(cpuctx, ctx);
        ctx_time_freeze(cpuctx, ctx);

        list_for_each_entry(event, &ctx->event_list, event_entry) {
                enabled |= event_enable_on_exec(event, ctx);
                event_type |= get_event_type(event);
        }

        /*
         * Unclone and reschedule this context if we enabled any event.
         */
        if (enabled) {
                clone_ctx = unclone_ctx(ctx);
                ctx_resched(cpuctx, ctx, NULL, event_type);
        }
        perf_ctx_unlock(cpuctx, ctx);

out:
        local_irq_restore(flags);

        if (clone_ctx)
                put_ctx(clone_ctx);
}

static void perf_remove_from_owner(struct perf_event *event);
static void perf_event_exit_event(struct perf_event *event,
                                  struct perf_event_context *ctx,
                                  bool revoke);

/*
 * Removes all events from the current task that have been marked
 * remove-on-exec, and feeds their values back to parent events.
 */
static void perf_event_remove_on_exec(struct perf_event_context *ctx)
{
        struct perf_event_context *clone_ctx = NULL;
        struct perf_event *event, *next;
        unsigned long flags;
        bool modified = false;

        mutex_lock(&ctx->mutex);

        if (WARN_ON_ONCE(ctx->task != current))
                goto unlock;

        list_for_each_entry_safe(event, next, &ctx->event_list, event_entry) {
                if (!event->attr.remove_on_exec)
                        continue;

                if (!is_kernel_event(event))
                        perf_remove_from_owner(event);

                modified = true;

                perf_event_exit_event(event, ctx, false);
        }

        raw_spin_lock_irqsave(&ctx->lock, flags);
        if (modified)
                clone_ctx = unclone_ctx(ctx);
        raw_spin_unlock_irqrestore(&ctx->lock, flags);

unlock:
        mutex_unlock(&ctx->mutex);

        if (clone_ctx)
                put_ctx(clone_ctx);
}

struct perf_read_data {
        struct perf_event *event;
        bool group;
        int ret;
};

static inline const struct cpumask *perf_scope_cpu_topology_cpumask(unsigned int scope, int cpu);

static int __perf_event_read_cpu(struct perf_event *event, int event_cpu)
{
        int local_cpu = smp_processor_id();
        u16 local_pkg, event_pkg;

        if ((unsigned)event_cpu >= nr_cpu_ids)
                return event_cpu;

        if (event->group_caps & PERF_EV_CAP_READ_SCOPE) {
                const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(event->pmu->scope, event_cpu);

                if (cpumask && cpumask_test_cpu(local_cpu, cpumask))
                        return local_cpu;
        }

        if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) {
                event_pkg = topology_physical_package_id(event_cpu);
                local_pkg = topology_physical_package_id(local_cpu);

                if (event_pkg == local_pkg)
                        return local_cpu;
        }

        return event_cpu;
}

/*
 * Cross CPU call to read the hardware event
 */
static void __perf_event_read(void *info)
{
        struct perf_read_data *data = info;
        struct perf_event *sub, *event = data->event;
        struct perf_event_context *ctx = event->ctx;
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct pmu *pmu = event->pmu;

        /*
         * If this is a task context, we need to check whether it is
         * the current task context of this cpu.  If not it has been
         * scheduled out before the smp call arrived.  In that case
         * event->count would have been updated to a recent sample
         * when the event was scheduled out.
         */
        if (ctx->task && cpuctx->task_ctx != ctx)
                return;

        raw_spin_lock(&ctx->lock);
        ctx_time_update_event(ctx, event);

        perf_event_update_time(event);
        if (data->group)
                perf_event_update_sibling_time(event);

        if (event->state != PERF_EVENT_STATE_ACTIVE)
                goto unlock;

        if (!data->group) {
                pmu->read(event);
                data->ret = 0;
                goto unlock;
        }

        pmu->start_txn(pmu, PERF_PMU_TXN_READ);

        pmu->read(event);

        for_each_sibling_event(sub, event)
                perf_pmu_read(sub);

        data->ret = pmu->commit_txn(pmu);

unlock:
        raw_spin_unlock(&ctx->lock);
}

static inline u64 perf_event_count(struct perf_event *event, bool self)
{
        if (self)
                return local64_read(&event->count);

        return local64_read(&event->count) + atomic64_read(&event->child_count);
}

static void calc_timer_values(struct perf_event *event,
                                u64 *now,
                                u64 *enabled,
                                u64 *running)
{
        u64 ctx_time;

        *now = perf_clock();
        ctx_time = perf_event_time_now(event, *now);
        __perf_update_times(event, ctx_time, enabled, running);
}

/*
 * NMI-safe method to read a local event, that is an event that
 * is:
 *   - either for the current task, or for this CPU
 *   - does not have inherit set, for inherited task events
 *     will not be local and we cannot read them atomically
 *   - must not have a pmu::count method
 */
int perf_event_read_local(struct perf_event *event, u64 *value,
                          u64 *enabled, u64 *running)
{
        unsigned long flags;
        int event_oncpu;
        int event_cpu;
        int ret = 0;

        /*
         * Disabling interrupts avoids all counter scheduling (context
         * switches, timer based rotation and IPIs).
         */
        local_irq_save(flags);

        /*
         * It must not be an event with inherit set, we cannot read
         * all child counters from atomic context.
         */
        if (event->attr.inherit) {
                ret = -EOPNOTSUPP;
                goto out;
        }

        /* If this is a per-task event, it must be for current */
        if ((event->attach_state & PERF_ATTACH_TASK) &&
            event->hw.target != current) {
                ret = -EINVAL;
                goto out;
        }

        /*
         * Get the event CPU numbers, and adjust them to local if the event is
         * a per-package event that can be read locally
         */
        event_oncpu = __perf_event_read_cpu(event, event->oncpu);
        event_cpu = __perf_event_read_cpu(event, event->cpu);

        /* If this is a per-CPU event, it must be for this CPU */
        if (!(event->attach_state & PERF_ATTACH_TASK) &&
            event_cpu != smp_processor_id()) {
                ret = -EINVAL;
                goto out;
        }

        /* If this is a pinned event it must be running on this CPU */
        if (event->attr.pinned && event_oncpu != smp_processor_id()) {
                ret = -EBUSY;
                goto out;
        }

        /*
         * If the event is currently on this CPU, its either a per-task event,
         * or local to this CPU. Furthermore it means its ACTIVE (otherwise
         * oncpu == -1).
         */
        if (event_oncpu == smp_processor_id())
                event->pmu->read(event);

        *value = local64_read(&event->count);
        if (enabled || running) {
                u64 __enabled, __running, __now;

                calc_timer_values(event, &__now, &__enabled, &__running);
                if (enabled)
                        *enabled = __enabled;
                if (running)
                        *running = __running;
        }
out:
        local_irq_restore(flags);

        return ret;
}

static int perf_event_read(struct perf_event *event, bool group)
{
        enum perf_event_state state = READ_ONCE(event->state);
        int event_cpu, ret = 0;

        /*
         * If event is enabled and currently active on a CPU, update the
         * value in the event structure:
         */
again:
        if (state == PERF_EVENT_STATE_ACTIVE) {
                struct perf_read_data data;

                /*
                 * Orders the ->state and ->oncpu loads such that if we see
                 * ACTIVE we must also see the right ->oncpu.
                 *
                 * Matches the smp_wmb() from event_sched_in().
                 */
                smp_rmb();

                event_cpu = READ_ONCE(event->oncpu);
                if ((unsigned)event_cpu >= nr_cpu_ids)
                        return 0;

                data = (struct perf_read_data){
                        .event = event,
                        .group = group,
                        .ret = 0,
                };

                preempt_disable();
                event_cpu = __perf_event_read_cpu(event, event_cpu);

                /*
                 * Purposely ignore the smp_call_function_single() return
                 * value.
                 *
                 * If event_cpu isn't a valid CPU it means the event got
                 * scheduled out and that will have updated the event count.
                 *
                 * Therefore, either way, we'll have an up-to-date event count
                 * after this.
                 */
                (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1);
                preempt_enable();
                ret = data.ret;

        } else if (state == PERF_EVENT_STATE_INACTIVE) {
                struct perf_event_context *ctx = event->ctx;
                unsigned long flags;

                raw_spin_lock_irqsave(&ctx->lock, flags);
                state = event->state;
                if (state != PERF_EVENT_STATE_INACTIVE) {
                        raw_spin_unlock_irqrestore(&ctx->lock, flags);
                        goto again;
                }

                /*
                 * May read while context is not active (e.g., thread is
                 * blocked), in that case we cannot update context time
                 */
                ctx_time_update_event(ctx, event);

                perf_event_update_time(event);
                if (group)
                        perf_event_update_sibling_time(event);
                raw_spin_unlock_irqrestore(&ctx->lock, flags);
        }

        return ret;
}

/*
 * Initialize the perf_event context in a task_struct:
 */
static void __perf_event_init_context(struct perf_event_context *ctx)
{
        raw_spin_lock_init(&ctx->lock);
        mutex_init(&ctx->mutex);
        INIT_LIST_HEAD(&ctx->pmu_ctx_list);
        perf_event_groups_init(&ctx->pinned_groups);
        perf_event_groups_init(&ctx->flexible_groups);
        INIT_LIST_HEAD(&ctx->event_list);
        refcount_set(&ctx->refcount, 1);
}

static void
__perf_init_event_pmu_context(struct perf_event_pmu_context *epc, struct pmu *pmu)
{
        epc->pmu = pmu;
        INIT_LIST_HEAD(&epc->pmu_ctx_entry);
        INIT_LIST_HEAD(&epc->pinned_active);
        INIT_LIST_HEAD(&epc->flexible_active);
        atomic_set(&epc->refcount, 1);
}

static struct perf_event_context *
alloc_perf_context(struct task_struct *task)
{
        struct perf_event_context *ctx;

        ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
        if (!ctx)
                return NULL;

        __perf_event_init_context(ctx);
        if (task)
                ctx->task = get_task_struct(task);

        return ctx;
}

static struct task_struct *
find_lively_task_by_vpid(pid_t vpid)
{
        struct task_struct *task;

        rcu_read_lock();
        if (!vpid)
                task = current;
        else
                task = find_task_by_vpid(vpid);
        if (task)
                get_task_struct(task);
        rcu_read_unlock();

        if (!task)
                return ERR_PTR(-ESRCH);

        return task;
}

/*
 * Returns a matching context with refcount and pincount.
 */
static struct perf_event_context *
find_get_context(struct task_struct *task, struct perf_event *event)
{
        struct perf_event_context *ctx, *clone_ctx = NULL;
        struct perf_cpu_context *cpuctx;
        unsigned long flags;
        int err;

        if (!task) {
                /* Must be root to operate on a CPU event: */
                err = perf_allow_cpu();
                if (err)
                        return ERR_PTR(err);

                cpuctx = per_cpu_ptr(&perf_cpu_context, event->cpu);
                ctx = &cpuctx->ctx;
                get_ctx(ctx);
                raw_spin_lock_irqsave(&ctx->lock, flags);
                ++ctx->pin_count;
                raw_spin_unlock_irqrestore(&ctx->lock, flags);

                return ctx;
        }

        err = -EINVAL;
retry:
        ctx = perf_lock_task_context(task, &flags);
        if (ctx) {
                clone_ctx = unclone_ctx(ctx);
                ++ctx->pin_count;

                raw_spin_unlock_irqrestore(&ctx->lock, flags);

                if (clone_ctx)
                        put_ctx(clone_ctx);
        } else {
                ctx = alloc_perf_context(task);
                err = -ENOMEM;
                if (!ctx)
                        goto errout;

                err = 0;
                mutex_lock(&task->perf_event_mutex);
                /*
                 * If it has already passed perf_event_exit_task().
                 * we must see PF_EXITING, it takes this mutex too.
                 */
                if (task->flags & PF_EXITING)
                        err = -ESRCH;
                else if (task->perf_event_ctxp)
                        err = -EAGAIN;
                else {
                        get_ctx(ctx);
                        ++ctx->pin_count;
                        rcu_assign_pointer(task->perf_event_ctxp, ctx);
                }
                mutex_unlock(&task->perf_event_mutex);

                if (unlikely(err)) {
                        put_ctx(ctx);

                        if (err == -EAGAIN)
                                goto retry;
                        goto errout;
                }
        }

        return ctx;

errout:
        return ERR_PTR(err);
}

static struct perf_event_pmu_context *
find_get_pmu_context(struct pmu *pmu, struct perf_event_context *ctx,
                     struct perf_event *event)
{
        struct perf_event_pmu_context *new = NULL, *pos = NULL, *epc;

        if (!ctx->task) {
                /*
                 * perf_pmu_migrate_context() / __perf_pmu_install_event()
                 * relies on the fact that find_get_pmu_context() cannot fail
                 * for CPU contexts.
                 */
                struct perf_cpu_pmu_context *cpc;

                cpc = *per_cpu_ptr(pmu->cpu_pmu_context, event->cpu);
                epc = &cpc->epc;
                raw_spin_lock_irq(&ctx->lock);
                if (!epc->ctx) {
                        /*
                         * One extra reference for the pmu; see perf_pmu_free().
                         */
                        atomic_set(&epc->refcount, 2);
                        epc->embedded = 1;
                        list_add(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list);
                        epc->ctx = ctx;
                } else {
                        WARN_ON_ONCE(epc->ctx != ctx);
                        atomic_inc(&epc->refcount);
                }
                raw_spin_unlock_irq(&ctx->lock);
                return epc;
        }

        new = kzalloc(sizeof(*epc), GFP_KERNEL);
        if (!new)
                return ERR_PTR(-ENOMEM);

        __perf_init_event_pmu_context(new, pmu);

        /*
         * XXX
         *
         * lockdep_assert_held(&ctx->mutex);
         *
         * can't because perf_event_init_task() doesn't actually hold the
         * child_ctx->mutex.
         */

        raw_spin_lock_irq(&ctx->lock);
        list_for_each_entry(epc, &ctx->pmu_ctx_list, pmu_ctx_entry) {
                if (epc->pmu == pmu) {
                        WARN_ON_ONCE(epc->ctx != ctx);
                        atomic_inc(&epc->refcount);
                        goto found_epc;
                }
                /* Make sure the pmu_ctx_list is sorted by PMU type: */
                if (!pos && epc->pmu->type > pmu->type)
                        pos = epc;
        }

        epc = new;
        new = NULL;

        if (!pos)
                list_add_tail(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list);
        else
                list_add(&epc->pmu_ctx_entry, pos->pmu_ctx_entry.prev);

        epc->ctx = ctx;

found_epc:
        raw_spin_unlock_irq(&ctx->lock);
        kfree(new);

        return epc;
}

static void get_pmu_ctx(struct perf_event_pmu_context *epc)
{
        WARN_ON_ONCE(!atomic_inc_not_zero(&epc->refcount));
}

static void free_cpc_rcu(struct rcu_head *head)
{
        struct perf_cpu_pmu_context *cpc =
                container_of(head, typeof(*cpc), epc.rcu_head);

        kfree(cpc);
}

static void free_epc_rcu(struct rcu_head *head)
{
        struct perf_event_pmu_context *epc = container_of(head, typeof(*epc), rcu_head);

        kfree(epc);
}

static void put_pmu_ctx(struct perf_event_pmu_context *epc)
{
        struct perf_event_context *ctx = epc->ctx;
        unsigned long flags;

        /*
         * XXX
         *
         * lockdep_assert_held(&ctx->mutex);
         *
         * can't because of the call-site in _free_event()/put_event()
         * which isn't always called under ctx->mutex.
         */
        if (!atomic_dec_and_raw_lock_irqsave(&epc->refcount, &ctx->lock, flags))
                return;

        WARN_ON_ONCE(list_empty(&epc->pmu_ctx_entry));

        list_del_init(&epc->pmu_ctx_entry);
        epc->ctx = NULL;

        WARN_ON_ONCE(!list_empty(&epc->pinned_active));
        WARN_ON_ONCE(!list_empty(&epc->flexible_active));

        raw_spin_unlock_irqrestore(&ctx->lock, flags);

        if (epc->embedded) {
                call_rcu(&epc->rcu_head, free_cpc_rcu);
                return;
        }

        call_rcu(&epc->rcu_head, free_epc_rcu);
}

static void perf_event_free_filter(struct perf_event *event);

static void free_event_rcu(struct rcu_head *head)
{
        struct perf_event *event = container_of(head, typeof(*event), rcu_head);

        if (event->ns)
                put_pid_ns(event->ns);
        perf_event_free_filter(event);
        kmem_cache_free(perf_event_cache, event);
}

static void ring_buffer_attach(struct perf_event *event,
                               struct perf_buffer *rb);

static void detach_sb_event(struct perf_event *event)
{
        struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);

        raw_spin_lock(&pel->lock);
        list_del_rcu(&event->sb_list);
        raw_spin_unlock(&pel->lock);
}

static bool is_sb_event(struct perf_event *event)
{
        struct perf_event_attr *attr = &event->attr;

        if (event->parent)
                return false;

        if (event->attach_state & PERF_ATTACH_TASK)
                return false;

        if (attr->mmap || attr->mmap_data || attr->mmap2 ||
            attr->comm || attr->comm_exec ||
            attr->task || attr->ksymbol ||
            attr->context_switch || attr->text_poke ||
            attr->bpf_event)
                return true;

        return false;
}

static void unaccount_pmu_sb_event(struct perf_event *event)
{
        if (is_sb_event(event))
                detach_sb_event(event);
}

#ifdef CONFIG_NO_HZ_FULL
static DEFINE_SPINLOCK(nr_freq_lock);
#endif

static void unaccount_freq_event_nohz(void)
{
#ifdef CONFIG_NO_HZ_FULL
        spin_lock(&nr_freq_lock);
        if (atomic_dec_and_test(&nr_freq_events))
                tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
        spin_unlock(&nr_freq_lock);
#endif
}

static void unaccount_freq_event(void)
{
        if (tick_nohz_full_enabled())
                unaccount_freq_event_nohz();
        else
                atomic_dec(&nr_freq_events);
}


static struct perf_ctx_data *
alloc_perf_ctx_data(struct kmem_cache *ctx_cache, bool global)
{
        struct perf_ctx_data *cd;

        cd = kzalloc(sizeof(*cd), GFP_KERNEL);
        if (!cd)
                return NULL;

        cd->data = kmem_cache_zalloc(ctx_cache, GFP_KERNEL);
        if (!cd->data) {
                kfree(cd);
                return NULL;
        }

        cd->global = global;
        cd->ctx_cache = ctx_cache;
        refcount_set(&cd->refcount, 1);

        return cd;
}

static void free_perf_ctx_data(struct perf_ctx_data *cd)
{
        kmem_cache_free(cd->ctx_cache, cd->data);
        kfree(cd);
}

static void __free_perf_ctx_data_rcu(struct rcu_head *rcu_head)
{
        struct perf_ctx_data *cd;

        cd = container_of(rcu_head, struct perf_ctx_data, rcu_head);
        free_perf_ctx_data(cd);
}

static inline void perf_free_ctx_data_rcu(struct perf_ctx_data *cd)
{
        call_rcu(&cd->rcu_head, __free_perf_ctx_data_rcu);
}

static int
attach_task_ctx_data(struct task_struct *task, struct kmem_cache *ctx_cache,
                     bool global)
{
        struct perf_ctx_data *cd, *old = NULL;

        cd = alloc_perf_ctx_data(ctx_cache, global);
        if (!cd)
                return -ENOMEM;

        for (;;) {
                if (try_cmpxchg((struct perf_ctx_data **)&task->perf_ctx_data, &old, cd)) {
                        if (old)
                                perf_free_ctx_data_rcu(old);
                        return 0;
                }

                if (!old) {
                        /*
                         * After seeing a dead @old, we raced with
                         * removal and lost, try again to install @cd.
                         */
                        continue;
                }

                if (refcount_inc_not_zero(&old->refcount)) {
                        free_perf_ctx_data(cd); /* unused */
                        return 0;
                }

                /*
                 * @old is a dead object, refcount==0 is stable, try and
                 * replace it with @cd.
                 */
        }
        return 0;
}

static void __detach_global_ctx_data(void);
DEFINE_STATIC_PERCPU_RWSEM(global_ctx_data_rwsem);
static refcount_t global_ctx_data_ref;

static int
attach_global_ctx_data(struct kmem_cache *ctx_cache)
{
        struct task_struct *g, *p;
        struct perf_ctx_data *cd;
        int ret;

        if (refcount_inc_not_zero(&global_ctx_data_ref))
                return 0;

        guard(percpu_write)(&global_ctx_data_rwsem);
        if (refcount_inc_not_zero(&global_ctx_data_ref))
                return 0;
again:
        /* Allocate everything */
        scoped_guard (rcu) {
                for_each_process_thread(g, p) {
                        cd = rcu_dereference(p->perf_ctx_data);
                        if (cd && !cd->global) {
                                cd->global = 1;
                                if (!refcount_inc_not_zero(&cd->refcount))
                                        cd = NULL;
                        }
                        if (!cd) {
                                get_task_struct(p);
                                goto alloc;
                        }
                }
        }

        refcount_set(&global_ctx_data_ref, 1);

        return 0;
alloc:
        ret = attach_task_ctx_data(p, ctx_cache, true);
        put_task_struct(p);
        if (ret) {
                __detach_global_ctx_data();
                return ret;
        }
        goto again;
}

static int
attach_perf_ctx_data(struct perf_event *event)
{
        struct task_struct *task = event->hw.target;
        struct kmem_cache *ctx_cache = event->pmu->task_ctx_cache;
        int ret;

        if (!ctx_cache)
                return -ENOMEM;

        if (task)
                return attach_task_ctx_data(task, ctx_cache, false);

        ret = attach_global_ctx_data(ctx_cache);
        if (ret)
                return ret;

        event->attach_state |= PERF_ATTACH_GLOBAL_DATA;
        return 0;
}

static void
detach_task_ctx_data(struct task_struct *p)
{
        struct perf_ctx_data *cd;

        scoped_guard (rcu) {
                cd = rcu_dereference(p->perf_ctx_data);
                if (!cd || !refcount_dec_and_test(&cd->refcount))
                        return;
        }

        /*
         * The old ctx_data may be lost because of the race.
         * Nothing is required to do for the case.
         * See attach_task_ctx_data().
         */
        if (try_cmpxchg((struct perf_ctx_data **)&p->perf_ctx_data, &cd, NULL))
                perf_free_ctx_data_rcu(cd);
}

static void __detach_global_ctx_data(void)
{
        struct task_struct *g, *p;
        struct perf_ctx_data *cd;

again:
        scoped_guard (rcu) {
                for_each_process_thread(g, p) {
                        cd = rcu_dereference(p->perf_ctx_data);
                        if (!cd || !cd->global)
                                continue;
                        cd->global = 0;
                        get_task_struct(p);
                        goto detach;
                }
        }
        return;
detach:
        detach_task_ctx_data(p);
        put_task_struct(p);
        goto again;
}

static void detach_global_ctx_data(void)
{
        if (refcount_dec_not_one(&global_ctx_data_ref))
                return;

        guard(percpu_write)(&global_ctx_data_rwsem);
        if (!refcount_dec_and_test(&global_ctx_data_ref))
                return;

        /* remove everything */
        __detach_global_ctx_data();
}

static void detach_perf_ctx_data(struct perf_event *event)
{
        struct task_struct *task = event->hw.target;

        event->attach_state &= ~PERF_ATTACH_TASK_DATA;

        if (task)
                return detach_task_ctx_data(task);

        if (event->attach_state & PERF_ATTACH_GLOBAL_DATA) {
                detach_global_ctx_data();
                event->attach_state &= ~PERF_ATTACH_GLOBAL_DATA;
        }
}

static void unaccount_event(struct perf_event *event)
{
        bool dec = false;

        if (event->parent)
                return;

        if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB))
                dec = true;
        if (event->attr.mmap || event->attr.mmap_data)
                atomic_dec(&nr_mmap_events);
        if (event->attr.build_id)
                atomic_dec(&nr_build_id_events);
        if (event->attr.comm)
                atomic_dec(&nr_comm_events);
        if (event->attr.namespaces)
                atomic_dec(&nr_namespaces_events);
        if (event->attr.cgroup)
                atomic_dec(&nr_cgroup_events);
        if (event->attr.task)
                atomic_dec(&nr_task_events);
        if (event->attr.freq)
                unaccount_freq_event();
        if (event->attr.context_switch) {
                dec = true;
                atomic_dec(&nr_switch_events);
        }
        if (is_cgroup_event(event))
                dec = true;
        if (has_branch_stack(event))
                dec = true;
        if (event->attr.ksymbol)
                atomic_dec(&nr_ksymbol_events);
        if (event->attr.bpf_event)
                atomic_dec(&nr_bpf_events);
        if (event->attr.text_poke)
                atomic_dec(&nr_text_poke_events);

        if (dec) {
                if (!atomic_add_unless(&perf_sched_count, -1, 1))
                        schedule_delayed_work(&perf_sched_work, HZ);
        }

        unaccount_pmu_sb_event(event);
}

static void perf_sched_delayed(struct work_struct *work)
{
        mutex_lock(&perf_sched_mutex);
        if (atomic_dec_and_test(&perf_sched_count))
                static_branch_disable(&perf_sched_events);
        mutex_unlock(&perf_sched_mutex);
}

/*
 * The following implement mutual exclusion of events on "exclusive" pmus
 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
 * at a time, so we disallow creating events that might conflict, namely:
 *
 *  1) cpu-wide events in the presence of per-task events,
 *  2) per-task events in the presence of cpu-wide events,
 *  3) two matching events on the same perf_event_context.
 *
 * The former two cases are handled in the allocation path (perf_event_alloc(),
 * _free_event()), the latter -- before the first perf_install_in_context().
 */
static int exclusive_event_init(struct perf_event *event)
{
        struct pmu *pmu = event->pmu;

        if (!is_exclusive_pmu(pmu))
                return 0;

        /*
         * Prevent co-existence of per-task and cpu-wide events on the
         * same exclusive pmu.
         *
         * Negative pmu::exclusive_cnt means there are cpu-wide
         * events on this "exclusive" pmu, positive means there are
         * per-task events.
         *
         * Since this is called in perf_event_alloc() path, event::ctx
         * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
         * to mean "per-task event", because unlike other attach states it
         * never gets cleared.
         */
        if (event->attach_state & PERF_ATTACH_TASK) {
                if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
                        return -EBUSY;
        } else {
                if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
                        return -EBUSY;
        }

        event->attach_state |= PERF_ATTACH_EXCLUSIVE;

        return 0;
}

static void exclusive_event_destroy(struct perf_event *event)
{
        struct pmu *pmu = event->pmu;

        /* see comment in exclusive_event_init() */
        if (event->attach_state & PERF_ATTACH_TASK)
                atomic_dec(&pmu->exclusive_cnt);
        else
                atomic_inc(&pmu->exclusive_cnt);

        event->attach_state &= ~PERF_ATTACH_EXCLUSIVE;
}

static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
{
        if ((e1->pmu == e2->pmu) &&
            (e1->cpu == e2->cpu ||
             e1->cpu == -1 ||
             e2->cpu == -1))
                return true;
        return false;
}

static bool exclusive_event_installable(struct perf_event *event,
                                        struct perf_event_context *ctx)
{
        struct perf_event *iter_event;
        struct pmu *pmu = event->pmu;

        lockdep_assert_held(&ctx->mutex);

        if (!is_exclusive_pmu(pmu))
                return true;

        list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
                if (exclusive_event_match(iter_event, event))
                        return false;
        }

        return true;
}

static void perf_free_addr_filters(struct perf_event *event);

/* vs perf_event_alloc() error */
static void __free_event(struct perf_event *event)
{
        struct pmu *pmu = event->pmu;

        if (event->attach_state & PERF_ATTACH_CALLCHAIN)
                put_callchain_buffers();

        kfree(event->addr_filter_ranges);

        if (event->attach_state & PERF_ATTACH_EXCLUSIVE)
                exclusive_event_destroy(event);

        if (is_cgroup_event(event))
                perf_detach_cgroup(event);

        if (event->attach_state & PERF_ATTACH_TASK_DATA)
                detach_perf_ctx_data(event);

        if (event->destroy)
                event->destroy(event);

        /*
         * Must be after ->destroy(), due to uprobe_perf_close() using
         * hw.target.
         */
        if (event->hw.target)
                put_task_struct(event->hw.target);

        if (event->pmu_ctx) {
                /*
                 * put_pmu_ctx() needs an event->ctx reference, because of
                 * epc->ctx.
                 */
                WARN_ON_ONCE(!pmu);
                WARN_ON_ONCE(!event->ctx);
                WARN_ON_ONCE(event->pmu_ctx->ctx != event->ctx);
                put_pmu_ctx(event->pmu_ctx);
        }

        /*
         * perf_event_free_task() relies on put_ctx() being 'last', in
         * particular all task references must be cleaned up.
         */
        if (event->ctx)
                put_ctx(event->ctx);

        if (pmu) {
                module_put(pmu->module);
                scoped_guard (spinlock, &pmu->events_lock) {
                        list_del(&event->pmu_list);
                        wake_up_var(pmu);
                }
        }

        call_rcu(&event->rcu_head, free_event_rcu);
}

DEFINE_FREE(__free_event, struct perf_event *, if (_T) __free_event(_T))

/* vs perf_event_alloc() success */
static void _free_event(struct perf_event *event)
{
        irq_work_sync(&event->pending_irq);
        irq_work_sync(&event->pending_disable_irq);

        unaccount_event(event);

        security_perf_event_free(event);

        if (event->rb) {
                /*
                 * Can happen when we close an event with re-directed output.
                 *
                 * Since we have a 0 refcount, perf_mmap_close() will skip
                 * over us; possibly making our ring_buffer_put() the last.
                 */
                mutex_lock(&event->mmap_mutex);
                ring_buffer_attach(event, NULL);
                mutex_unlock(&event->mmap_mutex);
        }

        perf_event_free_bpf_prog(event);
        perf_free_addr_filters(event);

        __free_event(event);
}

/*
 * Used to free events which have a known refcount of 1, such as in error paths
 * of inherited events.
 */
static void free_event(struct perf_event *event)
{
        if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
                                     "unexpected event refcount: %ld; ptr=%p\n",
                                     atomic_long_read(&event->refcount), event)) {
                /* leak to avoid use-after-free */
                return;
        }

        _free_event(event);
}

/*
 * Remove user event from the owner task.
 */
static void perf_remove_from_owner(struct perf_event *event)
{
        struct task_struct *owner;

        rcu_read_lock();
        /*
         * Matches the smp_store_release() in perf_event_exit_task(). If we
         * observe !owner it means the list deletion is complete and we can
         * indeed free this event, otherwise we need to serialize on
         * owner->perf_event_mutex.
         */
        owner = READ_ONCE(event->owner);
        if (owner) {
                /*
                 * Since delayed_put_task_struct() also drops the last
                 * task reference we can safely take a new reference
                 * while holding the rcu_read_lock().
                 */
                get_task_struct(owner);
        }
        rcu_read_unlock();

        if (owner) {
                /*
                 * If we're here through perf_event_exit_task() we're already
                 * holding ctx->mutex which would be an inversion wrt. the
                 * normal lock order.
                 *
                 * However we can safely take this lock because its the child
                 * ctx->mutex.
                 */
                mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);

                /*
                 * We have to re-check the event->owner field, if it is cleared
                 * we raced with perf_event_exit_task(), acquiring the mutex
                 * ensured they're done, and we can proceed with freeing the
                 * event.
                 */
                if (event->owner) {
                        list_del_init(&event->owner_entry);
                        smp_store_release(&event->owner, NULL);
                }
                mutex_unlock(&owner->perf_event_mutex);
                put_task_struct(owner);
        }
}

static void put_event(struct perf_event *event)
{
        struct perf_event *parent;

        if (!atomic_long_dec_and_test(&event->refcount))
                return;

        parent = event->parent;
        _free_event(event);

        /* Matches the refcount bump in inherit_event() */
        if (parent)
                put_event(parent);
}

/*
 * Kill an event dead; while event:refcount will preserve the event
 * object, it will not preserve its functionality. Once the last 'user'
 * gives up the object, we'll destroy the thing.
 */
int perf_event_release_kernel(struct perf_event *event)
{
        struct perf_event_context *ctx = event->ctx;
        struct perf_event *child, *tmp;

        /*
         * If we got here through err_alloc: free_event(event); we will not
         * have attached to a context yet.
         */
        if (!ctx) {
                WARN_ON_ONCE(event->attach_state &
                                (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
                goto no_ctx;
        }

        if (!is_kernel_event(event))
                perf_remove_from_owner(event);

        ctx = perf_event_ctx_lock(event);
        WARN_ON_ONCE(ctx->parent_ctx);

        /*
         * Mark this event as STATE_DEAD, there is no external reference to it
         * anymore.
         *
         * Anybody acquiring event->child_mutex after the below loop _must_
         * also see this, most importantly inherit_event() which will avoid
         * placing more children on the list.
         *
         * Thus this guarantees that we will in fact observe and kill _ALL_
         * child events.
         */
        if (event->state > PERF_EVENT_STATE_REVOKED) {
                perf_remove_from_context(event, DETACH_GROUP|DETACH_DEAD);
        } else {
                event->state = PERF_EVENT_STATE_DEAD;
        }

        perf_event_ctx_unlock(event, ctx);

again:
        mutex_lock(&event->child_mutex);
        list_for_each_entry(child, &event->child_list, child_list) {
                /*
                 * Cannot change, child events are not migrated, see the
                 * comment with perf_event_ctx_lock_nested().
                 */
                ctx = READ_ONCE(child->ctx);
                /*
                 * Since child_mutex nests inside ctx::mutex, we must jump
                 * through hoops. We start by grabbing a reference on the ctx.
                 *
                 * Since the event cannot get freed while we hold the
                 * child_mutex, the context must also exist and have a !0
                 * reference count.
                 */
                get_ctx(ctx);

                /*
                 * Now that we have a ctx ref, we can drop child_mutex, and
                 * acquire ctx::mutex without fear of it going away. Then we
                 * can re-acquire child_mutex.
                 */
                mutex_unlock(&event->child_mutex);
                mutex_lock(&ctx->mutex);
                mutex_lock(&event->child_mutex);

                /*
                 * Now that we hold ctx::mutex and child_mutex, revalidate our
                 * state, if child is still the first entry, it didn't get freed
                 * and we can continue doing so.
                 */
                tmp = list_first_entry_or_null(&event->child_list,
                                               struct perf_event, child_list);
                if (tmp == child) {
                        perf_remove_from_context(child, DETACH_GROUP | DETACH_CHILD);
                } else {
                        child = NULL;
                }

                mutex_unlock(&event->child_mutex);
                mutex_unlock(&ctx->mutex);

                if (child) {
                        /* Last reference unless ->pending_task work is pending */
                        put_event(child);
                }
                put_ctx(ctx);

                goto again;
        }
        mutex_unlock(&event->child_mutex);

no_ctx:
        /*
         * Last reference unless ->pending_task work is pending on this event
         * or any of its children.
         */
        put_event(event);
        return 0;
}
EXPORT_SYMBOL_GPL(perf_event_release_kernel);

/*
 * Called when the last reference to the file is gone.
 */
static int perf_release(struct inode *inode, struct file *file)
{
        perf_event_release_kernel(file->private_data);
        return 0;
}

static u64 __perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
{
        struct perf_event *child;
        u64 total = 0;

        *enabled = 0;
        *running = 0;

        mutex_lock(&event->child_mutex);

        (void)perf_event_read(event, false);
        total += perf_event_count(event, false);

        *enabled += event->total_time_enabled +
                        atomic64_read(&event->child_total_time_enabled);
        *running += event->total_time_running +
                        atomic64_read(&event->child_total_time_running);

        list_for_each_entry(child, &event->child_list, child_list) {
                (void)perf_event_read(child, false);
                total += perf_event_count(child, false);
                *enabled += child->total_time_enabled;
                *running += child->total_time_running;
        }
        mutex_unlock(&event->child_mutex);

        return total;
}

u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
{
        struct perf_event_context *ctx;
        u64 count;

        ctx = perf_event_ctx_lock(event);
        count = __perf_event_read_value(event, enabled, running);
        perf_event_ctx_unlock(event, ctx);

        return count;
}
EXPORT_SYMBOL_GPL(perf_event_read_value);

static int __perf_read_group_add(struct perf_event *leader,
                                        u64 read_format, u64 *values)
{
        struct perf_event_context *ctx = leader->ctx;
        struct perf_event *sub, *parent;
        unsigned long flags;
        int n = 1; /* skip @nr */
        int ret;

        ret = perf_event_read(leader, true);
        if (ret)
                return ret;

        raw_spin_lock_irqsave(&ctx->lock, flags);
        /*
         * Verify the grouping between the parent and child (inherited)
         * events is still in tact.
         *
         * Specifically:
         *  - leader->ctx->lock pins leader->sibling_list
         *  - parent->child_mutex pins parent->child_list
         *  - parent->ctx->mutex pins parent->sibling_list
         *
         * Because parent->ctx != leader->ctx (and child_list nests inside
         * ctx->mutex), group destruction is not atomic between children, also
         * see perf_event_release_kernel(). Additionally, parent can grow the
         * group.
         *
         * Therefore it is possible to have parent and child groups in a
         * different configuration and summing over such a beast makes no sense
         * what so ever.
         *
         * Reject this.
         */
        parent = leader->parent;
        if (parent &&
            (parent->group_generation != leader->group_generation ||
             parent->nr_siblings != leader->nr_siblings)) {
                ret = -ECHILD;
                goto unlock;
        }

        /*
         * Since we co-schedule groups, {enabled,running} times of siblings
         * will be identical to those of the leader, so we only publish one
         * set.
         */
        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
                values[n++] += leader->total_time_enabled +
                        atomic64_read(&leader->child_total_time_enabled);
        }

        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
                values[n++] += leader->total_time_running +
                        atomic64_read(&leader->child_total_time_running);
        }

        /*
         * Write {count,id} tuples for every sibling.
         */
        values[n++] += perf_event_count(leader, false);
        if (read_format & PERF_FORMAT_ID)
                values[n++] = primary_event_id(leader);
        if (read_format & PERF_FORMAT_LOST)
                values[n++] = atomic64_read(&leader->lost_samples);

        for_each_sibling_event(sub, leader) {
                values[n++] += perf_event_count(sub, false);
                if (read_format & PERF_FORMAT_ID)
                        values[n++] = primary_event_id(sub);
                if (read_format & PERF_FORMAT_LOST)
                        values[n++] = atomic64_read(&sub->lost_samples);
        }

unlock:
        raw_spin_unlock_irqrestore(&ctx->lock, flags);
        return ret;
}

static int perf_read_group(struct perf_event *event,
                                   u64 read_format, char __user *buf)
{
        struct perf_event *leader = event->group_leader, *child;
        struct perf_event_context *ctx = leader->ctx;
        int ret;
        u64 *values;

        lockdep_assert_held(&ctx->mutex);

        values = kzalloc(event->read_size, GFP_KERNEL);
        if (!values)
                return -ENOMEM;

        values[0] = 1 + leader->nr_siblings;

        mutex_lock(&leader->child_mutex);

        ret = __perf_read_group_add(leader, read_format, values);
        if (ret)
                goto unlock;

        list_for_each_entry(child, &leader->child_list, child_list) {
                ret = __perf_read_group_add(child, read_format, values);
                if (ret)
                        goto unlock;
        }

        mutex_unlock(&leader->child_mutex);

        ret = event->read_size;
        if (copy_to_user(buf, values, event->read_size))
                ret = -EFAULT;
        goto out;

unlock:
        mutex_unlock(&leader->child_mutex);
out:
        kfree(values);
        return ret;
}

static int perf_read_one(struct perf_event *event,
                                 u64 read_format, char __user *buf)
{
        u64 enabled, running;
        u64 values[5];
        int n = 0;

        values[n++] = __perf_event_read_value(event, &enabled, &running);
        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
                values[n++] = enabled;
        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
                values[n++] = running;
        if (read_format & PERF_FORMAT_ID)
                values[n++] = primary_event_id(event);
        if (read_format & PERF_FORMAT_LOST)
                values[n++] = atomic64_read(&event->lost_samples);

        if (copy_to_user(buf, values, n * sizeof(u64)))
                return -EFAULT;

        return n * sizeof(u64);
}

static bool is_event_hup(struct perf_event *event)
{
        bool no_children;

        if (event->state > PERF_EVENT_STATE_EXIT)
                return false;

        mutex_lock(&event->child_mutex);
        no_children = list_empty(&event->child_list);
        mutex_unlock(&event->child_mutex);
        return no_children;
}

/*
 * Read the performance event - simple non blocking version for now
 */
static ssize_t
__perf_read(struct perf_event *event, char __user *buf, size_t count)
{
        u64 read_format = event->attr.read_format;
        int ret;

        /*
         * Return end-of-file for a read on an event that is in
         * error state (i.e. because it was pinned but it couldn't be
         * scheduled on to the CPU at some point).
         */
        if (event->state == PERF_EVENT_STATE_ERROR)
                return 0;

        if (count < event->read_size)
                return -ENOSPC;

        WARN_ON_ONCE(event->ctx->parent_ctx);
        if (read_format & PERF_FORMAT_GROUP)
                ret = perf_read_group(event, read_format, buf);
        else
                ret = perf_read_one(event, read_format, buf);

        return ret;
}

static ssize_t
perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
        struct perf_event *event = file->private_data;
        struct perf_event_context *ctx;
        int ret;

        ret = security_perf_event_read(event);
        if (ret)
                return ret;

        ctx = perf_event_ctx_lock(event);
        ret = __perf_read(event, buf, count);
        perf_event_ctx_unlock(event, ctx);

        return ret;
}

static __poll_t perf_poll(struct file *file, poll_table *wait)
{
        struct perf_event *event = file->private_data;
        struct perf_buffer *rb;
        __poll_t events = EPOLLHUP;

        if (event->state <= PERF_EVENT_STATE_REVOKED)
                return EPOLLERR;

        poll_wait(file, &event->waitq, wait);

        if (event->state <= PERF_EVENT_STATE_REVOKED)
                return EPOLLERR;

        if (is_event_hup(event))
                return events;

        if (unlikely(READ_ONCE(event->state) == PERF_EVENT_STATE_ERROR &&
                     event->attr.pinned))
                return EPOLLERR;

        /*
         * Pin the event->rb by taking event->mmap_mutex; otherwise
         * perf_event_set_output() can swizzle our rb and make us miss wakeups.
         */
        mutex_lock(&event->mmap_mutex);
        rb = event->rb;
        if (rb)
                events = atomic_xchg(&rb->poll, 0);
        mutex_unlock(&event->mmap_mutex);
        return events;
}

static void _perf_event_reset(struct perf_event *event)
{
        (void)perf_event_read(event, false);
        local64_set(&event->count, 0);
        perf_event_update_userpage(event);
}

/* Assume it's not an event with inherit set. */
u64 perf_event_pause(struct perf_event *event, bool reset)
{
        struct perf_event_context *ctx;
        u64 count;

        ctx = perf_event_ctx_lock(event);
        WARN_ON_ONCE(event->attr.inherit);
        _perf_event_disable(event);
        count = local64_read(&event->count);
        if (reset)
                local64_set(&event->count, 0);
        perf_event_ctx_unlock(event, ctx);

        return count;
}
EXPORT_SYMBOL_GPL(perf_event_pause);

/*
 * Holding the top-level event's child_mutex means that any
 * descendant process that has inherited this event will block
 * in perf_event_exit_event() if it goes to exit, thus satisfying the
 * task existence requirements of perf_event_enable/disable.
 */
static void perf_event_for_each_child(struct perf_event *event,
                                        void (*func)(struct perf_event *))
{
        struct perf_event *child;

        WARN_ON_ONCE(event->ctx->parent_ctx);

        mutex_lock(&event->child_mutex);
        func(event);
        list_for_each_entry(child, &event->child_list, child_list)
                func(child);
        mutex_unlock(&event->child_mutex);
}

static void perf_event_for_each(struct perf_event *event,
                                  void (*func)(struct perf_event *))
{
        struct perf_event_context *ctx = event->ctx;
        struct perf_event *sibling;

        lockdep_assert_held(&ctx->mutex);

        event = event->group_leader;

        perf_event_for_each_child(event, func);
        for_each_sibling_event(sibling, event)
                perf_event_for_each_child(sibling, func);
}

static void __perf_event_period(struct perf_event *event,
                                struct perf_cpu_context *cpuctx,
                                struct perf_event_context *ctx,
                                void *info)
{
        u64 value = *((u64 *)info);
        bool active;

        if (event->attr.freq) {
                event->attr.sample_freq = value;
        } else {
                event->attr.sample_period = value;
                event->hw.sample_period = value;
        }

        active = (event->state == PERF_EVENT_STATE_ACTIVE);
        if (active) {
                perf_pmu_disable(event->pmu);
                event->pmu->stop(event, PERF_EF_UPDATE);
        }

        local64_set(&event->hw.period_left, 0);

        if (active) {
                event->pmu->start(event, PERF_EF_RELOAD);
                /*
                 * Once the period is force-reset, the event starts immediately.
                 * But the event/group could be throttled. Unthrottle the
                 * event/group now to avoid the next tick trying to unthrottle
                 * while we already re-started the event/group.
                 */
                if (event->hw.interrupts == MAX_INTERRUPTS)
                        perf_event_unthrottle_group(event, true);
                perf_pmu_enable(event->pmu);
        }
}

static int perf_event_check_period(struct perf_event *event, u64 value)
{
        return event->pmu->check_period(event, value);
}

static int _perf_event_period(struct perf_event *event, u64 value)
{
        if (!is_sampling_event(event))
                return -EINVAL;

        if (!value)
                return -EINVAL;

        if (event->attr.freq) {
                if (value > sysctl_perf_event_sample_rate)
                        return -EINVAL;
        } else {
                if (perf_event_check_period(event, value))
                        return -EINVAL;
                if (value & (1ULL << 63))
                        return -EINVAL;
        }

        event_function_call(event, __perf_event_period, &value);

        return 0;
}

int perf_event_period(struct perf_event *event, u64 value)
{
        struct perf_event_context *ctx;
        int ret;

        ctx = perf_event_ctx_lock(event);
        ret = _perf_event_period(event, value);
        perf_event_ctx_unlock(event, ctx);

        return ret;
}
EXPORT_SYMBOL_GPL(perf_event_period);

static const struct file_operations perf_fops;

static inline bool is_perf_file(struct fd f)
{
        return !fd_empty(f) && fd_file(f)->f_op == &perf_fops;
}

static int perf_event_set_output(struct perf_event *event,
                                 struct perf_event *output_event);
static int perf_event_set_filter(struct perf_event *event, void __user *arg);
static int perf_copy_attr(struct perf_event_attr __user *uattr,
                          struct perf_event_attr *attr);
static int __perf_event_set_bpf_prog(struct perf_event *event,
                                     struct bpf_prog *prog,
                                     u64 bpf_cookie);

static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
{
        void (*func)(struct perf_event *);
        u32 flags = arg;

        if (event->state <= PERF_EVENT_STATE_REVOKED)
                return -ENODEV;

        switch (cmd) {
        case PERF_EVENT_IOC_ENABLE:
                func = _perf_event_enable;
                break;
        case PERF_EVENT_IOC_DISABLE:
                func = _perf_event_disable;
                break;
        case PERF_EVENT_IOC_RESET:
                func = _perf_event_reset;
                break;

        case PERF_EVENT_IOC_REFRESH:
                return _perf_event_refresh(event, arg);

        case PERF_EVENT_IOC_PERIOD:
        {
                u64 value;

                if (copy_from_user(&value, (u64 __user *)arg, sizeof(value)))
                        return -EFAULT;

                return _perf_event_period(event, value);
        }
        case PERF_EVENT_IOC_ID:
        {
                u64 id = primary_event_id(event);

                if (copy_to_user((void __user *)arg, &id, sizeof(id)))
                        return -EFAULT;
                return 0;
        }

        case PERF_EVENT_IOC_SET_OUTPUT:
        {
                CLASS(fd, output)(arg);             // arg == -1 => empty
                struct perf_event *output_event = NULL;
                if (arg != -1) {
                        if (!is_perf_file(output))
                                return -EBADF;
                        output_event = fd_file(output)->private_data;
                }
                return perf_event_set_output(event, output_event);
        }

        case PERF_EVENT_IOC_SET_FILTER:
                return perf_event_set_filter(event, (void __user *)arg);

        case PERF_EVENT_IOC_SET_BPF:
        {
                struct bpf_prog *prog;
                int err;

                prog = bpf_prog_get(arg);
                if (IS_ERR(prog))
                        return PTR_ERR(prog);

                err = __perf_event_set_bpf_prog(event, prog, 0);
                if (err) {
                        bpf_prog_put(prog);
                        return err;
                }

                return 0;
        }

        case PERF_EVENT_IOC_PAUSE_OUTPUT: {
                struct perf_buffer *rb;

                rcu_read_lock();
                rb = rcu_dereference(event->rb);
                if (!rb || !rb->nr_pages) {
                        rcu_read_unlock();
                        return -EINVAL;
                }
                rb_toggle_paused(rb, !!arg);
                rcu_read_unlock();
                return 0;
        }

        case PERF_EVENT_IOC_QUERY_BPF:
                return perf_event_query_prog_array(event, (void __user *)arg);

        case PERF_EVENT_IOC_MODIFY_ATTRIBUTES: {
                struct perf_event_attr new_attr;
                int err = perf_copy_attr((struct perf_event_attr __user *)arg,
                                         &new_attr);

                if (err)
                        return err;

                return perf_event_modify_attr(event,  &new_attr);
        }
        default:
                return -ENOTTY;
        }

        if (flags & PERF_IOC_FLAG_GROUP)
                perf_event_for_each(event, func);
        else
                perf_event_for_each_child(event, func);

        return 0;
}

static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        struct perf_event *event = file->private_data;
        struct perf_event_context *ctx;
        long ret;

        /* Treat ioctl like writes as it is likely a mutating operation. */
        ret = security_perf_event_write(event);
        if (ret)
                return ret;

        ctx = perf_event_ctx_lock(event);
        ret = _perf_ioctl(event, cmd, arg);
        perf_event_ctx_unlock(event, ctx);

        return ret;
}

#ifdef CONFIG_COMPAT
static long perf_compat_ioctl(struct file *file, unsigned int cmd,
                                unsigned long arg)
{
        switch (_IOC_NR(cmd)) {
        case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
        case _IOC_NR(PERF_EVENT_IOC_ID):
        case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF):
        case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES):
                /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
                if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
                        cmd &= ~IOCSIZE_MASK;
                        cmd |= sizeof(void *) << IOCSIZE_SHIFT;
                }
                break;
        }
        return perf_ioctl(file, cmd, arg);
}
#else
# define perf_compat_ioctl NULL
#endif

int perf_event_task_enable(void)
{
        struct perf_event_context *ctx;
        struct perf_event *event;

        mutex_lock(&current->perf_event_mutex);
        list_for_each_entry(event, &current->perf_event_list, owner_entry) {
                ctx = perf_event_ctx_lock(event);
                perf_event_for_each_child(event, _perf_event_enable);
                perf_event_ctx_unlock(event, ctx);
        }
        mutex_unlock(&current->perf_event_mutex);

        return 0;
}

int perf_event_task_disable(void)
{
        struct perf_event_context *ctx;
        struct perf_event *event;

        mutex_lock(&current->perf_event_mutex);
        list_for_each_entry(event, &current->perf_event_list, owner_entry) {
                ctx = perf_event_ctx_lock(event);
                perf_event_for_each_child(event, _perf_event_disable);
                perf_event_ctx_unlock(event, ctx);
        }
        mutex_unlock(&current->perf_event_mutex);

        return 0;
}

static int perf_event_index(struct perf_event *event)
{
        if (event->hw.state & PERF_HES_STOPPED)
                return 0;

        if (event->state != PERF_EVENT_STATE_ACTIVE)
                return 0;

        return event->pmu->event_idx(event);
}

static void perf_event_init_userpage(struct perf_event *event)
{
        struct perf_event_mmap_page *userpg;
        struct perf_buffer *rb;

        rcu_read_lock();
        rb = rcu_dereference(event->rb);
        if (!rb)
                goto unlock;

        userpg = rb->user_page;

        /* Allow new userspace to detect that bit 0 is deprecated */
        userpg->cap_bit0_is_deprecated = 1;
        userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
        userpg->data_offset = PAGE_SIZE;
        userpg->data_size = perf_data_size(rb);

unlock:
        rcu_read_unlock();
}

void __weak arch_perf_update_userpage(
        struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
{
}

/*
 * Callers need to ensure there can be no nesting of this function, otherwise
 * the seqlock logic goes bad. We can not serialize this because the arch
 * code calls this from NMI context.
 */
void perf_event_update_userpage(struct perf_event *event)
{
        struct perf_event_mmap_page *userpg;
        struct perf_buffer *rb;
        u64 enabled, running, now;

        rcu_read_lock();
        rb = rcu_dereference(event->rb);
        if (!rb)
                goto unlock;

        /*
         * compute total_time_enabled, total_time_running
         * based on snapshot values taken when the event
         * was last scheduled in.
         *
         * we cannot simply called update_context_time()
         * because of locking issue as we can be called in
         * NMI context
         */
        calc_timer_values(event, &now, &enabled, &running);

        userpg = rb->user_page;
        /*
         * Disable preemption to guarantee consistent time stamps are stored to
         * the user page.
         */
        preempt_disable();
        ++userpg->lock;
        barrier();
        userpg->index = perf_event_index(event);
        userpg->offset = perf_event_count(event, false);
        if (userpg->index)
                userpg->offset -= local64_read(&event->hw.prev_count);

        userpg->time_enabled = enabled +
                        atomic64_read(&event->child_total_time_enabled);

        userpg->time_running = running +
                        atomic64_read(&event->child_total_time_running);

        arch_perf_update_userpage(event, userpg, now);

        barrier();
        ++userpg->lock;
        preempt_enable();
unlock:
        rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(perf_event_update_userpage);

static void ring_buffer_attach(struct perf_event *event,
                               struct perf_buffer *rb)
{
        struct perf_buffer *old_rb = NULL;
        unsigned long flags;

        WARN_ON_ONCE(event->parent);

        if (event->rb) {
                /*
                 * Should be impossible, we set this when removing
                 * event->rb_entry and wait/clear when adding event->rb_entry.
                 */
                WARN_ON_ONCE(event->rcu_pending);

                old_rb = event->rb;
                spin_lock_irqsave(&old_rb->event_lock, flags);
                list_del_rcu(&event->rb_entry);
                spin_unlock_irqrestore(&old_rb->event_lock, flags);

                event->rcu_batches = get_state_synchronize_rcu();
                event->rcu_pending = 1;
        }

        if (rb) {
                if (event->rcu_pending) {
                        cond_synchronize_rcu(event->rcu_batches);
                        event->rcu_pending = 0;
                }

                spin_lock_irqsave(&rb->event_lock, flags);
                list_add_rcu(&event->rb_entry, &rb->event_list);
                spin_unlock_irqrestore(&rb->event_lock, flags);
        }

        /*
         * Avoid racing with perf_mmap_close(AUX): stop the event
         * before swizzling the event::rb pointer; if it's getting
         * unmapped, its aux_mmap_count will be 0 and it won't
         * restart. See the comment in __perf_pmu_output_stop().
         *
         * Data will inevitably be lost when set_output is done in
         * mid-air, but then again, whoever does it like this is
         * not in for the data anyway.
         */
        if (has_aux(event))
                perf_event_stop(event, 0);

        rcu_assign_pointer(event->rb, rb);

        if (old_rb) {
                ring_buffer_put(old_rb);
                /*
                 * Since we detached before setting the new rb, so that we
                 * could attach the new rb, we could have missed a wakeup.
                 * Provide it now.
                 */
                wake_up_all(&event->waitq);
        }
}

static void ring_buffer_wakeup(struct perf_event *event)
{
        struct perf_buffer *rb;

        if (event->parent)
                event = event->parent;

        rcu_read_lock();
        rb = rcu_dereference(event->rb);
        if (rb) {
                list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
                        wake_up_all(&event->waitq);
        }
        rcu_read_unlock();
}

struct perf_buffer *ring_buffer_get(struct perf_event *event)
{
        struct perf_buffer *rb;

        if (event->parent)
                event = event->parent;

        rcu_read_lock();
        rb = rcu_dereference(event->rb);
        if (rb) {
                if (!refcount_inc_not_zero(&rb->refcount))
                        rb = NULL;
        }
        rcu_read_unlock();

        return rb;
}

void ring_buffer_put(struct perf_buffer *rb)
{
        if (!refcount_dec_and_test(&rb->refcount))
                return;

        WARN_ON_ONCE(!list_empty(&rb->event_list));

        call_rcu(&rb->rcu_head, rb_free_rcu);
}

typedef void (*mapped_f)(struct perf_event *event, struct mm_struct *mm);

#define get_mapped(event, func)                        \
({        struct pmu *pmu;                        \
        mapped_f f = NULL;                        \
        guard(rcu)();                                \
        pmu = READ_ONCE(event->pmu);                \
        if (pmu)                                \
                f = pmu->func;                        \
        f;                                        \
})

static void perf_mmap_open(struct vm_area_struct *vma)
{
        struct perf_event *event = vma->vm_file->private_data;
        mapped_f mapped = get_mapped(event, event_mapped);

        refcount_inc(&event->mmap_count);
        refcount_inc(&event->rb->mmap_count);

        if (vma->vm_pgoff)
                refcount_inc(&event->rb->aux_mmap_count);

        if (mapped)
                mapped(event, vma->vm_mm);
}

static void perf_pmu_output_stop(struct perf_event *event);

/*
 * A buffer can be mmap()ed multiple times; either directly through the same
 * event, or through other events by use of perf_event_set_output().
 *
 * In order to undo the VM accounting done by perf_mmap() we need to destroy
 * the buffer here, where we still have a VM context. This means we need
 * to detach all events redirecting to us.
 */
static void perf_mmap_close(struct vm_area_struct *vma)
{
        struct perf_event *event = vma->vm_file->private_data;
        mapped_f unmapped = get_mapped(event, event_unmapped);
        struct perf_buffer *rb = ring_buffer_get(event);
        struct user_struct *mmap_user = rb->mmap_user;
        int mmap_locked = rb->mmap_locked;
        unsigned long size = perf_data_size(rb);
        bool detach_rest = false;

        /* FIXIES vs perf_pmu_unregister() */
        if (unmapped)
                unmapped(event, vma->vm_mm);

        /*
         * The AUX buffer is strictly a sub-buffer, serialize using aux_mutex
         * to avoid complications.
         */
        if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
            refcount_dec_and_mutex_lock(&rb->aux_mmap_count, &rb->aux_mutex)) {
                /*
                 * Stop all AUX events that are writing to this buffer,
                 * so that we can free its AUX pages and corresponding PMU
                 * data. Note that after rb::aux_mmap_count dropped to zero,
                 * they won't start any more (see perf_aux_output_begin()).
                 */
                perf_pmu_output_stop(event);

                /* now it's safe to free the pages */
                atomic_long_sub(rb->aux_nr_pages - rb->aux_mmap_locked, &mmap_user->locked_vm);
                atomic64_sub(rb->aux_mmap_locked, &vma->vm_mm->pinned_vm);

                /* this has to be the last one */
                rb_free_aux(rb);
                WARN_ON_ONCE(refcount_read(&rb->aux_refcount));

                mutex_unlock(&rb->aux_mutex);
        }

        if (refcount_dec_and_test(&rb->mmap_count))
                detach_rest = true;

        if (!refcount_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
                goto out_put;

        ring_buffer_attach(event, NULL);
        mutex_unlock(&event->mmap_mutex);

        /* If there's still other mmap()s of this buffer, we're done. */
        if (!detach_rest)
                goto out_put;

        /*
         * No other mmap()s, detach from all other events that might redirect
         * into the now unreachable buffer. Somewhat complicated by the
         * fact that rb::event_lock otherwise nests inside mmap_mutex.
         */
again:
        rcu_read_lock();
        list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
                if (!atomic_long_inc_not_zero(&event->refcount)) {
                        /*
                         * This event is en-route to free_event() which will
                         * detach it and remove it from the list.
                         */
                        continue;
                }
                rcu_read_unlock();

                mutex_lock(&event->mmap_mutex);
                /*
                 * Check we didn't race with perf_event_set_output() which can
                 * swizzle the rb from under us while we were waiting to
                 * acquire mmap_mutex.
                 *
                 * If we find a different rb; ignore this event, a next
                 * iteration will no longer find it on the list. We have to
                 * still restart the iteration to make sure we're not now
                 * iterating the wrong list.
                 */
                if (event->rb == rb)
                        ring_buffer_attach(event, NULL);

                mutex_unlock(&event->mmap_mutex);
                put_event(event);

                /*
                 * Restart the iteration; either we're on the wrong list or
                 * destroyed its integrity by doing a deletion.
                 */
                goto again;
        }
        rcu_read_unlock();

        /*
         * It could be there's still a few 0-ref events on the list; they'll
         * get cleaned up by free_event() -- they'll also still have their
         * ref on the rb and will free it whenever they are done with it.
         *
         * Aside from that, this buffer is 'fully' detached and unmapped,
         * undo the VM accounting.
         */

        atomic_long_sub((size >> PAGE_SHIFT) + 1 - mmap_locked,
                        &mmap_user->locked_vm);
        atomic64_sub(mmap_locked, &vma->vm_mm->pinned_vm);
        free_uid(mmap_user);

out_put:
        ring_buffer_put(rb); /* could be last */
}

static vm_fault_t perf_mmap_pfn_mkwrite(struct vm_fault *vmf)
{
        /* The first page is the user control page, others are read-only. */
        return vmf->pgoff == 0 ? 0 : VM_FAULT_SIGBUS;
}

static int perf_mmap_may_split(struct vm_area_struct *vma, unsigned long addr)
{
        /*
         * Forbid splitting perf mappings to prevent refcount leaks due to
         * the resulting non-matching offsets and sizes. See open()/close().
         */
        return -EINVAL;
}

static const struct vm_operations_struct perf_mmap_vmops = {
        .open                = perf_mmap_open,
        .close                = perf_mmap_close, /* non mergeable */
        .pfn_mkwrite        = perf_mmap_pfn_mkwrite,
        .may_split        = perf_mmap_may_split,
};

static int map_range(struct perf_buffer *rb, struct vm_area_struct *vma)
{
        unsigned long nr_pages = vma_pages(vma);
        int err = 0;
        unsigned long pagenum;

        /*
         * We map this as a VM_PFNMAP VMA.
         *
         * This is not ideal as this is designed broadly for mappings of PFNs
         * referencing memory-mapped I/O ranges or non-system RAM i.e. for which
         * !pfn_valid(pfn).
         *
         * We are mapping kernel-allocated memory (memory we manage ourselves)
         * which would more ideally be mapped using vm_insert_page() or a
         * similar mechanism, that is as a VM_MIXEDMAP mapping.
         *
         * However this won't work here, because:
         *
         * 1. It uses vma->vm_page_prot, but this field has not been completely
         *    setup at the point of the f_op->mmp() hook, so we are unable to
         *    indicate that this should be mapped CoW in order that the
         *    mkwrite() hook can be invoked to make the first page R/W and the
         *    rest R/O as desired.
         *
         * 2. Anything other than a VM_PFNMAP of valid PFNs will result in
         *    vm_normal_page() returning a struct page * pointer, which means
         *    vm_ops->page_mkwrite() will be invoked rather than
         *    vm_ops->pfn_mkwrite(), and this means we have to set page->mapping
         *    to work around retry logic in the fault handler, however this
         *    field is no longer allowed to be used within struct page.
         *
         * 3. Having a struct page * made available in the fault logic also
         *    means that the page gets put on the rmap and becomes
         *    inappropriately accessible and subject to map and ref counting.
         *
         * Ideally we would have a mechanism that could explicitly express our
         * desires, but this is not currently the case, so we instead use
         * VM_PFNMAP.
         *
         * We manage the lifetime of these mappings with internal refcounts (see
         * perf_mmap_open() and perf_mmap_close()) so we ensure the lifetime of
         * this mapping is maintained correctly.
         */
        for (pagenum = 0; pagenum < nr_pages; pagenum++) {
                unsigned long va = vma->vm_start + PAGE_SIZE * pagenum;
                struct page *page = perf_mmap_to_page(rb, vma->vm_pgoff + pagenum);

                if (page == NULL) {
                        err = -EINVAL;
                        break;
                }

                /* Map readonly, perf_mmap_pfn_mkwrite() called on write fault. */
                err = remap_pfn_range(vma, va, page_to_pfn(page), PAGE_SIZE,
                                      vm_get_page_prot(vma->vm_flags & ~VM_SHARED));
                if (err)
                        break;
        }

#ifdef CONFIG_MMU
        /* Clear any partial mappings on error. */
        if (err)
                zap_page_range_single(vma, vma->vm_start, nr_pages * PAGE_SIZE, NULL);
#endif

        return err;
}

static bool perf_mmap_calc_limits(struct vm_area_struct *vma, long *user_extra, long *extra)
{
        unsigned long user_locked, user_lock_limit, locked, lock_limit;
        struct user_struct *user = current_user();

        user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
        /* Increase the limit linearly with more CPUs */
        user_lock_limit *= num_online_cpus();

        user_locked = atomic_long_read(&user->locked_vm);

        /*
         * sysctl_perf_event_mlock may have changed, so that
         *     user->locked_vm > user_lock_limit
         */
        if (user_locked > user_lock_limit)
                user_locked = user_lock_limit;
        user_locked += *user_extra;

        if (user_locked > user_lock_limit) {
                /*
                 * charge locked_vm until it hits user_lock_limit;
                 * charge the rest from pinned_vm
                 */
                *extra = user_locked - user_lock_limit;
                *user_extra -= *extra;
        }

        lock_limit = rlimit(RLIMIT_MEMLOCK);
        lock_limit >>= PAGE_SHIFT;
        locked = atomic64_read(&vma->vm_mm->pinned_vm) + *extra;

        return locked <= lock_limit || !perf_is_paranoid() || capable(CAP_IPC_LOCK);
}

static void perf_mmap_account(struct vm_area_struct *vma, long user_extra, long extra)
{
        struct user_struct *user = current_user();

        atomic_long_add(user_extra, &user->locked_vm);
        atomic64_add(extra, &vma->vm_mm->pinned_vm);
}

static int perf_mmap_rb(struct vm_area_struct *vma, struct perf_event *event,
                        unsigned long nr_pages)
{
        long extra = 0, user_extra = nr_pages;
        struct perf_buffer *rb;
        int rb_flags = 0;

        nr_pages -= 1;

        /*
         * If we have rb pages ensure they're a power-of-two number, so we
         * can do bitmasks instead of modulo.
         */
        if (nr_pages != 0 && !is_power_of_2(nr_pages))
                return -EINVAL;

        WARN_ON_ONCE(event->ctx->parent_ctx);

        if (event->rb) {
                if (data_page_nr(event->rb) != nr_pages)
                        return -EINVAL;

                if (refcount_inc_not_zero(&event->rb->mmap_count)) {
                        /*
                         * Success -- managed to mmap() the same buffer
                         * multiple times.
                         */
                        perf_mmap_account(vma, user_extra, extra);
                        refcount_inc(&event->mmap_count);
                        return 0;
                }

                /*
                 * Raced against perf_mmap_close()'s
                 * refcount_dec_and_mutex_lock() remove the
                 * event and continue as if !event->rb
                 */
                ring_buffer_attach(event, NULL);
        }

        if (!perf_mmap_calc_limits(vma, &user_extra, &extra))
                return -EPERM;

        if (vma->vm_flags & VM_WRITE)
                rb_flags |= RING_BUFFER_WRITABLE;

        rb = rb_alloc(nr_pages,
                      event->attr.watermark ? event->attr.wakeup_watermark : 0,
                      event->cpu, rb_flags);

        if (!rb)
                return -ENOMEM;

        refcount_set(&rb->mmap_count, 1);
        rb->mmap_user = get_current_user();
        rb->mmap_locked = extra;

        ring_buffer_attach(event, rb);

        perf_event_update_time(event);
        perf_event_init_userpage(event);
        perf_event_update_userpage(event);

        perf_mmap_account(vma, user_extra, extra);
        refcount_set(&event->mmap_count, 1);

        return 0;
}

static int perf_mmap_aux(struct vm_area_struct *vma, struct perf_event *event,
                         unsigned long nr_pages)
{
        long extra = 0, user_extra = nr_pages;
        u64 aux_offset, aux_size;
        struct perf_buffer *rb;
        int ret, rb_flags = 0;

        rb = event->rb;
        if (!rb)
                return -EINVAL;

        guard(mutex)(&rb->aux_mutex);

        /*
         * AUX area mapping: if rb->aux_nr_pages != 0, it's already
         * mapped, all subsequent mappings should have the same size
         * and offset. Must be above the normal perf buffer.
         */
        aux_offset = READ_ONCE(rb->user_page->aux_offset);
        aux_size = READ_ONCE(rb->user_page->aux_size);

        if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
                return -EINVAL;

        if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
                return -EINVAL;

        /* already mapped with a different offset */
        if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
                return -EINVAL;

        if (aux_size != nr_pages * PAGE_SIZE)
                return -EINVAL;

        /* already mapped with a different size */
        if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
                return -EINVAL;

        if (!is_power_of_2(nr_pages))
                return -EINVAL;

        if (!refcount_inc_not_zero(&rb->mmap_count))
                return -EINVAL;

        if (rb_has_aux(rb)) {
                refcount_inc(&rb->aux_mmap_count);

        } else {
                if (!perf_mmap_calc_limits(vma, &user_extra, &extra)) {
                        refcount_dec(&rb->mmap_count);
                        return -EPERM;
                }

                WARN_ON(!rb && event->rb);

                if (vma->vm_flags & VM_WRITE)
                        rb_flags |= RING_BUFFER_WRITABLE;

                ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
                                   event->attr.aux_watermark, rb_flags);
                if (ret) {
                        refcount_dec(&rb->mmap_count);
                        return ret;
                }

                refcount_set(&rb->aux_mmap_count, 1);
                rb->aux_mmap_locked = extra;
        }

        perf_mmap_account(vma, user_extra, extra);
        refcount_inc(&event->mmap_count);

        return 0;
}

static int perf_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct perf_event *event = file->private_data;
        unsigned long vma_size, nr_pages;
        mapped_f mapped;
        int ret;

        /*
         * Don't allow mmap() of inherited per-task counters. This would
         * create a performance issue due to all children writing to the
         * same rb.
         */
        if (event->cpu == -1 && event->attr.inherit)
                return -EINVAL;

        if (!(vma->vm_flags & VM_SHARED))
                return -EINVAL;

        ret = security_perf_event_read(event);
        if (ret)
                return ret;

        vma_size = vma->vm_end - vma->vm_start;
        nr_pages = vma_size / PAGE_SIZE;

        if (nr_pages > INT_MAX)
                return -ENOMEM;

        if (vma_size != PAGE_SIZE * nr_pages)
                return -EINVAL;

        scoped_guard (mutex, &event->mmap_mutex) {
                /*
                 * This relies on __pmu_detach_event() taking mmap_mutex after marking
                 * the event REVOKED. Either we observe the state, or __pmu_detach_event()
                 * will detach the rb created here.
                 */
                if (event->state <= PERF_EVENT_STATE_REVOKED)
                        return -ENODEV;

                if (vma->vm_pgoff == 0)
                        ret = perf_mmap_rb(vma, event, nr_pages);
                else
                        ret = perf_mmap_aux(vma, event, nr_pages);
                if (ret)
                        return ret;
        }

        /*
         * Since pinned accounting is per vm we cannot allow fork() to copy our
         * vma.
         */
        vm_flags_set(vma, VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP);
        vma->vm_ops = &perf_mmap_vmops;

        mapped = get_mapped(event, event_mapped);
        if (mapped)
                mapped(event, vma->vm_mm);

        /*
         * Try to map it into the page table. On fail, invoke
         * perf_mmap_close() to undo the above, as the callsite expects
         * full cleanup in this case and therefore does not invoke
         * vmops::close().
         */
        ret = map_range(event->rb, vma);
        if (ret)
                perf_mmap_close(vma);

        return ret;
}

static int perf_fasync(int fd, struct file *filp, int on)
{
        struct inode *inode = file_inode(filp);
        struct perf_event *event = filp->private_data;
        int retval;

        if (event->state <= PERF_EVENT_STATE_REVOKED)
                return -ENODEV;

        inode_lock(inode);
        retval = fasync_helper(fd, filp, on, &event->fasync);
        inode_unlock(inode);

        if (retval < 0)
                return retval;

        return 0;
}

static const struct file_operations perf_fops = {
        .release                = perf_release,
        .read                        = perf_read,
        .poll                        = perf_poll,
        .unlocked_ioctl                = perf_ioctl,
        .compat_ioctl                = perf_compat_ioctl,
        .mmap                        = perf_mmap,
        .fasync                        = perf_fasync,
};

/*
 * Perf event wakeup
 *
 * If there's data, ensure we set the poll() state and publish everything
 * to user-space before waking everybody up.
 */

void perf_event_wakeup(struct perf_event *event)
{
        ring_buffer_wakeup(event);

        if (event->pending_kill) {
                kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
                event->pending_kill = 0;
        }
}

static void perf_sigtrap(struct perf_event *event)
{
        /*
         * Both perf_pending_task() and perf_pending_irq() can race with the
         * task exiting.
         */
        if (current->flags & PF_EXITING)
                return;

        /*
         * We'd expect this to only occur if the irq_work is delayed and either
         * ctx->task or current has changed in the meantime. This can be the
         * case on architectures that do not implement arch_irq_work_raise().
         */
        if (WARN_ON_ONCE(event->ctx->task != current))
                return;

        send_sig_perf((void __user *)event->pending_addr,
                      event->orig_type, event->attr.sig_data);
}

/*
 * Deliver the pending work in-event-context or follow the context.
 */
static void __perf_pending_disable(struct perf_event *event)
{
        int cpu = READ_ONCE(event->oncpu);

        /*
         * If the event isn't running; we done. event_sched_out() will have
         * taken care of things.
         */
        if (cpu < 0)
                return;

        /*
         * Yay, we hit home and are in the context of the event.
         */
        if (cpu == smp_processor_id()) {
                if (event->pending_disable) {
                        event->pending_disable = 0;
                        perf_event_disable_local(event);
                }
                return;
        }

        /*
         *  CPU-A                        CPU-B
         *
         *  perf_event_disable_inatomic()
         *    @pending_disable = 1;
         *    irq_work_queue();
         *
         *  sched-out
         *    @pending_disable = 0;
         *
         *                                sched-in
         *                                perf_event_disable_inatomic()
         *                                  @pending_disable = 1;
         *                                  irq_work_queue(); // FAILS
         *
         *  irq_work_run()
         *    perf_pending_disable()
         *
         * But the event runs on CPU-B and wants disabling there.
         */
        irq_work_queue_on(&event->pending_disable_irq, cpu);
}

static void perf_pending_disable(struct irq_work *entry)
{
        struct perf_event *event = container_of(entry, struct perf_event, pending_disable_irq);
        int rctx;

        /*
         * If we 'fail' here, that's OK, it means recursion is already disabled
         * and we won't recurse 'further'.
         */
        rctx = perf_swevent_get_recursion_context();
        __perf_pending_disable(event);
        if (rctx >= 0)
                perf_swevent_put_recursion_context(rctx);
}

static void perf_pending_irq(struct irq_work *entry)
{
        struct perf_event *event = container_of(entry, struct perf_event, pending_irq);
        int rctx;

        /*
         * If we 'fail' here, that's OK, it means recursion is already disabled
         * and we won't recurse 'further'.
         */
        rctx = perf_swevent_get_recursion_context();

        /*
         * The wakeup isn't bound to the context of the event -- it can happen
         * irrespective of where the event is.
         */
        if (event->pending_wakeup) {
                event->pending_wakeup = 0;
                perf_event_wakeup(event);
        }

        if (rctx >= 0)
                perf_swevent_put_recursion_context(rctx);
}

static void perf_pending_task(struct callback_head *head)
{
        struct perf_event *event = container_of(head, struct perf_event, pending_task);
        int rctx;

        /*
         * If we 'fail' here, that's OK, it means recursion is already disabled
         * and we won't recurse 'further'.
         */
        rctx = perf_swevent_get_recursion_context();

        if (event->pending_work) {
                event->pending_work = 0;
                perf_sigtrap(event);
                local_dec(&event->ctx->nr_no_switch_fast);
        }
        put_event(event);

        if (rctx >= 0)
                perf_swevent_put_recursion_context(rctx);
}

#ifdef CONFIG_GUEST_PERF_EVENTS
struct perf_guest_info_callbacks __rcu *perf_guest_cbs;

DEFINE_STATIC_CALL_RET0(__perf_guest_state, *perf_guest_cbs->state);
DEFINE_STATIC_CALL_RET0(__perf_guest_get_ip, *perf_guest_cbs->get_ip);
DEFINE_STATIC_CALL_RET0(__perf_guest_handle_intel_pt_intr, *perf_guest_cbs->handle_intel_pt_intr);

void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
        if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs)))
                return;

        rcu_assign_pointer(perf_guest_cbs, cbs);
        static_call_update(__perf_guest_state, cbs->state);
        static_call_update(__perf_guest_get_ip, cbs->get_ip);

        /* Implementing ->handle_intel_pt_intr is optional. */
        if (cbs->handle_intel_pt_intr)
                static_call_update(__perf_guest_handle_intel_pt_intr,
                                   cbs->handle_intel_pt_intr);
}
EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);

void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
{
        if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs))
                return;

        rcu_assign_pointer(perf_guest_cbs, NULL);
        static_call_update(__perf_guest_state, (void *)&__static_call_return0);
        static_call_update(__perf_guest_get_ip, (void *)&__static_call_return0);
        static_call_update(__perf_guest_handle_intel_pt_intr,
                           (void *)&__static_call_return0);
        synchronize_rcu();
}
EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
#endif

static bool should_sample_guest(struct perf_event *event)
{
        return !event->attr.exclude_guest && perf_guest_state();
}

unsigned long perf_misc_flags(struct perf_event *event,
                              struct pt_regs *regs)
{
        if (should_sample_guest(event))
                return perf_arch_guest_misc_flags(regs);

        return perf_arch_misc_flags(regs);
}

unsigned long perf_instruction_pointer(struct perf_event *event,
                                       struct pt_regs *regs)
{
        if (should_sample_guest(event))
                return perf_guest_get_ip();

        return perf_arch_instruction_pointer(regs);
}

static void
perf_output_sample_regs(struct perf_output_handle *handle,
                        struct pt_regs *regs, u64 mask)
{
        int bit;
        DECLARE_BITMAP(_mask, 64);

        bitmap_from_u64(_mask, mask);
        for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) {
                u64 val;

                val = perf_reg_value(regs, bit);
                perf_output_put(handle, val);
        }
}

static void perf_sample_regs_user(struct perf_regs *regs_user,
                                  struct pt_regs *regs)
{
        if (user_mode(regs)) {
                regs_user->abi = perf_reg_abi(current);
                regs_user->regs = regs;
        } else if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER))) {
                perf_get_regs_user(regs_user, regs);
        } else {
                regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
                regs_user->regs = NULL;
        }
}

static void perf_sample_regs_intr(struct perf_regs *regs_intr,
                                  struct pt_regs *regs)
{
        regs_intr->regs = regs;
        regs_intr->abi  = perf_reg_abi(current);
}


/*
 * Get remaining task size from user stack pointer.
 *
 * It'd be better to take stack vma map and limit this more
 * precisely, but there's no way to get it safely under interrupt,
 * so using TASK_SIZE as limit.
 */
static u64 perf_ustack_task_size(struct pt_regs *regs)
{
        unsigned long addr = perf_user_stack_pointer(regs);

        if (!addr || addr >= TASK_SIZE)
                return 0;

        return TASK_SIZE - addr;
}

static u16
perf_sample_ustack_size(u16 stack_size, u16 header_size,
                        struct pt_regs *regs)
{
        u64 task_size;

        /* No regs, no stack pointer, no dump. */
        if (!regs)
                return 0;

        /* No mm, no stack, no dump. */
        if (!current->mm)
                return 0;

        /*
         * Check if we fit in with the requested stack size into the:
         * - TASK_SIZE
         *   If we don't, we limit the size to the TASK_SIZE.
         *
         * - remaining sample size
         *   If we don't, we customize the stack size to
         *   fit in to the remaining sample size.
         */

        task_size  = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
        stack_size = min(stack_size, (u16) task_size);

        /* Current header size plus static size and dynamic size. */
        header_size += 2 * sizeof(u64);

        /* Do we fit in with the current stack dump size? */
        if ((u16) (header_size + stack_size) < header_size) {
                /*
                 * If we overflow the maximum size for the sample,
                 * we customize the stack dump size to fit in.
                 */
                stack_size = USHRT_MAX - header_size - sizeof(u64);
                stack_size = round_up(stack_size, sizeof(u64));
        }

        return stack_size;
}

static void
perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
                          struct pt_regs *regs)
{
        /* Case of a kernel thread, nothing to dump */
        if (!regs) {
                u64 size = 0;
                perf_output_put(handle, size);
        } else {
                unsigned long sp;
                unsigned int rem;
                u64 dyn_size;

                /*
                 * We dump:
                 * static size
                 *   - the size requested by user or the best one we can fit
                 *     in to the sample max size
                 * data
                 *   - user stack dump data
                 * dynamic size
                 *   - the actual dumped size
                 */

                /* Static size. */
                perf_output_put(handle, dump_size);

                /* Data. */
                sp = perf_user_stack_pointer(regs);
                rem = __output_copy_user(handle, (void *) sp, dump_size);
                dyn_size = dump_size - rem;

                perf_output_skip(handle, rem);

                /* Dynamic size. */
                perf_output_put(handle, dyn_size);
        }
}

static unsigned long perf_prepare_sample_aux(struct perf_event *event,
                                          struct perf_sample_data *data,
                                          size_t size)
{
        struct perf_event *sampler = event->aux_event;
        struct perf_buffer *rb;

        data->aux_size = 0;

        if (!sampler)
                goto out;

        if (WARN_ON_ONCE(READ_ONCE(sampler->state) != PERF_EVENT_STATE_ACTIVE))
                goto out;

        if (WARN_ON_ONCE(READ_ONCE(sampler->oncpu) != smp_processor_id()))
                goto out;

        rb = ring_buffer_get(sampler);
        if (!rb)
                goto out;

        /*
         * If this is an NMI hit inside sampling code, don't take
         * the sample. See also perf_aux_sample_output().
         */
        if (READ_ONCE(rb->aux_in_sampling)) {
                data->aux_size = 0;
        } else {
                size = min_t(size_t, size, perf_aux_size(rb));
                data->aux_size = ALIGN(size, sizeof(u64));
        }
        ring_buffer_put(rb);

out:
        return data->aux_size;
}

static long perf_pmu_snapshot_aux(struct perf_buffer *rb,
                                 struct perf_event *event,
                                 struct perf_output_handle *handle,
                                 unsigned long size)
{
        unsigned long flags;
        long ret;

        /*
         * Normal ->start()/->stop() callbacks run in IRQ mode in scheduler
         * paths. If we start calling them in NMI context, they may race with
         * the IRQ ones, that is, for example, re-starting an event that's just
         * been stopped, which is why we're using a separate callback that
         * doesn't change the event state.
         *
         * IRQs need to be disabled to prevent IPIs from racing with us.
         */
        local_irq_save(flags);
        /*
         * Guard against NMI hits inside the critical section;
         * see also perf_prepare_sample_aux().
         */
        WRITE_ONCE(rb->aux_in_sampling, 1);
        barrier();

        ret = event->pmu->snapshot_aux(event, handle, size);

        barrier();
        WRITE_ONCE(rb->aux_in_sampling, 0);
        local_irq_restore(flags);

        return ret;
}

static void perf_aux_sample_output(struct perf_event *event,
                                   struct perf_output_handle *handle,
                                   struct perf_sample_data *data)
{
        struct perf_event *sampler = event->aux_event;
        struct perf_buffer *rb;
        unsigned long pad;
        long size;

        if (WARN_ON_ONCE(!sampler || !data->aux_size))
                return;

        rb = ring_buffer_get(sampler);
        if (!rb)
                return;

        size = perf_pmu_snapshot_aux(rb, sampler, handle, data->aux_size);

        /*
         * An error here means that perf_output_copy() failed (returned a
         * non-zero surplus that it didn't copy), which in its current
         * enlightened implementation is not possible. If that changes, we'd
         * like to know.
         */
        if (WARN_ON_ONCE(size < 0))
                goto out_put;

        /*
         * The pad comes from ALIGN()ing data->aux_size up to u64 in
         * perf_prepare_sample_aux(), so should not be more than that.
         */
        pad = data->aux_size - size;
        if (WARN_ON_ONCE(pad >= sizeof(u64)))
                pad = 8;

        if (pad) {
                u64 zero = 0;
                perf_output_copy(handle, &zero, pad);
        }

out_put:
        ring_buffer_put(rb);
}

/*
 * A set of common sample data types saved even for non-sample records
 * when event->attr.sample_id_all is set.
 */
#define PERF_SAMPLE_ID_ALL  (PERF_SAMPLE_TID | PERF_SAMPLE_TIME |        \
                             PERF_SAMPLE_ID | PERF_SAMPLE_STREAM_ID |        \
                             PERF_SAMPLE_CPU | PERF_SAMPLE_IDENTIFIER)

static void __perf_event_header__init_id(struct perf_sample_data *data,
                                         struct perf_event *event,
                                         u64 sample_type)
{
        data->type = event->attr.sample_type;
        data->sample_flags |= data->type & PERF_SAMPLE_ID_ALL;

        if (sample_type & PERF_SAMPLE_TID) {
                /* namespace issues */
                data->tid_entry.pid = perf_event_pid(event, current);
                data->tid_entry.tid = perf_event_tid(event, current);
        }

        if (sample_type & PERF_SAMPLE_TIME)
                data->time = perf_event_clock(event);

        if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
                data->id = primary_event_id(event);

        if (sample_type & PERF_SAMPLE_STREAM_ID)
                data->stream_id = event->id;

        if (sample_type & PERF_SAMPLE_CPU) {
                data->cpu_entry.cpu         = raw_smp_processor_id();
                data->cpu_entry.reserved = 0;
        }
}

void perf_event_header__init_id(struct perf_event_header *header,
                                struct perf_sample_data *data,
                                struct perf_event *event)
{
        if (event->attr.sample_id_all) {
                header->size += event->id_header_size;
                __perf_event_header__init_id(data, event, event->attr.sample_type);
        }
}

static void __perf_event__output_id_sample(struct perf_output_handle *handle,
                                           struct perf_sample_data *data)
{
        u64 sample_type = data->type;

        if (sample_type & PERF_SAMPLE_TID)
                perf_output_put(handle, data->tid_entry);

        if (sample_type & PERF_SAMPLE_TIME)
                perf_output_put(handle, data->time);

        if (sample_type & PERF_SAMPLE_ID)
                perf_output_put(handle, data->id);

        if (sample_type & PERF_SAMPLE_STREAM_ID)
                perf_output_put(handle, data->stream_id);

        if (sample_type & PERF_SAMPLE_CPU)
                perf_output_put(handle, data->cpu_entry);

        if (sample_type & PERF_SAMPLE_IDENTIFIER)
                perf_output_put(handle, data->id);
}

void perf_event__output_id_sample(struct perf_event *event,
                                  struct perf_output_handle *handle,
                                  struct perf_sample_data *sample)
{
        if (event->attr.sample_id_all)
                __perf_event__output_id_sample(handle, sample);
}

static void perf_output_read_one(struct perf_output_handle *handle,
                                 struct perf_event *event,
                                 u64 enabled, u64 running)
{
        u64 read_format = event->attr.read_format;
        u64 values[5];
        int n = 0;

        values[n++] = perf_event_count(event, has_inherit_and_sample_read(&event->attr));
        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
                values[n++] = enabled +
                        atomic64_read(&event->child_total_time_enabled);
        }
        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
                values[n++] = running +
                        atomic64_read(&event->child_total_time_running);
        }
        if (read_format & PERF_FORMAT_ID)
                values[n++] = primary_event_id(event);
        if (read_format & PERF_FORMAT_LOST)
                values[n++] = atomic64_read(&event->lost_samples);

        __output_copy(handle, values, n * sizeof(u64));
}

static void perf_output_read_group(struct perf_output_handle *handle,
                                   struct perf_event *event,
                                   u64 enabled, u64 running)
{
        struct perf_event *leader = event->group_leader, *sub;
        u64 read_format = event->attr.read_format;
        unsigned long flags;
        u64 values[6];
        int n = 0;
        bool self = has_inherit_and_sample_read(&event->attr);

        /*
         * Disabling interrupts avoids all counter scheduling
         * (context switches, timer based rotation and IPIs).
         */
        local_irq_save(flags);

        values[n++] = 1 + leader->nr_siblings;

        if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
                values[n++] = enabled;

        if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
                values[n++] = running;

        if ((leader != event) && !handle->skip_read)
                perf_pmu_read(leader);

        values[n++] = perf_event_count(leader, self);
        if (read_format & PERF_FORMAT_ID)
                values[n++] = primary_event_id(leader);
        if (read_format & PERF_FORMAT_LOST)
                values[n++] = atomic64_read(&leader->lost_samples);

        __output_copy(handle, values, n * sizeof(u64));

        for_each_sibling_event(sub, leader) {
                n = 0;

                if ((sub != event) && !handle->skip_read)
                        perf_pmu_read(sub);

                values[n++] = perf_event_count(sub, self);
                if (read_format & PERF_FORMAT_ID)
                        values[n++] = primary_event_id(sub);
                if (read_format & PERF_FORMAT_LOST)
                        values[n++] = atomic64_read(&sub->lost_samples);

                __output_copy(handle, values, n * sizeof(u64));
        }

        local_irq_restore(flags);
}

#define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
                                 PERF_FORMAT_TOTAL_TIME_RUNNING)

/*
 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
 *
 * The problem is that its both hard and excessively expensive to iterate the
 * child list, not to mention that its impossible to IPI the children running
 * on another CPU, from interrupt/NMI context.
 *
 * Instead the combination of PERF_SAMPLE_READ and inherit will track per-thread
 * counts rather than attempting to accumulate some value across all children on
 * all cores.
 */
static void perf_output_read(struct perf_output_handle *handle,
                             struct perf_event *event)
{
        u64 enabled = 0, running = 0, now;
        u64 read_format = event->attr.read_format;

        /*
         * compute total_time_enabled, total_time_running
         * based on snapshot values taken when the event
         * was last scheduled in.
         *
         * we cannot simply called update_context_time()
         * because of locking issue as we are called in
         * NMI context
         */
        if (read_format & PERF_FORMAT_TOTAL_TIMES)
                calc_timer_values(event, &now, &enabled, &running);

        if (event->attr.read_format & PERF_FORMAT_GROUP)
                perf_output_read_group(handle, event, enabled, running);
        else
                perf_output_read_one(handle, event, enabled, running);
}

void perf_output_sample(struct perf_output_handle *handle,
                        struct perf_event_header *header,
                        struct perf_sample_data *data,
                        struct perf_event *event)
{
        u64 sample_type = data->type;

        if (data->sample_flags & PERF_SAMPLE_READ)
                handle->skip_read = 1;

        perf_output_put(handle, *header);

        if (sample_type & PERF_SAMPLE_IDENTIFIER)
                perf_output_put(handle, data->id);

        if (sample_type & PERF_SAMPLE_IP)
                perf_output_put(handle, data->ip);

        if (sample_type & PERF_SAMPLE_TID)
                perf_output_put(handle, data->tid_entry);

        if (sample_type & PERF_SAMPLE_TIME)
                perf_output_put(handle, data->time);

        if (sample_type & PERF_SAMPLE_ADDR)
                perf_output_put(handle, data->addr);

        if (sample_type & PERF_SAMPLE_ID)
                perf_output_put(handle, data->id);

        if (sample_type & PERF_SAMPLE_STREAM_ID)
                perf_output_put(handle, data->stream_id);

        if (sample_type & PERF_SAMPLE_CPU)
                perf_output_put(handle, data->cpu_entry);

        if (sample_type & PERF_SAMPLE_PERIOD)
                perf_output_put(handle, data->period);

        if (sample_type & PERF_SAMPLE_READ)
                perf_output_read(handle, event);

        if (sample_type & PERF_SAMPLE_CALLCHAIN) {
                int size = 1;

                size += data->callchain->nr;
                size *= sizeof(u64);
                __output_copy(handle, data->callchain, size);
        }

        if (sample_type & PERF_SAMPLE_RAW) {
                struct perf_raw_record *raw = data->raw;

                if (raw) {
                        struct perf_raw_frag *frag = &raw->frag;

                        perf_output_put(handle, raw->size);
                        do {
                                if (frag->copy) {
                                        __output_custom(handle, frag->copy,
                                                        frag->data, frag->size);
                                } else {
                                        __output_copy(handle, frag->data,
                                                      frag->size);
                                }
                                if (perf_raw_frag_last(frag))
                                        break;
                                frag = frag->next;
                        } while (1);
                        if (frag->pad)
                                __output_skip(handle, NULL, frag->pad);
                } else {
                        struct {
                                u32        size;
                                u32        data;
                        } raw = {
                                .size = sizeof(u32),
                                .data = 0,
                        };
                        perf_output_put(handle, raw);
                }
        }

        if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
                if (data->br_stack) {
                        size_t size;

                        size = data->br_stack->nr
                             * sizeof(struct perf_branch_entry);

                        perf_output_put(handle, data->br_stack->nr);
                        if (branch_sample_hw_index(event))
                                perf_output_put(handle, data->br_stack->hw_idx);
                        perf_output_copy(handle, data->br_stack->entries, size);
                        /*
                         * Add the extension space which is appended
                         * right after the struct perf_branch_stack.
                         */
                        if (data->br_stack_cntr) {
                                size = data->br_stack->nr * sizeof(u64);
                                perf_output_copy(handle, data->br_stack_cntr, size);
                        }
                } else {
                        /*
                         * we always store at least the value of nr
                         */
                        u64 nr = 0;
                        perf_output_put(handle, nr);
                }
        }

        if (sample_type & PERF_SAMPLE_REGS_USER) {
                u64 abi = data->regs_user.abi;

                /*
                 * If there are no regs to dump, notice it through
                 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
                 */
                perf_output_put(handle, abi);

                if (abi) {
                        u64 mask = event->attr.sample_regs_user;
                        perf_output_sample_regs(handle,
                                                data->regs_user.regs,
                                                mask);
                }
        }

        if (sample_type & PERF_SAMPLE_STACK_USER) {
                perf_output_sample_ustack(handle,
                                          data->stack_user_size,
                                          data->regs_user.regs);
        }

        if (sample_type & PERF_SAMPLE_WEIGHT_TYPE)
                perf_output_put(handle, data->weight.full);

        if (sample_type & PERF_SAMPLE_DATA_SRC)
                perf_output_put(handle, data->data_src.val);

        if (sample_type & PERF_SAMPLE_TRANSACTION)
                perf_output_put(handle, data->txn);

        if (sample_type & PERF_SAMPLE_REGS_INTR) {
                u64 abi = data->regs_intr.abi;
                /*
                 * If there are no regs to dump, notice it through
                 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
                 */
                perf_output_put(handle, abi);

                if (abi) {
                        u64 mask = event->attr.sample_regs_intr;

                        perf_output_sample_regs(handle,
                                                data->regs_intr.regs,
                                                mask);
                }
        }

        if (sample_type & PERF_SAMPLE_PHYS_ADDR)
                perf_output_put(handle, data->phys_addr);

        if (sample_type & PERF_SAMPLE_CGROUP)
                perf_output_put(handle, data->cgroup);

        if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
                perf_output_put(handle, data->data_page_size);

        if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
                perf_output_put(handle, data->code_page_size);

        if (sample_type & PERF_SAMPLE_AUX) {
                perf_output_put(handle, data->aux_size);

                if (data->aux_size)
                        perf_aux_sample_output(event, handle, data);
        }

        if (!event->attr.watermark) {
                int wakeup_events = event->attr.wakeup_events;

                if (wakeup_events) {
                        struct perf_buffer *rb = handle->rb;
                        int events = local_inc_return(&rb->events);

                        if (events >= wakeup_events) {
                                local_sub(wakeup_events, &rb->events);
                                local_inc(&rb->wakeup);
                        }
                }
        }
}

static u64 perf_virt_to_phys(u64 virt)
{
        u64 phys_addr = 0;

        if (!virt)
                return 0;

        if (virt >= TASK_SIZE) {
                /* If it's vmalloc()d memory, leave phys_addr as 0 */
                if (virt_addr_valid((void *)(uintptr_t)virt) &&
                    !(virt >= VMALLOC_START && virt < VMALLOC_END))
                        phys_addr = (u64)virt_to_phys((void *)(uintptr_t)virt);
        } else {
                /*
                 * Walking the pages tables for user address.
                 * Interrupts are disabled, so it prevents any tear down
                 * of the page tables.
                 * Try IRQ-safe get_user_page_fast_only first.
                 * If failed, leave phys_addr as 0.
                 */
                if (!(current->flags & (PF_KTHREAD | PF_USER_WORKER))) {
                        struct page *p;

                        pagefault_disable();
                        if (get_user_page_fast_only(virt, 0, &p)) {
                                phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
                                put_page(p);
                        }
                        pagefault_enable();
                }
        }

        return phys_addr;
}

/*
 * Return the pagetable size of a given virtual address.
 */
static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
{
        u64 size = 0;

#ifdef CONFIG_HAVE_GUP_FAST
        pgd_t *pgdp, pgd;
        p4d_t *p4dp, p4d;
        pud_t *pudp, pud;
        pmd_t *pmdp, pmd;
        pte_t *ptep, pte;

        pgdp = pgd_offset(mm, addr);
        pgd = READ_ONCE(*pgdp);
        if (pgd_none(pgd))
                return 0;

        if (pgd_leaf(pgd))
                return pgd_leaf_size(pgd);

        p4dp = p4d_offset_lockless(pgdp, pgd, addr);
        p4d = READ_ONCE(*p4dp);
        if (!p4d_present(p4d))
                return 0;

        if (p4d_leaf(p4d))
                return p4d_leaf_size(p4d);

        pudp = pud_offset_lockless(p4dp, p4d, addr);
        pud = READ_ONCE(*pudp);
        if (!pud_present(pud))
                return 0;

        if (pud_leaf(pud))
                return pud_leaf_size(pud);

        pmdp = pmd_offset_lockless(pudp, pud, addr);
again:
        pmd = pmdp_get_lockless(pmdp);
        if (!pmd_present(pmd))
                return 0;

        if (pmd_leaf(pmd))
                return pmd_leaf_size(pmd);

        ptep = pte_offset_map(&pmd, addr);
        if (!ptep)
                goto again;

        pte = ptep_get_lockless(ptep);
        if (pte_present(pte))
                size = __pte_leaf_size(pmd, pte);
        pte_unmap(ptep);
#endif /* CONFIG_HAVE_GUP_FAST */

        return size;
}

static u64 perf_get_page_size(unsigned long addr)
{
        struct mm_struct *mm;
        unsigned long flags;
        u64 size;

        if (!addr)
                return 0;

        /*
         * Software page-table walkers must disable IRQs,
         * which prevents any tear down of the page tables.
         */
        local_irq_save(flags);

        mm = current->mm;
        if (!mm) {
                /*
                 * For kernel threads and the like, use init_mm so that
                 * we can find kernel memory.
                 */
                mm = &init_mm;
        }

        size = perf_get_pgtable_size(mm, addr);

        local_irq_restore(flags);

        return size;
}

static struct perf_callchain_entry __empty_callchain = { .nr = 0, };

struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
        bool kernel = !event->attr.exclude_callchain_kernel;
        bool user   = !event->attr.exclude_callchain_user &&
                !(current->flags & (PF_KTHREAD | PF_USER_WORKER));
        /* Disallow cross-task user callchains. */
        bool crosstask = event->ctx->task && event->ctx->task != current;
        const u32 max_stack = event->attr.sample_max_stack;
        struct perf_callchain_entry *callchain;

        if (!current->mm)
                user = false;

        if (!kernel && !user)
                return &__empty_callchain;

        callchain = get_perf_callchain(regs, kernel, user,
                                       max_stack, crosstask, true);
        return callchain ?: &__empty_callchain;
}

static __always_inline u64 __cond_set(u64 flags, u64 s, u64 d)
{
        return d * !!(flags & s);
}

void perf_prepare_sample(struct perf_sample_data *data,
                         struct perf_event *event,
                         struct pt_regs *regs)
{
        u64 sample_type = event->attr.sample_type;
        u64 filtered_sample_type;

        /*
         * Add the sample flags that are dependent to others.  And clear the
         * sample flags that have already been done by the PMU driver.
         */
        filtered_sample_type = sample_type;
        filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_CODE_PAGE_SIZE,
                                           PERF_SAMPLE_IP);
        filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_DATA_PAGE_SIZE |
                                           PERF_SAMPLE_PHYS_ADDR, PERF_SAMPLE_ADDR);
        filtered_sample_type |= __cond_set(sample_type, PERF_SAMPLE_STACK_USER,
                                           PERF_SAMPLE_REGS_USER);
        filtered_sample_type &= ~data->sample_flags;

        if (filtered_sample_type == 0) {
                /* Make sure it has the correct data->type for output */
                data->type = event->attr.sample_type;
                return;
        }

        __perf_event_header__init_id(data, event, filtered_sample_type);

        if (filtered_sample_type & PERF_SAMPLE_IP) {
                data->ip = perf_instruction_pointer(event, regs);
                data->sample_flags |= PERF_SAMPLE_IP;
        }

        if (filtered_sample_type & PERF_SAMPLE_CALLCHAIN)
                perf_sample_save_callchain(data, event, regs);

        if (filtered_sample_type & PERF_SAMPLE_RAW) {
                data->raw = NULL;
                data->dyn_size += sizeof(u64);
                data->sample_flags |= PERF_SAMPLE_RAW;
        }

        if (filtered_sample_type & PERF_SAMPLE_BRANCH_STACK) {
                data->br_stack = NULL;
                data->dyn_size += sizeof(u64);
                data->sample_flags |= PERF_SAMPLE_BRANCH_STACK;
        }

        if (filtered_sample_type & PERF_SAMPLE_REGS_USER)
                perf_sample_regs_user(&data->regs_user, regs);

        /*
         * It cannot use the filtered_sample_type here as REGS_USER can be set
         * by STACK_USER (using __cond_set() above) and we don't want to update
         * the dyn_size if it's not requested by users.
         */
        if ((sample_type & ~data->sample_flags) & PERF_SAMPLE_REGS_USER) {
                /* regs dump ABI info */
                int size = sizeof(u64);

                if (data->regs_user.regs) {
                        u64 mask = event->attr.sample_regs_user;
                        size += hweight64(mask) * sizeof(u64);
                }

                data->dyn_size += size;
                data->sample_flags |= PERF_SAMPLE_REGS_USER;
        }

        if (filtered_sample_type & PERF_SAMPLE_STACK_USER) {
                /*
                 * Either we need PERF_SAMPLE_STACK_USER bit to be always
                 * processed as the last one or have additional check added
                 * in case new sample type is added, because we could eat
                 * up the rest of the sample size.
                 */
                u16 stack_size = event->attr.sample_stack_user;
                u16 header_size = perf_sample_data_size(data, event);
                u16 size = sizeof(u64);

                stack_size = perf_sample_ustack_size(stack_size, header_size,
                                                     data->regs_user.regs);

                /*
                 * If there is something to dump, add space for the dump
                 * itself and for the field that tells the dynamic size,
                 * which is how many have been actually dumped.
                 */
                if (stack_size)
                        size += sizeof(u64) + stack_size;

                data->stack_user_size = stack_size;
                data->dyn_size += size;
                data->sample_flags |= PERF_SAMPLE_STACK_USER;
        }

        if (filtered_sample_type & PERF_SAMPLE_WEIGHT_TYPE) {
                data->weight.full = 0;
                data->sample_flags |= PERF_SAMPLE_WEIGHT_TYPE;
        }

        if (filtered_sample_type & PERF_SAMPLE_DATA_SRC) {
                data->data_src.val = PERF_MEM_NA;
                data->sample_flags |= PERF_SAMPLE_DATA_SRC;
        }

        if (filtered_sample_type & PERF_SAMPLE_TRANSACTION) {
                data->txn = 0;
                data->sample_flags |= PERF_SAMPLE_TRANSACTION;
        }

        if (filtered_sample_type & PERF_SAMPLE_ADDR) {
                data->addr = 0;
                data->sample_flags |= PERF_SAMPLE_ADDR;
        }

        if (filtered_sample_type & PERF_SAMPLE_REGS_INTR) {
                /* regs dump ABI info */
                int size = sizeof(u64);

                perf_sample_regs_intr(&data->regs_intr, regs);

                if (data->regs_intr.regs) {
                        u64 mask = event->attr.sample_regs_intr;

                        size += hweight64(mask) * sizeof(u64);
                }

                data->dyn_size += size;
                data->sample_flags |= PERF_SAMPLE_REGS_INTR;
        }

        if (filtered_sample_type & PERF_SAMPLE_PHYS_ADDR) {
                data->phys_addr = perf_virt_to_phys(data->addr);
                data->sample_flags |= PERF_SAMPLE_PHYS_ADDR;
        }

#ifdef CONFIG_CGROUP_PERF
        if (filtered_sample_type & PERF_SAMPLE_CGROUP) {
                struct cgroup *cgrp;

                /* protected by RCU */
                cgrp = task_css_check(current, perf_event_cgrp_id, 1)->cgroup;
                data->cgroup = cgroup_id(cgrp);
                data->sample_flags |= PERF_SAMPLE_CGROUP;
        }
#endif

        /*
         * PERF_DATA_PAGE_SIZE requires PERF_SAMPLE_ADDR. If the user doesn't
         * require PERF_SAMPLE_ADDR, kernel implicitly retrieve the data->addr,
         * but the value will not dump to the userspace.
         */
        if (filtered_sample_type & PERF_SAMPLE_DATA_PAGE_SIZE) {
                data->data_page_size = perf_get_page_size(data->addr);
                data->sample_flags |= PERF_SAMPLE_DATA_PAGE_SIZE;
        }

        if (filtered_sample_type & PERF_SAMPLE_CODE_PAGE_SIZE) {
                data->code_page_size = perf_get_page_size(data->ip);
                data->sample_flags |= PERF_SAMPLE_CODE_PAGE_SIZE;
        }

        if (filtered_sample_type & PERF_SAMPLE_AUX) {
                u64 size;
                u16 header_size = perf_sample_data_size(data, event);

                header_size += sizeof(u64); /* size */

                /*
                 * Given the 16bit nature of header::size, an AUX sample can
                 * easily overflow it, what with all the preceding sample bits.
                 * Make sure this doesn't happen by using up to U16_MAX bytes
                 * per sample in total (rounded down to 8 byte boundary).
                 */
                size = min_t(size_t, U16_MAX - header_size,
                             event->attr.aux_sample_size);
                size = rounddown(size, 8);
                size = perf_prepare_sample_aux(event, data, size);

                WARN_ON_ONCE(size + header_size > U16_MAX);
                data->dyn_size += size + sizeof(u64); /* size above */
                data->sample_flags |= PERF_SAMPLE_AUX;
        }
}

void perf_prepare_header(struct perf_event_header *header,
                         struct perf_sample_data *data,
                         struct perf_event *event,
                         struct pt_regs *regs)
{
        header->type = PERF_RECORD_SAMPLE;
        header->size = perf_sample_data_size(data, event);
        header->misc = perf_misc_flags(event, regs);

        /*
         * If you're adding more sample types here, you likely need to do
         * something about the overflowing header::size, like repurpose the
         * lowest 3 bits of size, which should be always zero at the moment.
         * This raises a more important question, do we really need 512k sized
         * samples and why, so good argumentation is in order for whatever you
         * do here next.
         */
        WARN_ON_ONCE(header->size & 7);
}

static void __perf_event_aux_pause(struct perf_event *event, bool pause)
{
        if (pause) {
                if (!event->hw.aux_paused) {
                        event->hw.aux_paused = 1;
                        event->pmu->stop(event, PERF_EF_PAUSE);
                }
        } else {
                if (event->hw.aux_paused) {
                        event->hw.aux_paused = 0;
                        event->pmu->start(event, PERF_EF_RESUME);
                }
        }
}

static void perf_event_aux_pause(struct perf_event *event, bool pause)
{
        struct perf_buffer *rb;

        if (WARN_ON_ONCE(!event))
                return;

        rb = ring_buffer_get(event);
        if (!rb)
                return;

        scoped_guard (irqsave) {
                /*
                 * Guard against self-recursion here. Another event could trip
                 * this same from NMI context.
                 */
                if (READ_ONCE(rb->aux_in_pause_resume))
                        break;

                WRITE_ONCE(rb->aux_in_pause_resume, 1);
                barrier();
                __perf_event_aux_pause(event, pause);
                barrier();
                WRITE_ONCE(rb->aux_in_pause_resume, 0);
        }
        ring_buffer_put(rb);
}

static __always_inline int
__perf_event_output(struct perf_event *event,
                    struct perf_sample_data *data,
                    struct pt_regs *regs,
                    int (*output_begin)(struct perf_output_handle *,
                                        struct perf_sample_data *,
                                        struct perf_event *,
                                        unsigned int))
{
        struct perf_output_handle handle;
        struct perf_event_header header;
        int err;

        /* protect the callchain buffers */
        rcu_read_lock();

        perf_prepare_sample(data, event, regs);
        perf_prepare_header(&header, data, event, regs);

        err = output_begin(&handle, data, event, header.size);
        if (err)
                goto exit;

        perf_output_sample(&handle, &header, data, event);

        perf_output_end(&handle);

exit:
        rcu_read_unlock();
        return err;
}

void
perf_event_output_forward(struct perf_event *event,
                         struct perf_sample_data *data,
                         struct pt_regs *regs)
{
        __perf_event_output(event, data, regs, perf_output_begin_forward);
}

void
perf_event_output_backward(struct perf_event *event,
                           struct perf_sample_data *data,
                           struct pt_regs *regs)
{
        __perf_event_output(event, data, regs, perf_output_begin_backward);
}

int
perf_event_output(struct perf_event *event,
                  struct perf_sample_data *data,
                  struct pt_regs *regs)
{
        return __perf_event_output(event, data, regs, perf_output_begin);
}

/*
 * read event_id
 */

struct perf_read_event {
        struct perf_event_header        header;

        u32                                pid;
        u32                                tid;
};

static void
perf_event_read_event(struct perf_event *event,
                        struct task_struct *task)
{
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        struct perf_read_event read_event = {
                .header = {
                        .type = PERF_RECORD_READ,
                        .misc = 0,
                        .size = sizeof(read_event) + event->read_size,
                },
                .pid = perf_event_pid(event, task),
                .tid = perf_event_tid(event, task),
        };
        int ret;

        perf_event_header__init_id(&read_event.header, &sample, event);
        ret = perf_output_begin(&handle, &sample, event, read_event.header.size);
        if (ret)
                return;

        perf_output_put(&handle, read_event);
        perf_output_read(&handle, event);
        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

typedef void (perf_iterate_f)(struct perf_event *event, void *data);

static void
perf_iterate_ctx(struct perf_event_context *ctx,
                   perf_iterate_f output,
                   void *data, bool all)
{
        struct perf_event *event;

        list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                if (!all) {
                        if (event->state < PERF_EVENT_STATE_INACTIVE)
                                continue;
                        if (!event_filter_match(event))
                                continue;
                }

                output(event, data);
        }
}

static void perf_iterate_sb_cpu(perf_iterate_f output, void *data)
{
        struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events);
        struct perf_event *event;

        list_for_each_entry_rcu(event, &pel->list, sb_list) {
                /*
                 * Skip events that are not fully formed yet; ensure that
                 * if we observe event->ctx, both event and ctx will be
                 * complete enough. See perf_install_in_context().
                 */
                if (!smp_load_acquire(&event->ctx))
                        continue;

                if (event->state < PERF_EVENT_STATE_INACTIVE)
                        continue;
                if (!event_filter_match(event))
                        continue;
                output(event, data);
        }
}

/*
 * Iterate all events that need to receive side-band events.
 *
 * For new callers; ensure that account_pmu_sb_event() includes
 * your event, otherwise it might not get delivered.
 */
static void
perf_iterate_sb(perf_iterate_f output, void *data,
               struct perf_event_context *task_ctx)
{
        struct perf_event_context *ctx;

        rcu_read_lock();
        preempt_disable();

        /*
         * If we have task_ctx != NULL we only notify the task context itself.
         * The task_ctx is set only for EXIT events before releasing task
         * context.
         */
        if (task_ctx) {
                perf_iterate_ctx(task_ctx, output, data, false);
                goto done;
        }

        perf_iterate_sb_cpu(output, data);

        ctx = rcu_dereference(current->perf_event_ctxp);
        if (ctx)
                perf_iterate_ctx(ctx, output, data, false);
done:
        preempt_enable();
        rcu_read_unlock();
}

/*
 * Clear all file-based filters at exec, they'll have to be
 * re-instated when/if these objects are mmapped again.
 */
static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
{
        struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
        struct perf_addr_filter *filter;
        unsigned int restart = 0, count = 0;
        unsigned long flags;

        if (!has_addr_filter(event))
                return;

        raw_spin_lock_irqsave(&ifh->lock, flags);
        list_for_each_entry(filter, &ifh->list, entry) {
                if (filter->path.dentry) {
                        event->addr_filter_ranges[count].start = 0;
                        event->addr_filter_ranges[count].size = 0;
                        restart++;
                }

                count++;
        }

        if (restart)
                event->addr_filters_gen++;
        raw_spin_unlock_irqrestore(&ifh->lock, flags);

        if (restart)
                perf_event_stop(event, 1);
}

void perf_event_exec(void)
{
        struct perf_event_context *ctx;

        ctx = perf_pin_task_context(current);
        if (!ctx)
                return;

        perf_event_enable_on_exec(ctx);
        perf_event_remove_on_exec(ctx);
        scoped_guard(rcu)
                perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true);

        perf_unpin_context(ctx);
        put_ctx(ctx);
}

struct remote_output {
        struct perf_buffer        *rb;
        int                        err;
};

static void __perf_event_output_stop(struct perf_event *event, void *data)
{
        struct perf_event *parent = event->parent;
        struct remote_output *ro = data;
        struct perf_buffer *rb = ro->rb;
        struct stop_event_data sd = {
                .event        = event,
        };

        if (!has_aux(event))
                return;

        if (!parent)
                parent = event;

        /*
         * In case of inheritance, it will be the parent that links to the
         * ring-buffer, but it will be the child that's actually using it.
         *
         * We are using event::rb to determine if the event should be stopped,
         * however this may race with ring_buffer_attach() (through set_output),
         * which will make us skip the event that actually needs to be stopped.
         * So ring_buffer_attach() has to stop an aux event before re-assigning
         * its rb pointer.
         */
        if (rcu_dereference(parent->rb) == rb)
                ro->err = __perf_event_stop(&sd);
}

static int __perf_pmu_output_stop(void *info)
{
        struct perf_event *event = info;
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct remote_output ro = {
                .rb        = event->rb,
        };

        rcu_read_lock();
        perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
        if (cpuctx->task_ctx)
                perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop,
                                   &ro, false);
        rcu_read_unlock();

        return ro.err;
}

static void perf_pmu_output_stop(struct perf_event *event)
{
        struct perf_event *iter;
        int err, cpu;

restart:
        rcu_read_lock();
        list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
                /*
                 * For per-CPU events, we need to make sure that neither they
                 * nor their children are running; for cpu==-1 events it's
                 * sufficient to stop the event itself if it's active, since
                 * it can't have children.
                 */
                cpu = iter->cpu;
                if (cpu == -1)
                        cpu = READ_ONCE(iter->oncpu);

                if (cpu == -1)
                        continue;

                err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
                if (err == -EAGAIN) {
                        rcu_read_unlock();
                        goto restart;
                }
        }
        rcu_read_unlock();
}

/*
 * task tracking -- fork/exit
 *
 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
 */

struct perf_task_event {
        struct task_struct                *task;
        struct perf_event_context        *task_ctx;

        struct {
                struct perf_event_header        header;

                u32                                pid;
                u32                                ppid;
                u32                                tid;
                u32                                ptid;
                u64                                time;
        } event_id;
};

static int perf_event_task_match(struct perf_event *event)
{
        return event->attr.comm  || event->attr.mmap ||
               event->attr.mmap2 || event->attr.mmap_data ||
               event->attr.task;
}

static void perf_event_task_output(struct perf_event *event,
                                   void *data)
{
        struct perf_task_event *task_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data        sample;
        struct task_struct *task = task_event->task;
        int ret, size = task_event->event_id.header.size;

        if (!perf_event_task_match(event))
                return;

        perf_event_header__init_id(&task_event->event_id.header, &sample, event);

        ret = perf_output_begin(&handle, &sample, event,
                                task_event->event_id.header.size);
        if (ret)
                goto out;

        task_event->event_id.pid = perf_event_pid(event, task);
        task_event->event_id.tid = perf_event_tid(event, task);

        if (task_event->event_id.header.type == PERF_RECORD_EXIT) {
                task_event->event_id.ppid = perf_event_pid(event,
                                                        task->real_parent);
                task_event->event_id.ptid = perf_event_pid(event,
                                                        task->real_parent);
        } else {  /* PERF_RECORD_FORK */
                task_event->event_id.ppid = perf_event_pid(event, current);
                task_event->event_id.ptid = perf_event_tid(event, current);
        }

        task_event->event_id.time = perf_event_clock(event);

        perf_output_put(&handle, task_event->event_id);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
out:
        task_event->event_id.header.size = size;
}

static void perf_event_task(struct task_struct *task,
                              struct perf_event_context *task_ctx,
                              int new)
{
        struct perf_task_event task_event;

        if (!atomic_read(&nr_comm_events) &&
            !atomic_read(&nr_mmap_events) &&
            !atomic_read(&nr_task_events))
                return;

        task_event = (struct perf_task_event){
                .task          = task,
                .task_ctx = task_ctx,
                .event_id    = {
                        .header = {
                                .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
                                .misc = 0,
                                .size = sizeof(task_event.event_id),
                        },
                        /* .pid  */
                        /* .ppid */
                        /* .tid  */
                        /* .ptid */
                        /* .time */
                },
        };

        perf_iterate_sb(perf_event_task_output,
                       &task_event,
                       task_ctx);
}

/*
 * Allocate data for a new task when profiling system-wide
 * events which require PMU specific data
 */
static void
perf_event_alloc_task_data(struct task_struct *child,
                           struct task_struct *parent)
{
        struct kmem_cache *ctx_cache = NULL;
        struct perf_ctx_data *cd;

        if (!refcount_read(&global_ctx_data_ref))
                return;

        scoped_guard (rcu) {
                cd = rcu_dereference(parent->perf_ctx_data);
                if (cd)
                        ctx_cache = cd->ctx_cache;
        }

        if (!ctx_cache)
                return;

        guard(percpu_read)(&global_ctx_data_rwsem);
        scoped_guard (rcu) {
                cd = rcu_dereference(child->perf_ctx_data);
                if (!cd) {
                        /*
                         * A system-wide event may be unaccount,
                         * when attaching the perf_ctx_data.
                         */
                        if (!refcount_read(&global_ctx_data_ref))
                                return;
                        goto attach;
                }

                if (!cd->global) {
                        cd->global = 1;
                        refcount_inc(&cd->refcount);
                }
        }

        return;
attach:
        attach_task_ctx_data(child, ctx_cache, true);
}

void perf_event_fork(struct task_struct *task)
{
        perf_event_task(task, NULL, 1);
        perf_event_namespaces(task);
        perf_event_alloc_task_data(task, current);
}

/*
 * comm tracking
 */

struct perf_comm_event {
        struct task_struct        *task;
        char                        *comm;
        int                        comm_size;

        struct {
                struct perf_event_header        header;

                u32                                pid;
                u32                                tid;
        } event_id;
};

static int perf_event_comm_match(struct perf_event *event)
{
        return event->attr.comm;
}

static void perf_event_comm_output(struct perf_event *event,
                                   void *data)
{
        struct perf_comm_event *comm_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int size = comm_event->event_id.header.size;
        int ret;

        if (!perf_event_comm_match(event))
                return;

        perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
        ret = perf_output_begin(&handle, &sample, event,
                                comm_event->event_id.header.size);

        if (ret)
                goto out;

        comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
        comm_event->event_id.tid = perf_event_tid(event, comm_event->task);

        perf_output_put(&handle, comm_event->event_id);
        __output_copy(&handle, comm_event->comm,
                                   comm_event->comm_size);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
out:
        comm_event->event_id.header.size = size;
}

static void perf_event_comm_event(struct perf_comm_event *comm_event)
{
        char comm[TASK_COMM_LEN];
        unsigned int size;

        memset(comm, 0, sizeof(comm));
        strscpy(comm, comm_event->task->comm);
        size = ALIGN(strlen(comm)+1, sizeof(u64));

        comm_event->comm = comm;
        comm_event->comm_size = size;

        comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;

        perf_iterate_sb(perf_event_comm_output,
                       comm_event,
                       NULL);
}

void perf_event_comm(struct task_struct *task, bool exec)
{
        struct perf_comm_event comm_event;

        if (!atomic_read(&nr_comm_events))
                return;

        comm_event = (struct perf_comm_event){
                .task        = task,
                /* .comm      */
                /* .comm_size */
                .event_id  = {
                        .header = {
                                .type = PERF_RECORD_COMM,
                                .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
                                /* .size */
                        },
                        /* .pid */
                        /* .tid */
                },
        };

        perf_event_comm_event(&comm_event);
}

/*
 * namespaces tracking
 */

struct perf_namespaces_event {
        struct task_struct                *task;

        struct {
                struct perf_event_header        header;

                u32                                pid;
                u32                                tid;
                u64                                nr_namespaces;
                struct perf_ns_link_info        link_info[NR_NAMESPACES];
        } event_id;
};

static int perf_event_namespaces_match(struct perf_event *event)
{
        return event->attr.namespaces;
}

static void perf_event_namespaces_output(struct perf_event *event,
                                         void *data)
{
        struct perf_namespaces_event *namespaces_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        u16 header_size = namespaces_event->event_id.header.size;
        int ret;

        if (!perf_event_namespaces_match(event))
                return;

        perf_event_header__init_id(&namespaces_event->event_id.header,
                                   &sample, event);
        ret = perf_output_begin(&handle, &sample, event,
                                namespaces_event->event_id.header.size);
        if (ret)
                goto out;

        namespaces_event->event_id.pid = perf_event_pid(event,
                                                        namespaces_event->task);
        namespaces_event->event_id.tid = perf_event_tid(event,
                                                        namespaces_event->task);

        perf_output_put(&handle, namespaces_event->event_id);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
out:
        namespaces_event->event_id.header.size = header_size;
}

static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info,
                                   struct task_struct *task,
                                   const struct proc_ns_operations *ns_ops)
{
        struct path ns_path;
        struct inode *ns_inode;
        int error;

        error = ns_get_path(&ns_path, task, ns_ops);
        if (!error) {
                ns_inode = ns_path.dentry->d_inode;
                ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev);
                ns_link_info->ino = ns_inode->i_ino;
                path_put(&ns_path);
        }
}

void perf_event_namespaces(struct task_struct *task)
{
        struct perf_namespaces_event namespaces_event;
        struct perf_ns_link_info *ns_link_info;

        if (!atomic_read(&nr_namespaces_events))
                return;

        namespaces_event = (struct perf_namespaces_event){
                .task        = task,
                .event_id  = {
                        .header = {
                                .type = PERF_RECORD_NAMESPACES,
                                .misc = 0,
                                .size = sizeof(namespaces_event.event_id),
                        },
                        /* .pid */
                        /* .tid */
                        .nr_namespaces = NR_NAMESPACES,
                        /* .link_info[NR_NAMESPACES] */
                },
        };

        ns_link_info = namespaces_event.event_id.link_info;

        perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX],
                               task, &mntns_operations);

#ifdef CONFIG_USER_NS
        perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX],
                               task, &userns_operations);
#endif
#ifdef CONFIG_NET_NS
        perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX],
                               task, &netns_operations);
#endif
#ifdef CONFIG_UTS_NS
        perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX],
                               task, &utsns_operations);
#endif
#ifdef CONFIG_IPC_NS
        perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX],
                               task, &ipcns_operations);
#endif
#ifdef CONFIG_PID_NS
        perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX],
                               task, &pidns_operations);
#endif
#ifdef CONFIG_CGROUPS
        perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX],
                               task, &cgroupns_operations);
#endif

        perf_iterate_sb(perf_event_namespaces_output,
                        &namespaces_event,
                        NULL);
}

/*
 * cgroup tracking
 */
#ifdef CONFIG_CGROUP_PERF

struct perf_cgroup_event {
        char                                *path;
        int                                path_size;
        struct {
                struct perf_event_header        header;
                u64                                id;
                char                                path[];
        } event_id;
};

static int perf_event_cgroup_match(struct perf_event *event)
{
        return event->attr.cgroup;
}

static void perf_event_cgroup_output(struct perf_event *event, void *data)
{
        struct perf_cgroup_event *cgroup_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        u16 header_size = cgroup_event->event_id.header.size;
        int ret;

        if (!perf_event_cgroup_match(event))
                return;

        perf_event_header__init_id(&cgroup_event->event_id.header,
                                   &sample, event);
        ret = perf_output_begin(&handle, &sample, event,
                                cgroup_event->event_id.header.size);
        if (ret)
                goto out;

        perf_output_put(&handle, cgroup_event->event_id);
        __output_copy(&handle, cgroup_event->path, cgroup_event->path_size);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
out:
        cgroup_event->event_id.header.size = header_size;
}

static void perf_event_cgroup(struct cgroup *cgrp)
{
        struct perf_cgroup_event cgroup_event;
        char path_enomem[16] = "//enomem";
        char *pathname;
        size_t size;

        if (!atomic_read(&nr_cgroup_events))
                return;

        cgroup_event = (struct perf_cgroup_event){
                .event_id  = {
                        .header = {
                                .type = PERF_RECORD_CGROUP,
                                .misc = 0,
                                .size = sizeof(cgroup_event.event_id),
                        },
                        .id = cgroup_id(cgrp),
                },
        };

        pathname = kmalloc(PATH_MAX, GFP_KERNEL);
        if (pathname == NULL) {
                cgroup_event.path = path_enomem;
        } else {
                /* just to be sure to have enough space for alignment */
                cgroup_path(cgrp, pathname, PATH_MAX - sizeof(u64));
                cgroup_event.path = pathname;
        }

        /*
         * Since our buffer works in 8 byte units we need to align our string
         * size to a multiple of 8. However, we must guarantee the tail end is
         * zero'd out to avoid leaking random bits to userspace.
         */
        size = strlen(cgroup_event.path) + 1;
        while (!IS_ALIGNED(size, sizeof(u64)))
                cgroup_event.path[size++] = '\0';

        cgroup_event.event_id.header.size += size;
        cgroup_event.path_size = size;

        perf_iterate_sb(perf_event_cgroup_output,
                        &cgroup_event,
                        NULL);

        kfree(pathname);
}

#endif

/*
 * mmap tracking
 */

struct perf_mmap_event {
        struct vm_area_struct        *vma;

        const char                *file_name;
        int                        file_size;
        int                        maj, min;
        u64                        ino;
        u64                        ino_generation;
        u32                        prot, flags;
        u8                        build_id[BUILD_ID_SIZE_MAX];
        u32                        build_id_size;

        struct {
                struct perf_event_header        header;

                u32                                pid;
                u32                                tid;
                u64                                start;
                u64                                len;
                u64                                pgoff;
        } event_id;
};

static int perf_event_mmap_match(struct perf_event *event,
                                 void *data)
{
        struct perf_mmap_event *mmap_event = data;
        struct vm_area_struct *vma = mmap_event->vma;
        int executable = vma->vm_flags & VM_EXEC;

        return (!executable && event->attr.mmap_data) ||
               (executable && (event->attr.mmap || event->attr.mmap2));
}

static void perf_event_mmap_output(struct perf_event *event,
                                   void *data)
{
        struct perf_mmap_event *mmap_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int size = mmap_event->event_id.header.size;
        u32 type = mmap_event->event_id.header.type;
        bool use_build_id;
        int ret;

        if (!perf_event_mmap_match(event, data))
                return;

        if (event->attr.mmap2) {
                mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
                mmap_event->event_id.header.size += sizeof(mmap_event->maj);
                mmap_event->event_id.header.size += sizeof(mmap_event->min);
                mmap_event->event_id.header.size += sizeof(mmap_event->ino);
                mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
                mmap_event->event_id.header.size += sizeof(mmap_event->prot);
                mmap_event->event_id.header.size += sizeof(mmap_event->flags);
        }

        perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
        ret = perf_output_begin(&handle, &sample, event,
                                mmap_event->event_id.header.size);
        if (ret)
                goto out;

        mmap_event->event_id.pid = perf_event_pid(event, current);
        mmap_event->event_id.tid = perf_event_tid(event, current);

        use_build_id = event->attr.build_id && mmap_event->build_id_size;

        if (event->attr.mmap2 && use_build_id)
                mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;

        perf_output_put(&handle, mmap_event->event_id);

        if (event->attr.mmap2) {
                if (use_build_id) {
                        u8 size[4] = { (u8) mmap_event->build_id_size, 0, 0, 0 };

                        __output_copy(&handle, size, 4);
                        __output_copy(&handle, mmap_event->build_id, BUILD_ID_SIZE_MAX);
                } else {
                        perf_output_put(&handle, mmap_event->maj);
                        perf_output_put(&handle, mmap_event->min);
                        perf_output_put(&handle, mmap_event->ino);
                        perf_output_put(&handle, mmap_event->ino_generation);
                }
                perf_output_put(&handle, mmap_event->prot);
                perf_output_put(&handle, mmap_event->flags);
        }

        __output_copy(&handle, mmap_event->file_name,
                                   mmap_event->file_size);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
out:
        mmap_event->event_id.header.size = size;
        mmap_event->event_id.header.type = type;
}

static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
{
        struct vm_area_struct *vma = mmap_event->vma;
        struct file *file = vma->vm_file;
        int maj = 0, min = 0;
        u64 ino = 0, gen = 0;
        u32 prot = 0, flags = 0;
        unsigned int size;
        char tmp[16];
        char *buf = NULL;
        char *name = NULL;

        if (vma->vm_flags & VM_READ)
                prot |= PROT_READ;
        if (vma->vm_flags & VM_WRITE)
                prot |= PROT_WRITE;
        if (vma->vm_flags & VM_EXEC)
                prot |= PROT_EXEC;

        if (vma->vm_flags & VM_MAYSHARE)
                flags = MAP_SHARED;
        else
                flags = MAP_PRIVATE;

        if (vma->vm_flags & VM_LOCKED)
                flags |= MAP_LOCKED;
        if (is_vm_hugetlb_page(vma))
                flags |= MAP_HUGETLB;

        if (file) {
                const struct inode *inode;
                dev_t dev;

                buf = kmalloc(PATH_MAX, GFP_KERNEL);
                if (!buf) {
                        name = "//enomem";
                        goto cpy_name;
                }
                /*
                 * d_path() works from the end of the rb backwards, so we
                 * need to add enough zero bytes after the string to handle
                 * the 64bit alignment we do later.
                 */
                name = d_path(file_user_path(file), buf, PATH_MAX - sizeof(u64));
                if (IS_ERR(name)) {
                        name = "//toolong";
                        goto cpy_name;
                }
                inode = file_user_inode(vma->vm_file);
                dev = inode->i_sb->s_dev;
                ino = inode->i_ino;
                gen = inode->i_generation;
                maj = MAJOR(dev);
                min = MINOR(dev);

                goto got_name;
        } else {
                if (vma->vm_ops && vma->vm_ops->name)
                        name = (char *) vma->vm_ops->name(vma);
                if (!name)
                        name = (char *)arch_vma_name(vma);
                if (!name) {
                        if (vma_is_initial_heap(vma))
                                name = "[heap]";
                        else if (vma_is_initial_stack(vma))
                                name = "[stack]";
                        else
                                name = "//anon";
                }
        }

cpy_name:
        strscpy(tmp, name);
        name = tmp;
got_name:
        /*
         * Since our buffer works in 8 byte units we need to align our string
         * size to a multiple of 8. However, we must guarantee the tail end is
         * zero'd out to avoid leaking random bits to userspace.
         */
        size = strlen(name)+1;
        while (!IS_ALIGNED(size, sizeof(u64)))
                name[size++] = '\0';

        mmap_event->file_name = name;
        mmap_event->file_size = size;
        mmap_event->maj = maj;
        mmap_event->min = min;
        mmap_event->ino = ino;
        mmap_event->ino_generation = gen;
        mmap_event->prot = prot;
        mmap_event->flags = flags;

        if (!(vma->vm_flags & VM_EXEC))
                mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;

        mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;

        if (atomic_read(&nr_build_id_events))
                build_id_parse_nofault(vma, mmap_event->build_id, &mmap_event->build_id_size);

        perf_iterate_sb(perf_event_mmap_output,
                       mmap_event,
                       NULL);

        kfree(buf);
}

/*
 * Check whether inode and address range match filter criteria.
 */
static bool perf_addr_filter_match(struct perf_addr_filter *filter,
                                     struct file *file, unsigned long offset,
                                     unsigned long size)
{
        /* d_inode(NULL) won't be equal to any mapped user-space file */
        if (!filter->path.dentry)
                return false;

        if (d_inode(filter->path.dentry) != file_user_inode(file))
                return false;

        if (filter->offset > offset + size)
                return false;

        if (filter->offset + filter->size < offset)
                return false;

        return true;
}

static bool perf_addr_filter_vma_adjust(struct perf_addr_filter *filter,
                                        struct vm_area_struct *vma,
                                        struct perf_addr_filter_range *fr)
{
        unsigned long vma_size = vma->vm_end - vma->vm_start;
        unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
        struct file *file = vma->vm_file;

        if (!perf_addr_filter_match(filter, file, off, vma_size))
                return false;

        if (filter->offset < off) {
                fr->start = vma->vm_start;
                fr->size = min(vma_size, filter->size - (off - filter->offset));
        } else {
                fr->start = vma->vm_start + filter->offset - off;
                fr->size = min(vma->vm_end - fr->start, filter->size);
        }

        return true;
}

static void __perf_addr_filters_adjust(struct perf_event *event, void *data)
{
        struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
        struct vm_area_struct *vma = data;
        struct perf_addr_filter *filter;
        unsigned int restart = 0, count = 0;
        unsigned long flags;

        if (!has_addr_filter(event))
                return;

        if (!vma->vm_file)
                return;

        raw_spin_lock_irqsave(&ifh->lock, flags);
        list_for_each_entry(filter, &ifh->list, entry) {
                if (perf_addr_filter_vma_adjust(filter, vma,
                                                &event->addr_filter_ranges[count]))
                        restart++;

                count++;
        }

        if (restart)
                event->addr_filters_gen++;
        raw_spin_unlock_irqrestore(&ifh->lock, flags);

        if (restart)
                perf_event_stop(event, 1);
}

/*
 * Adjust all task's events' filters to the new vma
 */
static void perf_addr_filters_adjust(struct vm_area_struct *vma)
{
        struct perf_event_context *ctx;

        /*
         * Data tracing isn't supported yet and as such there is no need
         * to keep track of anything that isn't related to executable code:
         */
        if (!(vma->vm_flags & VM_EXEC))
                return;

        rcu_read_lock();
        ctx = rcu_dereference(current->perf_event_ctxp);
        if (ctx)
                perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
        rcu_read_unlock();
}

void perf_event_mmap(struct vm_area_struct *vma)
{
        struct perf_mmap_event mmap_event;

        if (!atomic_read(&nr_mmap_events))
                return;

        mmap_event = (struct perf_mmap_event){
                .vma        = vma,
                /* .file_name */
                /* .file_size */
                .event_id  = {
                        .header = {
                                .type = PERF_RECORD_MMAP,
                                .misc = PERF_RECORD_MISC_USER,
                                /* .size */
                        },
                        /* .pid */
                        /* .tid */
                        .start  = vma->vm_start,
                        .len    = vma->vm_end - vma->vm_start,
                        .pgoff  = (u64)vma->vm_pgoff << PAGE_SHIFT,
                },
                /* .maj (attr_mmap2 only) */
                /* .min (attr_mmap2 only) */
                /* .ino (attr_mmap2 only) */
                /* .ino_generation (attr_mmap2 only) */
                /* .prot (attr_mmap2 only) */
                /* .flags (attr_mmap2 only) */
        };

        perf_addr_filters_adjust(vma);
        perf_event_mmap_event(&mmap_event);
}

void perf_event_aux_event(struct perf_event *event, unsigned long head,
                          unsigned long size, u64 flags)
{
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        struct perf_aux_event {
                struct perf_event_header        header;
                u64                                offset;
                u64                                size;
                u64                                flags;
        } rec = {
                .header = {
                        .type = PERF_RECORD_AUX,
                        .misc = 0,
                        .size = sizeof(rec),
                },
                .offset                = head,
                .size                = size,
                .flags                = flags,
        };
        int ret;

        perf_event_header__init_id(&rec.header, &sample, event);
        ret = perf_output_begin(&handle, &sample, event, rec.header.size);

        if (ret)
                return;

        perf_output_put(&handle, rec);
        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

/*
 * Lost/dropped samples logging
 */
void perf_log_lost_samples(struct perf_event *event, u64 lost)
{
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int ret;

        struct {
                struct perf_event_header        header;
                u64                                lost;
        } lost_samples_event = {
                .header = {
                        .type = PERF_RECORD_LOST_SAMPLES,
                        .misc = 0,
                        .size = sizeof(lost_samples_event),
                },
                .lost                = lost,
        };

        perf_event_header__init_id(&lost_samples_event.header, &sample, event);

        ret = perf_output_begin(&handle, &sample, event,
                                lost_samples_event.header.size);
        if (ret)
                return;

        perf_output_put(&handle, lost_samples_event);
        perf_event__output_id_sample(event, &handle, &sample);
        perf_output_end(&handle);
}

/*
 * context_switch tracking
 */

struct perf_switch_event {
        struct task_struct        *task;
        struct task_struct        *next_prev;

        struct {
                struct perf_event_header        header;
                u32                                next_prev_pid;
                u32                                next_prev_tid;
        } event_id;
};

static int perf_event_switch_match(struct perf_event *event)
{
        return event->attr.context_switch;
}

static void perf_event_switch_output(struct perf_event *event, void *data)
{
        struct perf_switch_event *se = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int ret;

        if (!perf_event_switch_match(event))
                return;

        /* Only CPU-wide events are allowed to see next/prev pid/tid */
        if (event->ctx->task) {
                se->event_id.header.type = PERF_RECORD_SWITCH;
                se->event_id.header.size = sizeof(se->event_id.header);
        } else {
                se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
                se->event_id.header.size = sizeof(se->event_id);
                se->event_id.next_prev_pid =
                                        perf_event_pid(event, se->next_prev);
                se->event_id.next_prev_tid =
                                        perf_event_tid(event, se->next_prev);
        }

        perf_event_header__init_id(&se->event_id.header, &sample, event);

        ret = perf_output_begin(&handle, &sample, event, se->event_id.header.size);
        if (ret)
                return;

        if (event->ctx->task)
                perf_output_put(&handle, se->event_id.header);
        else
                perf_output_put(&handle, se->event_id);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

static void perf_event_switch(struct task_struct *task,
                              struct task_struct *next_prev, bool sched_in)
{
        struct perf_switch_event switch_event;

        /* N.B. caller checks nr_switch_events != 0 */

        switch_event = (struct perf_switch_event){
                .task                = task,
                .next_prev        = next_prev,
                .event_id        = {
                        .header = {
                                /* .type */
                                .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
                                /* .size */
                        },
                        /* .next_prev_pid */
                        /* .next_prev_tid */
                },
        };

        if (!sched_in && task_is_runnable(task)) {
                switch_event.event_id.header.misc |=
                                PERF_RECORD_MISC_SWITCH_OUT_PREEMPT;
        }

        perf_iterate_sb(perf_event_switch_output, &switch_event, NULL);
}

/*
 * IRQ throttle logging
 */

static void perf_log_throttle(struct perf_event *event, int enable)
{
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int ret;

        struct {
                struct perf_event_header        header;
                u64                                time;
                u64                                id;
                u64                                stream_id;
        } throttle_event = {
                .header = {
                        .type = PERF_RECORD_THROTTLE,
                        .misc = 0,
                        .size = sizeof(throttle_event),
                },
                .time                = perf_event_clock(event),
                .id                = primary_event_id(event),
                .stream_id        = event->id,
        };

        if (enable)
                throttle_event.header.type = PERF_RECORD_UNTHROTTLE;

        perf_event_header__init_id(&throttle_event.header, &sample, event);

        ret = perf_output_begin(&handle, &sample, event,
                                throttle_event.header.size);
        if (ret)
                return;

        perf_output_put(&handle, throttle_event);
        perf_event__output_id_sample(event, &handle, &sample);
        perf_output_end(&handle);
}

/*
 * ksymbol register/unregister tracking
 */

struct perf_ksymbol_event {
        const char        *name;
        int                name_len;
        struct {
                struct perf_event_header        header;
                u64                                addr;
                u32                                len;
                u16                                ksym_type;
                u16                                flags;
        } event_id;
};

static int perf_event_ksymbol_match(struct perf_event *event)
{
        return event->attr.ksymbol;
}

static void perf_event_ksymbol_output(struct perf_event *event, void *data)
{
        struct perf_ksymbol_event *ksymbol_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int ret;

        if (!perf_event_ksymbol_match(event))
                return;

        perf_event_header__init_id(&ksymbol_event->event_id.header,
                                   &sample, event);
        ret = perf_output_begin(&handle, &sample, event,
                                ksymbol_event->event_id.header.size);
        if (ret)
                return;

        perf_output_put(&handle, ksymbol_event->event_id);
        __output_copy(&handle, ksymbol_event->name, ksymbol_event->name_len);
        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister,
                        const char *sym)
{
        struct perf_ksymbol_event ksymbol_event;
        char name[KSYM_NAME_LEN];
        u16 flags = 0;
        int name_len;

        if (!atomic_read(&nr_ksymbol_events))
                return;

        if (ksym_type >= PERF_RECORD_KSYMBOL_TYPE_MAX ||
            ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN)
                goto err;

        strscpy(name, sym);
        name_len = strlen(name) + 1;
        while (!IS_ALIGNED(name_len, sizeof(u64)))
                name[name_len++] = '\0';
        BUILD_BUG_ON(KSYM_NAME_LEN % sizeof(u64));

        if (unregister)
                flags |= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER;

        ksymbol_event = (struct perf_ksymbol_event){
                .name = name,
                .name_len = name_len,
                .event_id = {
                        .header = {
                                .type = PERF_RECORD_KSYMBOL,
                                .size = sizeof(ksymbol_event.event_id) +
                                        name_len,
                        },
                        .addr = addr,
                        .len = len,
                        .ksym_type = ksym_type,
                        .flags = flags,
                },
        };

        perf_iterate_sb(perf_event_ksymbol_output, &ksymbol_event, NULL);
        return;
err:
        WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__, ksym_type);
}

/*
 * bpf program load/unload tracking
 */

struct perf_bpf_event {
        struct bpf_prog        *prog;
        struct {
                struct perf_event_header        header;
                u16                                type;
                u16                                flags;
                u32                                id;
                u8                                tag[BPF_TAG_SIZE];
        } event_id;
};

static int perf_event_bpf_match(struct perf_event *event)
{
        return event->attr.bpf_event;
}

static void perf_event_bpf_output(struct perf_event *event, void *data)
{
        struct perf_bpf_event *bpf_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        int ret;

        if (!perf_event_bpf_match(event))
                return;

        perf_event_header__init_id(&bpf_event->event_id.header,
                                   &sample, event);
        ret = perf_output_begin(&handle, &sample, event,
                                bpf_event->event_id.header.size);
        if (ret)
                return;

        perf_output_put(&handle, bpf_event->event_id);
        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

static void perf_event_bpf_emit_ksymbols(struct bpf_prog *prog,
                                         enum perf_bpf_event_type type)
{
        bool unregister = type == PERF_BPF_EVENT_PROG_UNLOAD;
        int i;

        perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF,
                           (u64)(unsigned long)prog->bpf_func,
                           prog->jited_len, unregister,
                           prog->aux->ksym.name);

        for (i = 1; i < prog->aux->func_cnt; i++) {
                struct bpf_prog *subprog = prog->aux->func[i];

                perf_event_ksymbol(
                        PERF_RECORD_KSYMBOL_TYPE_BPF,
                        (u64)(unsigned long)subprog->bpf_func,
                        subprog->jited_len, unregister,
                        subprog->aux->ksym.name);
        }
}

void perf_event_bpf_event(struct bpf_prog *prog,
                          enum perf_bpf_event_type type,
                          u16 flags)
{
        struct perf_bpf_event bpf_event;

        switch (type) {
        case PERF_BPF_EVENT_PROG_LOAD:
        case PERF_BPF_EVENT_PROG_UNLOAD:
                if (atomic_read(&nr_ksymbol_events))
                        perf_event_bpf_emit_ksymbols(prog, type);
                break;
        default:
                return;
        }

        if (!atomic_read(&nr_bpf_events))
                return;

        bpf_event = (struct perf_bpf_event){
                .prog = prog,
                .event_id = {
                        .header = {
                                .type = PERF_RECORD_BPF_EVENT,
                                .size = sizeof(bpf_event.event_id),
                        },
                        .type = type,
                        .flags = flags,
                        .id = prog->aux->id,
                },
        };

        BUILD_BUG_ON(BPF_TAG_SIZE % sizeof(u64));

        memcpy(bpf_event.event_id.tag, prog->tag, BPF_TAG_SIZE);
        perf_iterate_sb(perf_event_bpf_output, &bpf_event, NULL);
}

struct perf_text_poke_event {
        const void                *old_bytes;
        const void                *new_bytes;
        size_t                        pad;
        u16                        old_len;
        u16                        new_len;

        struct {
                struct perf_event_header        header;

                u64                                addr;
        } event_id;
};

static int perf_event_text_poke_match(struct perf_event *event)
{
        return event->attr.text_poke;
}

static void perf_event_text_poke_output(struct perf_event *event, void *data)
{
        struct perf_text_poke_event *text_poke_event = data;
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        u64 padding = 0;
        int ret;

        if (!perf_event_text_poke_match(event))
                return;

        perf_event_header__init_id(&text_poke_event->event_id.header, &sample, event);

        ret = perf_output_begin(&handle, &sample, event,
                                text_poke_event->event_id.header.size);
        if (ret)
                return;

        perf_output_put(&handle, text_poke_event->event_id);
        perf_output_put(&handle, text_poke_event->old_len);
        perf_output_put(&handle, text_poke_event->new_len);

        __output_copy(&handle, text_poke_event->old_bytes, text_poke_event->old_len);
        __output_copy(&handle, text_poke_event->new_bytes, text_poke_event->new_len);

        if (text_poke_event->pad)
                __output_copy(&handle, &padding, text_poke_event->pad);

        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

void perf_event_text_poke(const void *addr, const void *old_bytes,
                          size_t old_len, const void *new_bytes, size_t new_len)
{
        struct perf_text_poke_event text_poke_event;
        size_t tot, pad;

        if (!atomic_read(&nr_text_poke_events))
                return;

        tot  = sizeof(text_poke_event.old_len) + old_len;
        tot += sizeof(text_poke_event.new_len) + new_len;
        pad  = ALIGN(tot, sizeof(u64)) - tot;

        text_poke_event = (struct perf_text_poke_event){
                .old_bytes    = old_bytes,
                .new_bytes    = new_bytes,
                .pad          = pad,
                .old_len      = old_len,
                .new_len      = new_len,
                .event_id  = {
                        .header = {
                                .type = PERF_RECORD_TEXT_POKE,
                                .misc = PERF_RECORD_MISC_KERNEL,
                                .size = sizeof(text_poke_event.event_id) + tot + pad,
                        },
                        .addr = (unsigned long)addr,
                },
        };

        perf_iterate_sb(perf_event_text_poke_output, &text_poke_event, NULL);
}

void perf_event_itrace_started(struct perf_event *event)
{
        WRITE_ONCE(event->attach_state, event->attach_state | PERF_ATTACH_ITRACE);
}

static void perf_log_itrace_start(struct perf_event *event)
{
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        struct perf_aux_event {
                struct perf_event_header        header;
                u32                                pid;
                u32                                tid;
        } rec;
        int ret;

        if (event->parent)
                event = event->parent;

        if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
            event->attach_state & PERF_ATTACH_ITRACE)
                return;

        rec.header.type        = PERF_RECORD_ITRACE_START;
        rec.header.misc        = 0;
        rec.header.size        = sizeof(rec);
        rec.pid        = perf_event_pid(event, current);
        rec.tid        = perf_event_tid(event, current);

        perf_event_header__init_id(&rec.header, &sample, event);
        ret = perf_output_begin(&handle, &sample, event, rec.header.size);

        if (ret)
                return;

        perf_output_put(&handle, rec);
        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}

void perf_report_aux_output_id(struct perf_event *event, u64 hw_id)
{
        struct perf_output_handle handle;
        struct perf_sample_data sample;
        struct perf_aux_event {
                struct perf_event_header        header;
                u64                                hw_id;
        } rec;
        int ret;

        if (event->parent)
                event = event->parent;

        rec.header.type        = PERF_RECORD_AUX_OUTPUT_HW_ID;
        rec.header.misc        = 0;
        rec.header.size        = sizeof(rec);
        rec.hw_id        = hw_id;

        perf_event_header__init_id(&rec.header, &sample, event);
        ret = perf_output_begin(&handle, &sample, event, rec.header.size);

        if (ret)
                return;

        perf_output_put(&handle, rec);
        perf_event__output_id_sample(event, &handle, &sample);

        perf_output_end(&handle);
}
EXPORT_SYMBOL_GPL(perf_report_aux_output_id);

static int
__perf_event_account_interrupt(struct perf_event *event, int throttle)
{
        struct hw_perf_event *hwc = &event->hw;
        int ret = 0;
        u64 seq;

        seq = __this_cpu_read(perf_throttled_seq);
        if (seq != hwc->interrupts_seq) {
                hwc->interrupts_seq = seq;
                hwc->interrupts = 1;
        } else {
                hwc->interrupts++;
        }

        if (unlikely(throttle && hwc->interrupts >= max_samples_per_tick)) {
                __this_cpu_inc(perf_throttled_count);
                tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
                perf_event_throttle_group(event);
                ret = 1;
        }

        if (event->attr.freq) {
                u64 now = perf_clock();
                s64 delta = now - hwc->freq_time_stamp;

                hwc->freq_time_stamp = now;

                if (delta > 0 && delta < 2*TICK_NSEC)
                        perf_adjust_period(event, delta, hwc->last_period, true);
        }

        return ret;
}

int perf_event_account_interrupt(struct perf_event *event)
{
        return __perf_event_account_interrupt(event, 1);
}

static inline bool sample_is_allowed(struct perf_event *event, struct pt_regs *regs)
{
        /*
         * Due to interrupt latency (AKA "skid"), we may enter the
         * kernel before taking an overflow, even if the PMU is only
         * counting user events.
         */
        if (event->attr.exclude_kernel && !user_mode(regs))
                return false;

        return true;
}

#ifdef CONFIG_BPF_SYSCALL
static int bpf_overflow_handler(struct perf_event *event,
                                struct perf_sample_data *data,
                                struct pt_regs *regs)
{
        struct bpf_perf_event_data_kern ctx = {
                .data = data,
                .event = event,
        };
        struct bpf_prog *prog;
        int ret = 0;

        ctx.regs = perf_arch_bpf_user_pt_regs(regs);
        if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
                goto out;
        rcu_read_lock();
        prog = READ_ONCE(event->prog);
        if (prog) {
                perf_prepare_sample(data, event, regs);
                ret = bpf_prog_run(prog, &ctx);
        }
        rcu_read_unlock();
out:
        __this_cpu_dec(bpf_prog_active);

        return ret;
}

static inline int perf_event_set_bpf_handler(struct perf_event *event,
                                             struct bpf_prog *prog,
                                             u64 bpf_cookie)
{
        if (event->overflow_handler_context)
                /* hw breakpoint or kernel counter */
                return -EINVAL;

        if (event->prog)
                return -EEXIST;

        if (prog->type != BPF_PROG_TYPE_PERF_EVENT)
                return -EINVAL;

        if (event->attr.precise_ip &&
            prog->call_get_stack &&
            (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) ||
             event->attr.exclude_callchain_kernel ||
             event->attr.exclude_callchain_user)) {
                /*
                 * On perf_event with precise_ip, calling bpf_get_stack()
                 * may trigger unwinder warnings and occasional crashes.
                 * bpf_get_[stack|stackid] works around this issue by using
                 * callchain attached to perf_sample_data. If the
                 * perf_event does not full (kernel and user) callchain
                 * attached to perf_sample_data, do not allow attaching BPF
                 * program that calls bpf_get_[stack|stackid].
                 */
                return -EPROTO;
        }

        event->prog = prog;
        event->bpf_cookie = bpf_cookie;
        return 0;
}

static inline void perf_event_free_bpf_handler(struct perf_event *event)
{
        struct bpf_prog *prog = event->prog;

        if (!prog)
                return;

        event->prog = NULL;
        bpf_prog_put(prog);
}
#else
static inline int bpf_overflow_handler(struct perf_event *event,
                                       struct perf_sample_data *data,
                                       struct pt_regs *regs)
{
        return 1;
}

static inline int perf_event_set_bpf_handler(struct perf_event *event,
                                             struct bpf_prog *prog,
                                             u64 bpf_cookie)
{
        return -EOPNOTSUPP;
}

static inline void perf_event_free_bpf_handler(struct perf_event *event)
{
}
#endif

/*
 * Generic event overflow handling, sampling.
 */

static int __perf_event_overflow(struct perf_event *event,
                                 int throttle, struct perf_sample_data *data,
                                 struct pt_regs *regs)
{
        int events = atomic_read(&event->event_limit);
        int ret = 0;

        /*
         * Non-sampling counters might still use the PMI to fold short
         * hardware counters, ignore those.
         */
        if (unlikely(!is_sampling_event(event)))
                return 0;

        ret = __perf_event_account_interrupt(event, throttle);

        if (event->attr.aux_pause)
                perf_event_aux_pause(event->aux_event, true);

        if (event->prog && event->prog->type == BPF_PROG_TYPE_PERF_EVENT &&
            !bpf_overflow_handler(event, data, regs))
                goto out;

        /*
         * XXX event_limit might not quite work as expected on inherited
         * events
         */

        event->pending_kill = POLL_IN;
        if (events && atomic_dec_and_test(&event->event_limit)) {
                ret = 1;
                event->pending_kill = POLL_HUP;
                perf_event_disable_inatomic(event);
                event->pmu->stop(event, 0);
        }

        if (event->attr.sigtrap) {
                /*
                 * The desired behaviour of sigtrap vs invalid samples is a bit
                 * tricky; on the one hand, one should not loose the SIGTRAP if
                 * it is the first event, on the other hand, we should also not
                 * trigger the WARN or override the data address.
                 */
                bool valid_sample = sample_is_allowed(event, regs);
                unsigned int pending_id = 1;
                enum task_work_notify_mode notify_mode;

                if (regs)
                        pending_id = hash32_ptr((void *)instruction_pointer(regs)) ?: 1;

                notify_mode = in_nmi() ? TWA_NMI_CURRENT : TWA_RESUME;

                if (!event->pending_work &&
                    !task_work_add(current, &event->pending_task, notify_mode)) {
                        event->pending_work = pending_id;
                        local_inc(&event->ctx->nr_no_switch_fast);
                        WARN_ON_ONCE(!atomic_long_inc_not_zero(&event->refcount));

                        event->pending_addr = 0;
                        if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))
                                event->pending_addr = data->addr;

                } else if (event->attr.exclude_kernel && valid_sample) {
                        /*
                         * Should not be able to return to user space without
                         * consuming pending_work; with exceptions:
                         *
                         *  1. Where !exclude_kernel, events can overflow again
                         *     in the kernel without returning to user space.
                         *
                         *  2. Events that can overflow again before the IRQ-
                         *     work without user space progress (e.g. hrtimer).
                         *     To approximate progress (with false negatives),
                         *     check 32-bit hash of the current IP.
                         */
                        WARN_ON_ONCE(event->pending_work != pending_id);
                }
        }

        READ_ONCE(event->overflow_handler)(event, data, regs);

        if (*perf_event_fasync(event) && event->pending_kill) {
                event->pending_wakeup = 1;
                irq_work_queue(&event->pending_irq);
        }
out:
        if (event->attr.aux_resume)
                perf_event_aux_pause(event->aux_event, false);

        return ret;
}

int perf_event_overflow(struct perf_event *event,
                        struct perf_sample_data *data,
                        struct pt_regs *regs)
{
        return __perf_event_overflow(event, 1, data, regs);
}

/*
 * Generic software event infrastructure
 */

struct swevent_htable {
        struct swevent_hlist                *swevent_hlist;
        struct mutex                        hlist_mutex;
        int                                hlist_refcount;
};
static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);

/*
 * We directly increment event->count and keep a second value in
 * event->hw.period_left to count intervals. This period event
 * is kept in the range [-sample_period, 0] so that we can use the
 * sign as trigger.
 */

u64 perf_swevent_set_period(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        u64 period = hwc->last_period;
        u64 nr, offset;
        s64 old, val;

        hwc->last_period = hwc->sample_period;

        old = local64_read(&hwc->period_left);
        do {
                val = old;
                if (val < 0)
                        return 0;

                nr = div64_u64(period + val, period);
                offset = nr * period;
                val -= offset;
        } while (!local64_try_cmpxchg(&hwc->period_left, &old, val));

        return nr;
}

static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
                                    struct perf_sample_data *data,
                                    struct pt_regs *regs)
{
        struct hw_perf_event *hwc = &event->hw;
        int throttle = 0;

        if (!overflow)
                overflow = perf_swevent_set_period(event);

        if (hwc->interrupts == MAX_INTERRUPTS)
                return;

        for (; overflow; overflow--) {
                if (__perf_event_overflow(event, throttle,
                                            data, regs)) {
                        /*
                         * We inhibit the overflow from happening when
                         * hwc->interrupts == MAX_INTERRUPTS.
                         */
                        break;
                }
                throttle = 1;
        }
}

static void perf_swevent_event(struct perf_event *event, u64 nr,
                               struct perf_sample_data *data,
                               struct pt_regs *regs)
{
        struct hw_perf_event *hwc = &event->hw;

        local64_add(nr, &event->count);

        if (!regs)
                return;

        if (!is_sampling_event(event))
                return;

        if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
                data->period = nr;
                return perf_swevent_overflow(event, 1, data, regs);
        } else
                data->period = event->hw.last_period;

        if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
                return perf_swevent_overflow(event, 1, data, regs);

        if (local64_add_negative(nr, &hwc->period_left))
                return;

        perf_swevent_overflow(event, 0, data, regs);
}

int perf_exclude_event(struct perf_event *event, struct pt_regs *regs)
{
        if (event->hw.state & PERF_HES_STOPPED)
                return 1;

        if (regs) {
                if (event->attr.exclude_user && user_mode(regs))
                        return 1;

                if (event->attr.exclude_kernel && !user_mode(regs))
                        return 1;
        }

        return 0;
}

static int perf_swevent_match(struct perf_event *event,
                                enum perf_type_id type,
                                u32 event_id,
                                struct perf_sample_data *data,
                                struct pt_regs *regs)
{
        if (event->attr.type != type)
                return 0;

        if (event->attr.config != event_id)
                return 0;

        if (perf_exclude_event(event, regs))
                return 0;

        return 1;
}

static inline u64 swevent_hash(u64 type, u32 event_id)
{
        u64 val = event_id | (type << 32);

        return hash_64(val, SWEVENT_HLIST_BITS);
}

static inline struct hlist_head *
__find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
{
        u64 hash = swevent_hash(type, event_id);

        return &hlist->heads[hash];
}

/* For the read side: events when they trigger */
static inline struct hlist_head *
find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
{
        struct swevent_hlist *hlist;

        hlist = rcu_dereference(swhash->swevent_hlist);
        if (!hlist)
                return NULL;

        return __find_swevent_head(hlist, type, event_id);
}

/* For the event head insertion and removal in the hlist */
static inline struct hlist_head *
find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
{
        struct swevent_hlist *hlist;
        u32 event_id = event->attr.config;
        u64 type = event->attr.type;

        /*
         * Event scheduling is always serialized against hlist allocation
         * and release. Which makes the protected version suitable here.
         * The context lock guarantees that.
         */
        hlist = rcu_dereference_protected(swhash->swevent_hlist,
                                          lockdep_is_held(&event->ctx->lock));
        if (!hlist)
                return NULL;

        return __find_swevent_head(hlist, type, event_id);
}

static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
                                    u64 nr,
                                    struct perf_sample_data *data,
                                    struct pt_regs *regs)
{
        struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
        struct perf_event *event;
        struct hlist_head *head;

        rcu_read_lock();
        head = find_swevent_head_rcu(swhash, type, event_id);
        if (!head)
                goto end;

        hlist_for_each_entry_rcu(event, head, hlist_entry) {
                if (perf_swevent_match(event, type, event_id, data, regs))
                        perf_swevent_event(event, nr, data, regs);
        }
end:
        rcu_read_unlock();
}

DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);

int perf_swevent_get_recursion_context(void)
{
        return get_recursion_context(current->perf_recursion);
}
EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);

void perf_swevent_put_recursion_context(int rctx)
{
        put_recursion_context(current->perf_recursion, rctx);
}

void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
        struct perf_sample_data data;

        if (WARN_ON_ONCE(!regs))
                return;

        perf_sample_data_init(&data, addr, 0);
        do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
}

void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
{
        int rctx;

        preempt_disable_notrace();
        rctx = perf_swevent_get_recursion_context();
        if (unlikely(rctx < 0))
                goto fail;

        ___perf_sw_event(event_id, nr, regs, addr);

        perf_swevent_put_recursion_context(rctx);
fail:
        preempt_enable_notrace();
}

static void perf_swevent_read(struct perf_event *event)
{
}

static int perf_swevent_add(struct perf_event *event, int flags)
{
        struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
        struct hw_perf_event *hwc = &event->hw;
        struct hlist_head *head;

        if (is_sampling_event(event)) {
                hwc->last_period = hwc->sample_period;
                perf_swevent_set_period(event);
        }

        hwc->state = !(flags & PERF_EF_START);

        head = find_swevent_head(swhash, event);
        if (WARN_ON_ONCE(!head))
                return -EINVAL;

        hlist_add_head_rcu(&event->hlist_entry, head);
        perf_event_update_userpage(event);

        return 0;
}

static void perf_swevent_del(struct perf_event *event, int flags)
{
        hlist_del_rcu(&event->hlist_entry);
}

static void perf_swevent_start(struct perf_event *event, int flags)
{
        event->hw.state = 0;
}

static void perf_swevent_stop(struct perf_event *event, int flags)
{
        event->hw.state = PERF_HES_STOPPED;
}

/* Deref the hlist from the update side */
static inline struct swevent_hlist *
swevent_hlist_deref(struct swevent_htable *swhash)
{
        return rcu_dereference_protected(swhash->swevent_hlist,
                                         lockdep_is_held(&swhash->hlist_mutex));
}

static void swevent_hlist_release(struct swevent_htable *swhash)
{
        struct swevent_hlist *hlist = swevent_hlist_deref(swhash);

        if (!hlist)
                return;

        RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
        kfree_rcu(hlist, rcu_head);
}

static void swevent_hlist_put_cpu(int cpu)
{
        struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);

        mutex_lock(&swhash->hlist_mutex);

        if (!--swhash->hlist_refcount)
                swevent_hlist_release(swhash);

        mutex_unlock(&swhash->hlist_mutex);
}

static void swevent_hlist_put(void)
{
        int cpu;

        for_each_possible_cpu(cpu)
                swevent_hlist_put_cpu(cpu);
}

static int swevent_hlist_get_cpu(int cpu)
{
        struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
        int err = 0;

        mutex_lock(&swhash->hlist_mutex);
        if (!swevent_hlist_deref(swhash) &&
            cpumask_test_cpu(cpu, perf_online_mask)) {
                struct swevent_hlist *hlist;

                hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
                if (!hlist) {
                        err = -ENOMEM;
                        goto exit;
                }
                rcu_assign_pointer(swhash->swevent_hlist, hlist);
        }
        swhash->hlist_refcount++;
exit:
        mutex_unlock(&swhash->hlist_mutex);

        return err;
}

static int swevent_hlist_get(void)
{
        int err, cpu, failed_cpu;

        mutex_lock(&pmus_lock);
        for_each_possible_cpu(cpu) {
                err = swevent_hlist_get_cpu(cpu);
                if (err) {
                        failed_cpu = cpu;
                        goto fail;
                }
        }
        mutex_unlock(&pmus_lock);
        return 0;
fail:
        for_each_possible_cpu(cpu) {
                if (cpu == failed_cpu)
                        break;
                swevent_hlist_put_cpu(cpu);
        }
        mutex_unlock(&pmus_lock);
        return err;
}

struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];

static void sw_perf_event_destroy(struct perf_event *event)
{
        u64 event_id = event->attr.config;

        WARN_ON(event->parent);

        static_key_slow_dec(&perf_swevent_enabled[event_id]);
        swevent_hlist_put();
}

static struct pmu perf_cpu_clock; /* fwd declaration */
static struct pmu perf_task_clock;

static int perf_swevent_init(struct perf_event *event)
{
        u64 event_id = event->attr.config;

        if (event->attr.type != PERF_TYPE_SOFTWARE)
                return -ENOENT;

        /*
         * no branch sampling for software events
         */
        if (has_branch_stack(event))
                return -EOPNOTSUPP;

        switch (event_id) {
        case PERF_COUNT_SW_CPU_CLOCK:
                event->attr.type = perf_cpu_clock.type;
                return -ENOENT;
        case PERF_COUNT_SW_TASK_CLOCK:
                event->attr.type = perf_task_clock.type;
                return -ENOENT;

        default:
                break;
        }

        if (event_id >= PERF_COUNT_SW_MAX)
                return -ENOENT;

        if (!event->parent) {
                int err;

                err = swevent_hlist_get();
                if (err)
                        return err;

                static_key_slow_inc(&perf_swevent_enabled[event_id]);
                event->destroy = sw_perf_event_destroy;
        }

        return 0;
}

static struct pmu perf_swevent = {
        .task_ctx_nr        = perf_sw_context,

        .capabilities        = PERF_PMU_CAP_NO_NMI,

        .event_init        = perf_swevent_init,
        .add                = perf_swevent_add,
        .del                = perf_swevent_del,
        .start                = perf_swevent_start,
        .stop                = perf_swevent_stop,
        .read                = perf_swevent_read,
};

#ifdef CONFIG_EVENT_TRACING

static void tp_perf_event_destroy(struct perf_event *event)
{
        perf_trace_destroy(event);
}

static int perf_tp_event_init(struct perf_event *event)
{
        int err;

        if (event->attr.type != PERF_TYPE_TRACEPOINT)
                return -ENOENT;

        /*
         * no branch sampling for tracepoint events
         */
        if (has_branch_stack(event))
                return -EOPNOTSUPP;

        err = perf_trace_init(event);
        if (err)
                return err;

        event->destroy = tp_perf_event_destroy;

        return 0;
}

static struct pmu perf_tracepoint = {
        .task_ctx_nr        = perf_sw_context,

        .event_init        = perf_tp_event_init,
        .add                = perf_trace_add,
        .del                = perf_trace_del,
        .start                = perf_swevent_start,
        .stop                = perf_swevent_stop,
        .read                = perf_swevent_read,
};

static int perf_tp_filter_match(struct perf_event *event,
                                struct perf_raw_record *raw)
{
        void *record = raw->frag.data;

        /* only top level events have filters set */
        if (event->parent)
                event = event->parent;

        if (likely(!event->filter) || filter_match_preds(event->filter, record))
                return 1;
        return 0;
}

static int perf_tp_event_match(struct perf_event *event,
                                struct perf_raw_record *raw,
                                struct pt_regs *regs)
{
        if (event->hw.state & PERF_HES_STOPPED)
                return 0;
        /*
         * If exclude_kernel, only trace user-space tracepoints (uprobes)
         */
        if (event->attr.exclude_kernel && !user_mode(regs))
                return 0;

        if (!perf_tp_filter_match(event, raw))
                return 0;

        return 1;
}

void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
                               struct trace_event_call *call, u64 count,
                               struct pt_regs *regs, struct hlist_head *head,
                               struct task_struct *task)
{
        if (bpf_prog_array_valid(call)) {
                *(struct pt_regs **)raw_data = regs;
                if (!trace_call_bpf(call, raw_data) || hlist_empty(head)) {
                        perf_swevent_put_recursion_context(rctx);
                        return;
                }
        }
        perf_tp_event(call->event.type, count, raw_data, size, regs, head,
                      rctx, task);
}
EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);

static void __perf_tp_event_target_task(u64 count, void *record,
                                        struct pt_regs *regs,
                                        struct perf_sample_data *data,
                                        struct perf_raw_record *raw,
                                        struct perf_event *event)
{
        struct trace_entry *entry = record;

        if (event->attr.config != entry->type)
                return;
        /* Cannot deliver synchronous signal to other task. */
        if (event->attr.sigtrap)
                return;
        if (perf_tp_event_match(event, raw, regs)) {
                perf_sample_data_init(data, 0, 0);
                perf_sample_save_raw_data(data, event, raw);
                perf_swevent_event(event, count, data, regs);
        }
}

static void perf_tp_event_target_task(u64 count, void *record,
                                      struct pt_regs *regs,
                                      struct perf_sample_data *data,
                                      struct perf_raw_record *raw,
                                      struct perf_event_context *ctx)
{
        unsigned int cpu = smp_processor_id();
        struct pmu *pmu = &perf_tracepoint;
        struct perf_event *event, *sibling;

        perf_event_groups_for_cpu_pmu(event, &ctx->pinned_groups, cpu, pmu) {
                __perf_tp_event_target_task(count, record, regs, data, raw, event);
                for_each_sibling_event(sibling, event)
                        __perf_tp_event_target_task(count, record, regs, data, raw, sibling);
        }

        perf_event_groups_for_cpu_pmu(event, &ctx->flexible_groups, cpu, pmu) {
                __perf_tp_event_target_task(count, record, regs, data, raw, event);
                for_each_sibling_event(sibling, event)
                        __perf_tp_event_target_task(count, record, regs, data, raw, sibling);
        }
}

void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
                   struct pt_regs *regs, struct hlist_head *head, int rctx,
                   struct task_struct *task)
{
        struct perf_sample_data data;
        struct perf_event *event;

        struct perf_raw_record raw = {
                .frag = {
                        .size = entry_size,
                        .data = record,
                },
        };

        perf_trace_buf_update(record, event_type);

        hlist_for_each_entry_rcu(event, head, hlist_entry) {
                if (perf_tp_event_match(event, &raw, regs)) {
                        /*
                         * Here use the same on-stack perf_sample_data,
                         * some members in data are event-specific and
                         * need to be re-computed for different sweveents.
                         * Re-initialize data->sample_flags safely to avoid
                         * the problem that next event skips preparing data
                         * because data->sample_flags is set.
                         */
                        perf_sample_data_init(&data, 0, 0);
                        perf_sample_save_raw_data(&data, event, &raw);
                        perf_swevent_event(event, count, &data, regs);
                }
        }

        /*
         * If we got specified a target task, also iterate its context and
         * deliver this event there too.
         */
        if (task && task != current) {
                struct perf_event_context *ctx;

                rcu_read_lock();
                ctx = rcu_dereference(task->perf_event_ctxp);
                if (!ctx)
                        goto unlock;

                raw_spin_lock(&ctx->lock);
                perf_tp_event_target_task(count, record, regs, &data, &raw, ctx);
                raw_spin_unlock(&ctx->lock);
unlock:
                rcu_read_unlock();
        }

        perf_swevent_put_recursion_context(rctx);
}
EXPORT_SYMBOL_GPL(perf_tp_event);

#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
/*
 * Flags in config, used by dynamic PMU kprobe and uprobe
 * The flags should match following PMU_FORMAT_ATTR().
 *
 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
 *                               if not set, create kprobe/uprobe
 *
 * The following values specify a reference counter (or semaphore in the
 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
 *
 * PERF_UPROBE_REF_CTR_OFFSET_BITS        # of bits in config as th offset
 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT        # of bits to shift left
 */
enum perf_probe_config {
        PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0,  /* [k,u]retprobe */
        PERF_UPROBE_REF_CTR_OFFSET_BITS = 32,
        PERF_UPROBE_REF_CTR_OFFSET_SHIFT = 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS,
};

PMU_FORMAT_ATTR(retprobe, "config:0");
#endif

#ifdef CONFIG_KPROBE_EVENTS
static struct attribute *kprobe_attrs[] = {
        &format_attr_retprobe.attr,
        NULL,
};

static struct attribute_group kprobe_format_group = {
        .name = "format",
        .attrs = kprobe_attrs,
};

static const struct attribute_group *kprobe_attr_groups[] = {
        &kprobe_format_group,
        NULL,
};

static int perf_kprobe_event_init(struct perf_event *event);
static struct pmu perf_kprobe = {
        .task_ctx_nr        = perf_sw_context,
        .event_init        = perf_kprobe_event_init,
        .add                = perf_trace_add,
        .del                = perf_trace_del,
        .start                = perf_swevent_start,
        .stop                = perf_swevent_stop,
        .read                = perf_swevent_read,
        .attr_groups        = kprobe_attr_groups,
};

static int perf_kprobe_event_init(struct perf_event *event)
{
        int err;
        bool is_retprobe;

        if (event->attr.type != perf_kprobe.type)
                return -ENOENT;

        if (!perfmon_capable())
                return -EACCES;

        /*
         * no branch sampling for probe events
         */
        if (has_branch_stack(event))
                return -EOPNOTSUPP;

        is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
        err = perf_kprobe_init(event, is_retprobe);
        if (err)
                return err;

        event->destroy = perf_kprobe_destroy;

        return 0;
}
#endif /* CONFIG_KPROBE_EVENTS */

#ifdef CONFIG_UPROBE_EVENTS
PMU_FORMAT_ATTR(ref_ctr_offset, "config:32-63");

static struct attribute *uprobe_attrs[] = {
        &format_attr_retprobe.attr,
        &format_attr_ref_ctr_offset.attr,
        NULL,
};

static struct attribute_group uprobe_format_group = {
        .name = "format",
        .attrs = uprobe_attrs,
};

static const struct attribute_group *uprobe_attr_groups[] = {
        &uprobe_format_group,
        NULL,
};

static int perf_uprobe_event_init(struct perf_event *event);
static struct pmu perf_uprobe = {
        .task_ctx_nr        = perf_sw_context,
        .event_init        = perf_uprobe_event_init,
        .add                = perf_trace_add,
        .del                = perf_trace_del,
        .start                = perf_swevent_start,
        .stop                = perf_swevent_stop,
        .read                = perf_swevent_read,
        .attr_groups        = uprobe_attr_groups,
};

static int perf_uprobe_event_init(struct perf_event *event)
{
        int err;
        unsigned long ref_ctr_offset;
        bool is_retprobe;

        if (event->attr.type != perf_uprobe.type)
                return -ENOENT;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        /*
         * no branch sampling for probe events
         */
        if (has_branch_stack(event))
                return -EOPNOTSUPP;

        is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
        ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
        err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe);
        if (err)
                return err;

        event->destroy = perf_uprobe_destroy;

        return 0;
}
#endif /* CONFIG_UPROBE_EVENTS */

static inline void perf_tp_register(void)
{
        perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
#ifdef CONFIG_KPROBE_EVENTS
        perf_pmu_register(&perf_kprobe, "kprobe", -1);
#endif
#ifdef CONFIG_UPROBE_EVENTS
        perf_pmu_register(&perf_uprobe, "uprobe", -1);
#endif
}

static void perf_event_free_filter(struct perf_event *event)
{
        ftrace_profile_free_filter(event);
}

/*
 * returns true if the event is a tracepoint, or a kprobe/upprobe created
 * with perf_event_open()
 */
static inline bool perf_event_is_tracing(struct perf_event *event)
{
        if (event->pmu == &perf_tracepoint)
                return true;
#ifdef CONFIG_KPROBE_EVENTS
        if (event->pmu == &perf_kprobe)
                return true;
#endif
#ifdef CONFIG_UPROBE_EVENTS
        if (event->pmu == &perf_uprobe)
                return true;
#endif
        return false;
}

static int __perf_event_set_bpf_prog(struct perf_event *event,
                                     struct bpf_prog *prog,
                                     u64 bpf_cookie)
{
        bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp;

        if (event->state <= PERF_EVENT_STATE_REVOKED)
                return -ENODEV;

        if (!perf_event_is_tracing(event))
                return perf_event_set_bpf_handler(event, prog, bpf_cookie);

        is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_KPROBE;
        is_uprobe = event->tp_event->flags & TRACE_EVENT_FL_UPROBE;
        is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT;
        is_syscall_tp = is_syscall_trace_event(event->tp_event);
        if (!is_kprobe && !is_uprobe && !is_tracepoint && !is_syscall_tp)
                /* bpf programs can only be attached to u/kprobe or tracepoint */
                return -EINVAL;

        if (((is_kprobe || is_uprobe) && prog->type != BPF_PROG_TYPE_KPROBE) ||
            (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) ||
            (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT))
                return -EINVAL;

        if (prog->type == BPF_PROG_TYPE_KPROBE && prog->sleepable && !is_uprobe)
                /* only uprobe programs are allowed to be sleepable */
                return -EINVAL;

        /* Kprobe override only works for kprobes, not uprobes. */
        if (prog->kprobe_override && !is_kprobe)
                return -EINVAL;

        /* Writing to context allowed only for uprobes. */
        if (prog->aux->kprobe_write_ctx && !is_uprobe)
                return -EINVAL;

        if (is_tracepoint || is_syscall_tp) {
                int off = trace_event_get_offsets(event->tp_event);

                if (prog->aux->max_ctx_offset > off)
                        return -EACCES;
        }

        return perf_event_attach_bpf_prog(event, prog, bpf_cookie);
}

int perf_event_set_bpf_prog(struct perf_event *event,
                            struct bpf_prog *prog,
                            u64 bpf_cookie)
{
        struct perf_event_context *ctx;
        int ret;

        ctx = perf_event_ctx_lock(event);
        ret = __perf_event_set_bpf_prog(event, prog, bpf_cookie);
        perf_event_ctx_unlock(event, ctx);

        return ret;
}

void perf_event_free_bpf_prog(struct perf_event *event)
{
        if (!event->prog)
                return;

        if (!perf_event_is_tracing(event)) {
                perf_event_free_bpf_handler(event);
                return;
        }
        perf_event_detach_bpf_prog(event);
}

#else

static inline void perf_tp_register(void)
{
}

static void perf_event_free_filter(struct perf_event *event)
{
}

static int __perf_event_set_bpf_prog(struct perf_event *event,
                                     struct bpf_prog *prog,
                                     u64 bpf_cookie)
{
        return -ENOENT;
}

int perf_event_set_bpf_prog(struct perf_event *event,
                            struct bpf_prog *prog,
                            u64 bpf_cookie)
{
        return -ENOENT;
}

void perf_event_free_bpf_prog(struct perf_event *event)
{
}
#endif /* CONFIG_EVENT_TRACING */

#ifdef CONFIG_HAVE_HW_BREAKPOINT
void perf_bp_event(struct perf_event *bp, void *data)
{
        struct perf_sample_data sample;
        struct pt_regs *regs = data;

        perf_sample_data_init(&sample, bp->attr.bp_addr, 0);

        if (!bp->hw.state && !perf_exclude_event(bp, regs))
                perf_swevent_event(bp, 1, &sample, regs);
}
#endif

/*
 * Allocate a new address filter
 */
static struct perf_addr_filter *
perf_addr_filter_new(struct perf_event *event, struct list_head *filters)
{
        int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu);
        struct perf_addr_filter *filter;

        filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node);
        if (!filter)
                return NULL;

        INIT_LIST_HEAD(&filter->entry);
        list_add_tail(&filter->entry, filters);

        return filter;
}

static void free_filters_list(struct list_head *filters)
{
        struct perf_addr_filter *filter, *iter;

        list_for_each_entry_safe(filter, iter, filters, entry) {
                path_put(&filter->path);
                list_del(&filter->entry);
                kfree(filter);
        }
}

/*
 * Free existing address filters and optionally install new ones
 */
static void perf_addr_filters_splice(struct perf_event *event,
                                     struct list_head *head)
{
        unsigned long flags;
        LIST_HEAD(list);

        if (!has_addr_filter(event))
                return;

        /* don't bother with children, they don't have their own filters */
        if (event->parent)
                return;

        raw_spin_lock_irqsave(&event->addr_filters.lock, flags);

        list_splice_init(&event->addr_filters.list, &list);
        if (head)
                list_splice(head, &event->addr_filters.list);

        raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);

        free_filters_list(&list);
}

static void perf_free_addr_filters(struct perf_event *event)
{
        /*
         * Used during free paths, there is no concurrency.
         */
        if (list_empty(&event->addr_filters.list))
                return;

        perf_addr_filters_splice(event, NULL);
}

/*
 * Scan through mm's vmas and see if one of them matches the
 * @filter; if so, adjust filter's address range.
 * Called with mm::mmap_lock down for reading.
 */
static void perf_addr_filter_apply(struct perf_addr_filter *filter,
                                   struct mm_struct *mm,
                                   struct perf_addr_filter_range *fr)
{
        struct vm_area_struct *vma;
        VMA_ITERATOR(vmi, mm, 0);

        for_each_vma(vmi, vma) {
                if (!vma->vm_file)
                        continue;

                if (perf_addr_filter_vma_adjust(filter, vma, fr))
                        return;
        }
}

/*
 * Update event's address range filters based on the
 * task's existing mappings, if any.
 */
static void perf_event_addr_filters_apply(struct perf_event *event)
{
        struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
        struct task_struct *task = READ_ONCE(event->ctx->task);
        struct perf_addr_filter *filter;
        struct mm_struct *mm = NULL;
        unsigned int count = 0;
        unsigned long flags;

        /*
         * We may observe TASK_TOMBSTONE, which means that the event tear-down
         * will stop on the parent's child_mutex that our caller is also holding
         */
        if (task == TASK_TOMBSTONE)
                return;

        if (ifh->nr_file_filters) {
                mm = get_task_mm(task);
                if (!mm)
                        goto restart;

                mmap_read_lock(mm);
        }

        raw_spin_lock_irqsave(&ifh->lock, flags);
        list_for_each_entry(filter, &ifh->list, entry) {
                if (filter->path.dentry) {
                        /*
                         * Adjust base offset if the filter is associated to a
                         * binary that needs to be mapped:
                         */
                        event->addr_filter_ranges[count].start = 0;
                        event->addr_filter_ranges[count].size = 0;

                        perf_addr_filter_apply(filter, mm, &event->addr_filter_ranges[count]);
                } else {
                        event->addr_filter_ranges[count].start = filter->offset;
                        event->addr_filter_ranges[count].size  = filter->size;
                }

                count++;
        }

        event->addr_filters_gen++;
        raw_spin_unlock_irqrestore(&ifh->lock, flags);

        if (ifh->nr_file_filters) {
                mmap_read_unlock(mm);

                mmput(mm);
        }

restart:
        perf_event_stop(event, 1);
}

/*
 * Address range filtering: limiting the data to certain
 * instruction address ranges. Filters are ioctl()ed to us from
 * userspace as ascii strings.
 *
 * Filter string format:
 *
 * ACTION RANGE_SPEC
 * where ACTION is one of the
 *  * "filter": limit the trace to this region
 *  * "start": start tracing from this address
 *  * "stop": stop tracing at this address/region;
 * RANGE_SPEC is
 *  * for kernel addresses: <start address>[/<size>]
 *  * for object files:     <start address>[/<size>]@</path/to/object/file>
 *
 * if <size> is not specified or is zero, the range is treated as a single
 * address; not valid for ACTION=="filter".
 */
enum {
        IF_ACT_NONE = -1,
        IF_ACT_FILTER,
        IF_ACT_START,
        IF_ACT_STOP,
        IF_SRC_FILE,
        IF_SRC_KERNEL,
        IF_SRC_FILEADDR,
        IF_SRC_KERNELADDR,
};

enum {
        IF_STATE_ACTION = 0,
        IF_STATE_SOURCE,
        IF_STATE_END,
};

static const match_table_t if_tokens = {
        { IF_ACT_FILTER,        "filter" },
        { IF_ACT_START,                "start" },
        { IF_ACT_STOP,                "stop" },
        { IF_SRC_FILE,                "%u/%u@%s" },
        { IF_SRC_KERNEL,        "%u/%u" },
        { IF_SRC_FILEADDR,        "%u@%s" },
        { IF_SRC_KERNELADDR,        "%u" },
        { IF_ACT_NONE,                NULL },
};

/*
 * Address filter string parser
 */
static int
perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
                             struct list_head *filters)
{
        struct perf_addr_filter *filter = NULL;
        char *start, *orig, *filename = NULL;
        substring_t args[MAX_OPT_ARGS];
        int state = IF_STATE_ACTION, token;
        unsigned int kernel = 0;
        int ret = -EINVAL;

        orig = fstr = kstrdup(fstr, GFP_KERNEL);
        if (!fstr)
                return -ENOMEM;

        while ((start = strsep(&fstr, " ,\n")) != NULL) {
                static const enum perf_addr_filter_action_t actions[] = {
                        [IF_ACT_FILTER]        = PERF_ADDR_FILTER_ACTION_FILTER,
                        [IF_ACT_START]        = PERF_ADDR_FILTER_ACTION_START,
                        [IF_ACT_STOP]        = PERF_ADDR_FILTER_ACTION_STOP,
                };
                ret = -EINVAL;

                if (!*start)
                        continue;

                /* filter definition begins */
                if (state == IF_STATE_ACTION) {
                        filter = perf_addr_filter_new(event, filters);
                        if (!filter)
                                goto fail;
                }

                token = match_token(start, if_tokens, args);
                switch (token) {
                case IF_ACT_FILTER:
                case IF_ACT_START:
                case IF_ACT_STOP:
                        if (state != IF_STATE_ACTION)
                                goto fail;

                        filter->action = actions[token];
                        state = IF_STATE_SOURCE;
                        break;

                case IF_SRC_KERNELADDR:
                case IF_SRC_KERNEL:
                        kernel = 1;
                        fallthrough;

                case IF_SRC_FILEADDR:
                case IF_SRC_FILE:
                        if (state != IF_STATE_SOURCE)
                                goto fail;

                        *args[0].to = 0;
                        ret = kstrtoul(args[0].from, 0, &filter->offset);
                        if (ret)
                                goto fail;

                        if (token == IF_SRC_KERNEL || token == IF_SRC_FILE) {
                                *args[1].to = 0;
                                ret = kstrtoul(args[1].from, 0, &filter->size);
                                if (ret)
                                        goto fail;
                        }

                        if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
                                int fpos = token == IF_SRC_FILE ? 2 : 1;

                                kfree(filename);
                                filename = match_strdup(&args[fpos]);
                                if (!filename) {
                                        ret = -ENOMEM;
                                        goto fail;
                                }
                        }

                        state = IF_STATE_END;
                        break;

                default:
                        goto fail;
                }

                /*
                 * Filter definition is fully parsed, validate and install it.
                 * Make sure that it doesn't contradict itself or the event's
                 * attribute.
                 */
                if (state == IF_STATE_END) {
                        ret = -EINVAL;

                        /*
                         * ACTION "filter" must have a non-zero length region
                         * specified.
                         */
                        if (filter->action == PERF_ADDR_FILTER_ACTION_FILTER &&
                            !filter->size)
                                goto fail;

                        if (!kernel) {
                                if (!filename)
                                        goto fail;

                                /*
                                 * For now, we only support file-based filters
                                 * in per-task events; doing so for CPU-wide
                                 * events requires additional context switching
                                 * trickery, since same object code will be
                                 * mapped at different virtual addresses in
                                 * different processes.
                                 */
                                ret = -EOPNOTSUPP;
                                if (!event->ctx->task)
                                        goto fail;

                                /* look up the path and grab its inode */
                                ret = kern_path(filename, LOOKUP_FOLLOW,
                                                &filter->path);
                                if (ret)
                                        goto fail;

                                ret = -EINVAL;
                                if (!filter->path.dentry ||
                                    !S_ISREG(d_inode(filter->path.dentry)
                                             ->i_mode))
                                        goto fail;

                                event->addr_filters.nr_file_filters++;
                        }

                        /* ready to consume more filters */
                        kfree(filename);
                        filename = NULL;
                        state = IF_STATE_ACTION;
                        filter = NULL;
                        kernel = 0;
                }
        }

        if (state != IF_STATE_ACTION)
                goto fail;

        kfree(filename);
        kfree(orig);

        return 0;

fail:
        kfree(filename);
        free_filters_list(filters);
        kfree(orig);

        return ret;
}

static int
perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
{
        LIST_HEAD(filters);
        int ret;

        /*
         * Since this is called in perf_ioctl() path, we're already holding
         * ctx::mutex.
         */
        lockdep_assert_held(&event->ctx->mutex);

        if (WARN_ON_ONCE(event->parent))
                return -EINVAL;

        ret = perf_event_parse_addr_filter(event, filter_str, &filters);
        if (ret)
                goto fail_clear_files;

        ret = event->pmu->addr_filters_validate(&filters);
        if (ret)
                goto fail_free_filters;

        /* remove existing filters, if any */
        perf_addr_filters_splice(event, &filters);

        /* install new filters */
        perf_event_for_each_child(event, perf_event_addr_filters_apply);

        return ret;

fail_free_filters:
        free_filters_list(&filters);

fail_clear_files:
        event->addr_filters.nr_file_filters = 0;

        return ret;
}

static int perf_event_set_filter(struct perf_event *event, void __user *arg)
{
        int ret = -EINVAL;
        char *filter_str;

        filter_str = strndup_user(arg, PAGE_SIZE);
        if (IS_ERR(filter_str))
                return PTR_ERR(filter_str);

#ifdef CONFIG_EVENT_TRACING
        if (perf_event_is_tracing(event)) {
                struct perf_event_context *ctx = event->ctx;

                /*
                 * Beware, here be dragons!!
                 *
                 * the tracepoint muck will deadlock against ctx->mutex, but
                 * the tracepoint stuff does not actually need it. So
                 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
                 * already have a reference on ctx.
                 *
                 * This can result in event getting moved to a different ctx,
                 * but that does not affect the tracepoint state.
                 */
                mutex_unlock(&ctx->mutex);
                ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);
                mutex_lock(&ctx->mutex);
        } else
#endif
        if (has_addr_filter(event))
                ret = perf_event_set_addr_filter(event, filter_str);

        kfree(filter_str);
        return ret;
}

/*
 * hrtimer based swevent callback
 */

static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
{
        enum hrtimer_restart ret = HRTIMER_RESTART;
        struct perf_sample_data data;
        struct pt_regs *regs;
        struct perf_event *event;
        u64 period;

        event = container_of(hrtimer, struct perf_event, hw.hrtimer);

        if (event->state != PERF_EVENT_STATE_ACTIVE)
                return HRTIMER_NORESTART;

        event->pmu->read(event);

        perf_sample_data_init(&data, 0, event->hw.last_period);
        regs = get_irq_regs();

        if (regs && !perf_exclude_event(event, regs)) {
                if (!(event->attr.exclude_idle && is_idle_task(current)))
                        if (__perf_event_overflow(event, 1, &data, regs))
                                ret = HRTIMER_NORESTART;
        }

        period = max_t(u64, 10000, event->hw.sample_period);
        hrtimer_forward_now(hrtimer, ns_to_ktime(period));

        return ret;
}

static void perf_swevent_start_hrtimer(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        s64 period;

        if (!is_sampling_event(event))
                return;

        period = local64_read(&hwc->period_left);
        if (period) {
                if (period < 0)
                        period = 10000;

                local64_set(&hwc->period_left, 0);
        } else {
                period = max_t(u64, 10000, hwc->sample_period);
        }
        hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
                      HRTIMER_MODE_REL_PINNED_HARD);
}

static void perf_swevent_cancel_hrtimer(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        /*
         * The throttle can be triggered in the hrtimer handler.
         * The HRTIMER_NORESTART should be used to stop the timer,
         * rather than hrtimer_cancel(). See perf_swevent_hrtimer()
         */
        if (is_sampling_event(event) && (hwc->interrupts != MAX_INTERRUPTS)) {
                ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
                local64_set(&hwc->period_left, ktime_to_ns(remaining));

                hrtimer_cancel(&hwc->hrtimer);
        }
}

static void perf_swevent_init_hrtimer(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        if (!is_sampling_event(event))
                return;

        hrtimer_setup(&hwc->hrtimer, perf_swevent_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);

        /*
         * Since hrtimers have a fixed rate, we can do a static freq->period
         * mapping and avoid the whole period adjust feedback stuff.
         */
        if (event->attr.freq) {
                long freq = event->attr.sample_freq;

                event->attr.sample_period = NSEC_PER_SEC / freq;
                hwc->sample_period = event->attr.sample_period;
                local64_set(&hwc->period_left, hwc->sample_period);
                hwc->last_period = hwc->sample_period;
                event->attr.freq = 0;
        }
}

/*
 * Software event: cpu wall time clock
 */

static void cpu_clock_event_update(struct perf_event *event)
{
        s64 prev;
        u64 now;

        now = local_clock();
        prev = local64_xchg(&event->hw.prev_count, now);
        local64_add(now - prev, &event->count);
}

static void cpu_clock_event_start(struct perf_event *event, int flags)
{
        local64_set(&event->hw.prev_count, local_clock());
        perf_swevent_start_hrtimer(event);
}

static void cpu_clock_event_stop(struct perf_event *event, int flags)
{
        perf_swevent_cancel_hrtimer(event);
        if (flags & PERF_EF_UPDATE)
                cpu_clock_event_update(event);
}

static int cpu_clock_event_add(struct perf_event *event, int flags)
{
        if (flags & PERF_EF_START)
                cpu_clock_event_start(event, flags);
        perf_event_update_userpage(event);

        return 0;
}

static void cpu_clock_event_del(struct perf_event *event, int flags)
{
        cpu_clock_event_stop(event, flags);
}

static void cpu_clock_event_read(struct perf_event *event)
{
        cpu_clock_event_update(event);
}

static int cpu_clock_event_init(struct perf_event *event)
{
        if (event->attr.type != perf_cpu_clock.type)
                return -ENOENT;

        if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
                return -ENOENT;

        /*
         * no branch sampling for software events
         */
        if (has_branch_stack(event))
                return -EOPNOTSUPP;

        perf_swevent_init_hrtimer(event);

        return 0;
}

static struct pmu perf_cpu_clock = {
        .task_ctx_nr        = perf_sw_context,

        .capabilities        = PERF_PMU_CAP_NO_NMI,
        .dev                = PMU_NULL_DEV,

        .event_init        = cpu_clock_event_init,
        .add                = cpu_clock_event_add,
        .del                = cpu_clock_event_del,
        .start                = cpu_clock_event_start,
        .stop                = cpu_clock_event_stop,
        .read                = cpu_clock_event_read,
};

/*
 * Software event: task time clock
 */

static void task_clock_event_update(struct perf_event *event, u64 now)
{
        u64 prev;
        s64 delta;

        prev = local64_xchg(&event->hw.prev_count, now);
        delta = now - prev;
        local64_add(delta, &event->count);
}

static void task_clock_event_start(struct perf_event *event, int flags)
{
        local64_set(&event->hw.prev_count, event->ctx->time);
        perf_swevent_start_hrtimer(event);
}

static void task_clock_event_stop(struct perf_event *event, int flags)
{
        perf_swevent_cancel_hrtimer(event);
        if (flags & PERF_EF_UPDATE)
                task_clock_event_update(event, event->ctx->time);
}

static int task_clock_event_add(struct perf_event *event, int flags)
{
        if (flags & PERF_EF_START)
                task_clock_event_start(event, flags);
        perf_event_update_userpage(event);

        return 0;
}

static void task_clock_event_del(struct perf_event *event, int flags)
{
        task_clock_event_stop(event, PERF_EF_UPDATE);
}

static void task_clock_event_read(struct perf_event *event)
{
        u64 now = perf_clock();
        u64 delta = now - event->ctx->timestamp;
        u64 time = event->ctx->time + delta;

        task_clock_event_update(event, time);
}

static int task_clock_event_init(struct perf_event *event)
{
        if (event->attr.type != perf_task_clock.type)
                return -ENOENT;

        if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
                return -ENOENT;

        /*
         * no branch sampling for software events
         */
        if (has_branch_stack(event))
                return -EOPNOTSUPP;

        perf_swevent_init_hrtimer(event);

        return 0;
}

static struct pmu perf_task_clock = {
        .task_ctx_nr        = perf_sw_context,

        .capabilities        = PERF_PMU_CAP_NO_NMI,
        .dev                = PMU_NULL_DEV,

        .event_init        = task_clock_event_init,
        .add                = task_clock_event_add,
        .del                = task_clock_event_del,
        .start                = task_clock_event_start,
        .stop                = task_clock_event_stop,
        .read                = task_clock_event_read,
};

static void perf_pmu_nop_void(struct pmu *pmu)
{
}

static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
{
}

static int perf_pmu_nop_int(struct pmu *pmu)
{
        return 0;
}

static int perf_event_nop_int(struct perf_event *event, u64 value)
{
        return 0;
}

static DEFINE_PER_CPU(unsigned int, nop_txn_flags);

static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
{
        __this_cpu_write(nop_txn_flags, flags);

        if (flags & ~PERF_PMU_TXN_ADD)
                return;

        perf_pmu_disable(pmu);
}

static int perf_pmu_commit_txn(struct pmu *pmu)
{
        unsigned int flags = __this_cpu_read(nop_txn_flags);

        __this_cpu_write(nop_txn_flags, 0);

        if (flags & ~PERF_PMU_TXN_ADD)
                return 0;

        perf_pmu_enable(pmu);
        return 0;
}

static void perf_pmu_cancel_txn(struct pmu *pmu)
{
        unsigned int flags =  __this_cpu_read(nop_txn_flags);

        __this_cpu_write(nop_txn_flags, 0);

        if (flags & ~PERF_PMU_TXN_ADD)
                return;

        perf_pmu_enable(pmu);
}

static int perf_event_idx_default(struct perf_event *event)
{
        return 0;
}

/*
 * Let userspace know that this PMU supports address range filtering:
 */
static ssize_t nr_addr_filters_show(struct device *dev,
                                    struct device_attribute *attr,
                                    char *page)
{
        struct pmu *pmu = dev_get_drvdata(dev);

        return sysfs_emit(page, "%d\n", pmu->nr_addr_filters);
}
DEVICE_ATTR_RO(nr_addr_filters);

static struct idr pmu_idr;

static ssize_t
type_show(struct device *dev, struct device_attribute *attr, char *page)
{
        struct pmu *pmu = dev_get_drvdata(dev);

        return sysfs_emit(page, "%d\n", pmu->type);
}
static DEVICE_ATTR_RO(type);

static ssize_t
perf_event_mux_interval_ms_show(struct device *dev,
                                struct device_attribute *attr,
                                char *page)
{
        struct pmu *pmu = dev_get_drvdata(dev);

        return sysfs_emit(page, "%d\n", pmu->hrtimer_interval_ms);
}

static DEFINE_MUTEX(mux_interval_mutex);

static ssize_t
perf_event_mux_interval_ms_store(struct device *dev,
                                 struct device_attribute *attr,
                                 const char *buf, size_t count)
{
        struct pmu *pmu = dev_get_drvdata(dev);
        int timer, cpu, ret;

        ret = kstrtoint(buf, 0, &timer);
        if (ret)
                return ret;

        if (timer < 1)
                return -EINVAL;

        /* same value, noting to do */
        if (timer == pmu->hrtimer_interval_ms)
                return count;

        mutex_lock(&mux_interval_mutex);
        pmu->hrtimer_interval_ms = timer;

        /* update all cpuctx for this PMU */
        cpus_read_lock();
        for_each_online_cpu(cpu) {
                struct perf_cpu_pmu_context *cpc;
                cpc = *per_cpu_ptr(pmu->cpu_pmu_context, cpu);
                cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);

                cpu_function_call(cpu, perf_mux_hrtimer_restart_ipi, cpc);
        }
        cpus_read_unlock();
        mutex_unlock(&mux_interval_mutex);

        return count;
}
static DEVICE_ATTR_RW(perf_event_mux_interval_ms);

static inline const struct cpumask *perf_scope_cpu_topology_cpumask(unsigned int scope, int cpu)
{
        switch (scope) {
        case PERF_PMU_SCOPE_CORE:
                return topology_sibling_cpumask(cpu);
        case PERF_PMU_SCOPE_DIE:
                return topology_die_cpumask(cpu);
        case PERF_PMU_SCOPE_CLUSTER:
                return topology_cluster_cpumask(cpu);
        case PERF_PMU_SCOPE_PKG:
                return topology_core_cpumask(cpu);
        case PERF_PMU_SCOPE_SYS_WIDE:
                return cpu_online_mask;
        }

        return NULL;
}

static inline struct cpumask *perf_scope_cpumask(unsigned int scope)
{
        switch (scope) {
        case PERF_PMU_SCOPE_CORE:
                return perf_online_core_mask;
        case PERF_PMU_SCOPE_DIE:
                return perf_online_die_mask;
        case PERF_PMU_SCOPE_CLUSTER:
                return perf_online_cluster_mask;
        case PERF_PMU_SCOPE_PKG:
                return perf_online_pkg_mask;
        case PERF_PMU_SCOPE_SYS_WIDE:
                return perf_online_sys_mask;
        }

        return NULL;
}

static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
                            char *buf)
{
        struct pmu *pmu = dev_get_drvdata(dev);
        struct cpumask *mask = perf_scope_cpumask(pmu->scope);

        if (mask)
                return cpumap_print_to_pagebuf(true, buf, mask);
        return 0;
}

static DEVICE_ATTR_RO(cpumask);

static struct attribute *pmu_dev_attrs[] = {
        &dev_attr_type.attr,
        &dev_attr_perf_event_mux_interval_ms.attr,
        &dev_attr_nr_addr_filters.attr,
        &dev_attr_cpumask.attr,
        NULL,
};

static umode_t pmu_dev_is_visible(struct kobject *kobj, struct attribute *a, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct pmu *pmu = dev_get_drvdata(dev);

        if (n == 2 && !pmu->nr_addr_filters)
                return 0;

        /* cpumask */
        if (n == 3 && pmu->scope == PERF_PMU_SCOPE_NONE)
                return 0;

        return a->mode;
}

static struct attribute_group pmu_dev_attr_group = {
        .is_visible = pmu_dev_is_visible,
        .attrs = pmu_dev_attrs,
};

static const struct attribute_group *pmu_dev_groups[] = {
        &pmu_dev_attr_group,
        NULL,
};

static int pmu_bus_running;
static const struct bus_type pmu_bus = {
        .name                = "event_source",
        .dev_groups        = pmu_dev_groups,
};

static void pmu_dev_release(struct device *dev)
{
        kfree(dev);
}

static int pmu_dev_alloc(struct pmu *pmu)
{
        int ret = -ENOMEM;

        pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
        if (!pmu->dev)
                goto out;

        pmu->dev->groups = pmu->attr_groups;
        device_initialize(pmu->dev);

        dev_set_drvdata(pmu->dev, pmu);
        pmu->dev->bus = &pmu_bus;
        pmu->dev->parent = pmu->parent;
        pmu->dev->release = pmu_dev_release;

        ret = dev_set_name(pmu->dev, "%s", pmu->name);
        if (ret)
                goto free_dev;

        ret = device_add(pmu->dev);
        if (ret)
                goto free_dev;

        if (pmu->attr_update) {
                ret = sysfs_update_groups(&pmu->dev->kobj, pmu->attr_update);
                if (ret)
                        goto del_dev;
        }

out:
        return ret;

del_dev:
        device_del(pmu->dev);

free_dev:
        put_device(pmu->dev);
        pmu->dev = NULL;
        goto out;
}

static struct lock_class_key cpuctx_mutex;
static struct lock_class_key cpuctx_lock;

static bool idr_cmpxchg(struct idr *idr, unsigned long id, void *old, void *new)
{
        void *tmp, *val = idr_find(idr, id);

        if (val != old)
                return false;

        tmp = idr_replace(idr, new, id);
        if (IS_ERR(tmp))
                return false;

        WARN_ON_ONCE(tmp != val);
        return true;
}

static void perf_pmu_free(struct pmu *pmu)
{
        if (pmu_bus_running && pmu->dev && pmu->dev != PMU_NULL_DEV) {
                if (pmu->nr_addr_filters)
                        device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
                device_del(pmu->dev);
                put_device(pmu->dev);
        }

        if (pmu->cpu_pmu_context) {
                int cpu;

                for_each_possible_cpu(cpu) {
                        struct perf_cpu_pmu_context *cpc;

                        cpc = *per_cpu_ptr(pmu->cpu_pmu_context, cpu);
                        if (!cpc)
                                continue;
                        if (cpc->epc.embedded) {
                                /* refcount managed */
                                put_pmu_ctx(&cpc->epc);
                                continue;
                        }
                        kfree(cpc);
                }
                free_percpu(pmu->cpu_pmu_context);
        }
}

DEFINE_FREE(pmu_unregister, struct pmu *, if (_T) perf_pmu_free(_T))

int perf_pmu_register(struct pmu *_pmu, const char *name, int type)
{
        int cpu, max = PERF_TYPE_MAX;

        struct pmu *pmu __free(pmu_unregister) = _pmu;
        guard(mutex)(&pmus_lock);

        if (WARN_ONCE(!name, "Can not register anonymous pmu.\n"))
                return -EINVAL;

        if (WARN_ONCE(pmu->scope >= PERF_PMU_MAX_SCOPE,
                      "Can not register a pmu with an invalid scope.\n"))
                return -EINVAL;

        pmu->name = name;

        if (type >= 0)
                max = type;

        CLASS(idr_alloc, pmu_type)(&pmu_idr, NULL, max, 0, GFP_KERNEL);
        if (pmu_type.id < 0)
                return pmu_type.id;

        WARN_ON(type >= 0 && pmu_type.id != type);

        pmu->type = pmu_type.id;
        atomic_set(&pmu->exclusive_cnt, 0);

        if (pmu_bus_running && !pmu->dev) {
                int ret = pmu_dev_alloc(pmu);
                if (ret)
                        return ret;
        }

        pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context *);
        if (!pmu->cpu_pmu_context)
                return -ENOMEM;

        for_each_possible_cpu(cpu) {
                struct perf_cpu_pmu_context *cpc =
                        kmalloc_node(sizeof(struct perf_cpu_pmu_context),
                                     GFP_KERNEL | __GFP_ZERO,
                                     cpu_to_node(cpu));

                if (!cpc)
                        return -ENOMEM;

                *per_cpu_ptr(pmu->cpu_pmu_context, cpu) = cpc;
                __perf_init_event_pmu_context(&cpc->epc, pmu);
                __perf_mux_hrtimer_init(cpc, cpu);
        }

        if (!pmu->start_txn) {
                if (pmu->pmu_enable) {
                        /*
                         * If we have pmu_enable/pmu_disable calls, install
                         * transaction stubs that use that to try and batch
                         * hardware accesses.
                         */
                        pmu->start_txn  = perf_pmu_start_txn;
                        pmu->commit_txn = perf_pmu_commit_txn;
                        pmu->cancel_txn = perf_pmu_cancel_txn;
                } else {
                        pmu->start_txn  = perf_pmu_nop_txn;
                        pmu->commit_txn = perf_pmu_nop_int;
                        pmu->cancel_txn = perf_pmu_nop_void;
                }
        }

        if (!pmu->pmu_enable) {
                pmu->pmu_enable  = perf_pmu_nop_void;
                pmu->pmu_disable = perf_pmu_nop_void;
        }

        if (!pmu->check_period)
                pmu->check_period = perf_event_nop_int;

        if (!pmu->event_idx)
                pmu->event_idx = perf_event_idx_default;

        INIT_LIST_HEAD(&pmu->events);
        spin_lock_init(&pmu->events_lock);

        /*
         * Now that the PMU is complete, make it visible to perf_try_init_event().
         */
        if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu))
                return -EINVAL;
        list_add_rcu(&pmu->entry, &pmus);

        take_idr_id(pmu_type);
        _pmu = no_free_ptr(pmu); // let it rip
        return 0;
}
EXPORT_SYMBOL_GPL(perf_pmu_register);

static void __pmu_detach_event(struct pmu *pmu, struct perf_event *event,
                               struct perf_event_context *ctx)
{
        /*
         * De-schedule the event and mark it REVOKED.
         */
        perf_event_exit_event(event, ctx, true);

        /*
         * All _free_event() bits that rely on event->pmu:
         *
         * Notably, perf_mmap() relies on the ordering here.
         */
        scoped_guard (mutex, &event->mmap_mutex) {
                WARN_ON_ONCE(pmu->event_unmapped);
                /*
                 * Mostly an empty lock sequence, such that perf_mmap(), which
                 * relies on mmap_mutex, is sure to observe the state change.
                 */
        }

        perf_event_free_bpf_prog(event);
        perf_free_addr_filters(event);

        if (event->destroy) {
                event->destroy(event);
                event->destroy = NULL;
        }

        if (event->pmu_ctx) {
                put_pmu_ctx(event->pmu_ctx);
                event->pmu_ctx = NULL;
        }

        exclusive_event_destroy(event);
        module_put(pmu->module);

        event->pmu = NULL; /* force fault instead of UAF */
}

static void pmu_detach_event(struct pmu *pmu, struct perf_event *event)
{
        struct perf_event_context *ctx;

        ctx = perf_event_ctx_lock(event);
        __pmu_detach_event(pmu, event, ctx);
        perf_event_ctx_unlock(event, ctx);

        scoped_guard (spinlock, &pmu->events_lock)
                list_del(&event->pmu_list);
}

static struct perf_event *pmu_get_event(struct pmu *pmu)
{
        struct perf_event *event;

        guard(spinlock)(&pmu->events_lock);
        list_for_each_entry(event, &pmu->events, pmu_list) {
                if (atomic_long_inc_not_zero(&event->refcount))
                        return event;
        }

        return NULL;
}

static bool pmu_empty(struct pmu *pmu)
{
        guard(spinlock)(&pmu->events_lock);
        return list_empty(&pmu->events);
}

static void pmu_detach_events(struct pmu *pmu)
{
        struct perf_event *event;

        for (;;) {
                event = pmu_get_event(pmu);
                if (!event)
                        break;

                pmu_detach_event(pmu, event);
                put_event(event);
        }

        /*
         * wait for pending _free_event()s
         */
        wait_var_event(pmu, pmu_empty(pmu));
}

int perf_pmu_unregister(struct pmu *pmu)
{
        scoped_guard (mutex, &pmus_lock) {
                if (!idr_cmpxchg(&pmu_idr, pmu->type, pmu, NULL))
                        return -EINVAL;

                list_del_rcu(&pmu->entry);
        }

        /*
         * We dereference the pmu list under both SRCU and regular RCU, so
         * synchronize against both of those.
         *
         * Notably, the entirety of event creation, from perf_init_event()
         * (which will now fail, because of the above) until
         * perf_install_in_context() should be under SRCU such that
         * this synchronizes against event creation. This avoids trying to
         * detach events that are not fully formed.
         */
        synchronize_srcu(&pmus_srcu);
        synchronize_rcu();

        if (pmu->event_unmapped && !pmu_empty(pmu)) {
                /*
                 * Can't force remove events when pmu::event_unmapped()
                 * is used in perf_mmap_close().
                 */
                guard(mutex)(&pmus_lock);
                idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu);
                list_add_rcu(&pmu->entry, &pmus);
                return -EBUSY;
        }

        scoped_guard (mutex, &pmus_lock)
                idr_remove(&pmu_idr, pmu->type);

        /*
         * PMU is removed from the pmus list, so no new events will
         * be created, now take care of the existing ones.
         */
        pmu_detach_events(pmu);

        /*
         * PMU is unused, make it go away.
         */
        perf_pmu_free(pmu);
        return 0;
}
EXPORT_SYMBOL_GPL(perf_pmu_unregister);

static inline bool has_extended_regs(struct perf_event *event)
{
        return (event->attr.sample_regs_user & PERF_REG_EXTENDED_MASK) ||
               (event->attr.sample_regs_intr & PERF_REG_EXTENDED_MASK);
}

static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
{
        struct perf_event_context *ctx = NULL;
        int ret;

        if (!try_module_get(pmu->module))
                return -ENODEV;

        /*
         * A number of pmu->event_init() methods iterate the sibling_list to,
         * for example, validate if the group fits on the PMU. Therefore,
         * if this is a sibling event, acquire the ctx->mutex to protect
         * the sibling_list.
         */
        if (event->group_leader != event && pmu->task_ctx_nr != perf_sw_context) {
                /*
                 * This ctx->mutex can nest when we're called through
                 * inheritance. See the perf_event_ctx_lock_nested() comment.
                 */
                ctx = perf_event_ctx_lock_nested(event->group_leader,
                                                 SINGLE_DEPTH_NESTING);
                BUG_ON(!ctx);
        }

        event->pmu = pmu;
        ret = pmu->event_init(event);

        if (ctx)
                perf_event_ctx_unlock(event->group_leader, ctx);

        if (ret)
                goto err_pmu;

        if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
            has_extended_regs(event)) {
                ret = -EOPNOTSUPP;
                goto err_destroy;
        }

        if (pmu->capabilities & PERF_PMU_CAP_NO_EXCLUDE &&
            event_has_any_exclude_flag(event)) {
                ret = -EINVAL;
                goto err_destroy;
        }

        if (pmu->scope != PERF_PMU_SCOPE_NONE && event->cpu >= 0) {
                const struct cpumask *cpumask;
                struct cpumask *pmu_cpumask;
                int cpu;

                cpumask = perf_scope_cpu_topology_cpumask(pmu->scope, event->cpu);
                pmu_cpumask = perf_scope_cpumask(pmu->scope);

                ret = -ENODEV;
                if (!pmu_cpumask || !cpumask)
                        goto err_destroy;

                cpu = cpumask_any_and(pmu_cpumask, cpumask);
                if (cpu >= nr_cpu_ids)
                        goto err_destroy;

                event->event_caps |= PERF_EV_CAP_READ_SCOPE;
        }

        return 0;

err_destroy:
        if (event->destroy) {
                event->destroy(event);
                event->destroy = NULL;
        }

err_pmu:
        event->pmu = NULL;
        module_put(pmu->module);
        return ret;
}

static struct pmu *perf_init_event(struct perf_event *event)
{
        bool extended_type = false;
        struct pmu *pmu;
        int type, ret;

        guard(srcu)(&pmus_srcu); /* pmu idr/list access */

        /*
         * Save original type before calling pmu->event_init() since certain
         * pmus overwrites event->attr.type to forward event to another pmu.
         */
        event->orig_type = event->attr.type;

        /* Try parent's PMU first: */
        if (event->parent && event->parent->pmu) {
                pmu = event->parent->pmu;
                ret = perf_try_init_event(pmu, event);
                if (!ret)
                        return pmu;
        }

        /*
         * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE
         * are often aliases for PERF_TYPE_RAW.
         */
        type = event->attr.type;
        if (type == PERF_TYPE_HARDWARE || type == PERF_TYPE_HW_CACHE) {
                type = event->attr.config >> PERF_PMU_TYPE_SHIFT;
                if (!type) {
                        type = PERF_TYPE_RAW;
                } else {
                        extended_type = true;
                        event->attr.config &= PERF_HW_EVENT_MASK;
                }
        }

again:
        scoped_guard (rcu)
                pmu = idr_find(&pmu_idr, type);
        if (pmu) {
                if (event->attr.type != type && type != PERF_TYPE_RAW &&
                    !(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))
                        return ERR_PTR(-ENOENT);

                ret = perf_try_init_event(pmu, event);
                if (ret == -ENOENT && event->attr.type != type && !extended_type) {
                        type = event->attr.type;
                        goto again;
                }

                if (ret)
                        return ERR_PTR(ret);

                return pmu;
        }

        list_for_each_entry_rcu(pmu, &pmus, entry, lockdep_is_held(&pmus_srcu)) {
                ret = perf_try_init_event(pmu, event);
                if (!ret)
                        return pmu;

                if (ret != -ENOENT)
                        return ERR_PTR(ret);
        }

        return ERR_PTR(-ENOENT);
}

static void attach_sb_event(struct perf_event *event)
{
        struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);

        raw_spin_lock(&pel->lock);
        list_add_rcu(&event->sb_list, &pel->list);
        raw_spin_unlock(&pel->lock);
}

/*
 * We keep a list of all !task (and therefore per-cpu) events
 * that need to receive side-band records.
 *
 * This avoids having to scan all the various PMU per-cpu contexts
 * looking for them.
 */
static void account_pmu_sb_event(struct perf_event *event)
{
        if (is_sb_event(event))
                attach_sb_event(event);
}

/* Freq events need the tick to stay alive (see perf_event_task_tick). */
static void account_freq_event_nohz(void)
{
#ifdef CONFIG_NO_HZ_FULL
        /* Lock so we don't race with concurrent unaccount */
        spin_lock(&nr_freq_lock);
        if (atomic_inc_return(&nr_freq_events) == 1)
                tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
        spin_unlock(&nr_freq_lock);
#endif
}

static void account_freq_event(void)
{
        if (tick_nohz_full_enabled())
                account_freq_event_nohz();
        else
                atomic_inc(&nr_freq_events);
}


static void account_event(struct perf_event *event)
{
        bool inc = false;

        if (event->parent)
                return;

        if (event->attach_state & (PERF_ATTACH_TASK | PERF_ATTACH_SCHED_CB))
                inc = true;
        if (event->attr.mmap || event->attr.mmap_data)
                atomic_inc(&nr_mmap_events);
        if (event->attr.build_id)
                atomic_inc(&nr_build_id_events);
        if (event->attr.comm)
                atomic_inc(&nr_comm_events);
        if (event->attr.namespaces)
                atomic_inc(&nr_namespaces_events);
        if (event->attr.cgroup)
                atomic_inc(&nr_cgroup_events);
        if (event->attr.task)
                atomic_inc(&nr_task_events);
        if (event->attr.freq)
                account_freq_event();
        if (event->attr.context_switch) {
                atomic_inc(&nr_switch_events);
                inc = true;
        }
        if (has_branch_stack(event))
                inc = true;
        if (is_cgroup_event(event))
                inc = true;
        if (event->attr.ksymbol)
                atomic_inc(&nr_ksymbol_events);
        if (event->attr.bpf_event)
                atomic_inc(&nr_bpf_events);
        if (event->attr.text_poke)
                atomic_inc(&nr_text_poke_events);

        if (inc) {
                /*
                 * We need the mutex here because static_branch_enable()
                 * must complete *before* the perf_sched_count increment
                 * becomes visible.
                 */
                if (atomic_inc_not_zero(&perf_sched_count))
                        goto enabled;

                mutex_lock(&perf_sched_mutex);
                if (!atomic_read(&perf_sched_count)) {
                        static_branch_enable(&perf_sched_events);
                        /*
                         * Guarantee that all CPUs observe they key change and
                         * call the perf scheduling hooks before proceeding to
                         * install events that need them.
                         */
                        synchronize_rcu();
                }
                /*
                 * Now that we have waited for the sync_sched(), allow further
                 * increments to by-pass the mutex.
                 */
                atomic_inc(&perf_sched_count);
                mutex_unlock(&perf_sched_mutex);
        }
enabled:

        account_pmu_sb_event(event);
}

/*
 * Allocate and initialize an event structure
 */
static struct perf_event *
perf_event_alloc(struct perf_event_attr *attr, int cpu,
                 struct task_struct *task,
                 struct perf_event *group_leader,
                 struct perf_event *parent_event,
                 perf_overflow_handler_t overflow_handler,
                 void *context, int cgroup_fd)
{
        struct pmu *pmu;
        struct hw_perf_event *hwc;
        long err = -EINVAL;
        int node;

        if ((unsigned)cpu >= nr_cpu_ids) {
                if (!task || cpu != -1)
                        return ERR_PTR(-EINVAL);
        }
        if (attr->sigtrap && !task) {
                /* Requires a task: avoid signalling random tasks. */
                return ERR_PTR(-EINVAL);
        }

        node = (cpu >= 0) ? cpu_to_node(cpu) : -1;
        struct perf_event *event __free(__free_event) =
                kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO, node);
        if (!event)
                return ERR_PTR(-ENOMEM);

        /*
         * Single events are their own group leaders, with an
         * empty sibling list:
         */
        if (!group_leader)
                group_leader = event;

        mutex_init(&event->child_mutex);
        INIT_LIST_HEAD(&event->child_list);

        INIT_LIST_HEAD(&event->event_entry);
        INIT_LIST_HEAD(&event->sibling_list);
        INIT_LIST_HEAD(&event->active_list);
        init_event_group(event);
        INIT_LIST_HEAD(&event->rb_entry);
        INIT_LIST_HEAD(&event->active_entry);
        INIT_LIST_HEAD(&event->addr_filters.list);
        INIT_HLIST_NODE(&event->hlist_entry);
        INIT_LIST_HEAD(&event->pmu_list);


        init_waitqueue_head(&event->waitq);
        init_irq_work(&event->pending_irq, perf_pending_irq);
        event->pending_disable_irq = IRQ_WORK_INIT_HARD(perf_pending_disable);
        init_task_work(&event->pending_task, perf_pending_task);

        mutex_init(&event->mmap_mutex);
        raw_spin_lock_init(&event->addr_filters.lock);

        atomic_long_set(&event->refcount, 1);
        event->cpu                = cpu;
        event->attr                = *attr;
        event->group_leader        = group_leader;
        event->pmu                = NULL;
        event->oncpu                = -1;

        event->parent                = parent_event;

        event->ns                = get_pid_ns(task_active_pid_ns(current));
        event->id                = atomic64_inc_return(&perf_event_id);

        event->state                = PERF_EVENT_STATE_INACTIVE;

        if (parent_event)
                event->event_caps = parent_event->event_caps;

        if (task) {
                event->attach_state = PERF_ATTACH_TASK;
                /*
                 * XXX pmu::event_init needs to know what task to account to
                 * and we cannot use the ctx information because we need the
                 * pmu before we get a ctx.
                 */
                event->hw.target = get_task_struct(task);
        }

        event->clock = &local_clock;
        if (parent_event)
                event->clock = parent_event->clock;

        if (!overflow_handler && parent_event) {
                overflow_handler = parent_event->overflow_handler;
                context = parent_event->overflow_handler_context;
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
                if (parent_event->prog) {
                        struct bpf_prog *prog = parent_event->prog;

                        bpf_prog_inc(prog);
                        event->prog = prog;
                }
#endif
        }

        if (overflow_handler) {
                event->overflow_handler        = overflow_handler;
                event->overflow_handler_context = context;
        } else if (is_write_backward(event)){
                event->overflow_handler = perf_event_output_backward;
                event->overflow_handler_context = NULL;
        } else {
                event->overflow_handler = perf_event_output_forward;
                event->overflow_handler_context = NULL;
        }

        perf_event__state_init(event);

        pmu = NULL;

        hwc = &event->hw;
        hwc->sample_period = attr->sample_period;
        if (is_event_in_freq_mode(event))
                hwc->sample_period = 1;
        hwc->last_period = hwc->sample_period;

        local64_set(&hwc->period_left, hwc->sample_period);

        /*
         * We do not support PERF_SAMPLE_READ on inherited events unless
         * PERF_SAMPLE_TID is also selected, which allows inherited events to
         * collect per-thread samples.
         * See perf_output_read().
         */
        if (has_inherit_and_sample_read(attr) && !(attr->sample_type & PERF_SAMPLE_TID))
                return ERR_PTR(-EINVAL);

        if (!has_branch_stack(event))
                event->attr.branch_sample_type = 0;

        pmu = perf_init_event(event);
        if (IS_ERR(pmu))
                return (void*)pmu;

        /*
         * The PERF_ATTACH_TASK_DATA is set in the event_init()->hw_config().
         * The attach should be right after the perf_init_event().
         * Otherwise, the __free_event() would mistakenly detach the non-exist
         * perf_ctx_data because of the other errors between them.
         */
        if (event->attach_state & PERF_ATTACH_TASK_DATA) {
                err = attach_perf_ctx_data(event);
                if (err)
                        return ERR_PTR(err);
        }

        /*
         * Disallow uncore-task events. Similarly, disallow uncore-cgroup
         * events (they don't make sense as the cgroup will be different
         * on other CPUs in the uncore mask).
         */
        if (pmu->task_ctx_nr == perf_invalid_context && (task || cgroup_fd != -1))
                return ERR_PTR(-EINVAL);

        if (event->attr.aux_output &&
            (!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT) ||
             event->attr.aux_pause || event->attr.aux_resume))
                return ERR_PTR(-EOPNOTSUPP);

        if (event->attr.aux_pause && event->attr.aux_resume)
                return ERR_PTR(-EINVAL);

        if (event->attr.aux_start_paused) {
                if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE))
                        return ERR_PTR(-EOPNOTSUPP);
                event->hw.aux_paused = 1;
        }

        if (cgroup_fd != -1) {
                err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
                if (err)
                        return ERR_PTR(err);
        }

        err = exclusive_event_init(event);
        if (err)
                return ERR_PTR(err);

        if (has_addr_filter(event)) {
                event->addr_filter_ranges = kcalloc(pmu->nr_addr_filters,
                                                    sizeof(struct perf_addr_filter_range),
                                                    GFP_KERNEL);
                if (!event->addr_filter_ranges)
                        return ERR_PTR(-ENOMEM);

                /*
                 * Clone the parent's vma offsets: they are valid until exec()
                 * even if the mm is not shared with the parent.
                 */
                if (event->parent) {
                        struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);

                        raw_spin_lock_irq(&ifh->lock);
                        memcpy(event->addr_filter_ranges,
                               event->parent->addr_filter_ranges,
                               pmu->nr_addr_filters * sizeof(struct perf_addr_filter_range));
                        raw_spin_unlock_irq(&ifh->lock);
                }

                /* force hw sync on the address filters */
                event->addr_filters_gen = 1;
        }

        if (!event->parent) {
                if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
                        err = get_callchain_buffers(attr->sample_max_stack);
                        if (err)
                                return ERR_PTR(err);
                        event->attach_state |= PERF_ATTACH_CALLCHAIN;
                }
        }

        err = security_perf_event_alloc(event);
        if (err)
                return ERR_PTR(err);

        /* symmetric to unaccount_event() in _free_event() */
        account_event(event);

        /*
         * Event creation should be under SRCU, see perf_pmu_unregister().
         */
        lockdep_assert_held(&pmus_srcu);
        scoped_guard (spinlock, &pmu->events_lock)
                list_add(&event->pmu_list, &pmu->events);

        return_ptr(event);
}

static int perf_copy_attr(struct perf_event_attr __user *uattr,
                          struct perf_event_attr *attr)
{
        u32 size;
        int ret;

        /* Zero the full structure, so that a short copy will be nice. */
        memset(attr, 0, sizeof(*attr));

        ret = get_user(size, &uattr->size);
        if (ret)
                return ret;

        /* ABI compatibility quirk: */
        if (!size)
                size = PERF_ATTR_SIZE_VER0;
        if (size < PERF_ATTR_SIZE_VER0 || size > PAGE_SIZE)
                goto err_size;

        ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size);
        if (ret) {
                if (ret == -E2BIG)
                        goto err_size;
                return ret;
        }

        attr->size = size;

        if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3)
                return -EINVAL;

        if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
                return -EINVAL;

        if (attr->read_format & ~(PERF_FORMAT_MAX-1))
                return -EINVAL;

        if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
                u64 mask = attr->branch_sample_type;

                /* only using defined bits */
                if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
                        return -EINVAL;

                /* at least one branch bit must be set */
                if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
                        return -EINVAL;

                /* propagate priv level, when not set for branch */
                if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {

                        /* exclude_kernel checked on syscall entry */
                        if (!attr->exclude_kernel)
                                mask |= PERF_SAMPLE_BRANCH_KERNEL;

                        if (!attr->exclude_user)
                                mask |= PERF_SAMPLE_BRANCH_USER;

                        if (!attr->exclude_hv)
                                mask |= PERF_SAMPLE_BRANCH_HV;
                        /*
                         * adjust user setting (for HW filter setup)
                         */
                        attr->branch_sample_type = mask;
                }
                /* privileged levels capture (kernel, hv): check permissions */
                if (mask & PERF_SAMPLE_BRANCH_PERM_PLM) {
                        ret = perf_allow_kernel();
                        if (ret)
                                return ret;
                }
        }

        if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
                ret = perf_reg_validate(attr->sample_regs_user);
                if (ret)
                        return ret;
        }

        if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
                if (!arch_perf_have_user_stack_dump())
                        return -ENOSYS;

                /*
                 * We have __u32 type for the size, but so far
                 * we can only use __u16 as maximum due to the
                 * __u16 sample size limit.
                 */
                if (attr->sample_stack_user >= USHRT_MAX)
                        return -EINVAL;
                else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
                        return -EINVAL;
        }

        if (!attr->sample_max_stack)
                attr->sample_max_stack = sysctl_perf_event_max_stack;

        if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
                ret = perf_reg_validate(attr->sample_regs_intr);

#ifndef CONFIG_CGROUP_PERF
        if (attr->sample_type & PERF_SAMPLE_CGROUP)
                return -EINVAL;
#endif
        if ((attr->sample_type & PERF_SAMPLE_WEIGHT) &&
            (attr->sample_type & PERF_SAMPLE_WEIGHT_STRUCT))
                return -EINVAL;

        if (!attr->inherit && attr->inherit_thread)
                return -EINVAL;

        if (attr->remove_on_exec && attr->enable_on_exec)
                return -EINVAL;

        if (attr->sigtrap && !attr->remove_on_exec)
                return -EINVAL;

out:
        return ret;

err_size:
        put_user(sizeof(*attr), &uattr->size);
        ret = -E2BIG;
        goto out;
}

static void mutex_lock_double(struct mutex *a, struct mutex *b)
{
        if (b < a)
                swap(a, b);

        mutex_lock(a);
        mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
}

static int
perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
{
        struct perf_buffer *rb = NULL;
        int ret = -EINVAL;

        if (!output_event) {
                mutex_lock(&event->mmap_mutex);
                goto set;
        }

        /* don't allow circular references */
        if (event == output_event)
                goto out;

        /*
         * Don't allow cross-cpu buffers
         */
        if (output_event->cpu != event->cpu)
                goto out;

        /*
         * If its not a per-cpu rb, it must be the same task.
         */
        if (output_event->cpu == -1 && output_event->hw.target != event->hw.target)
                goto out;

        /*
         * Mixing clocks in the same buffer is trouble you don't need.
         */
        if (output_event->clock != event->clock)
                goto out;

        /*
         * Either writing ring buffer from beginning or from end.
         * Mixing is not allowed.
         */
        if (is_write_backward(output_event) != is_write_backward(event))
                goto out;

        /*
         * If both events generate aux data, they must be on the same PMU
         */
        if (has_aux(event) && has_aux(output_event) &&
            event->pmu != output_event->pmu)
                goto out;

        /*
         * Hold both mmap_mutex to serialize against perf_mmap_close().  Since
         * output_event is already on rb->event_list, and the list iteration
         * restarts after every removal, it is guaranteed this new event is
         * observed *OR* if output_event is already removed, it's guaranteed we
         * observe !rb->mmap_count.
         */
        mutex_lock_double(&event->mmap_mutex, &output_event->mmap_mutex);
set:
        /* Can't redirect output if we've got an active mmap() */
        if (refcount_read(&event->mmap_count))
                goto unlock;

        if (output_event) {
                if (output_event->state <= PERF_EVENT_STATE_REVOKED)
                        goto unlock;

                /* get the rb we want to redirect to */
                rb = ring_buffer_get(output_event);
                if (!rb)
                        goto unlock;

                /* did we race against perf_mmap_close() */
                if (!refcount_read(&rb->mmap_count)) {
                        ring_buffer_put(rb);
                        goto unlock;
                }
        }

        ring_buffer_attach(event, rb);

        ret = 0;
unlock:
        mutex_unlock(&event->mmap_mutex);
        if (output_event)
                mutex_unlock(&output_event->mmap_mutex);

out:
        return ret;
}

static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
{
        bool nmi_safe = false;

        switch (clk_id) {
        case CLOCK_MONOTONIC:
                event->clock = &ktime_get_mono_fast_ns;
                nmi_safe = true;
                break;

        case CLOCK_MONOTONIC_RAW:
                event->clock = &ktime_get_raw_fast_ns;
                nmi_safe = true;
                break;

        case CLOCK_REALTIME:
                event->clock = &ktime_get_real_ns;
                break;

        case CLOCK_BOOTTIME:
                event->clock = &ktime_get_boottime_ns;
                break;

        case CLOCK_TAI:
                event->clock = &ktime_get_clocktai_ns;
                break;

        default:
                return -EINVAL;
        }

        if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
                return -EINVAL;

        return 0;
}

static bool
perf_check_permission(struct perf_event_attr *attr, struct task_struct *task)
{
        unsigned int ptrace_mode = PTRACE_MODE_READ_REALCREDS;
        bool is_capable = perfmon_capable();

        if (attr->sigtrap) {
                /*
                 * perf_event_attr::sigtrap sends signals to the other task.
                 * Require the current task to also have CAP_KILL.
                 */
                rcu_read_lock();
                is_capable &= ns_capable(__task_cred(task)->user_ns, CAP_KILL);
                rcu_read_unlock();

                /*
                 * If the required capabilities aren't available, checks for
                 * ptrace permissions: upgrade to ATTACH, since sending signals
                 * can effectively change the target task.
                 */
                ptrace_mode = PTRACE_MODE_ATTACH_REALCREDS;
        }

        /*
         * Preserve ptrace permission check for backwards compatibility. The
         * ptrace check also includes checks that the current task and other
         * task have matching uids, and is therefore not done here explicitly.
         */
        return is_capable || ptrace_may_access(task, ptrace_mode);
}

/**
 * sys_perf_event_open - open a performance event, associate it to a task/cpu
 *
 * @attr_uptr:        event_id type attributes for monitoring/sampling
 * @pid:                target pid
 * @cpu:                target cpu
 * @group_fd:                group leader event fd
 * @flags:                perf event open flags
 */
SYSCALL_DEFINE5(perf_event_open,
                struct perf_event_attr __user *, attr_uptr,
                pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
{
        struct perf_event *group_leader = NULL, *output_event = NULL;
        struct perf_event_pmu_context *pmu_ctx;
        struct perf_event *event, *sibling;
        struct perf_event_attr attr;
        struct perf_event_context *ctx;
        struct file *event_file = NULL;
        struct task_struct *task = NULL;
        struct pmu *pmu;
        int event_fd;
        int move_group = 0;
        int err;
        int f_flags = O_RDWR;
        int cgroup_fd = -1;

        /* for future expandability... */
        if (flags & ~PERF_FLAG_ALL)
                return -EINVAL;

        err = perf_copy_attr(attr_uptr, &attr);
        if (err)
                return err;

        /* Do we allow access to perf_event_open(2) ? */
        err = security_perf_event_open(PERF_SECURITY_OPEN);
        if (err)
                return err;

        if (!attr.exclude_kernel) {
                err = perf_allow_kernel();
                if (err)
                        return err;
        }

        if (attr.namespaces) {
                if (!perfmon_capable())
                        return -EACCES;
        }

        if (attr.freq) {
                if (attr.sample_freq > sysctl_perf_event_sample_rate)
                        return -EINVAL;
        } else {
                if (attr.sample_period & (1ULL << 63))
                        return -EINVAL;
        }

        /* Only privileged users can get physical addresses */
        if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR)) {
                err = perf_allow_kernel();
                if (err)
                        return err;
        }

        /* REGS_INTR can leak data, lockdown must prevent this */
        if (attr.sample_type & PERF_SAMPLE_REGS_INTR) {
                err = security_locked_down(LOCKDOWN_PERF);
                if (err)
                        return err;
        }

        /*
         * In cgroup mode, the pid argument is used to pass the fd
         * opened to the cgroup directory in cgroupfs. The cpu argument
         * designates the cpu on which to monitor threads from that
         * cgroup.
         */
        if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
                return -EINVAL;

        if (flags & PERF_FLAG_FD_CLOEXEC)
                f_flags |= O_CLOEXEC;

        event_fd = get_unused_fd_flags(f_flags);
        if (event_fd < 0)
                return event_fd;

        /*
         * Event creation should be under SRCU, see perf_pmu_unregister().
         */
        guard(srcu)(&pmus_srcu);

        CLASS(fd, group)(group_fd);     // group_fd == -1 => empty
        if (group_fd != -1) {
                if (!is_perf_file(group)) {
                        err = -EBADF;
                        goto err_fd;
                }
                group_leader = fd_file(group)->private_data;
                if (group_leader->state <= PERF_EVENT_STATE_REVOKED) {
                        err = -ENODEV;
                        goto err_fd;
                }
                if (flags & PERF_FLAG_FD_OUTPUT)
                        output_event = group_leader;
                if (flags & PERF_FLAG_FD_NO_GROUP)
                        group_leader = NULL;
        }

        if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
                task = find_lively_task_by_vpid(pid);
                if (IS_ERR(task)) {
                        err = PTR_ERR(task);
                        goto err_fd;
                }
        }

        if (task && group_leader &&
            group_leader->attr.inherit != attr.inherit) {
                err = -EINVAL;
                goto err_task;
        }

        if (flags & PERF_FLAG_PID_CGROUP)
                cgroup_fd = pid;

        event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
                                 NULL, NULL, cgroup_fd);
        if (IS_ERR(event)) {
                err = PTR_ERR(event);
                goto err_task;
        }

        if (is_sampling_event(event)) {
                if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
                        err = -EOPNOTSUPP;
                        goto err_alloc;
                }
        }

        /*
         * Special case software events and allow them to be part of
         * any hardware group.
         */
        pmu = event->pmu;

        if (attr.use_clockid) {
                err = perf_event_set_clock(event, attr.clockid);
                if (err)
                        goto err_alloc;
        }

        if (pmu->task_ctx_nr == perf_sw_context)
                event->event_caps |= PERF_EV_CAP_SOFTWARE;

        if (task) {
                err = down_read_interruptible(&task->signal->exec_update_lock);
                if (err)
                        goto err_alloc;

                /*
                 * We must hold exec_update_lock across this and any potential
                 * perf_install_in_context() call for this new event to
                 * serialize against exec() altering our credentials (and the
                 * perf_event_exit_task() that could imply).
                 */
                err = -EACCES;
                if (!perf_check_permission(&attr, task))
                        goto err_cred;
        }

        /*
         * Get the target context (task or percpu):
         */
        ctx = find_get_context(task, event);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto err_cred;
        }

        mutex_lock(&ctx->mutex);

        if (ctx->task == TASK_TOMBSTONE) {
                err = -ESRCH;
                goto err_locked;
        }

        if (!task) {
                /*
                 * Check if the @cpu we're creating an event for is online.
                 *
                 * We use the perf_cpu_context::ctx::mutex to serialize against
                 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
                 */
                struct perf_cpu_context *cpuctx = per_cpu_ptr(&perf_cpu_context, event->cpu);

                if (!cpuctx->online) {
                        err = -ENODEV;
                        goto err_locked;
                }
        }

        if (group_leader) {
                err = -EINVAL;

                /*
                 * Do not allow a recursive hierarchy (this new sibling
                 * becoming part of another group-sibling):
                 */
                if (group_leader->group_leader != group_leader)
                        goto err_locked;

                /* All events in a group should have the same clock */
                if (group_leader->clock != event->clock)
                        goto err_locked;

                /*
                 * Make sure we're both events for the same CPU;
                 * grouping events for different CPUs is broken; since
                 * you can never concurrently schedule them anyhow.
                 */
                if (group_leader->cpu != event->cpu)
                        goto err_locked;

                /*
                 * Make sure we're both on the same context; either task or cpu.
                 */
                if (group_leader->ctx != ctx)
                        goto err_locked;

                /*
                 * Only a group leader can be exclusive or pinned
                 */
                if (attr.exclusive || attr.pinned)
                        goto err_locked;

                if (is_software_event(event) &&
                    !in_software_context(group_leader)) {
                        /*
                         * If the event is a sw event, but the group_leader
                         * is on hw context.
                         *
                         * Allow the addition of software events to hw
                         * groups, this is safe because software events
                         * never fail to schedule.
                         *
                         * Note the comment that goes with struct
                         * perf_event_pmu_context.
                         */
                        pmu = group_leader->pmu_ctx->pmu;
                } else if (!is_software_event(event)) {
                        if (is_software_event(group_leader) &&
                            (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
                                /*
                                 * In case the group is a pure software group, and we
                                 * try to add a hardware event, move the whole group to
                                 * the hardware context.
                                 */
                                move_group = 1;
                        }

                        /* Don't allow group of multiple hw events from different pmus */
                        if (!in_software_context(group_leader) &&
                            group_leader->pmu_ctx->pmu != pmu)
                                goto err_locked;
                }
        }

        /*
         * Now that we're certain of the pmu; find the pmu_ctx.
         */
        pmu_ctx = find_get_pmu_context(pmu, ctx, event);
        if (IS_ERR(pmu_ctx)) {
                err = PTR_ERR(pmu_ctx);
                goto err_locked;
        }
        event->pmu_ctx = pmu_ctx;

        if (output_event) {
                err = perf_event_set_output(event, output_event);
                if (err)
                        goto err_context;
        }

        if (!perf_event_validate_size(event)) {
                err = -E2BIG;
                goto err_context;
        }

        if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader)) {
                err = -EINVAL;
                goto err_context;
        }

        /*
         * Must be under the same ctx::mutex as perf_install_in_context(),
         * because we need to serialize with concurrent event creation.
         */
        if (!exclusive_event_installable(event, ctx)) {
                err = -EBUSY;
                goto err_context;
        }

        WARN_ON_ONCE(ctx->parent_ctx);

        event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, f_flags);
        if (IS_ERR(event_file)) {
                err = PTR_ERR(event_file);
                event_file = NULL;
                goto err_context;
        }

        /*
         * This is the point on no return; we cannot fail hereafter. This is
         * where we start modifying current state.
         */

        if (move_group) {
                perf_remove_from_context(group_leader, 0);
                put_pmu_ctx(group_leader->pmu_ctx);

                for_each_sibling_event(sibling, group_leader) {
                        perf_remove_from_context(sibling, 0);
                        put_pmu_ctx(sibling->pmu_ctx);
                }

                /*
                 * Install the group siblings before the group leader.
                 *
                 * Because a group leader will try and install the entire group
                 * (through the sibling list, which is still in-tact), we can
                 * end up with siblings installed in the wrong context.
                 *
                 * By installing siblings first we NO-OP because they're not
                 * reachable through the group lists.
                 */
                for_each_sibling_event(sibling, group_leader) {
                        sibling->pmu_ctx = pmu_ctx;
                        get_pmu_ctx(pmu_ctx);
                        perf_event__state_init(sibling);
                        perf_install_in_context(ctx, sibling, sibling->cpu);
                }

                /*
                 * Removing from the context ends up with disabled
                 * event. What we want here is event in the initial
                 * startup state, ready to be add into new context.
                 */
                group_leader->pmu_ctx = pmu_ctx;
                get_pmu_ctx(pmu_ctx);
                perf_event__state_init(group_leader);
                perf_install_in_context(ctx, group_leader, group_leader->cpu);
        }

        /*
         * Precalculate sample_data sizes; do while holding ctx::mutex such
         * that we're serialized against further additions and before
         * perf_install_in_context() which is the point the event is active and
         * can use these values.
         */
        perf_event__header_size(event);
        perf_event__id_header_size(event);

        event->owner = current;

        perf_install_in_context(ctx, event, event->cpu);
        perf_unpin_context(ctx);

        mutex_unlock(&ctx->mutex);

        if (task) {
                up_read(&task->signal->exec_update_lock);
                put_task_struct(task);
        }

        mutex_lock(&current->perf_event_mutex);
        list_add_tail(&event->owner_entry, &current->perf_event_list);
        mutex_unlock(&current->perf_event_mutex);

        /*
         * File reference in group guarantees that group_leader has been
         * kept alive until we place the new event on the sibling_list.
         * This ensures destruction of the group leader will find
         * the pointer to itself in perf_group_detach().
         */
        fd_install(event_fd, event_file);
        return event_fd;

err_context:
        put_pmu_ctx(event->pmu_ctx);
        event->pmu_ctx = NULL; /* _free_event() */
err_locked:
        mutex_unlock(&ctx->mutex);
        perf_unpin_context(ctx);
        put_ctx(ctx);
err_cred:
        if (task)
                up_read(&task->signal->exec_update_lock);
err_alloc:
        put_event(event);
err_task:
        if (task)
                put_task_struct(task);
err_fd:
        put_unused_fd(event_fd);
        return err;
}

/**
 * perf_event_create_kernel_counter
 *
 * @attr: attributes of the counter to create
 * @cpu: cpu in which the counter is bound
 * @task: task to profile (NULL for percpu)
 * @overflow_handler: callback to trigger when we hit the event
 * @context: context data could be used in overflow_handler callback
 */
struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
                                 struct task_struct *task,
                                 perf_overflow_handler_t overflow_handler,
                                 void *context)
{
        struct perf_event_pmu_context *pmu_ctx;
        struct perf_event_context *ctx;
        struct perf_event *event;
        struct pmu *pmu;
        int err;

        /*
         * Grouping is not supported for kernel events, neither is 'AUX',
         * make sure the caller's intentions are adjusted.
         */
        if (attr->aux_output || attr->aux_action)
                return ERR_PTR(-EINVAL);

        /*
         * Event creation should be under SRCU, see perf_pmu_unregister().
         */
        guard(srcu)(&pmus_srcu);

        event = perf_event_alloc(attr, cpu, task, NULL, NULL,
                                 overflow_handler, context, -1);
        if (IS_ERR(event)) {
                err = PTR_ERR(event);
                goto err;
        }

        /* Mark owner so we could distinguish it from user events. */
        event->owner = TASK_TOMBSTONE;
        pmu = event->pmu;

        if (pmu->task_ctx_nr == perf_sw_context)
                event->event_caps |= PERF_EV_CAP_SOFTWARE;

        /*
         * Get the target context (task or percpu):
         */
        ctx = find_get_context(task, event);
        if (IS_ERR(ctx)) {
                err = PTR_ERR(ctx);
                goto err_alloc;
        }

        WARN_ON_ONCE(ctx->parent_ctx);
        mutex_lock(&ctx->mutex);
        if (ctx->task == TASK_TOMBSTONE) {
                err = -ESRCH;
                goto err_unlock;
        }

        pmu_ctx = find_get_pmu_context(pmu, ctx, event);
        if (IS_ERR(pmu_ctx)) {
                err = PTR_ERR(pmu_ctx);
                goto err_unlock;
        }
        event->pmu_ctx = pmu_ctx;

        if (!task) {
                /*
                 * Check if the @cpu we're creating an event for is online.
                 *
                 * We use the perf_cpu_context::ctx::mutex to serialize against
                 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
                 */
                struct perf_cpu_context *cpuctx =
                        container_of(ctx, struct perf_cpu_context, ctx);
                if (!cpuctx->online) {
                        err = -ENODEV;
                        goto err_pmu_ctx;
                }
        }

        if (!exclusive_event_installable(event, ctx)) {
                err = -EBUSY;
                goto err_pmu_ctx;
        }

        perf_install_in_context(ctx, event, event->cpu);
        perf_unpin_context(ctx);
        mutex_unlock(&ctx->mutex);

        return event;

err_pmu_ctx:
        put_pmu_ctx(pmu_ctx);
        event->pmu_ctx = NULL; /* _free_event() */
err_unlock:
        mutex_unlock(&ctx->mutex);
        perf_unpin_context(ctx);
        put_ctx(ctx);
err_alloc:
        put_event(event);
err:
        return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);

static void __perf_pmu_remove(struct perf_event_context *ctx,
                              int cpu, struct pmu *pmu,
                              struct perf_event_groups *groups,
                              struct list_head *events)
{
        struct perf_event *event, *sibling;

        perf_event_groups_for_cpu_pmu(event, groups, cpu, pmu) {
                perf_remove_from_context(event, 0);
                put_pmu_ctx(event->pmu_ctx);
                list_add(&event->migrate_entry, events);

                for_each_sibling_event(sibling, event) {
                        perf_remove_from_context(sibling, 0);
                        put_pmu_ctx(sibling->pmu_ctx);
                        list_add(&sibling->migrate_entry, events);
                }
        }
}

static void __perf_pmu_install_event(struct pmu *pmu,
                                     struct perf_event_context *ctx,
                                     int cpu, struct perf_event *event)
{
        struct perf_event_pmu_context *epc;
        struct perf_event_context *old_ctx = event->ctx;

        get_ctx(ctx); /* normally find_get_context() */

        event->cpu = cpu;
        epc = find_get_pmu_context(pmu, ctx, event);
        event->pmu_ctx = epc;

        if (event->state >= PERF_EVENT_STATE_OFF)
                event->state = PERF_EVENT_STATE_INACTIVE;
        perf_install_in_context(ctx, event, cpu);

        /*
         * Now that event->ctx is updated and visible, put the old ctx.
         */
        put_ctx(old_ctx);
}

static void __perf_pmu_install(struct perf_event_context *ctx,
                               int cpu, struct pmu *pmu, struct list_head *events)
{
        struct perf_event *event, *tmp;

        /*
         * Re-instate events in 2 passes.
         *
         * Skip over group leaders and only install siblings on this first
         * pass, siblings will not get enabled without a leader, however a
         * leader will enable its siblings, even if those are still on the old
         * context.
         */
        list_for_each_entry_safe(event, tmp, events, migrate_entry) {
                if (event->group_leader == event)
                        continue;

                list_del(&event->migrate_entry);
                __perf_pmu_install_event(pmu, ctx, cpu, event);
        }

        /*
         * Once all the siblings are setup properly, install the group leaders
         * to make it go.
         */
        list_for_each_entry_safe(event, tmp, events, migrate_entry) {
                list_del(&event->migrate_entry);
                __perf_pmu_install_event(pmu, ctx, cpu, event);
        }
}

void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
{
        struct perf_event_context *src_ctx, *dst_ctx;
        LIST_HEAD(events);

        /*
         * Since per-cpu context is persistent, no need to grab an extra
         * reference.
         */
        src_ctx = &per_cpu_ptr(&perf_cpu_context, src_cpu)->ctx;
        dst_ctx = &per_cpu_ptr(&perf_cpu_context, dst_cpu)->ctx;

        /*
         * See perf_event_ctx_lock() for comments on the details
         * of swizzling perf_event::ctx.
         */
        mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);

        __perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->pinned_groups, &events);
        __perf_pmu_remove(src_ctx, src_cpu, pmu, &src_ctx->flexible_groups, &events);

        if (!list_empty(&events)) {
                /*
                 * Wait for the events to quiesce before re-instating them.
                 */
                synchronize_rcu();

                __perf_pmu_install(dst_ctx, dst_cpu, pmu, &events);
        }

        mutex_unlock(&dst_ctx->mutex);
        mutex_unlock(&src_ctx->mutex);
}
EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);

static void sync_child_event(struct perf_event *child_event)
{
        struct perf_event *parent_event = child_event->parent;
        u64 child_val;

        if (child_event->attr.inherit_stat) {
                struct task_struct *task = child_event->ctx->task;

                if (task && task != TASK_TOMBSTONE)
                        perf_event_read_event(child_event, task);
        }

        child_val = perf_event_count(child_event, false);

        /*
         * Add back the child's count to the parent's count:
         */
        atomic64_add(child_val, &parent_event->child_count);
        atomic64_add(child_event->total_time_enabled,
                     &parent_event->child_total_time_enabled);
        atomic64_add(child_event->total_time_running,
                     &parent_event->child_total_time_running);
}

static void
perf_event_exit_event(struct perf_event *event,
                      struct perf_event_context *ctx, bool revoke)
{
        struct perf_event *parent_event = event->parent;
        unsigned long detach_flags = DETACH_EXIT;
        unsigned int attach_state;

        if (parent_event) {
                /*
                 * Do not destroy the 'original' grouping; because of the
                 * context switch optimization the original events could've
                 * ended up in a random child task.
                 *
                 * If we were to destroy the original group, all group related
                 * operations would cease to function properly after this
                 * random child dies.
                 *
                 * Do destroy all inherited groups, we don't care about those
                 * and being thorough is better.
                 */
                detach_flags |= DETACH_GROUP | DETACH_CHILD;
                mutex_lock(&parent_event->child_mutex);
                /* PERF_ATTACH_ITRACE might be set concurrently */
                attach_state = READ_ONCE(event->attach_state);
        }

        if (revoke)
                detach_flags |= DETACH_GROUP | DETACH_REVOKE;

        perf_remove_from_context(event, detach_flags);
        /*
         * Child events can be freed.
         */
        if (parent_event) {
                mutex_unlock(&parent_event->child_mutex);

                /*
                 * Match the refcount initialization. Make sure it doesn't happen
                 * twice if pmu_detach_event() calls it on an already exited task.
                 */
                if (attach_state & PERF_ATTACH_CHILD) {
                        /*
                         * Kick perf_poll() for is_event_hup();
                         */
                        perf_event_wakeup(parent_event);
                        /*
                         * pmu_detach_event() will have an extra refcount.
                         * perf_pending_task() might have one too.
                         */
                        put_event(event);
                }

                return;
        }

        /*
         * Parent events are governed by their filedesc, retain them.
         */
        perf_event_wakeup(event);
}

static void perf_event_exit_task_context(struct task_struct *task, bool exit)
{
        struct perf_event_context *ctx, *clone_ctx = NULL;
        struct perf_event *child_event, *next;

        ctx = perf_pin_task_context(task);
        if (!ctx)
                return;

        /*
         * In order to reduce the amount of tricky in ctx tear-down, we hold
         * ctx::mutex over the entire thing. This serializes against almost
         * everything that wants to access the ctx.
         *
         * The exception is sys_perf_event_open() /
         * perf_event_create_kernel_count() which does find_get_context()
         * without ctx::mutex (it cannot because of the move_group double mutex
         * lock thing). See the comments in perf_install_in_context().
         */
        mutex_lock(&ctx->mutex);

        /*
         * In a single ctx::lock section, de-schedule the events and detach the
         * context from the task such that we cannot ever get it scheduled back
         * in.
         */
        raw_spin_lock_irq(&ctx->lock);
        if (exit)
                task_ctx_sched_out(ctx, NULL, EVENT_ALL);

        /*
         * Now that the context is inactive, destroy the task <-> ctx relation
         * and mark the context dead.
         */
        RCU_INIT_POINTER(task->perf_event_ctxp, NULL);
        put_ctx(ctx); /* cannot be last */
        WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
        put_task_struct(task); /* cannot be last */

        clone_ctx = unclone_ctx(ctx);
        raw_spin_unlock_irq(&ctx->lock);

        if (clone_ctx)
                put_ctx(clone_ctx);

        /*
         * Report the task dead after unscheduling the events so that we
         * won't get any samples after PERF_RECORD_EXIT. We can however still
         * get a few PERF_RECORD_READ events.
         */
        if (exit)
                perf_event_task(task, ctx, 0);

        list_for_each_entry_safe(child_event, next, &ctx->event_list, event_entry)
                perf_event_exit_event(child_event, ctx, false);

        mutex_unlock(&ctx->mutex);

        if (!exit) {
                /*
                 * perf_event_release_kernel() could still have a reference on
                 * this context. In that case we must wait for these events to
                 * have been freed (in particular all their references to this
                 * task must've been dropped).
                 *
                 * Without this copy_process() will unconditionally free this
                 * task (irrespective of its reference count) and
                 * _free_event()'s put_task_struct(event->hw.target) will be a
                 * use-after-free.
                 *
                 * Wait for all events to drop their context reference.
                 */
                wait_var_event(&ctx->refcount,
                               refcount_read(&ctx->refcount) == 1);
        }
        put_ctx(ctx);
}

/*
 * When a task exits, feed back event values to parent events.
 *
 * Can be called with exec_update_lock held when called from
 * setup_new_exec().
 */
void perf_event_exit_task(struct task_struct *task)
{
        struct perf_event *event, *tmp;

        WARN_ON_ONCE(task != current);

        mutex_lock(&task->perf_event_mutex);
        list_for_each_entry_safe(event, tmp, &task->perf_event_list,
                                 owner_entry) {
                list_del_init(&event->owner_entry);

                /*
                 * Ensure the list deletion is visible before we clear
                 * the owner, closes a race against perf_release() where
                 * we need to serialize on the owner->perf_event_mutex.
                 */
                smp_store_release(&event->owner, NULL);
        }
        mutex_unlock(&task->perf_event_mutex);

        perf_event_exit_task_context(task, true);

        /*
         * The perf_event_exit_task_context calls perf_event_task
         * with task's task_ctx, which generates EXIT events for
         * task contexts and sets task->perf_event_ctxp[] to NULL.
         * At this point we need to send EXIT events to cpu contexts.
         */
        perf_event_task(task, NULL, 0);

        /*
         * Detach the perf_ctx_data for the system-wide event.
         */
        guard(percpu_read)(&global_ctx_data_rwsem);
        detach_task_ctx_data(task);
}

/*
 * Free a context as created by inheritance by perf_event_init_task() below,
 * used by fork() in case of fail.
 *
 * Even though the task has never lived, the context and events have been
 * exposed through the child_list, so we must take care tearing it all down.
 */
void perf_event_free_task(struct task_struct *task)
{
        perf_event_exit_task_context(task, false);
}

void perf_event_delayed_put(struct task_struct *task)
{
        WARN_ON_ONCE(task->perf_event_ctxp);
}

struct file *perf_event_get(unsigned int fd)
{
        struct file *file = fget(fd);
        if (!file)
                return ERR_PTR(-EBADF);

        if (file->f_op != &perf_fops) {
                fput(file);
                return ERR_PTR(-EBADF);
        }

        return file;
}

const struct perf_event *perf_get_event(struct file *file)
{
        if (file->f_op != &perf_fops)
                return ERR_PTR(-EINVAL);

        return file->private_data;
}

const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
{
        if (!event)
                return ERR_PTR(-EINVAL);

        return &event->attr;
}

int perf_allow_kernel(void)
{
        if (sysctl_perf_event_paranoid > 1 && !perfmon_capable())
                return -EACCES;

        return security_perf_event_open(PERF_SECURITY_KERNEL);
}
EXPORT_SYMBOL_GPL(perf_allow_kernel);

/*
 * Inherit an event from parent task to child task.
 *
 * Returns:
 *  - valid pointer on success
 *  - NULL for orphaned events
 *  - IS_ERR() on error
 */
static struct perf_event *
inherit_event(struct perf_event *parent_event,
              struct task_struct *parent,
              struct perf_event_context *parent_ctx,
              struct task_struct *child,
              struct perf_event *group_leader,
              struct perf_event_context *child_ctx)
{
        enum perf_event_state parent_state = parent_event->state;
        struct perf_event_pmu_context *pmu_ctx;
        struct perf_event *child_event;
        unsigned long flags;

        /*
         * Instead of creating recursive hierarchies of events,
         * we link inherited events back to the original parent,
         * which has a filp for sure, which we use as the reference
         * count:
         */
        if (parent_event->parent)
                parent_event = parent_event->parent;

        if (parent_event->state <= PERF_EVENT_STATE_REVOKED)
                return NULL;

        /*
         * Event creation should be under SRCU, see perf_pmu_unregister().
         */
        guard(srcu)(&pmus_srcu);

        child_event = perf_event_alloc(&parent_event->attr,
                                           parent_event->cpu,
                                           child,
                                           group_leader, parent_event,
                                           NULL, NULL, -1);
        if (IS_ERR(child_event))
                return child_event;

        get_ctx(child_ctx);
        child_event->ctx = child_ctx;

        pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);
        if (IS_ERR(pmu_ctx)) {
                free_event(child_event);
                return ERR_CAST(pmu_ctx);
        }
        child_event->pmu_ctx = pmu_ctx;

        /*
         * is_orphaned_event() and list_add_tail(&parent_event->child_list)
         * must be under the same lock in order to serialize against
         * perf_event_release_kernel(), such that either we must observe
         * is_orphaned_event() or they will observe us on the child_list.
         */
        mutex_lock(&parent_event->child_mutex);
        if (is_orphaned_event(parent_event) ||
            !atomic_long_inc_not_zero(&parent_event->refcount)) {
                mutex_unlock(&parent_event->child_mutex);
                free_event(child_event);
                return NULL;
        }

        /*
         * Make the child state follow the state of the parent event,
         * not its attr.disabled bit.  We hold the parent's mutex,
         * so we won't race with perf_event_{en, dis}able_family.
         */
        if (parent_state >= PERF_EVENT_STATE_INACTIVE)
                child_event->state = PERF_EVENT_STATE_INACTIVE;
        else
                child_event->state = PERF_EVENT_STATE_OFF;

        if (parent_event->attr.freq) {
                u64 sample_period = parent_event->hw.sample_period;
                struct hw_perf_event *hwc = &child_event->hw;

                hwc->sample_period = sample_period;
                hwc->last_period   = sample_period;

                local64_set(&hwc->period_left, sample_period);
        }

        child_event->overflow_handler = parent_event->overflow_handler;
        child_event->overflow_handler_context
                = parent_event->overflow_handler_context;

        /*
         * Precalculate sample_data sizes
         */
        perf_event__header_size(child_event);
        perf_event__id_header_size(child_event);

        /*
         * Link it up in the child's context:
         */
        raw_spin_lock_irqsave(&child_ctx->lock, flags);
        add_event_to_ctx(child_event, child_ctx);
        child_event->attach_state |= PERF_ATTACH_CHILD;
        raw_spin_unlock_irqrestore(&child_ctx->lock, flags);

        /*
         * Link this into the parent event's child list
         */
        list_add_tail(&child_event->child_list, &parent_event->child_list);
        mutex_unlock(&parent_event->child_mutex);

        return child_event;
}

/*
 * Inherits an event group.
 *
 * This will quietly suppress orphaned events; !inherit_event() is not an error.
 * This matches with perf_event_release_kernel() removing all child events.
 *
 * Returns:
 *  - 0 on success
 *  - <0 on error
 */
static int inherit_group(struct perf_event *parent_event,
              struct task_struct *parent,
              struct perf_event_context *parent_ctx,
              struct task_struct *child,
              struct perf_event_context *child_ctx)
{
        struct perf_event *leader;
        struct perf_event *sub;
        struct perf_event *child_ctr;

        leader = inherit_event(parent_event, parent, parent_ctx,
                                 child, NULL, child_ctx);
        if (IS_ERR(leader))
                return PTR_ERR(leader);
        /*
         * @leader can be NULL here because of is_orphaned_event(). In this
         * case inherit_event() will create individual events, similar to what
         * perf_group_detach() would do anyway.
         */
        for_each_sibling_event(sub, parent_event) {
                child_ctr = inherit_event(sub, parent, parent_ctx,
                                            child, leader, child_ctx);
                if (IS_ERR(child_ctr))
                        return PTR_ERR(child_ctr);

                if (sub->aux_event == parent_event && child_ctr &&
                    !perf_get_aux_event(child_ctr, leader))
                        return -EINVAL;
        }
        if (leader)
                leader->group_generation = parent_event->group_generation;
        return 0;
}

/*
 * Creates the child task context and tries to inherit the event-group.
 *
 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
 * inherited_all set when we 'fail' to inherit an orphaned event; this is
 * consistent with perf_event_release_kernel() removing all child events.
 *
 * Returns:
 *  - 0 on success
 *  - <0 on error
 */
static int
inherit_task_group(struct perf_event *event, struct task_struct *parent,
                   struct perf_event_context *parent_ctx,
                   struct task_struct *child,
                   u64 clone_flags, int *inherited_all)
{
        struct perf_event_context *child_ctx;
        int ret;

        if (!event->attr.inherit ||
            (event->attr.inherit_thread && !(clone_flags & CLONE_THREAD)) ||
            /* Do not inherit if sigtrap and signal handlers were cleared. */
            (event->attr.sigtrap && (clone_flags & CLONE_CLEAR_SIGHAND))) {
                *inherited_all = 0;
                return 0;
        }

        child_ctx = child->perf_event_ctxp;
        if (!child_ctx) {
                /*
                 * This is executed from the parent task context, so
                 * inherit events that have been marked for cloning.
                 * First allocate and initialize a context for the
                 * child.
                 */
                child_ctx = alloc_perf_context(child);
                if (!child_ctx)
                        return -ENOMEM;

                child->perf_event_ctxp = child_ctx;
        }

        ret = inherit_group(event, parent, parent_ctx, child, child_ctx);
        if (ret)
                *inherited_all = 0;

        return ret;
}

/*
 * Initialize the perf_event context in task_struct
 */
static int perf_event_init_context(struct task_struct *child, u64 clone_flags)
{
        struct perf_event_context *child_ctx, *parent_ctx;
        struct perf_event_context *cloned_ctx;
        struct perf_event *event;
        struct task_struct *parent = current;
        int inherited_all = 1;
        unsigned long flags;
        int ret = 0;

        if (likely(!parent->perf_event_ctxp))
                return 0;

        /*
         * If the parent's context is a clone, pin it so it won't get
         * swapped under us.
         */
        parent_ctx = perf_pin_task_context(parent);
        if (!parent_ctx)
                return 0;

        /*
         * No need to check if parent_ctx != NULL here; since we saw
         * it non-NULL earlier, the only reason for it to become NULL
         * is if we exit, and since we're currently in the middle of
         * a fork we can't be exiting at the same time.
         */

        /*
         * Lock the parent list. No need to lock the child - not PID
         * hashed yet and not running, so nobody can access it.
         */
        mutex_lock(&parent_ctx->mutex);

        /*
         * We dont have to disable NMIs - we are only looking at
         * the list, not manipulating it:
         */
        perf_event_groups_for_each(event, &parent_ctx->pinned_groups) {
                ret = inherit_task_group(event, parent, parent_ctx,
                                         child, clone_flags, &inherited_all);
                if (ret)
                        goto out_unlock;
        }

        /*
         * We can't hold ctx->lock when iterating the ->flexible_group list due
         * to allocations, but we need to prevent rotation because
         * rotate_ctx() will change the list from interrupt context.
         */
        raw_spin_lock_irqsave(&parent_ctx->lock, flags);
        parent_ctx->rotate_disable = 1;
        raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);

        perf_event_groups_for_each(event, &parent_ctx->flexible_groups) {
                ret = inherit_task_group(event, parent, parent_ctx,
                                         child, clone_flags, &inherited_all);
                if (ret)
                        goto out_unlock;
        }

        raw_spin_lock_irqsave(&parent_ctx->lock, flags);
        parent_ctx->rotate_disable = 0;

        child_ctx = child->perf_event_ctxp;

        if (child_ctx && inherited_all) {
                /*
                 * Mark the child context as a clone of the parent
                 * context, or of whatever the parent is a clone of.
                 *
                 * Note that if the parent is a clone, the holding of
                 * parent_ctx->lock avoids it from being uncloned.
                 */
                cloned_ctx = parent_ctx->parent_ctx;
                if (cloned_ctx) {
                        child_ctx->parent_ctx = cloned_ctx;
                        child_ctx->parent_gen = parent_ctx->parent_gen;
                } else {
                        child_ctx->parent_ctx = parent_ctx;
                        child_ctx->parent_gen = parent_ctx->generation;
                }
                get_ctx(child_ctx->parent_ctx);
        }

        raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
out_unlock:
        mutex_unlock(&parent_ctx->mutex);

        perf_unpin_context(parent_ctx);
        put_ctx(parent_ctx);

        return ret;
}

/*
 * Initialize the perf_event context in task_struct
 */
int perf_event_init_task(struct task_struct *child, u64 clone_flags)
{
        int ret;

        memset(child->perf_recursion, 0, sizeof(child->perf_recursion));
        child->perf_event_ctxp = NULL;
        mutex_init(&child->perf_event_mutex);
        INIT_LIST_HEAD(&child->perf_event_list);
        child->perf_ctx_data = NULL;

        ret = perf_event_init_context(child, clone_flags);
        if (ret) {
                perf_event_free_task(child);
                return ret;
        }

        return 0;
}

static void __init perf_event_init_all_cpus(void)
{
        struct swevent_htable *swhash;
        struct perf_cpu_context *cpuctx;
        int cpu;

        zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL);
        zalloc_cpumask_var(&perf_online_core_mask, GFP_KERNEL);
        zalloc_cpumask_var(&perf_online_die_mask, GFP_KERNEL);
        zalloc_cpumask_var(&perf_online_cluster_mask, GFP_KERNEL);
        zalloc_cpumask_var(&perf_online_pkg_mask, GFP_KERNEL);
        zalloc_cpumask_var(&perf_online_sys_mask, GFP_KERNEL);


        for_each_possible_cpu(cpu) {
                swhash = &per_cpu(swevent_htable, cpu);
                mutex_init(&swhash->hlist_mutex);

                INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
                raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));

                INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));

                cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
                __perf_event_init_context(&cpuctx->ctx);
                lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
                lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
                cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask);
                cpuctx->heap_size = ARRAY_SIZE(cpuctx->heap_default);
                cpuctx->heap = cpuctx->heap_default;
        }
}

static void perf_swevent_init_cpu(unsigned int cpu)
{
        struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);

        mutex_lock(&swhash->hlist_mutex);
        if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
                struct swevent_hlist *hlist;

                hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
                WARN_ON(!hlist);
                rcu_assign_pointer(swhash->swevent_hlist, hlist);
        }
        mutex_unlock(&swhash->hlist_mutex);
}

#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
static void __perf_event_exit_context(void *__info)
{
        struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
        struct perf_event_context *ctx = __info;
        struct perf_event *event;

        raw_spin_lock(&ctx->lock);
        ctx_sched_out(ctx, NULL, EVENT_TIME);
        list_for_each_entry(event, &ctx->event_list, event_entry)
                __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
        raw_spin_unlock(&ctx->lock);
}

static void perf_event_clear_cpumask(unsigned int cpu)
{
        int target[PERF_PMU_MAX_SCOPE];
        unsigned int scope;
        struct pmu *pmu;

        cpumask_clear_cpu(cpu, perf_online_mask);

        for (scope = PERF_PMU_SCOPE_NONE + 1; scope < PERF_PMU_MAX_SCOPE; scope++) {
                const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(scope, cpu);
                struct cpumask *pmu_cpumask = perf_scope_cpumask(scope);

                target[scope] = -1;
                if (WARN_ON_ONCE(!pmu_cpumask || !cpumask))
                        continue;

                if (!cpumask_test_and_clear_cpu(cpu, pmu_cpumask))
                        continue;
                target[scope] = cpumask_any_but(cpumask, cpu);
                if (target[scope] < nr_cpu_ids)
                        cpumask_set_cpu(target[scope], pmu_cpumask);
        }

        /* migrate */
        list_for_each_entry(pmu, &pmus, entry) {
                if (pmu->scope == PERF_PMU_SCOPE_NONE ||
                    WARN_ON_ONCE(pmu->scope >= PERF_PMU_MAX_SCOPE))
                        continue;

                if (target[pmu->scope] >= 0 && target[pmu->scope] < nr_cpu_ids)
                        perf_pmu_migrate_context(pmu, cpu, target[pmu->scope]);
        }
}

static void perf_event_exit_cpu_context(int cpu)
{
        struct perf_cpu_context *cpuctx;
        struct perf_event_context *ctx;

        // XXX simplify cpuctx->online
        mutex_lock(&pmus_lock);
        /*
         * Clear the cpumasks, and migrate to other CPUs if possible.
         * Must be invoked before the __perf_event_exit_context.
         */
        perf_event_clear_cpumask(cpu);
        cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
        ctx = &cpuctx->ctx;

        mutex_lock(&ctx->mutex);
        smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
        cpuctx->online = 0;
        mutex_unlock(&ctx->mutex);
        mutex_unlock(&pmus_lock);
}
#else

static void perf_event_exit_cpu_context(int cpu) { }

#endif

static void perf_event_setup_cpumask(unsigned int cpu)
{
        struct cpumask *pmu_cpumask;
        unsigned int scope;

        /*
         * Early boot stage, the cpumask hasn't been set yet.
         * The perf_online_<domain>_masks includes the first CPU of each domain.
         * Always unconditionally set the boot CPU for the perf_online_<domain>_masks.
         */
        if (cpumask_empty(perf_online_mask)) {
                for (scope = PERF_PMU_SCOPE_NONE + 1; scope < PERF_PMU_MAX_SCOPE; scope++) {
                        pmu_cpumask = perf_scope_cpumask(scope);
                        if (WARN_ON_ONCE(!pmu_cpumask))
                                continue;
                        cpumask_set_cpu(cpu, pmu_cpumask);
                }
                goto end;
        }

        for (scope = PERF_PMU_SCOPE_NONE + 1; scope < PERF_PMU_MAX_SCOPE; scope++) {
                const struct cpumask *cpumask = perf_scope_cpu_topology_cpumask(scope, cpu);

                pmu_cpumask = perf_scope_cpumask(scope);

                if (WARN_ON_ONCE(!pmu_cpumask || !cpumask))
                        continue;

                if (!cpumask_empty(cpumask) &&
                    cpumask_any_and(pmu_cpumask, cpumask) >= nr_cpu_ids)
                        cpumask_set_cpu(cpu, pmu_cpumask);
        }
end:
        cpumask_set_cpu(cpu, perf_online_mask);
}

int perf_event_init_cpu(unsigned int cpu)
{
        struct perf_cpu_context *cpuctx;
        struct perf_event_context *ctx;

        perf_swevent_init_cpu(cpu);

        mutex_lock(&pmus_lock);
        perf_event_setup_cpumask(cpu);
        cpuctx = per_cpu_ptr(&perf_cpu_context, cpu);
        ctx = &cpuctx->ctx;

        mutex_lock(&ctx->mutex);
        cpuctx->online = 1;
        mutex_unlock(&ctx->mutex);
        mutex_unlock(&pmus_lock);

        return 0;
}

int perf_event_exit_cpu(unsigned int cpu)
{
        perf_event_exit_cpu_context(cpu);
        return 0;
}

static int
perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
{
        int cpu;

        for_each_online_cpu(cpu)
                perf_event_exit_cpu(cpu);

        return NOTIFY_OK;
}

/*
 * Run the perf reboot notifier at the very last possible moment so that
 * the generic watchdog code runs as long as possible.
 */
static struct notifier_block perf_reboot_notifier = {
        .notifier_call = perf_reboot,
        .priority = INT_MIN,
};

void __init perf_event_init(void)
{
        int ret;

        idr_init(&pmu_idr);

        perf_event_init_all_cpus();
        init_srcu_struct(&pmus_srcu);
        perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
        perf_pmu_register(&perf_cpu_clock, "cpu_clock", -1);
        perf_pmu_register(&perf_task_clock, "task_clock", -1);
        perf_tp_register();
        perf_event_init_cpu(smp_processor_id());
        register_reboot_notifier(&perf_reboot_notifier);

        ret = init_hw_breakpoint();
        WARN(ret, "hw_breakpoint initialization failed with: %d", ret);

        perf_event_cache = KMEM_CACHE(perf_event, SLAB_PANIC);

        /*
         * Build time assertion that we keep the data_head at the intended
         * location.  IOW, validation we got the __reserved[] size right.
         */
        BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
                     != 1024);
}

ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
                              char *page)
{
        struct perf_pmu_events_attr *pmu_attr =
                container_of(attr, struct perf_pmu_events_attr, attr);

        if (pmu_attr->event_str)
                return sprintf(page, "%s\n", pmu_attr->event_str);

        return 0;
}
EXPORT_SYMBOL_GPL(perf_event_sysfs_show);

static int __init perf_event_sysfs_init(void)
{
        struct pmu *pmu;
        int ret;

        mutex_lock(&pmus_lock);

        ret = bus_register(&pmu_bus);
        if (ret)
                goto unlock;

        list_for_each_entry(pmu, &pmus, entry) {
                if (pmu->dev)
                        continue;

                ret = pmu_dev_alloc(pmu);
                WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
        }
        pmu_bus_running = 1;
        ret = 0;

unlock:
        mutex_unlock(&pmus_lock);

        return ret;
}
device_initcall(perf_event_sysfs_init);

#ifdef CONFIG_CGROUP_PERF
static struct cgroup_subsys_state *
perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
{
        struct perf_cgroup *jc;

        jc = kzalloc(sizeof(*jc), GFP_KERNEL);
        if (!jc)
                return ERR_PTR(-ENOMEM);

        jc->info = alloc_percpu(struct perf_cgroup_info);
        if (!jc->info) {
                kfree(jc);
                return ERR_PTR(-ENOMEM);
        }

        return &jc->css;
}

static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
{
        struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);

        free_percpu(jc->info);
        kfree(jc);
}

static int perf_cgroup_css_online(struct cgroup_subsys_state *css)
{
        perf_event_cgroup(css->cgroup);
        return 0;
}

static int __perf_cgroup_move(void *info)
{
        struct task_struct *task = info;

        preempt_disable();
        perf_cgroup_switch(task);
        preempt_enable();

        return 0;
}

static void perf_cgroup_attach(struct cgroup_taskset *tset)
{
        struct task_struct *task;
        struct cgroup_subsys_state *css;

        cgroup_taskset_for_each(task, css, tset)
                task_function_call(task, __perf_cgroup_move, task);
}

struct cgroup_subsys perf_event_cgrp_subsys = {
        .css_alloc        = perf_cgroup_css_alloc,
        .css_free        = perf_cgroup_css_free,
        .css_online        = perf_cgroup_css_online,
        .attach                = perf_cgroup_attach,
        /*
         * Implicitly enable on dfl hierarchy so that perf events can
         * always be filtered by cgroup2 path as long as perf_event
         * controller is not mounted on a legacy hierarchy.
         */
        .implicit_on_dfl = true,
        .threaded        = true,
};
#endif /* CONFIG_CGROUP_PERF */

DEFINE_STATIC_CALL_RET0(perf_snapshot_branch_stack, perf_snapshot_branch_stack_t);



































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// SPDX-License-Identifier: GPL-2.0
/*
 * media.c - Media Controller specific ALSA driver code
 *
 * Copyright (c) 2019 Shuah Khan <shuah@kernel.org>
 *
 */

/*
 * This file adds Media Controller support to the ALSA driver
 * to use the Media Controller API to share the tuner with DVB
 * and V4L2 drivers that control the media device.
 *
 * The media device is created based on the existing quirks framework.
 * Using this approach, the media controller API usage can be added for
 * a specific device.
 */

#include <linux/init.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/usb.h>

#include <sound/pcm.h>
#include <sound/core.h>

#include "usbaudio.h"
#include "card.h"
#include "mixer.h"
#include "media.h"

int snd_media_stream_init(struct snd_usb_substream *subs, struct snd_pcm *pcm,
                          int stream)
{
        struct media_device *mdev;
        struct media_ctl *mctl;
        struct device *pcm_dev = pcm->streams[stream].dev;
        u32 intf_type;
        int ret = 0;
        u16 mixer_pad;
        struct media_entity *entity;

        mdev = subs->stream->chip->media_dev;
        if (!mdev)
                return 0;

        if (subs->media_ctl)
                return 0;

        /* allocate media_ctl */
        mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
        if (!mctl)
                return -ENOMEM;

        mctl->media_dev = mdev;
        if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
                intf_type = MEDIA_INTF_T_ALSA_PCM_PLAYBACK;
                mctl->media_entity.function = MEDIA_ENT_F_AUDIO_PLAYBACK;
                mctl->media_pad.flags = MEDIA_PAD_FL_SOURCE;
                mixer_pad = 1;
        } else {
                intf_type = MEDIA_INTF_T_ALSA_PCM_CAPTURE;
                mctl->media_entity.function = MEDIA_ENT_F_AUDIO_CAPTURE;
                mctl->media_pad.flags = MEDIA_PAD_FL_SINK;
                mixer_pad = 2;
        }
        mctl->media_entity.name = pcm->name;
        media_entity_pads_init(&mctl->media_entity, 1, &mctl->media_pad);
        ret =  media_device_register_entity(mctl->media_dev,
                                            &mctl->media_entity);
        if (ret)
                goto free_mctl;

        mctl->intf_devnode = media_devnode_create(mdev, intf_type, 0,
                                                  MAJOR(pcm_dev->devt),
                                                  MINOR(pcm_dev->devt));
        if (!mctl->intf_devnode) {
                ret = -ENOMEM;
                goto unregister_entity;
        }
        mctl->intf_link = media_create_intf_link(&mctl->media_entity,
                                                 &mctl->intf_devnode->intf,
                                                 MEDIA_LNK_FL_ENABLED);
        if (!mctl->intf_link) {
                ret = -ENOMEM;
                goto devnode_remove;
        }

        /* create link between mixer and audio */
        media_device_for_each_entity(entity, mdev) {
                switch (entity->function) {
                case MEDIA_ENT_F_AUDIO_MIXER:
                        ret = media_create_pad_link(entity, mixer_pad,
                                                    &mctl->media_entity, 0,
                                                    MEDIA_LNK_FL_ENABLED);
                        if (ret)
                                goto remove_intf_link;
                        break;
                }
        }

        subs->media_ctl = mctl;
        return 0;

remove_intf_link:
        media_remove_intf_link(mctl->intf_link);
devnode_remove:
        media_devnode_remove(mctl->intf_devnode);
unregister_entity:
        media_device_unregister_entity(&mctl->media_entity);
free_mctl:
        kfree(mctl);
        return ret;
}

void snd_media_stream_delete(struct snd_usb_substream *subs)
{
        struct media_ctl *mctl = subs->media_ctl;

        if (mctl) {
                struct media_device *mdev;

                mdev = mctl->media_dev;
                if (mdev && media_devnode_is_registered(mdev->devnode)) {
                        media_devnode_remove(mctl->intf_devnode);
                        media_device_unregister_entity(&mctl->media_entity);
                        media_entity_cleanup(&mctl->media_entity);
                }
                kfree(mctl);
                subs->media_ctl = NULL;
        }
}

int snd_media_start_pipeline(struct snd_usb_substream *subs)
{
        struct media_ctl *mctl = subs->media_ctl;
        int ret = 0;

        if (!mctl)
                return 0;

        guard(mutex)(&mctl->media_dev->graph_mutex);
        if (mctl->media_dev->enable_source)
                ret = mctl->media_dev->enable_source(&mctl->media_entity,
                                                     &mctl->media_pipe);
        return ret;
}

void snd_media_stop_pipeline(struct snd_usb_substream *subs)
{
        struct media_ctl *mctl = subs->media_ctl;

        if (!mctl)
                return;

        guard(mutex)(&mctl->media_dev->graph_mutex);
        if (mctl->media_dev->disable_source)
                mctl->media_dev->disable_source(&mctl->media_entity);
}

static int snd_media_mixer_init(struct snd_usb_audio *chip)
{
        struct device *ctl_dev = chip->card->ctl_dev;
        struct media_intf_devnode *ctl_intf;
        struct usb_mixer_interface *mixer;
        struct media_device *mdev = chip->media_dev;
        struct media_mixer_ctl *mctl;
        u32 intf_type = MEDIA_INTF_T_ALSA_CONTROL;
        int ret;

        if (!mdev)
                return -ENODEV;

        ctl_intf = chip->ctl_intf_media_devnode;
        if (!ctl_intf) {
                ctl_intf = media_devnode_create(mdev, intf_type, 0,
                                                MAJOR(ctl_dev->devt),
                                                MINOR(ctl_dev->devt));
                if (!ctl_intf)
                        return -ENOMEM;
                chip->ctl_intf_media_devnode = ctl_intf;
        }

        list_for_each_entry(mixer, &chip->mixer_list, list) {

                if (mixer->media_mixer_ctl)
                        continue;

                /* allocate media_mixer_ctl */
                mctl = kzalloc(sizeof(*mctl), GFP_KERNEL);
                if (!mctl)
                        return -ENOMEM;

                mctl->media_dev = mdev;
                mctl->media_entity.function = MEDIA_ENT_F_AUDIO_MIXER;
                mctl->media_entity.name = chip->card->mixername;
                mctl->media_pad[0].flags = MEDIA_PAD_FL_SINK;
                mctl->media_pad[1].flags = MEDIA_PAD_FL_SOURCE;
                mctl->media_pad[2].flags = MEDIA_PAD_FL_SOURCE;
                media_entity_pads_init(&mctl->media_entity, MEDIA_MIXER_PAD_MAX,
                                  mctl->media_pad);
                ret =  media_device_register_entity(mctl->media_dev,
                                                    &mctl->media_entity);
                if (ret) {
                        kfree(mctl);
                        return ret;
                }

                mctl->intf_link = media_create_intf_link(&mctl->media_entity,
                                                         &ctl_intf->intf,
                                                         MEDIA_LNK_FL_ENABLED);
                if (!mctl->intf_link) {
                        media_device_unregister_entity(&mctl->media_entity);
                        media_entity_cleanup(&mctl->media_entity);
                        kfree(mctl);
                        return -ENOMEM;
                }
                mctl->intf_devnode = ctl_intf;
                mixer->media_mixer_ctl = mctl;
        }
        return 0;
}

static void snd_media_mixer_delete(struct snd_usb_audio *chip)
{
        struct usb_mixer_interface *mixer;
        struct media_device *mdev = chip->media_dev;

        if (!mdev)
                return;

        list_for_each_entry(mixer, &chip->mixer_list, list) {
                struct media_mixer_ctl *mctl;

                mctl = mixer->media_mixer_ctl;
                if (!mixer->media_mixer_ctl)
                        continue;

                if (media_devnode_is_registered(mdev->devnode)) {
                        media_device_unregister_entity(&mctl->media_entity);
                        media_entity_cleanup(&mctl->media_entity);
                }
                kfree(mctl);
                mixer->media_mixer_ctl = NULL;
        }
        if (media_devnode_is_registered(mdev->devnode))
                media_devnode_remove(chip->ctl_intf_media_devnode);
        chip->ctl_intf_media_devnode = NULL;
}

int snd_media_device_create(struct snd_usb_audio *chip,
                        struct usb_interface *iface)
{
        struct media_device *mdev;
        struct usb_device *usbdev = interface_to_usbdev(iface);
        int ret = 0;

        /* usb-audio driver is probed for each usb interface, and
         * there are multiple interfaces per device. Avoid calling
         * media_device_usb_allocate() each time usb_audio_probe()
         * is called. Do it only once.
         */
        if (chip->media_dev) {
                mdev = chip->media_dev;
                goto snd_mixer_init;
        }

        mdev = media_device_usb_allocate(usbdev, KBUILD_MODNAME, THIS_MODULE);
        if (IS_ERR(mdev))
                return -ENOMEM;

        /* save media device - avoid lookups */
        chip->media_dev = mdev;

snd_mixer_init:
        /* Create media entities for mixer and control dev */
        ret = snd_media_mixer_init(chip);
        /* media_device might be registered, print error and continue */
        if (ret)
                dev_err(&usbdev->dev,
                        "Couldn't create media mixer entities. Error: %d\n",
                        ret);

        if (!media_devnode_is_registered(mdev->devnode)) {
                /* don't register if snd_media_mixer_init() failed */
                if (ret)
                        goto create_fail;

                /* register media_device */
                ret = media_device_register(mdev);
create_fail:
                if (ret) {
                        snd_media_mixer_delete(chip);
                        media_device_delete(mdev, KBUILD_MODNAME, THIS_MODULE);
                        /* clear saved media_dev */
                        chip->media_dev = NULL;
                        dev_err(&usbdev->dev,
                                "Couldn't register media device. Error: %d\n",
                                ret);
                        return ret;
                }
        }

        return ret;
}

void snd_media_device_delete(struct snd_usb_audio *chip)
{
        struct media_device *mdev = chip->media_dev;
        struct snd_usb_stream *stream;

        /* release resources */
        list_for_each_entry(stream, &chip->pcm_list, list) {
                snd_media_stream_delete(&stream->substream[0]);
                snd_media_stream_delete(&stream->substream[1]);
        }

        snd_media_mixer_delete(chip);

        if (mdev) {
                media_device_delete(mdev, KBUILD_MODNAME, THIS_MODULE);
                chip->media_dev = NULL;
        }
}



























































































































































































































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/* Bottleneck Bandwidth and RTT (BBR) congestion control
 *
 * BBR congestion control computes the sending rate based on the delivery
 * rate (throughput) estimated from ACKs. In a nutshell:
 *
 *   On each ACK, update our model of the network path:
 *      bottleneck_bandwidth = windowed_max(delivered / elapsed, 10 round trips)
 *      min_rtt = windowed_min(rtt, 10 seconds)
 *   pacing_rate = pacing_gain * bottleneck_bandwidth
 *   cwnd = max(cwnd_gain * bottleneck_bandwidth * min_rtt, 4)
 *
 * The core algorithm does not react directly to packet losses or delays,
 * although BBR may adjust the size of next send per ACK when loss is
 * observed, or adjust the sending rate if it estimates there is a
 * traffic policer, in order to keep the drop rate reasonable.
 *
 * Here is a state transition diagram for BBR:
 *
 *             |
 *             V
 *    +---> STARTUP  ----+
 *    |        |         |
 *    |        V         |
 *    |      DRAIN   ----+
 *    |        |         |
 *    |        V         |
 *    +---> PROBE_BW ----+
 *    |      ^    |      |
 *    |      |    |      |
 *    |      +----+      |
 *    |                  |
 *    +---- PROBE_RTT <--+
 *
 * A BBR flow starts in STARTUP, and ramps up its sending rate quickly.
 * When it estimates the pipe is full, it enters DRAIN to drain the queue.
 * In steady state a BBR flow only uses PROBE_BW and PROBE_RTT.
 * A long-lived BBR flow spends the vast majority of its time remaining
 * (repeatedly) in PROBE_BW, fully probing and utilizing the pipe's bandwidth
 * in a fair manner, with a small, bounded queue. *If* a flow has been
 * continuously sending for the entire min_rtt window, and hasn't seen an RTT
 * sample that matches or decreases its min_rtt estimate for 10 seconds, then
 * it briefly enters PROBE_RTT to cut inflight to a minimum value to re-probe
 * the path's two-way propagation delay (min_rtt). When exiting PROBE_RTT, if
 * we estimated that we reached the full bw of the pipe then we enter PROBE_BW;
 * otherwise we enter STARTUP to try to fill the pipe.
 *
 * BBR is described in detail in:
 *   "BBR: Congestion-Based Congestion Control",
 *   Neal Cardwell, Yuchung Cheng, C. Stephen Gunn, Soheil Hassas Yeganeh,
 *   Van Jacobson. ACM Queue, Vol. 14 No. 5, September-October 2016.
 *
 * There is a public e-mail list for discussing BBR development and testing:
 *   https://groups.google.com/forum/#!forum/bbr-dev
 *
 * NOTE: BBR might be used with the fq qdisc ("man tc-fq") with pacing enabled,
 * otherwise TCP stack falls back to an internal pacing using one high
 * resolution timer per TCP socket and may use more resources.
 */
#include <linux/btf.h>
#include <linux/btf_ids.h>
#include <linux/module.h>
#include <net/tcp.h>
#include <linux/inet_diag.h>
#include <linux/inet.h>
#include <linux/random.h>
#include <linux/win_minmax.h>

/* Scale factor for rate in pkt/uSec unit to avoid truncation in bandwidth
 * estimation. The rate unit ~= (1500 bytes / 1 usec / 2^24) ~= 715 bps.
 * This handles bandwidths from 0.06pps (715bps) to 256Mpps (3Tbps) in a u32.
 * Since the minimum window is >=4 packets, the lower bound isn't
 * an issue. The upper bound isn't an issue with existing technologies.
 */
#define BW_SCALE 24
#define BW_UNIT (1 << BW_SCALE)

#define BBR_SCALE 8        /* scaling factor for fractions in BBR (e.g. gains) */
#define BBR_UNIT (1 << BBR_SCALE)

/* BBR has the following modes for deciding how fast to send: */
enum bbr_mode {
        BBR_STARTUP,        /* ramp up sending rate rapidly to fill pipe */
        BBR_DRAIN,        /* drain any queue created during startup */
        BBR_PROBE_BW,        /* discover, share bw: pace around estimated bw */
        BBR_PROBE_RTT,        /* cut inflight to min to probe min_rtt */
};

/* BBR congestion control block */
struct bbr {
        u32        min_rtt_us;                /* min RTT in min_rtt_win_sec window */
        u32        min_rtt_stamp;                /* timestamp of min_rtt_us */
        u32        probe_rtt_done_stamp;   /* end time for BBR_PROBE_RTT mode */
        struct minmax bw;        /* Max recent delivery rate in pkts/uS << 24 */
        u32        rtt_cnt;            /* count of packet-timed rounds elapsed */
        u32     next_rtt_delivered; /* scb->tx.delivered at end of round */
        u64        cycle_mstamp;             /* time of this cycle phase start */
        u32     mode:3,                     /* current bbr_mode in state machine */
                prev_ca_state:3,     /* CA state on previous ACK */
                packet_conservation:1,  /* use packet conservation? */
                round_start:1,             /* start of packet-timed tx->ack round? */
                idle_restart:1,             /* restarting after idle? */
                probe_rtt_round_done:1,  /* a BBR_PROBE_RTT round at 4 pkts? */
                unused:13,
                lt_is_sampling:1,    /* taking long-term ("LT") samples now? */
                lt_rtt_cnt:7,             /* round trips in long-term interval */
                lt_use_bw:1;             /* use lt_bw as our bw estimate? */
        u32        lt_bw;                     /* LT est delivery rate in pkts/uS << 24 */
        u32        lt_last_delivered;   /* LT intvl start: tp->delivered */
        u32        lt_last_stamp;             /* LT intvl start: tp->delivered_mstamp */
        u32        lt_last_lost;             /* LT intvl start: tp->lost */
        u32        pacing_gain:10,        /* current gain for setting pacing rate */
                cwnd_gain:10,        /* current gain for setting cwnd */
                full_bw_reached:1,   /* reached full bw in Startup? */
                full_bw_cnt:2,        /* number of rounds without large bw gains */
                cycle_idx:3,        /* current index in pacing_gain cycle array */
                has_seen_rtt:1, /* have we seen an RTT sample yet? */
                unused_b:5;
        u32        prior_cwnd;        /* prior cwnd upon entering loss recovery */
        u32        full_bw;        /* recent bw, to estimate if pipe is full */

        /* For tracking ACK aggregation: */
        u64        ack_epoch_mstamp;        /* start of ACK sampling epoch */
        u16        extra_acked[2];                /* max excess data ACKed in epoch */
        u32        ack_epoch_acked:20,        /* packets (S)ACKed in sampling epoch */
                extra_acked_win_rtts:5,        /* age of extra_acked, in round trips */
                extra_acked_win_idx:1,        /* current index in extra_acked array */
                unused_c:6;
};

#define CYCLE_LEN        8        /* number of phases in a pacing gain cycle */

/* Window length of bw filter (in rounds): */
static const int bbr_bw_rtts = CYCLE_LEN + 2;
/* Window length of min_rtt filter (in sec): */
static const u32 bbr_min_rtt_win_sec = 10;
/* Minimum time (in ms) spent at bbr_cwnd_min_target in BBR_PROBE_RTT mode: */
static const u32 bbr_probe_rtt_mode_ms = 200;
/* Skip TSO below the following bandwidth (bits/sec): */
static const int bbr_min_tso_rate = 1200000;

/* Pace at ~1% below estimated bw, on average, to reduce queue at bottleneck.
 * In order to help drive the network toward lower queues and low latency while
 * maintaining high utilization, the average pacing rate aims to be slightly
 * lower than the estimated bandwidth. This is an important aspect of the
 * design.
 */
static const int bbr_pacing_margin_percent = 1;

/* We use a high_gain value of 2/ln(2) because it's the smallest pacing gain
 * that will allow a smoothly increasing pacing rate that will double each RTT
 * and send the same number of packets per RTT that an un-paced, slow-starting
 * Reno or CUBIC flow would:
 */
static const int bbr_high_gain  = BBR_UNIT * 2885 / 1000 + 1;
/* The pacing gain of 1/high_gain in BBR_DRAIN is calculated to typically drain
 * the queue created in BBR_STARTUP in a single round:
 */
static const int bbr_drain_gain = BBR_UNIT * 1000 / 2885;
/* The gain for deriving steady-state cwnd tolerates delayed/stretched ACKs: */
static const int bbr_cwnd_gain  = BBR_UNIT * 2;
/* The pacing_gain values for the PROBE_BW gain cycle, to discover/share bw: */
static const int bbr_pacing_gain[] = {
        BBR_UNIT * 5 / 4,        /* probe for more available bw */
        BBR_UNIT * 3 / 4,        /* drain queue and/or yield bw to other flows */
        BBR_UNIT, BBR_UNIT, BBR_UNIT,        /* cruise at 1.0*bw to utilize pipe, */
        BBR_UNIT, BBR_UNIT, BBR_UNIT        /* without creating excess queue... */
};
/* Randomize the starting gain cycling phase over N phases: */
static const u32 bbr_cycle_rand = 7;

/* Try to keep at least this many packets in flight, if things go smoothly. For
 * smooth functioning, a sliding window protocol ACKing every other packet
 * needs at least 4 packets in flight:
 */
static const u32 bbr_cwnd_min_target = 4;

/* To estimate if BBR_STARTUP mode (i.e. high_gain) has filled pipe... */
/* If bw has increased significantly (1.25x), there may be more bw available: */
static const u32 bbr_full_bw_thresh = BBR_UNIT * 5 / 4;
/* But after 3 rounds w/o significant bw growth, estimate pipe is full: */
static const u32 bbr_full_bw_cnt = 3;

/* "long-term" ("LT") bandwidth estimator parameters... */
/* The minimum number of rounds in an LT bw sampling interval: */
static const u32 bbr_lt_intvl_min_rtts = 4;
/* If lost/delivered ratio > 20%, interval is "lossy" and we may be policed: */
static const u32 bbr_lt_loss_thresh = 50;
/* If 2 intervals have a bw ratio <= 1/8, their bw is "consistent": */
static const u32 bbr_lt_bw_ratio = BBR_UNIT / 8;
/* If 2 intervals have a bw diff <= 4 Kbit/sec their bw is "consistent": */
static const u32 bbr_lt_bw_diff = 4000 / 8;
/* If we estimate we're policed, use lt_bw for this many round trips: */
static const u32 bbr_lt_bw_max_rtts = 48;

/* Gain factor for adding extra_acked to target cwnd: */
static const int bbr_extra_acked_gain = BBR_UNIT;
/* Window length of extra_acked window. */
static const u32 bbr_extra_acked_win_rtts = 5;
/* Max allowed val for ack_epoch_acked, after which sampling epoch is reset */
static const u32 bbr_ack_epoch_acked_reset_thresh = 1U << 20;
/* Time period for clamping cwnd increment due to ack aggregation */
static const u32 bbr_extra_acked_max_us = 100 * 1000;

static void bbr_check_probe_rtt_done(struct sock *sk);

/* Do we estimate that STARTUP filled the pipe? */
static bool bbr_full_bw_reached(const struct sock *sk)
{
        const struct bbr *bbr = inet_csk_ca(sk);

        return bbr->full_bw_reached;
}

/* Return the windowed max recent bandwidth sample, in pkts/uS << BW_SCALE. */
static u32 bbr_max_bw(const struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        return minmax_get(&bbr->bw);
}

/* Return the estimated bandwidth of the path, in pkts/uS << BW_SCALE. */
static u32 bbr_bw(const struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        return bbr->lt_use_bw ? bbr->lt_bw : bbr_max_bw(sk);
}

/* Return maximum extra acked in past k-2k round trips,
 * where k = bbr_extra_acked_win_rtts.
 */
static u16 bbr_extra_acked(const struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        return max(bbr->extra_acked[0], bbr->extra_acked[1]);
}

/* Return rate in bytes per second, optionally with a gain.
 * The order here is chosen carefully to avoid overflow of u64. This should
 * work for input rates of up to 2.9Tbit/sec and gain of 2.89x.
 */
static u64 bbr_rate_bytes_per_sec(struct sock *sk, u64 rate, int gain)
{
        unsigned int mss = tcp_sk(sk)->mss_cache;

        rate *= mss;
        rate *= gain;
        rate >>= BBR_SCALE;
        rate *= USEC_PER_SEC / 100 * (100 - bbr_pacing_margin_percent);
        return rate >> BW_SCALE;
}

/* Convert a BBR bw and gain factor to a pacing rate in bytes per second. */
static unsigned long bbr_bw_to_pacing_rate(struct sock *sk, u32 bw, int gain)
{
        u64 rate = bw;

        rate = bbr_rate_bytes_per_sec(sk, rate, gain);
        rate = min_t(u64, rate, READ_ONCE(sk->sk_max_pacing_rate));
        return rate;
}

/* Initialize pacing rate to: high_gain * init_cwnd / RTT. */
static void bbr_init_pacing_rate_from_rtt(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        u64 bw;
        u32 rtt_us;

        if (tp->srtt_us) {                /* any RTT sample yet? */
                rtt_us = max(tp->srtt_us >> 3, 1U);
                bbr->has_seen_rtt = 1;
        } else {                         /* no RTT sample yet */
                rtt_us = USEC_PER_MSEC;         /* use nominal default RTT */
        }
        bw = (u64)tcp_snd_cwnd(tp) * BW_UNIT;
        do_div(bw, rtt_us);
        WRITE_ONCE(sk->sk_pacing_rate,
                   bbr_bw_to_pacing_rate(sk, bw, bbr_high_gain));
}

/* Pace using current bw estimate and a gain factor. */
static void bbr_set_pacing_rate(struct sock *sk, u32 bw, int gain)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        unsigned long rate = bbr_bw_to_pacing_rate(sk, bw, gain);

        if (unlikely(!bbr->has_seen_rtt && tp->srtt_us))
                bbr_init_pacing_rate_from_rtt(sk);
        if (bbr_full_bw_reached(sk) || rate > READ_ONCE(sk->sk_pacing_rate))
                WRITE_ONCE(sk->sk_pacing_rate, rate);
}

/* override sysctl_tcp_min_tso_segs */
__bpf_kfunc static u32 bbr_min_tso_segs(struct sock *sk)
{
        return READ_ONCE(sk->sk_pacing_rate) < (bbr_min_tso_rate >> 3) ? 1 : 2;
}

static u32 bbr_tso_segs_goal(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        u32 segs, bytes;

        /* Sort of tcp_tso_autosize() but ignoring
         * driver provided sk_gso_max_size.
         */
        bytes = min_t(unsigned long,
                      READ_ONCE(sk->sk_pacing_rate) >> READ_ONCE(sk->sk_pacing_shift),
                      GSO_LEGACY_MAX_SIZE - 1 - MAX_TCP_HEADER);
        segs = max_t(u32, bytes / tp->mss_cache, bbr_min_tso_segs(sk));

        return min(segs, 0x7FU);
}

/* Save "last known good" cwnd so we can restore it after losses or PROBE_RTT */
static void bbr_save_cwnd(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);

        if (bbr->prev_ca_state < TCP_CA_Recovery && bbr->mode != BBR_PROBE_RTT)
                bbr->prior_cwnd = tcp_snd_cwnd(tp);  /* this cwnd is good enough */
        else  /* loss recovery or BBR_PROBE_RTT have temporarily cut cwnd */
                bbr->prior_cwnd = max(bbr->prior_cwnd, tcp_snd_cwnd(tp));
}

__bpf_kfunc static void bbr_cwnd_event(struct sock *sk, enum tcp_ca_event event)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);

        if (event == CA_EVENT_TX_START && tp->app_limited) {
                bbr->idle_restart = 1;
                bbr->ack_epoch_mstamp = tp->tcp_mstamp;
                bbr->ack_epoch_acked = 0;
                /* Avoid pointless buffer overflows: pace at est. bw if we don't
                 * need more speed (we're restarting from idle and app-limited).
                 */
                if (bbr->mode == BBR_PROBE_BW)
                        bbr_set_pacing_rate(sk, bbr_bw(sk), BBR_UNIT);
                else if (bbr->mode == BBR_PROBE_RTT)
                        bbr_check_probe_rtt_done(sk);
        }
}

/* Calculate bdp based on min RTT and the estimated bottleneck bandwidth:
 *
 * bdp = ceil(bw * min_rtt * gain)
 *
 * The key factor, gain, controls the amount of queue. While a small gain
 * builds a smaller queue, it becomes more vulnerable to noise in RTT
 * measurements (e.g., delayed ACKs or other ACK compression effects). This
 * noise may cause BBR to under-estimate the rate.
 */
static u32 bbr_bdp(struct sock *sk, u32 bw, int gain)
{
        struct bbr *bbr = inet_csk_ca(sk);
        u32 bdp;
        u64 w;

        /* If we've never had a valid RTT sample, cap cwnd at the initial
         * default. This should only happen when the connection is not using TCP
         * timestamps and has retransmitted all of the SYN/SYNACK/data packets
         * ACKed so far. In this case, an RTO can cut cwnd to 1, in which
         * case we need to slow-start up toward something safe: TCP_INIT_CWND.
         */
        if (unlikely(bbr->min_rtt_us == ~0U))         /* no valid RTT samples yet? */
                return TCP_INIT_CWND;  /* be safe: cap at default initial cwnd*/

        w = (u64)bw * bbr->min_rtt_us;

        /* Apply a gain to the given value, remove the BW_SCALE shift, and
         * round the value up to avoid a negative feedback loop.
         */
        bdp = (((w * gain) >> BBR_SCALE) + BW_UNIT - 1) / BW_UNIT;

        return bdp;
}

/* To achieve full performance in high-speed paths, we budget enough cwnd to
 * fit full-sized skbs in-flight on both end hosts to fully utilize the path:
 *   - one skb in sending host Qdisc,
 *   - one skb in sending host TSO/GSO engine
 *   - one skb being received by receiver host LRO/GRO/delayed-ACK engine
 * Don't worry, at low rates (bbr_min_tso_rate) this won't bloat cwnd because
 * in such cases tso_segs_goal is 1. The minimum cwnd is 4 packets,
 * which allows 2 outstanding 2-packet sequences, to try to keep pipe
 * full even with ACK-every-other-packet delayed ACKs.
 */
static u32 bbr_quantization_budget(struct sock *sk, u32 cwnd)
{
        struct bbr *bbr = inet_csk_ca(sk);

        /* Allow enough full-sized skbs in flight to utilize end systems. */
        cwnd += 3 * bbr_tso_segs_goal(sk);

        /* Reduce delayed ACKs by rounding up cwnd to the next even number. */
        cwnd = (cwnd + 1) & ~1U;

        /* Ensure gain cycling gets inflight above BDP even for small BDPs. */
        if (bbr->mode == BBR_PROBE_BW && bbr->cycle_idx == 0)
                cwnd += 2;

        return cwnd;
}

/* Find inflight based on min RTT and the estimated bottleneck bandwidth. */
static u32 bbr_inflight(struct sock *sk, u32 bw, int gain)
{
        u32 inflight;

        inflight = bbr_bdp(sk, bw, gain);
        inflight = bbr_quantization_budget(sk, inflight);

        return inflight;
}

/* With pacing at lower layers, there's often less data "in the network" than
 * "in flight". With TSQ and departure time pacing at lower layers (e.g. fq),
 * we often have several skbs queued in the pacing layer with a pre-scheduled
 * earliest departure time (EDT). BBR adapts its pacing rate based on the
 * inflight level that it estimates has already been "baked in" by previous
 * departure time decisions. We calculate a rough estimate of the number of our
 * packets that might be in the network at the earliest departure time for the
 * next skb scheduled:
 *   in_network_at_edt = inflight_at_edt - (EDT - now) * bw
 * If we're increasing inflight, then we want to know if the transmit of the
 * EDT skb will push inflight above the target, so inflight_at_edt includes
 * bbr_tso_segs_goal() from the skb departing at EDT. If decreasing inflight,
 * then estimate if inflight will sink too low just before the EDT transmit.
 */
static u32 bbr_packets_in_net_at_edt(struct sock *sk, u32 inflight_now)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        u64 now_ns, edt_ns, interval_us;
        u32 interval_delivered, inflight_at_edt;

        now_ns = tp->tcp_clock_cache;
        edt_ns = max(tp->tcp_wstamp_ns, now_ns);
        interval_us = div_u64(edt_ns - now_ns, NSEC_PER_USEC);
        interval_delivered = (u64)bbr_bw(sk) * interval_us >> BW_SCALE;
        inflight_at_edt = inflight_now;
        if (bbr->pacing_gain > BBR_UNIT)              /* increasing inflight */
                inflight_at_edt += bbr_tso_segs_goal(sk);  /* include EDT skb */
        if (interval_delivered >= inflight_at_edt)
                return 0;
        return inflight_at_edt - interval_delivered;
}

/* Find the cwnd increment based on estimate of ack aggregation */
static u32 bbr_ack_aggregation_cwnd(struct sock *sk)
{
        u32 max_aggr_cwnd, aggr_cwnd = 0;

        if (bbr_extra_acked_gain && bbr_full_bw_reached(sk)) {
                max_aggr_cwnd = ((u64)bbr_bw(sk) * bbr_extra_acked_max_us)
                                / BW_UNIT;
                aggr_cwnd = (bbr_extra_acked_gain * bbr_extra_acked(sk))
                             >> BBR_SCALE;
                aggr_cwnd = min(aggr_cwnd, max_aggr_cwnd);
        }

        return aggr_cwnd;
}

/* An optimization in BBR to reduce losses: On the first round of recovery, we
 * follow the packet conservation principle: send P packets per P packets acked.
 * After that, we slow-start and send at most 2*P packets per P packets acked.
 * After recovery finishes, or upon undo, we restore the cwnd we had when
 * recovery started (capped by the target cwnd based on estimated BDP).
 *
 * TODO(ycheng/ncardwell): implement a rate-based approach.
 */
static bool bbr_set_cwnd_to_recover_or_restore(
        struct sock *sk, const struct rate_sample *rs, u32 acked, u32 *new_cwnd)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        u8 prev_state = bbr->prev_ca_state, state = inet_csk(sk)->icsk_ca_state;
        u32 cwnd = tcp_snd_cwnd(tp);

        /* An ACK for P pkts should release at most 2*P packets. We do this
         * in two steps. First, here we deduct the number of lost packets.
         * Then, in bbr_set_cwnd() we slow start up toward the target cwnd.
         */
        if (rs->losses > 0)
                cwnd = max_t(s32, cwnd - rs->losses, 1);

        if (state == TCP_CA_Recovery && prev_state != TCP_CA_Recovery) {
                /* Starting 1st round of Recovery, so do packet conservation. */
                bbr->packet_conservation = 1;
                bbr->next_rtt_delivered = tp->delivered;  /* start round now */
                /* Cut unused cwnd from app behavior, TSQ, or TSO deferral: */
                cwnd = tcp_packets_in_flight(tp) + acked;
        } else if (prev_state >= TCP_CA_Recovery && state < TCP_CA_Recovery) {
                /* Exiting loss recovery; restore cwnd saved before recovery. */
                cwnd = max(cwnd, bbr->prior_cwnd);
                bbr->packet_conservation = 0;
        }
        bbr->prev_ca_state = state;

        if (bbr->packet_conservation) {
                *new_cwnd = max(cwnd, tcp_packets_in_flight(tp) + acked);
                return true;        /* yes, using packet conservation */
        }
        *new_cwnd = cwnd;
        return false;
}

/* Slow-start up toward target cwnd (if bw estimate is growing, or packet loss
 * has drawn us down below target), or snap down to target if we're above it.
 */
static void bbr_set_cwnd(struct sock *sk, const struct rate_sample *rs,
                         u32 acked, u32 bw, int gain)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        u32 cwnd = tcp_snd_cwnd(tp), target_cwnd = 0;

        if (!acked)
                goto done;  /* no packet fully ACKed; just apply caps */

        if (bbr_set_cwnd_to_recover_or_restore(sk, rs, acked, &cwnd))
                goto done;

        target_cwnd = bbr_bdp(sk, bw, gain);

        /* Increment the cwnd to account for excess ACKed data that seems
         * due to aggregation (of data and/or ACKs) visible in the ACK stream.
         */
        target_cwnd += bbr_ack_aggregation_cwnd(sk);
        target_cwnd = bbr_quantization_budget(sk, target_cwnd);

        /* If we're below target cwnd, slow start cwnd toward target cwnd. */
        if (bbr_full_bw_reached(sk))  /* only cut cwnd if we filled the pipe */
                cwnd = min(cwnd + acked, target_cwnd);
        else if (cwnd < target_cwnd || tp->delivered < TCP_INIT_CWND)
                cwnd = cwnd + acked;
        cwnd = max(cwnd, bbr_cwnd_min_target);

done:
        tcp_snd_cwnd_set(tp, min(cwnd, tp->snd_cwnd_clamp));        /* apply global cap */
        if (bbr->mode == BBR_PROBE_RTT)  /* drain queue, refresh min_rtt */
                tcp_snd_cwnd_set(tp, min(tcp_snd_cwnd(tp), bbr_cwnd_min_target));
}

/* End cycle phase if it's time and/or we hit the phase's in-flight target. */
static bool bbr_is_next_cycle_phase(struct sock *sk,
                                    const struct rate_sample *rs)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        bool is_full_length =
                tcp_stamp_us_delta(tp->delivered_mstamp, bbr->cycle_mstamp) >
                bbr->min_rtt_us;
        u32 inflight, bw;

        /* The pacing_gain of 1.0 paces at the estimated bw to try to fully
         * use the pipe without increasing the queue.
         */
        if (bbr->pacing_gain == BBR_UNIT)
                return is_full_length;                /* just use wall clock time */

        inflight = bbr_packets_in_net_at_edt(sk, rs->prior_in_flight);
        bw = bbr_max_bw(sk);

        /* A pacing_gain > 1.0 probes for bw by trying to raise inflight to at
         * least pacing_gain*BDP; this may take more than min_rtt if min_rtt is
         * small (e.g. on a LAN). We do not persist if packets are lost, since
         * a path with small buffers may not hold that much.
         */
        if (bbr->pacing_gain > BBR_UNIT)
                return is_full_length &&
                        (rs->losses ||  /* perhaps pacing_gain*BDP won't fit */
                         inflight >= bbr_inflight(sk, bw, bbr->pacing_gain));

        /* A pacing_gain < 1.0 tries to drain extra queue we added if bw
         * probing didn't find more bw. If inflight falls to match BDP then we
         * estimate queue is drained; persisting would underutilize the pipe.
         */
        return is_full_length ||
                inflight <= bbr_inflight(sk, bw, BBR_UNIT);
}

static void bbr_advance_cycle_phase(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->cycle_idx = (bbr->cycle_idx + 1) & (CYCLE_LEN - 1);
        bbr->cycle_mstamp = tp->delivered_mstamp;
}

/* Gain cycling: cycle pacing gain to converge to fair share of available bw. */
static void bbr_update_cycle_phase(struct sock *sk,
                                   const struct rate_sample *rs)
{
        struct bbr *bbr = inet_csk_ca(sk);

        if (bbr->mode == BBR_PROBE_BW && bbr_is_next_cycle_phase(sk, rs))
                bbr_advance_cycle_phase(sk);
}

static void bbr_reset_startup_mode(struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->mode = BBR_STARTUP;
}

static void bbr_reset_probe_bw_mode(struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->mode = BBR_PROBE_BW;
        bbr->cycle_idx = CYCLE_LEN - 1 - get_random_u32_below(bbr_cycle_rand);
        bbr_advance_cycle_phase(sk);        /* flip to next phase of gain cycle */
}

static void bbr_reset_mode(struct sock *sk)
{
        if (!bbr_full_bw_reached(sk))
                bbr_reset_startup_mode(sk);
        else
                bbr_reset_probe_bw_mode(sk);
}

/* Start a new long-term sampling interval. */
static void bbr_reset_lt_bw_sampling_interval(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->lt_last_stamp = div_u64(tp->delivered_mstamp, USEC_PER_MSEC);
        bbr->lt_last_delivered = tp->delivered;
        bbr->lt_last_lost = tp->lost;
        bbr->lt_rtt_cnt = 0;
}

/* Completely reset long-term bandwidth sampling. */
static void bbr_reset_lt_bw_sampling(struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->lt_bw = 0;
        bbr->lt_use_bw = 0;
        bbr->lt_is_sampling = false;
        bbr_reset_lt_bw_sampling_interval(sk);
}

/* Long-term bw sampling interval is done. Estimate whether we're policed. */
static void bbr_lt_bw_interval_done(struct sock *sk, u32 bw)
{
        struct bbr *bbr = inet_csk_ca(sk);
        u32 diff;

        if (bbr->lt_bw) {  /* do we have bw from a previous interval? */
                /* Is new bw close to the lt_bw from the previous interval? */
                diff = abs(bw - bbr->lt_bw);
                if ((diff * BBR_UNIT <= bbr_lt_bw_ratio * bbr->lt_bw) ||
                    (bbr_rate_bytes_per_sec(sk, diff, BBR_UNIT) <=
                     bbr_lt_bw_diff)) {
                        /* All criteria are met; estimate we're policed. */
                        bbr->lt_bw = (bw + bbr->lt_bw) >> 1;  /* avg 2 intvls */
                        bbr->lt_use_bw = 1;
                        bbr->pacing_gain = BBR_UNIT;  /* try to avoid drops */
                        bbr->lt_rtt_cnt = 0;
                        return;
                }
        }
        bbr->lt_bw = bw;
        bbr_reset_lt_bw_sampling_interval(sk);
}

/* Token-bucket traffic policers are common (see "An Internet-Wide Analysis of
 * Traffic Policing", SIGCOMM 2016). BBR detects token-bucket policers and
 * explicitly models their policed rate, to reduce unnecessary losses. We
 * estimate that we're policed if we see 2 consecutive sampling intervals with
 * consistent throughput and high packet loss. If we think we're being policed,
 * set lt_bw to the "long-term" average delivery rate from those 2 intervals.
 */
static void bbr_lt_bw_sampling(struct sock *sk, const struct rate_sample *rs)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        u32 lost, delivered;
        u64 bw;
        u32 t;

        if (bbr->lt_use_bw) {        /* already using long-term rate, lt_bw? */
                if (bbr->mode == BBR_PROBE_BW && bbr->round_start &&
                    ++bbr->lt_rtt_cnt >= bbr_lt_bw_max_rtts) {
                        bbr_reset_lt_bw_sampling(sk);    /* stop using lt_bw */
                        bbr_reset_probe_bw_mode(sk);  /* restart gain cycling */
                }
                return;
        }

        /* Wait for the first loss before sampling, to let the policer exhaust
         * its tokens and estimate the steady-state rate allowed by the policer.
         * Starting samples earlier includes bursts that over-estimate the bw.
         */
        if (!bbr->lt_is_sampling) {
                if (!rs->losses)
                        return;
                bbr_reset_lt_bw_sampling_interval(sk);
                bbr->lt_is_sampling = true;
        }

        /* To avoid underestimates, reset sampling if we run out of data. */
        if (rs->is_app_limited) {
                bbr_reset_lt_bw_sampling(sk);
                return;
        }

        if (bbr->round_start)
                bbr->lt_rtt_cnt++;        /* count round trips in this interval */
        if (bbr->lt_rtt_cnt < bbr_lt_intvl_min_rtts)
                return;                /* sampling interval needs to be longer */
        if (bbr->lt_rtt_cnt > 4 * bbr_lt_intvl_min_rtts) {
                bbr_reset_lt_bw_sampling(sk);  /* interval is too long */
                return;
        }

        /* End sampling interval when a packet is lost, so we estimate the
         * policer tokens were exhausted. Stopping the sampling before the
         * tokens are exhausted under-estimates the policed rate.
         */
        if (!rs->losses)
                return;

        /* Calculate packets lost and delivered in sampling interval. */
        lost = tp->lost - bbr->lt_last_lost;
        delivered = tp->delivered - bbr->lt_last_delivered;
        /* Is loss rate (lost/delivered) >= lt_loss_thresh? If not, wait. */
        if (!delivered || (lost << BBR_SCALE) < bbr_lt_loss_thresh * delivered)
                return;

        /* Find average delivery rate in this sampling interval. */
        t = div_u64(tp->delivered_mstamp, USEC_PER_MSEC) - bbr->lt_last_stamp;
        if ((s32)t < 1)
                return;                /* interval is less than one ms, so wait */
        /* Check if can multiply without overflow */
        if (t >= ~0U / USEC_PER_MSEC) {
                bbr_reset_lt_bw_sampling(sk);  /* interval too long; reset */
                return;
        }
        t *= USEC_PER_MSEC;
        bw = (u64)delivered * BW_UNIT;
        do_div(bw, t);
        bbr_lt_bw_interval_done(sk, bw);
}

/* Estimate the bandwidth based on how fast packets are delivered */
static void bbr_update_bw(struct sock *sk, const struct rate_sample *rs)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        u64 bw;

        bbr->round_start = 0;
        if (rs->delivered < 0 || rs->interval_us <= 0)
                return; /* Not a valid observation */

        /* See if we've reached the next RTT */
        if (!before(rs->prior_delivered, bbr->next_rtt_delivered)) {
                bbr->next_rtt_delivered = tp->delivered;
                bbr->rtt_cnt++;
                bbr->round_start = 1;
                bbr->packet_conservation = 0;
        }

        bbr_lt_bw_sampling(sk, rs);

        /* Divide delivered by the interval to find a (lower bound) bottleneck
         * bandwidth sample. Delivered is in packets and interval_us in uS and
         * ratio will be <<1 for most connections. So delivered is first scaled.
         */
        bw = div64_long((u64)rs->delivered * BW_UNIT, rs->interval_us);

        /* If this sample is application-limited, it is likely to have a very
         * low delivered count that represents application behavior rather than
         * the available network rate. Such a sample could drag down estimated
         * bw, causing needless slow-down. Thus, to continue to send at the
         * last measured network rate, we filter out app-limited samples unless
         * they describe the path bw at least as well as our bw model.
         *
         * So the goal during app-limited phase is to proceed with the best
         * network rate no matter how long. We automatically leave this
         * phase when app writes faster than the network can deliver :)
         */
        if (!rs->is_app_limited || bw >= bbr_max_bw(sk)) {
                /* Incorporate new sample into our max bw filter. */
                minmax_running_max(&bbr->bw, bbr_bw_rtts, bbr->rtt_cnt, bw);
        }
}

/* Estimates the windowed max degree of ack aggregation.
 * This is used to provision extra in-flight data to keep sending during
 * inter-ACK silences.
 *
 * Degree of ack aggregation is estimated as extra data acked beyond expected.
 *
 * max_extra_acked = "maximum recent excess data ACKed beyond max_bw * interval"
 * cwnd += max_extra_acked
 *
 * Max extra_acked is clamped by cwnd and bw * bbr_extra_acked_max_us (100 ms).
 * Max filter is an approximate sliding window of 5-10 (packet timed) round
 * trips.
 */
static void bbr_update_ack_aggregation(struct sock *sk,
                                       const struct rate_sample *rs)
{
        u32 epoch_us, expected_acked, extra_acked;
        struct bbr *bbr = inet_csk_ca(sk);
        struct tcp_sock *tp = tcp_sk(sk);

        if (!bbr_extra_acked_gain || rs->acked_sacked <= 0 ||
            rs->delivered < 0 || rs->interval_us <= 0)
                return;

        if (bbr->round_start) {
                bbr->extra_acked_win_rtts = min(0x1F,
                                                bbr->extra_acked_win_rtts + 1);
                if (bbr->extra_acked_win_rtts >= bbr_extra_acked_win_rtts) {
                        bbr->extra_acked_win_rtts = 0;
                        bbr->extra_acked_win_idx = bbr->extra_acked_win_idx ?
                                                   0 : 1;
                        bbr->extra_acked[bbr->extra_acked_win_idx] = 0;
                }
        }

        /* Compute how many packets we expected to be delivered over epoch. */
        epoch_us = tcp_stamp_us_delta(tp->delivered_mstamp,
                                      bbr->ack_epoch_mstamp);
        expected_acked = ((u64)bbr_bw(sk) * epoch_us) / BW_UNIT;

        /* Reset the aggregation epoch if ACK rate is below expected rate or
         * significantly large no. of ack received since epoch (potentially
         * quite old epoch).
         */
        if (bbr->ack_epoch_acked <= expected_acked ||
            (bbr->ack_epoch_acked + rs->acked_sacked >=
             bbr_ack_epoch_acked_reset_thresh)) {
                bbr->ack_epoch_acked = 0;
                bbr->ack_epoch_mstamp = tp->delivered_mstamp;
                expected_acked = 0;
        }

        /* Compute excess data delivered, beyond what was expected. */
        bbr->ack_epoch_acked = min_t(u32, 0xFFFFF,
                                     bbr->ack_epoch_acked + rs->acked_sacked);
        extra_acked = bbr->ack_epoch_acked - expected_acked;
        extra_acked = min(extra_acked, tcp_snd_cwnd(tp));
        if (extra_acked > bbr->extra_acked[bbr->extra_acked_win_idx])
                bbr->extra_acked[bbr->extra_acked_win_idx] = extra_acked;
}

/* Estimate when the pipe is full, using the change in delivery rate: BBR
 * estimates that STARTUP filled the pipe if the estimated bw hasn't changed by
 * at least bbr_full_bw_thresh (25%) after bbr_full_bw_cnt (3) non-app-limited
 * rounds. Why 3 rounds: 1: rwin autotuning grows the rwin, 2: we fill the
 * higher rwin, 3: we get higher delivery rate samples. Or transient
 * cross-traffic or radio noise can go away. CUBIC Hystart shares a similar
 * design goal, but uses delay and inter-ACK spacing instead of bandwidth.
 */
static void bbr_check_full_bw_reached(struct sock *sk,
                                      const struct rate_sample *rs)
{
        struct bbr *bbr = inet_csk_ca(sk);
        u32 bw_thresh;

        if (bbr_full_bw_reached(sk) || !bbr->round_start || rs->is_app_limited)
                return;

        bw_thresh = (u64)bbr->full_bw * bbr_full_bw_thresh >> BBR_SCALE;
        if (bbr_max_bw(sk) >= bw_thresh) {
                bbr->full_bw = bbr_max_bw(sk);
                bbr->full_bw_cnt = 0;
                return;
        }
        ++bbr->full_bw_cnt;
        bbr->full_bw_reached = bbr->full_bw_cnt >= bbr_full_bw_cnt;
}

/* If pipe is probably full, drain the queue and then enter steady-state. */
static void bbr_check_drain(struct sock *sk, const struct rate_sample *rs)
{
        struct bbr *bbr = inet_csk_ca(sk);

        if (bbr->mode == BBR_STARTUP && bbr_full_bw_reached(sk)) {
                bbr->mode = BBR_DRAIN;        /* drain queue we created */
                tcp_sk(sk)->snd_ssthresh =
                                bbr_inflight(sk, bbr_max_bw(sk), BBR_UNIT);
        }        /* fall through to check if in-flight is already small: */
        if (bbr->mode == BBR_DRAIN &&
            bbr_packets_in_net_at_edt(sk, tcp_packets_in_flight(tcp_sk(sk))) <=
            bbr_inflight(sk, bbr_max_bw(sk), BBR_UNIT))
                bbr_reset_probe_bw_mode(sk);  /* we estimate queue is drained */
}

static void bbr_check_probe_rtt_done(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);

        if (!(bbr->probe_rtt_done_stamp &&
              after(tcp_jiffies32, bbr->probe_rtt_done_stamp)))
                return;

        bbr->min_rtt_stamp = tcp_jiffies32;  /* wait a while until PROBE_RTT */
        tcp_snd_cwnd_set(tp, max(tcp_snd_cwnd(tp), bbr->prior_cwnd));
        bbr_reset_mode(sk);
}

/* The goal of PROBE_RTT mode is to have BBR flows cooperatively and
 * periodically drain the bottleneck queue, to converge to measure the true
 * min_rtt (unloaded propagation delay). This allows the flows to keep queues
 * small (reducing queuing delay and packet loss) and achieve fairness among
 * BBR flows.
 *
 * The min_rtt filter window is 10 seconds. When the min_rtt estimate expires,
 * we enter PROBE_RTT mode and cap the cwnd at bbr_cwnd_min_target=4 packets.
 * After at least bbr_probe_rtt_mode_ms=200ms and at least one packet-timed
 * round trip elapsed with that flight size <= 4, we leave PROBE_RTT mode and
 * re-enter the previous mode. BBR uses 200ms to approximately bound the
 * performance penalty of PROBE_RTT's cwnd capping to roughly 2% (200ms/10s).
 *
 * Note that flows need only pay 2% if they are busy sending over the last 10
 * seconds. Interactive applications (e.g., Web, RPCs, video chunks) often have
 * natural silences or low-rate periods within 10 seconds where the rate is low
 * enough for long enough to drain its queue in the bottleneck. We pick up
 * these min RTT measurements opportunistically with our min_rtt filter. :-)
 */
static void bbr_update_min_rtt(struct sock *sk, const struct rate_sample *rs)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);
        bool filter_expired;

        /* Track min RTT seen in the min_rtt_win_sec filter window: */
        filter_expired = after(tcp_jiffies32,
                               bbr->min_rtt_stamp + bbr_min_rtt_win_sec * HZ);
        if (rs->rtt_us >= 0 &&
            (rs->rtt_us < bbr->min_rtt_us ||
             (filter_expired && !rs->is_ack_delayed))) {
                bbr->min_rtt_us = rs->rtt_us;
                bbr->min_rtt_stamp = tcp_jiffies32;
        }

        if (bbr_probe_rtt_mode_ms > 0 && filter_expired &&
            !bbr->idle_restart && bbr->mode != BBR_PROBE_RTT) {
                bbr->mode = BBR_PROBE_RTT;  /* dip, drain queue */
                bbr_save_cwnd(sk);  /* note cwnd so we can restore it */
                bbr->probe_rtt_done_stamp = 0;
        }

        if (bbr->mode == BBR_PROBE_RTT) {
                /* Ignore low rate samples during this mode. */
                tp->app_limited =
                        (tp->delivered + tcp_packets_in_flight(tp)) ? : 1;
                /* Maintain min packets in flight for max(200 ms, 1 round). */
                if (!bbr->probe_rtt_done_stamp &&
                    tcp_packets_in_flight(tp) <= bbr_cwnd_min_target) {
                        bbr->probe_rtt_done_stamp = tcp_jiffies32 +
                                msecs_to_jiffies(bbr_probe_rtt_mode_ms);
                        bbr->probe_rtt_round_done = 0;
                        bbr->next_rtt_delivered = tp->delivered;
                } else if (bbr->probe_rtt_done_stamp) {
                        if (bbr->round_start)
                                bbr->probe_rtt_round_done = 1;
                        if (bbr->probe_rtt_round_done)
                                bbr_check_probe_rtt_done(sk);
                }
        }
        /* Restart after idle ends only once we process a new S/ACK for data */
        if (rs->delivered > 0)
                bbr->idle_restart = 0;
}

static void bbr_update_gains(struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        switch (bbr->mode) {
        case BBR_STARTUP:
                bbr->pacing_gain = bbr_high_gain;
                bbr->cwnd_gain         = bbr_high_gain;
                break;
        case BBR_DRAIN:
                bbr->pacing_gain = bbr_drain_gain;        /* slow, to drain */
                bbr->cwnd_gain         = bbr_high_gain;        /* keep cwnd */
                break;
        case BBR_PROBE_BW:
                bbr->pacing_gain = (bbr->lt_use_bw ?
                                    BBR_UNIT :
                                    bbr_pacing_gain[bbr->cycle_idx]);
                bbr->cwnd_gain         = bbr_cwnd_gain;
                break;
        case BBR_PROBE_RTT:
                bbr->pacing_gain = BBR_UNIT;
                bbr->cwnd_gain         = BBR_UNIT;
                break;
        default:
                WARN_ONCE(1, "BBR bad mode: %u\n", bbr->mode);
                break;
        }
}

static void bbr_update_model(struct sock *sk, const struct rate_sample *rs)
{
        bbr_update_bw(sk, rs);
        bbr_update_ack_aggregation(sk, rs);
        bbr_update_cycle_phase(sk, rs);
        bbr_check_full_bw_reached(sk, rs);
        bbr_check_drain(sk, rs);
        bbr_update_min_rtt(sk, rs);
        bbr_update_gains(sk);
}

__bpf_kfunc static void bbr_main(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs)
{
        struct bbr *bbr = inet_csk_ca(sk);
        u32 bw;

        bbr_update_model(sk, rs);

        bw = bbr_bw(sk);
        bbr_set_pacing_rate(sk, bw, bbr->pacing_gain);
        bbr_set_cwnd(sk, rs, rs->acked_sacked, bw, bbr->cwnd_gain);
}

__bpf_kfunc static void bbr_init(struct sock *sk)
{
        struct tcp_sock *tp = tcp_sk(sk);
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->prior_cwnd = 0;
        tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
        bbr->rtt_cnt = 0;
        bbr->next_rtt_delivered = tp->delivered;
        bbr->prev_ca_state = TCP_CA_Open;
        bbr->packet_conservation = 0;

        bbr->probe_rtt_done_stamp = 0;
        bbr->probe_rtt_round_done = 0;
        bbr->min_rtt_us = tcp_min_rtt(tp);
        bbr->min_rtt_stamp = tcp_jiffies32;

        minmax_reset(&bbr->bw, bbr->rtt_cnt, 0);  /* init max bw to 0 */

        bbr->has_seen_rtt = 0;
        bbr_init_pacing_rate_from_rtt(sk);

        bbr->round_start = 0;
        bbr->idle_restart = 0;
        bbr->full_bw_reached = 0;
        bbr->full_bw = 0;
        bbr->full_bw_cnt = 0;
        bbr->cycle_mstamp = 0;
        bbr->cycle_idx = 0;
        bbr_reset_lt_bw_sampling(sk);
        bbr_reset_startup_mode(sk);

        bbr->ack_epoch_mstamp = tp->tcp_mstamp;
        bbr->ack_epoch_acked = 0;
        bbr->extra_acked_win_rtts = 0;
        bbr->extra_acked_win_idx = 0;
        bbr->extra_acked[0] = 0;
        bbr->extra_acked[1] = 0;

        cmpxchg(&sk->sk_pacing_status, SK_PACING_NONE, SK_PACING_NEEDED);
}

__bpf_kfunc static u32 bbr_sndbuf_expand(struct sock *sk)
{
        /* Provision 3 * cwnd since BBR may slow-start even during recovery. */
        return 3;
}

/* In theory BBR does not need to undo the cwnd since it does not
 * always reduce cwnd on losses (see bbr_main()). Keep it for now.
 */
__bpf_kfunc static u32 bbr_undo_cwnd(struct sock *sk)
{
        struct bbr *bbr = inet_csk_ca(sk);

        bbr->full_bw = 0;   /* spurious slow-down; reset full pipe detection */
        bbr->full_bw_cnt = 0;
        bbr_reset_lt_bw_sampling(sk);
        return tcp_snd_cwnd(tcp_sk(sk));
}

/* Entering loss recovery, so save cwnd for when we exit or undo recovery. */
__bpf_kfunc static u32 bbr_ssthresh(struct sock *sk)
{
        bbr_save_cwnd(sk);
        return tcp_sk(sk)->snd_ssthresh;
}

static size_t bbr_get_info(struct sock *sk, u32 ext, int *attr,
                           union tcp_cc_info *info)
{
        if (ext & (1 << (INET_DIAG_BBRINFO - 1)) ||
            ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
                struct tcp_sock *tp = tcp_sk(sk);
                struct bbr *bbr = inet_csk_ca(sk);
                u64 bw = bbr_bw(sk);

                bw = bw * tp->mss_cache * USEC_PER_SEC >> BW_SCALE;
                memset(&info->bbr, 0, sizeof(info->bbr));
                info->bbr.bbr_bw_lo                = (u32)bw;
                info->bbr.bbr_bw_hi                = (u32)(bw >> 32);
                info->bbr.bbr_min_rtt                = bbr->min_rtt_us;
                info->bbr.bbr_pacing_gain        = bbr->pacing_gain;
                info->bbr.bbr_cwnd_gain                = bbr->cwnd_gain;
                *attr = INET_DIAG_BBRINFO;
                return sizeof(info->bbr);
        }
        return 0;
}

__bpf_kfunc static void bbr_set_state(struct sock *sk, u8 new_state)
{
        struct bbr *bbr = inet_csk_ca(sk);

        if (new_state == TCP_CA_Loss) {
                struct rate_sample rs = { .losses = 1 };

                bbr->prev_ca_state = TCP_CA_Loss;
                bbr->full_bw = 0;
                bbr->round_start = 1;        /* treat RTO like end of a round */
                bbr_lt_bw_sampling(sk, &rs);
        }
}

static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = {
        .flags                = TCP_CONG_NON_RESTRICTED,
        .name                = "bbr",
        .owner                = THIS_MODULE,
        .init                = bbr_init,
        .cong_control        = bbr_main,
        .sndbuf_expand        = bbr_sndbuf_expand,
        .undo_cwnd        = bbr_undo_cwnd,
        .cwnd_event        = bbr_cwnd_event,
        .ssthresh        = bbr_ssthresh,
        .min_tso_segs        = bbr_min_tso_segs,
        .get_info        = bbr_get_info,
        .set_state        = bbr_set_state,
};

BTF_KFUNCS_START(tcp_bbr_check_kfunc_ids)
BTF_ID_FLAGS(func, bbr_init)
BTF_ID_FLAGS(func, bbr_main)
BTF_ID_FLAGS(func, bbr_sndbuf_expand)
BTF_ID_FLAGS(func, bbr_undo_cwnd)
BTF_ID_FLAGS(func, bbr_cwnd_event)
BTF_ID_FLAGS(func, bbr_ssthresh)
BTF_ID_FLAGS(func, bbr_min_tso_segs)
BTF_ID_FLAGS(func, bbr_set_state)
BTF_KFUNCS_END(tcp_bbr_check_kfunc_ids)

static const struct btf_kfunc_id_set tcp_bbr_kfunc_set = {
        .owner = THIS_MODULE,
        .set   = &tcp_bbr_check_kfunc_ids,
};

static int __init bbr_register(void)
{
        int ret;

        BUILD_BUG_ON(sizeof(struct bbr) > ICSK_CA_PRIV_SIZE);

        ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &tcp_bbr_kfunc_set);
        if (ret < 0)
                return ret;
        return tcp_register_congestion_control(&tcp_bbr_cong_ops);
}

static void __exit bbr_unregister(void)
{
        tcp_unregister_congestion_control(&tcp_bbr_cong_ops);
}

module_init(bbr_register);
module_exit(bbr_unregister);

MODULE_AUTHOR("Van Jacobson <vanj@google.com>");
MODULE_AUTHOR("Neal Cardwell <ncardwell@google.com>");
MODULE_AUTHOR("Yuchung Cheng <ycheng@google.com>");
MODULE_AUTHOR("Soheil Hassas Yeganeh <soheil@google.com>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("TCP BBR (Bottleneck Bandwidth and RTT)");











































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// SPDX-License-Identifier: GPL-2.0
/*
 * fs/ext4/verity.c: fs-verity support for ext4
 *
 * Copyright 2019 Google LLC
 */

/*
 * Implementation of fsverity_operations for ext4.
 *
 * ext4 stores the verity metadata (Merkle tree and fsverity_descriptor) past
 * the end of the file, starting at the first 64K boundary beyond i_size.  This
 * approach works because (a) verity files are readonly, and (b) pages fully
 * beyond i_size aren't visible to userspace but can be read/written internally
 * by ext4 with only some relatively small changes to ext4.  This approach
 * avoids having to depend on the EA_INODE feature and on rearchitecturing
 * ext4's xattr support to support paging multi-gigabyte xattrs into memory, and
 * to support encrypting xattrs.  Note that the verity metadata *must* be
 * encrypted when the file is, since it contains hashes of the plaintext data.
 *
 * Using a 64K boundary rather than a 4K one keeps things ready for
 * architectures with 64K pages, and it doesn't necessarily waste space on-disk
 * since there can be a hole between i_size and the start of the Merkle tree.
 */

#include <linux/quotaops.h>

#include "ext4.h"
#include "ext4_extents.h"
#include "ext4_jbd2.h"

static inline loff_t ext4_verity_metadata_pos(const struct inode *inode)
{
        return round_up(inode->i_size, 65536);
}

/*
 * Read some verity metadata from the inode.  __vfs_read() can't be used because
 * we need to read beyond i_size.
 */
static int pagecache_read(struct inode *inode, void *buf, size_t count,
                          loff_t pos)
{
        while (count) {
                struct folio *folio;
                size_t n;

                folio = read_mapping_folio(inode->i_mapping, pos >> PAGE_SHIFT,
                                         NULL);
                if (IS_ERR(folio))
                        return PTR_ERR(folio);

                n = memcpy_from_file_folio(buf, folio, pos, count);
                folio_put(folio);

                buf += n;
                pos += n;
                count -= n;
        }
        return 0;
}

/*
 * Write some verity metadata to the inode for FS_IOC_ENABLE_VERITY.
 * kernel_write() can't be used because the file descriptor is readonly.
 */
static int pagecache_write(struct inode *inode, const void *buf, size_t count,
                           loff_t pos)
{
        struct address_space *mapping = inode->i_mapping;
        const struct address_space_operations *aops = mapping->a_ops;

        if (pos + count > inode->i_sb->s_maxbytes)
                return -EFBIG;

        while (count) {
                size_t n = min_t(size_t, count,
                                 PAGE_SIZE - offset_in_page(pos));
                struct folio *folio;
                void *fsdata = NULL;
                int res;

                res = aops->write_begin(NULL, mapping, pos, n, &folio, &fsdata);
                if (res)
                        return res;

                memcpy_to_folio(folio, offset_in_folio(folio, pos), buf, n);

                res = aops->write_end(NULL, mapping, pos, n, n, folio, fsdata);
                if (res < 0)
                        return res;
                if (res != n)
                        return -EIO;

                buf += n;
                pos += n;
                count -= n;
        }
        return 0;
}

static int ext4_begin_enable_verity(struct file *filp)
{
        struct inode *inode = file_inode(filp);
        const int credits = 2; /* superblock and inode for ext4_orphan_add() */
        handle_t *handle;
        int err;

        if (IS_DAX(inode) || ext4_test_inode_flag(inode, EXT4_INODE_DAX))
                return -EINVAL;

        if (ext4_verity_in_progress(inode))
                return -EBUSY;

        /*
         * Since the file was opened readonly, we have to initialize the jbd
         * inode and quotas here and not rely on ->open() doing it.  This must
         * be done before evicting the inline data.
         */

        err = ext4_inode_attach_jinode(inode);
        if (err)
                return err;

        err = dquot_initialize(inode);
        if (err)
                return err;

        err = ext4_convert_inline_data(inode);
        if (err)
                return err;

        if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
                ext4_warning_inode(inode,
                                   "verity is only allowed on extent-based files");
                return -EOPNOTSUPP;
        }

        /*
         * ext4 uses the last allocated block to find the verity descriptor, so
         * we must remove any other blocks past EOF which might confuse things.
         */
        err = ext4_truncate(inode);
        if (err)
                return err;

        handle = ext4_journal_start(inode, EXT4_HT_INODE, credits);
        if (IS_ERR(handle))
                return PTR_ERR(handle);

        err = ext4_orphan_add(handle, inode);
        if (err == 0)
                ext4_set_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);

        ext4_journal_stop(handle);
        return err;
}

/*
 * ext4 stores the verity descriptor beginning on the next filesystem block
 * boundary after the Merkle tree.  Then, the descriptor size is stored in the
 * last 4 bytes of the last allocated filesystem block --- which is either the
 * block in which the descriptor ends, or the next block after that if there
 * weren't at least 4 bytes remaining.
 *
 * We can't simply store the descriptor in an xattr because it *must* be
 * encrypted when ext4 encryption is used, but ext4 encryption doesn't encrypt
 * xattrs.  Also, if the descriptor includes a large signature blob it may be
 * too large to store in an xattr without the EA_INODE feature.
 */
static int ext4_write_verity_descriptor(struct inode *inode, const void *desc,
                                        size_t desc_size, u64 merkle_tree_size)
{
        const u64 desc_pos = round_up(ext4_verity_metadata_pos(inode) +
                                      merkle_tree_size, i_blocksize(inode));
        const u64 desc_end = desc_pos + desc_size;
        const __le32 desc_size_disk = cpu_to_le32(desc_size);
        const u64 desc_size_pos = round_up(desc_end + sizeof(desc_size_disk),
                                           i_blocksize(inode)) -
                                  sizeof(desc_size_disk);
        int err;

        err = pagecache_write(inode, desc, desc_size, desc_pos);
        if (err)
                return err;

        return pagecache_write(inode, &desc_size_disk, sizeof(desc_size_disk),
                               desc_size_pos);
}

static int ext4_end_enable_verity(struct file *filp, const void *desc,
                                  size_t desc_size, u64 merkle_tree_size)
{
        struct inode *inode = file_inode(filp);
        const int credits = 2; /* superblock and inode for ext4_orphan_del() */
        handle_t *handle;
        struct ext4_iloc iloc;
        int err = 0;

        /*
         * If an error already occurred (which fs/verity/ signals by passing
         * desc == NULL), then only clean-up is needed.
         */
        if (desc == NULL)
                goto cleanup;

        /* Append the verity descriptor. */
        err = ext4_write_verity_descriptor(inode, desc, desc_size,
                                           merkle_tree_size);
        if (err)
                goto cleanup;

        /*
         * Write all pages (both data and verity metadata).  Note that this must
         * happen before clearing EXT4_STATE_VERITY_IN_PROGRESS; otherwise pages
         * beyond i_size won't be written properly.  For crash consistency, this
         * also must happen before the verity inode flag gets persisted.
         */
        err = filemap_write_and_wait(inode->i_mapping);
        if (err)
                goto cleanup;

        /*
         * Finally, set the verity inode flag and remove the inode from the
         * orphan list (in a single transaction).
         */

        handle = ext4_journal_start(inode, EXT4_HT_INODE, credits);
        if (IS_ERR(handle)) {
                err = PTR_ERR(handle);
                goto cleanup;
        }

        err = ext4_orphan_del(handle, inode);
        if (err)
                goto stop_and_cleanup;

        err = ext4_reserve_inode_write(handle, inode, &iloc);
        if (err)
                goto stop_and_cleanup;

        ext4_set_inode_flag(inode, EXT4_INODE_VERITY);
        ext4_set_inode_flags(inode, false);
        err = ext4_mark_iloc_dirty(handle, inode, &iloc);
        if (err)
                goto stop_and_cleanup;

        ext4_journal_stop(handle);

        ext4_clear_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
        return 0;

stop_and_cleanup:
        ext4_journal_stop(handle);
cleanup:
        /*
         * Verity failed to be enabled, so clean up by truncating any verity
         * metadata that was written beyond i_size (both from cache and from
         * disk), removing the inode from the orphan list (if it wasn't done
         * already), and clearing EXT4_STATE_VERITY_IN_PROGRESS.
         */
        truncate_inode_pages(inode->i_mapping, inode->i_size);
        ext4_truncate(inode);
        ext4_orphan_del(NULL, inode);
        ext4_clear_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
        return err;
}

static int ext4_get_verity_descriptor_location(struct inode *inode,
                                               size_t *desc_size_ret,
                                               u64 *desc_pos_ret)
{
        struct ext4_ext_path *path;
        struct ext4_extent *last_extent;
        u32 end_lblk;
        u64 desc_size_pos;
        __le32 desc_size_disk;
        u32 desc_size;
        u64 desc_pos;
        int err;

        /*
         * Descriptor size is in last 4 bytes of last allocated block.
         * See ext4_write_verity_descriptor().
         */

        if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
                EXT4_ERROR_INODE(inode, "verity file doesn't use extents");
                return -EFSCORRUPTED;
        }

        path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
        if (IS_ERR(path))
                return PTR_ERR(path);

        last_extent = path[path->p_depth].p_ext;
        if (!last_extent) {
                EXT4_ERROR_INODE(inode, "verity file has no extents");
                ext4_free_ext_path(path);
                return -EFSCORRUPTED;
        }

        end_lblk = le32_to_cpu(last_extent->ee_block) +
                   ext4_ext_get_actual_len(last_extent);
        desc_size_pos = (u64)end_lblk << inode->i_blkbits;
        ext4_free_ext_path(path);

        if (desc_size_pos < sizeof(desc_size_disk))
                goto bad;
        desc_size_pos -= sizeof(desc_size_disk);

        err = pagecache_read(inode, &desc_size_disk, sizeof(desc_size_disk),
                             desc_size_pos);
        if (err)
                return err;
        desc_size = le32_to_cpu(desc_size_disk);

        /*
         * The descriptor is stored just before the desc_size_disk, but starting
         * on a filesystem block boundary.
         */

        if (desc_size > INT_MAX || desc_size > desc_size_pos)
                goto bad;

        desc_pos = round_down(desc_size_pos - desc_size, i_blocksize(inode));
        if (desc_pos < ext4_verity_metadata_pos(inode))
                goto bad;

        *desc_size_ret = desc_size;
        *desc_pos_ret = desc_pos;
        return 0;

bad:
        EXT4_ERROR_INODE(inode, "verity file corrupted; can't find descriptor");
        return -EFSCORRUPTED;
}

static int ext4_get_verity_descriptor(struct inode *inode, void *buf,
                                      size_t buf_size)
{
        size_t desc_size = 0;
        u64 desc_pos = 0;
        int err;

        err = ext4_get_verity_descriptor_location(inode, &desc_size, &desc_pos);
        if (err)
                return err;

        if (buf_size) {
                if (desc_size > buf_size)
                        return -ERANGE;
                err = pagecache_read(inode, buf, desc_size, desc_pos);
                if (err)
                        return err;
        }
        return desc_size;
}

static struct page *ext4_read_merkle_tree_page(struct inode *inode,
                                               pgoff_t index,
                                               unsigned long num_ra_pages)
{
        struct folio *folio;

        index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT;

        folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);
        if (IS_ERR(folio) || !folio_test_uptodate(folio)) {
                DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);

                if (!IS_ERR(folio))
                        folio_put(folio);
                else if (num_ra_pages > 1)
                        page_cache_ra_unbounded(&ractl, num_ra_pages, 0);
                folio = read_mapping_folio(inode->i_mapping, index, NULL);
                if (IS_ERR(folio))
                        return ERR_CAST(folio);
        }
        return folio_file_page(folio, index);
}

static int ext4_write_merkle_tree_block(struct inode *inode, const void *buf,
                                        u64 pos, unsigned int size)
{
        pos += ext4_verity_metadata_pos(inode);

        return pagecache_write(inode, buf, size, pos);
}

const struct fsverity_operations ext4_verityops = {
        .inode_info_offs        = (int)offsetof(struct ext4_inode_info, i_verity_info) -
                                  (int)offsetof(struct ext4_inode_info, vfs_inode),
        .begin_enable_verity        = ext4_begin_enable_verity,
        .end_enable_verity        = ext4_end_enable_verity,
        .get_verity_descriptor        = ext4_get_verity_descriptor,
        .read_merkle_tree_page        = ext4_read_merkle_tree_page,
        .write_merkle_tree_block = ext4_write_merkle_tree_block,
};























































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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_STRINGHASH_H
#define __LINUX_STRINGHASH_H

#include <linux/compiler.h>        /* For __pure */
#include <linux/types.h>        /* For u32, u64 */
#include <linux/hash.h>

/*
 * Routines for hashing strings of bytes to a 32-bit hash value.
 *
 * These hash functions are NOT GUARANTEED STABLE between kernel
 * versions, architectures, or even repeated boots of the same kernel.
 * (E.g. they may depend on boot-time hardware detection or be
 * deliberately randomized.)
 *
 * They are also not intended to be secure against collisions caused by
 * malicious inputs; much slower hash functions are required for that.
 *
 * They are optimized for pathname components, meaning short strings.
 * Even if a majority of files have longer names, the dynamic profile of
 * pathname components skews short due to short directory names.
 * (E.g. /usr/lib/libsesquipedalianism.so.3.141.)
 */

/*
 * Version 1: one byte at a time.  Example of use:
 *
 * unsigned long hash = init_name_hash;
 * while (*p)
 *        hash = partial_name_hash(tolower(*p++), hash);
 * hash = end_name_hash(hash);
 *
 * Although this is designed for bytes, fs/hfsplus/unicode.c
 * abuses it to hash 16-bit values.
 */

/* Hash courtesy of the R5 hash in reiserfs modulo sign bits */
#define init_name_hash(salt)                (unsigned long)(salt)

/* partial hash update function. Assume roughly 4 bits per character */
static inline unsigned long
partial_name_hash(unsigned long c, unsigned long prevhash)
{
        return (prevhash + (c << 4) + (c >> 4)) * 11;
}

/*
 * Finally: cut down the number of bits to a int value (and try to avoid
 * losing bits).  This also has the property (wanted by the dcache)
 * that the msbits make a good hash table index.
 */
static inline unsigned int end_name_hash(unsigned long hash)
{
        return hash_long(hash, 32);
}

/*
 * Version 2: One word (32 or 64 bits) at a time.
 * If CONFIG_DCACHE_WORD_ACCESS is defined (meaning <asm/word-at-a-time.h>
 * exists, which describes major Linux platforms like x86 and ARM), then
 * this computes a different hash function much faster.
 *
 * If not set, this falls back to a wrapper around the preceding.
 */
extern unsigned int __pure full_name_hash(const void *salt, const char *, unsigned int);

/*
 * A hash_len is a u64 with the hash of a string in the low
 * half and the length in the high half.
 */
#define hashlen_hash(hashlen) ((u32)(hashlen))
#define hashlen_len(hashlen)  ((u32)((hashlen) >> 32))
#define hashlen_create(hash, len) ((u64)(len)<<32 | (u32)(hash))

/* Return the "hash_len" (hash and length) of a null-terminated string */
extern u64 __pure hashlen_string(const void *salt, const char *name);

#endif        /* __LINUX_STRINGHASH_H */





























































































































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// SPDX-License-Identifier: GPL-2.0-only
/*
 * Kernel Connection Multiplexor
 *
 * Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
 */

#include <linux/bpf.h>
#include <linux/errno.h>
#include <linux/errqueue.h>
#include <linux/file.h>
#include <linux/filter.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/poll.h>
#include <linux/rculist.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/splice.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>
#include <linux/syscalls.h>
#include <linux/sched/signal.h>

#include <net/kcm.h>
#include <net/netns/generic.h>
#include <net/sock.h>
#include <uapi/linux/kcm.h>
#include <trace/events/sock.h>

unsigned int kcm_net_id;

static struct kmem_cache *kcm_psockp __read_mostly;
static struct kmem_cache *kcm_muxp __read_mostly;
static struct workqueue_struct *kcm_wq;

static inline struct kcm_sock *kcm_sk(const struct sock *sk)
{
        return (struct kcm_sock *)sk;
}

static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb)
{
        return (struct kcm_tx_msg *)skb->cb;
}

static void report_csk_error(struct sock *csk, int err)
{
        csk->sk_err = EPIPE;
        sk_error_report(csk);
}

static void kcm_abort_tx_psock(struct kcm_psock *psock, int err,
                               bool wakeup_kcm)
{
        struct sock *csk = psock->sk;
        struct kcm_mux *mux = psock->mux;

        /* Unrecoverable error in transmit */

        spin_lock_bh(&mux->lock);

        if (psock->tx_stopped) {
                spin_unlock_bh(&mux->lock);
                return;
        }

        psock->tx_stopped = 1;
        KCM_STATS_INCR(psock->stats.tx_aborts);

        if (!psock->tx_kcm) {
                /* Take off psocks_avail list */
                list_del(&psock->psock_avail_list);
        } else if (wakeup_kcm) {
                /* In this case psock is being aborted while outside of
                 * write_msgs and psock is reserved. Schedule tx_work
                 * to handle the failure there. Need to commit tx_stopped
                 * before queuing work.
                 */
                smp_mb();

                queue_work(kcm_wq, &psock->tx_kcm->tx_work);
        }

        spin_unlock_bh(&mux->lock);

        /* Report error on lower socket */
        report_csk_error(csk, err);
}

/* RX mux lock held. */
static void kcm_update_rx_mux_stats(struct kcm_mux *mux,
                                    struct kcm_psock *psock)
{
        STRP_STATS_ADD(mux->stats.rx_bytes,
                       psock->strp.stats.bytes -
                       psock->saved_rx_bytes);
        mux->stats.rx_msgs +=
                psock->strp.stats.msgs - psock->saved_rx_msgs;
        psock->saved_rx_msgs = psock->strp.stats.msgs;
        psock->saved_rx_bytes = psock->strp.stats.bytes;
}

static void kcm_update_tx_mux_stats(struct kcm_mux *mux,
                                    struct kcm_psock *psock)
{
        KCM_STATS_ADD(mux->stats.tx_bytes,
                      psock->stats.tx_bytes - psock->saved_tx_bytes);
        mux->stats.tx_msgs +=
                psock->stats.tx_msgs - psock->saved_tx_msgs;
        psock->saved_tx_msgs = psock->stats.tx_msgs;
        psock->saved_tx_bytes = psock->stats.tx_bytes;
}

static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);

/* KCM is ready to receive messages on its queue-- either the KCM is new or
 * has become unblocked after being blocked on full socket buffer. Queue any
 * pending ready messages on a psock. RX mux lock held.
 */
static void kcm_rcv_ready(struct kcm_sock *kcm)
{
        struct kcm_mux *mux = kcm->mux;
        struct kcm_psock *psock;
        struct sk_buff *skb;

        if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled))
                return;

        while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) {
                if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
                        /* Assuming buffer limit has been reached */
                        skb_queue_head(&mux->rx_hold_queue, skb);
                        WARN_ON(!sk_rmem_alloc_get(&kcm->sk));
                        return;
                }
        }

        while (!list_empty(&mux->psocks_ready)) {
                psock = list_first_entry(&mux->psocks_ready, struct kcm_psock,
                                         psock_ready_list);

                if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) {
                        /* Assuming buffer limit has been reached */
                        WARN_ON(!sk_rmem_alloc_get(&kcm->sk));
                        return;
                }

                /* Consumed the ready message on the psock. Schedule rx_work to
                 * get more messages.
                 */
                list_del(&psock->psock_ready_list);
                psock->ready_rx_msg = NULL;
                /* Commit clearing of ready_rx_msg for queuing work */
                smp_mb();

                strp_unpause(&psock->strp);
                strp_check_rcv(&psock->strp);
        }

        /* Buffer limit is okay now, add to ready list */
        list_add_tail(&kcm->wait_rx_list,
                      &kcm->mux->kcm_rx_waiters);
        /* paired with lockless reads in kcm_rfree() */
        WRITE_ONCE(kcm->rx_wait, true);
}

static void kcm_rfree(struct sk_buff *skb)
{
        struct sock *sk = skb->sk;
        struct kcm_sock *kcm = kcm_sk(sk);
        struct kcm_mux *mux = kcm->mux;
        unsigned int len = skb->truesize;

        sk_mem_uncharge(sk, len);
        atomic_sub(len, &sk->sk_rmem_alloc);

        /* For reading rx_wait and rx_psock without holding lock */
        smp_mb__after_atomic();

        if (!READ_ONCE(kcm->rx_wait) && !READ_ONCE(kcm->rx_psock) &&
            sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) {
                spin_lock_bh(&mux->rx_lock);
                kcm_rcv_ready(kcm);
                spin_unlock_bh(&mux->rx_lock);
        }
}

static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
        struct sk_buff_head *list = &sk->sk_receive_queue;

        if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
                return -ENOMEM;

        if (!sk_rmem_schedule(sk, skb, skb->truesize))
                return -ENOBUFS;

        skb->dev = NULL;

        skb_orphan(skb);
        skb->sk = sk;
        skb->destructor = kcm_rfree;
        atomic_add(skb->truesize, &sk->sk_rmem_alloc);
        sk_mem_charge(sk, skb->truesize);

        skb_queue_tail(list, skb);

        if (!sock_flag(sk, SOCK_DEAD))
                sk->sk_data_ready(sk);

        return 0;
}

/* Requeue received messages for a kcm socket to other kcm sockets. This is
 * called with a kcm socket is receive disabled.
 * RX mux lock held.
 */
static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head)
{
        struct sk_buff *skb;
        struct kcm_sock *kcm;

        while ((skb = skb_dequeue(head))) {
                /* Reset destructor to avoid calling kcm_rcv_ready */
                skb->destructor = sock_rfree;
                skb_orphan(skb);
try_again:
                if (list_empty(&mux->kcm_rx_waiters)) {
                        skb_queue_tail(&mux->rx_hold_queue, skb);
                        continue;
                }

                kcm = list_first_entry(&mux->kcm_rx_waiters,
                                       struct kcm_sock, wait_rx_list);

                if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
                        /* Should mean socket buffer full */
                        list_del(&kcm->wait_rx_list);
                        /* paired with lockless reads in kcm_rfree() */
                        WRITE_ONCE(kcm->rx_wait, false);

                        /* Commit rx_wait to read in kcm_free */
                        smp_wmb();

                        goto try_again;
                }
        }
}

/* Lower sock lock held */
static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock,
                                       struct sk_buff *head)
{
        struct kcm_mux *mux = psock->mux;
        struct kcm_sock *kcm;

        WARN_ON(psock->ready_rx_msg);

        if (psock->rx_kcm)
                return psock->rx_kcm;

        spin_lock_bh(&mux->rx_lock);

        if (psock->rx_kcm) {
                spin_unlock_bh(&mux->rx_lock);
                return psock->rx_kcm;
        }

        kcm_update_rx_mux_stats(mux, psock);

        if (list_empty(&mux->kcm_rx_waiters)) {
                psock->ready_rx_msg = head;
                strp_pause(&psock->strp);
                list_add_tail(&psock->psock_ready_list,
                              &mux->psocks_ready);
                spin_unlock_bh(&mux->rx_lock);
                return NULL;
        }

        kcm = list_first_entry(&mux->kcm_rx_waiters,
                               struct kcm_sock, wait_rx_list);
        list_del(&kcm->wait_rx_list);
        /* paired with lockless reads in kcm_rfree() */
        WRITE_ONCE(kcm->rx_wait, false);

        psock->rx_kcm = kcm;
        /* paired with lockless reads in kcm_rfree() */
        WRITE_ONCE(kcm->rx_psock, psock);

        spin_unlock_bh(&mux->rx_lock);

        return kcm;
}

static void kcm_done(struct kcm_sock *kcm);

static void kcm_done_work(struct work_struct *w)
{
        kcm_done(container_of(w, struct kcm_sock, done_work));
}

/* Lower sock held */
static void unreserve_rx_kcm(struct kcm_psock *psock,
                             bool rcv_ready)
{
        struct kcm_sock *kcm = psock->rx_kcm;
        struct kcm_mux *mux = psock->mux;

        if (!kcm)
                return;

        spin_lock_bh(&mux->rx_lock);

        psock->rx_kcm = NULL;
        /* paired with lockless reads in kcm_rfree() */
        WRITE_ONCE(kcm->rx_psock, NULL);

        /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with
         * kcm_rfree
         */
        smp_mb();

        if (unlikely(kcm->done)) {
                spin_unlock_bh(&mux->rx_lock);

                /* Need to run kcm_done in a task since we need to qcquire
                 * callback locks which may already be held here.
                 */
                INIT_WORK(&kcm->done_work, kcm_done_work);
                schedule_work(&kcm->done_work);
                return;
        }

        if (unlikely(kcm->rx_disabled)) {
                requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue);
        } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) {
                /* Check for degenerative race with rx_wait that all
                 * data was dequeued (accounted for in kcm_rfree).
                 */
                kcm_rcv_ready(kcm);
        }
        spin_unlock_bh(&mux->rx_lock);
}

/* Lower sock lock held */
static void psock_data_ready(struct sock *sk)
{
        struct kcm_psock *psock;

        trace_sk_data_ready(sk);

        read_lock_bh(&sk->sk_callback_lock);

        psock = (struct kcm_psock *)sk->sk_user_data;
        if (likely(psock))
                strp_data_ready(&psock->strp);

        read_unlock_bh(&sk->sk_callback_lock);
}

/* Called with lower sock held */
static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb)
{
        struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
        struct kcm_sock *kcm;

try_queue:
        kcm = reserve_rx_kcm(psock, skb);
        if (!kcm) {
                 /* Unable to reserve a KCM, message is held in psock and strp
                  * is paused.
                  */
                return;
        }

        if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
                /* Should mean socket buffer full */
                unreserve_rx_kcm(psock, false);
                goto try_queue;
        }
}

static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb)
{
        struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
        struct bpf_prog *prog = psock->bpf_prog;
        int res;

        res = bpf_prog_run_pin_on_cpu(prog, skb);
        return res;
}

static int kcm_read_sock_done(struct strparser *strp, int err)
{
        struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);

        unreserve_rx_kcm(psock, true);

        return err;
}

static void psock_state_change(struct sock *sk)
{
        /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here
         * since application will normally not poll with EPOLLIN
         * on the TCP sockets.
         */

        report_csk_error(sk, EPIPE);
}

static void psock_write_space(struct sock *sk)
{
        struct kcm_psock *psock;
        struct kcm_mux *mux;
        struct kcm_sock *kcm;

        read_lock_bh(&sk->sk_callback_lock);

        psock = (struct kcm_psock *)sk->sk_user_data;
        if (unlikely(!psock))
                goto out;
        mux = psock->mux;

        spin_lock_bh(&mux->lock);

        /* Check if the socket is reserved so someone is waiting for sending. */
        kcm = psock->tx_kcm;
        if (kcm)
                queue_work(kcm_wq, &kcm->tx_work);

        spin_unlock_bh(&mux->lock);
out:
        read_unlock_bh(&sk->sk_callback_lock);
}

static void unreserve_psock(struct kcm_sock *kcm);

/* kcm sock is locked. */
static struct kcm_psock *reserve_psock(struct kcm_sock *kcm)
{
        struct kcm_mux *mux = kcm->mux;
        struct kcm_psock *psock;

        psock = kcm->tx_psock;

        smp_rmb(); /* Must read tx_psock before tx_wait */

        if (psock) {
                WARN_ON(kcm->tx_wait);
                if (unlikely(psock->tx_stopped))
                        unreserve_psock(kcm);
                else
                        return kcm->tx_psock;
        }

        spin_lock_bh(&mux->lock);

        /* Check again under lock to see if psock was reserved for this
         * psock via psock_unreserve.
         */
        psock = kcm->tx_psock;
        if (unlikely(psock)) {
                WARN_ON(kcm->tx_wait);
                spin_unlock_bh(&mux->lock);
                return kcm->tx_psock;
        }

        if (!list_empty(&mux->psocks_avail)) {
                psock = list_first_entry(&mux->psocks_avail,
                                         struct kcm_psock,
                                         psock_avail_list);
                list_del(&psock->psock_avail_list);
                if (kcm->tx_wait) {
                        list_del(&kcm->wait_psock_list);
                        kcm->tx_wait = false;
                }
                kcm->tx_psock = psock;
                psock->tx_kcm = kcm;
                KCM_STATS_INCR(psock->stats.reserved);
        } else if (!kcm->tx_wait) {
                list_add_tail(&kcm->wait_psock_list,
                              &mux->kcm_tx_waiters);
                kcm->tx_wait = true;
        }

        spin_unlock_bh(&mux->lock);

        return psock;
}

/* mux lock held */
static void psock_now_avail(struct kcm_psock *psock)
{
        struct kcm_mux *mux = psock->mux;
        struct kcm_sock *kcm;

        if (list_empty(&mux->kcm_tx_waiters)) {
                list_add_tail(&psock->psock_avail_list,
                              &mux->psocks_avail);
        } else {
                kcm = list_first_entry(&mux->kcm_tx_waiters,
                                       struct kcm_sock,
                                       wait_psock_list);
                list_del(&kcm->wait_psock_list);
                kcm->tx_wait = false;
                psock->tx_kcm = kcm;

                /* Commit before changing tx_psock since that is read in
                 * reserve_psock before queuing work.
                 */
                smp_mb();

                kcm->tx_psock = psock;
                KCM_STATS_INCR(psock->stats.reserved);
                queue_work(kcm_wq, &kcm->tx_work);
        }
}

/* kcm sock is locked. */
static void unreserve_psock(struct kcm_sock *kcm)
{
        struct kcm_psock *psock;
        struct kcm_mux *mux = kcm->mux;

        spin_lock_bh(&mux->lock);

        psock = kcm->tx_psock;

        if (WARN_ON(!psock)) {
                spin_unlock_bh(&mux->lock);
                return;
        }

        smp_rmb(); /* Read tx_psock before tx_wait */

        kcm_update_tx_mux_stats(mux, psock);

        WARN_ON(kcm->tx_wait);

        kcm->tx_psock = NULL;
        psock->tx_kcm = NULL;
        KCM_STATS_INCR(psock->stats.unreserved);

        if (unlikely(psock->tx_stopped)) {
                if (psock->done) {
                        /* Deferred free */
                        list_del(&psock->psock_list);
                        mux->psocks_cnt--;
                        sock_put(psock->sk);
                        fput(psock->sk->sk_socket->file);
                        kmem_cache_free(kcm_psockp, psock);
                }

                /* Don't put back on available list */

                spin_unlock_bh(&mux->lock);

                return;
        }

        psock_now_avail(psock);

        spin_unlock_bh(&mux->lock);
}

static void kcm_report_tx_retry(struct kcm_sock *kcm)
{
        struct kcm_mux *mux = kcm->mux;

        spin_lock_bh(&mux->lock);
        KCM_STATS_INCR(mux->stats.tx_retries);
        spin_unlock_bh(&mux->lock);
}

/* Write any messages ready on the kcm socket.  Called with kcm sock lock
 * held.  Return bytes actually sent or error.
 */
static int kcm_write_msgs(struct kcm_sock *kcm)
{
        unsigned int total_sent = 0;
        struct sock *sk = &kcm->sk;
        struct kcm_psock *psock;
        struct sk_buff *head;
        int ret = 0;

        kcm->tx_wait_more = false;
        psock = kcm->tx_psock;
        if (unlikely(psock && psock->tx_stopped)) {
                /* A reserved psock was aborted asynchronously. Unreserve
                 * it and we'll retry the message.
                 */
                unreserve_psock(kcm);
                kcm_report_tx_retry(kcm);
                if (skb_queue_empty(&sk->sk_write_queue))
                        return 0;

                kcm_tx_msg(skb_peek(&sk->sk_write_queue))->started_tx = false;
        }

retry:
        while ((head = skb_peek(&sk->sk_write_queue))) {
                struct msghdr msg = {
                        .msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES,
                };
                struct kcm_tx_msg *txm = kcm_tx_msg(head);
                struct sk_buff *skb;
                unsigned int msize;
                int i;

                if (!txm->started_tx) {
                        psock = reserve_psock(kcm);
                        if (!psock)
                                goto out;
                        skb = head;
                        txm->frag_offset = 0;
                        txm->sent = 0;
                        txm->started_tx = true;
                } else {
                        if (WARN_ON(!psock)) {
                                ret = -EINVAL;
                                goto out;
                        }
                        skb = txm->frag_skb;
                }

                if (WARN_ON(!skb_shinfo(skb)->nr_frags) ||
                    WARN_ON_ONCE(!skb_frag_page(&skb_shinfo(skb)->frags[0]))) {
                        ret = -EINVAL;
                        goto out;
                }

                msize = 0;
                for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
                        msize += skb_frag_size(&skb_shinfo(skb)->frags[i]);

                iov_iter_bvec(&msg.msg_iter, ITER_SOURCE,
                              (const struct bio_vec *)skb_shinfo(skb)->frags,
                              skb_shinfo(skb)->nr_frags, msize);
                iov_iter_advance(&msg.msg_iter, txm->frag_offset);

                do {
                        ret = sock_sendmsg(psock->sk->sk_socket, &msg);
                        if (ret <= 0) {
                                if (ret == -EAGAIN) {
                                        /* Save state to try again when there's
                                         * write space on the socket
                                         */
                                        txm->frag_skb = skb;
                                        ret = 0;
                                        goto out;
                                }

                                /* Hard failure in sending message, abort this
                                 * psock since it has lost framing
                                 * synchronization and retry sending the
                                 * message from the beginning.
                                 */
                                kcm_abort_tx_psock(psock, ret ? -ret : EPIPE,
                                                   true);
                                unreserve_psock(kcm);
                                psock = NULL;

                                txm->started_tx = false;
                                kcm_report_tx_retry(kcm);
                                ret = 0;
                                goto retry;
                        }

                        txm->sent += ret;
                        txm->frag_offset += ret;
                        KCM_STATS_ADD(psock->stats.tx_bytes, ret);
                } while (msg.msg_iter.count > 0);

                if (skb == head) {
                        if (skb_has_frag_list(skb)) {
                                txm->frag_skb = skb_shinfo(skb)->frag_list;
                                txm->frag_offset = 0;
                                continue;
                        }
                } else if (skb->next) {
                        txm->frag_skb = skb->next;
                        txm->frag_offset = 0;
                        continue;
                }

                /* Successfully sent the whole packet, account for it. */
                sk->sk_wmem_queued -= txm->sent;
                total_sent += txm->sent;
                skb_dequeue(&sk->sk_write_queue);
                kfree_skb(head);
                KCM_STATS_INCR(psock->stats.tx_msgs);
        }
out:
        if (!head) {
                /* Done with all queued messages. */
                WARN_ON(!skb_queue_empty(&sk->sk_write_queue));
                if (psock)
                        unreserve_psock(kcm);
        }

        /* Check if write space is available */
        sk->sk_write_space(sk);

        return total_sent ? : ret;
}

static void kcm_tx_work(struct work_struct *w)
{
        struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work);
        struct sock *sk = &kcm->sk;
        int err;

        lock_sock(sk);

        /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx
         * aborts
         */
        err = kcm_write_msgs(kcm);
        if (err < 0) {
                /* Hard failure in write, report error on KCM socket */
                pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err);
                report_csk_error(&kcm->sk, -err);
                goto out;
        }

        /* Primarily for SOCK_SEQPACKET sockets */
        if (likely(sk->sk_socket) &&
            test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
                clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
                sk->sk_write_space(sk);
        }

out:
        release_sock(sk);
}

static void kcm_push(struct kcm_sock *kcm)
{
        if (kcm->tx_wait_more)
                kcm_write_msgs(kcm);
}

static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
        struct sock *sk = sock->sk;
        struct kcm_sock *kcm = kcm_sk(sk);
        struct sk_buff *skb = NULL, *head = NULL;
        size_t copy, copied = 0;
        long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
        int eor = (sock->type == SOCK_DGRAM) ?
                  !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR);
        int err = -EPIPE;

        mutex_lock(&kcm->tx_mutex);
        lock_sock(sk);

        /* Per tcp_sendmsg this should be in poll */
        sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);

        if (sk->sk_err)
                goto out_error;

        if (kcm->seq_skb) {
                /* Previously opened message */
                head = kcm->seq_skb;
                skb = kcm_tx_msg(head)->last_skb;
                goto start;
        }

        /* Call the sk_stream functions to manage the sndbuf mem. */
        if (!sk_stream_memory_free(sk)) {
                kcm_push(kcm);
                set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
                err = sk_stream_wait_memory(sk, &timeo);
                if (err)
                        goto out_error;
        }

        if (msg_data_left(msg)) {
                /* New message, alloc head skb */
                head = alloc_skb(0, sk->sk_allocation);
                while (!head) {
                        kcm_push(kcm);
                        err = sk_stream_wait_memory(sk, &timeo);
                        if (err)
                                goto out_error;

                        head = alloc_skb(0, sk->sk_allocation);
                }

                skb = head;

                /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling
                 * csum_and_copy_from_iter from skb_do_copy_data_nocache.
                 */
                skb->ip_summed = CHECKSUM_UNNECESSARY;
        }

start:
        while (msg_data_left(msg)) {
                bool merge = true;
                int i = skb_shinfo(skb)->nr_frags;
                struct page_frag *pfrag = sk_page_frag(sk);

                if (!sk_page_frag_refill(sk, pfrag))
                        goto wait_for_memory;

                if (!skb_can_coalesce(skb, i, pfrag->page,
                                      pfrag->offset)) {
                        if (i == MAX_SKB_FRAGS) {
                                struct sk_buff *tskb;

                                tskb = alloc_skb(0, sk->sk_allocation);
                                if (!tskb)
                                        goto wait_for_memory;

                                if (head == skb)
                                        skb_shinfo(head)->frag_list = tskb;
                                else
                                        skb->next = tskb;

                                skb = tskb;
                                skb->ip_summed = CHECKSUM_UNNECESSARY;
                                continue;
                        }
                        merge = false;
                }

                if (msg->msg_flags & MSG_SPLICE_PAGES) {
                        copy = msg_data_left(msg);
                        if (!sk_wmem_schedule(sk, copy))
                                goto wait_for_memory;

                        err = skb_splice_from_iter(skb, &msg->msg_iter, copy);
                        if (err < 0) {
                                if (err == -EMSGSIZE)
                                        goto wait_for_memory;
                                goto out_error;
                        }

                        copy = err;
                        skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
                        sk_wmem_queued_add(sk, copy);
                        sk_mem_charge(sk, copy);

                        if (head != skb)
                                head->truesize += copy;
                } else {
                        copy = min_t(int, msg_data_left(msg),
                                     pfrag->size - pfrag->offset);
                        if (!sk_wmem_schedule(sk, copy))
                                goto wait_for_memory;

                        err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
                                                       pfrag->page,
                                                       pfrag->offset,
                                                       copy);
                        if (err)
                                goto out_error;

                        /* Update the skb. */
                        if (merge) {
                                skb_frag_size_add(
                                        &skb_shinfo(skb)->frags[i - 1], copy);
                        } else {
                                skb_fill_page_desc(skb, i, pfrag->page,
                                                   pfrag->offset, copy);
                                get_page(pfrag->page);
                        }

                        pfrag->offset += copy;
                }

                copied += copy;
                if (head != skb) {
                        head->len += copy;
                        head->data_len += copy;
                }

                continue;

wait_for_memory:
                kcm_push(kcm);
                err = sk_stream_wait_memory(sk, &timeo);
                if (err)
                        goto out_error;
        }

        if (eor) {
                bool not_busy = skb_queue_empty(&sk->sk_write_queue);

                if (head) {
                        /* Message complete, queue it on send buffer */
                        __skb_queue_tail(&sk->sk_write_queue, head);
                        kcm->seq_skb = NULL;
                        KCM_STATS_INCR(kcm->stats.tx_msgs);
                }

                if (msg->msg_flags & MSG_BATCH) {
                        kcm->tx_wait_more = true;
                } else if (kcm->tx_wait_more || not_busy) {
                        err = kcm_write_msgs(kcm);
                        if (err < 0) {
                                /* We got a hard error in write_msgs but have
                                 * already queued this message. Report an error
                                 * in the socket, but don't affect return value
                                 * from sendmsg
                                 */
                                pr_warn("KCM: Hard failure on kcm_write_msgs\n");
                                report_csk_error(&kcm->sk, -err);
                        }
                }
        } else {
                /* Message not complete, save state */
partial_message:
                if (head) {
                        kcm->seq_skb = head;
                        kcm_tx_msg(head)->last_skb = skb;
                }
        }

        KCM_STATS_ADD(kcm->stats.tx_bytes, copied);

        release_sock(sk);
        mutex_unlock(&kcm->tx_mutex);
        return copied;

out_error:
        kcm_push(kcm);

        if (sock->type == SOCK_SEQPACKET) {
                /* Wrote some bytes before encountering an
                 * error, return partial success.
                 */
                if (copied)
                        goto partial_message;
                if (head != kcm->seq_skb)
                        kfree_skb(head);
        } else {
                kfree_skb(head);
                kcm->seq_skb = NULL;
        }

        err = sk_stream_error(sk, msg->msg_flags, err);

        /* make sure we wake any epoll edge trigger waiter */
        if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
                sk->sk_write_space(sk);

        release_sock(sk);
        mutex_unlock(&kcm->tx_mutex);
        return err;
}

static void kcm_splice_eof(struct socket *sock)
{
        struct sock *sk = sock->sk;
        struct kcm_sock *kcm = kcm_sk(sk);

        if (skb_queue_empty_lockless(&sk->sk_write_queue))
                return;

        lock_sock(sk);
        kcm_write_msgs(kcm);
        release_sock(sk);
}

static int kcm_recvmsg(struct socket *sock, struct msghdr *msg,
                       size_t len, int flags)
{
        struct sock *sk = sock->sk;
        struct kcm_sock *kcm = kcm_sk(sk);
        int err = 0;
        struct strp_msg *stm;
        int copied = 0;
        struct sk_buff *skb;

        skb = skb_recv_datagram(sk, flags, &err);
        if (!skb)
                goto out;

        /* Okay, have a message on the receive queue */

        stm = strp_msg(skb);

        if (len > stm->full_len)
                len = stm->full_len;

        err = skb_copy_datagram_msg(skb, stm->offset, msg, len);
        if (err < 0)
                goto out;

        copied = len;
        if (likely(!(flags & MSG_PEEK))) {
                KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
                if (copied < stm->full_len) {
                        if (sock->type == SOCK_DGRAM) {
                                /* Truncated message */
                                msg->msg_flags |= MSG_TRUNC;
                                goto msg_finished;
                        }
                        stm->offset += copied;
                        stm->full_len -= copied;
                } else {
msg_finished:
                        /* Finished with message */
                        msg->msg_flags |= MSG_EOR;
                        KCM_STATS_INCR(kcm->stats.rx_msgs);
                }
        }

out:
        skb_free_datagram(sk, skb);
        return copied ? : err;
}

static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
                               struct pipe_inode_info *pipe, size_t len,
                               unsigned int flags)
{
        struct sock *sk = sock->sk;
        struct kcm_sock *kcm = kcm_sk(sk);
        struct strp_msg *stm;
        int err = 0;
        ssize_t copied;
        struct sk_buff *skb;

        if (sock->file->f_flags & O_NONBLOCK || flags & SPLICE_F_NONBLOCK)
                flags = MSG_DONTWAIT;
        else
                flags = 0;

        /* Only support splice for SOCKSEQPACKET */

        skb = skb_recv_datagram(sk, flags, &err);
        if (!skb)
                goto err_out;

        /* Okay, have a message on the receive queue */

        stm = strp_msg(skb);

        if (len > stm->full_len)
                len = stm->full_len;

        copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags);
        if (copied < 0) {
                err = copied;
                goto err_out;
        }

        KCM_STATS_ADD(kcm->stats.rx_bytes, copied);

        stm->offset += copied;
        stm->full_len -= copied;

        /* We have no way to return MSG_EOR. If all the bytes have been
         * read we still leave the message in the receive socket buffer.
         * A subsequent recvmsg needs to be done to return MSG_EOR and
         * finish reading the message.
         */

        skb_free_datagram(sk, skb);
        return copied;

err_out:
        skb_free_datagram(sk, skb);
        return err;
}

/* kcm sock lock held */
static void kcm_recv_disable(struct kcm_sock *kcm)
{
        struct kcm_mux *mux = kcm->mux;

        if (kcm->rx_disabled)
                return;

        spin_lock_bh(&mux->rx_lock);

        kcm->rx_disabled = 1;

        /* If a psock is reserved we'll do cleanup in unreserve */
        if (!kcm->rx_psock) {
                if (kcm->rx_wait) {
                        list_del(&kcm->wait_rx_list);
                        /* paired with lockless reads in kcm_rfree() */
                        WRITE_ONCE(kcm->rx_wait, false);
                }

                requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue);
        }

        spin_unlock_bh(&mux->rx_lock);
}

/* kcm sock lock held */
static void kcm_recv_enable(struct kcm_sock *kcm)
{
        struct kcm_mux *mux = kcm->mux;

        if (!kcm->rx_disabled)
                return;

        spin_lock_bh(&mux->rx_lock);

        kcm->rx_disabled = 0;
        kcm_rcv_ready(kcm);

        spin_unlock_bh(&mux->rx_lock);
}

static int kcm_setsockopt(struct socket *sock, int level, int optname,
                          sockptr_t optval, unsigned int optlen)
{
        struct kcm_sock *kcm = kcm_sk(sock->sk);
        int val, valbool;
        int err = 0;

        if (level != SOL_KCM)
                return -ENOPROTOOPT;

        if (optlen < sizeof(int))
                return -EINVAL;

        if (copy_from_sockptr(&val, optval, sizeof(int)))
                return -EFAULT;

        valbool = val ? 1 : 0;

        switch (optname) {
        case KCM_RECV_DISABLE:
                lock_sock(&kcm->sk);
                if (valbool)
                        kcm_recv_disable(kcm);
                else
                        kcm_recv_enable(kcm);
                release_sock(&kcm->sk);
                break;
        default:
                err = -ENOPROTOOPT;
        }

        return err;
}

static int kcm_getsockopt(struct socket *sock, int level, int optname,
                          char __user *optval, int __user *optlen)
{
        struct kcm_sock *kcm = kcm_sk(sock->sk);
        int val, len;

        if (level != SOL_KCM)
                return -ENOPROTOOPT;

        if (get_user(len, optlen))
                return -EFAULT;

        if (len < 0)
                return -EINVAL;

        len = min_t(unsigned int, len, sizeof(int));

        switch (optname) {
        case KCM_RECV_DISABLE:
                val = kcm->rx_disabled;
                break;
        default:
                return -ENOPROTOOPT;
        }

        if (put_user(len, optlen))
                return -EFAULT;
        if (copy_to_user(optval, &val, len))
                return -EFAULT;
        return 0;
}

static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux)
{
        struct kcm_sock *tkcm;
        struct list_head *head;
        int index = 0;

        /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so
         * we set sk_state, otherwise epoll_wait always returns right away with
         * EPOLLHUP
         */
        kcm->sk.sk_state = TCP_ESTABLISHED;

        /* Add to mux's kcm sockets list */
        kcm->mux = mux;
        spin_lock_bh(&mux->lock);

        head = &mux->kcm_socks;
        list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) {
                if (tkcm->index != index)
                        break;
                head = &tkcm->kcm_sock_list;
                index++;
        }

        list_add(&kcm->kcm_sock_list, head);
        kcm->index = index;

        mux->kcm_socks_cnt++;
        spin_unlock_bh(&mux->lock);

        INIT_WORK(&kcm->tx_work, kcm_tx_work);
        mutex_init(&kcm->tx_mutex);

        spin_lock_bh(&mux->rx_lock);
        kcm_rcv_ready(kcm);
        spin_unlock_bh(&mux->rx_lock);
}

static int kcm_attach(struct socket *sock, struct socket *csock,
                      struct bpf_prog *prog)
{
        struct kcm_sock *kcm = kcm_sk(sock->sk);
        struct kcm_mux *mux = kcm->mux;
        struct sock *csk;
        struct kcm_psock *psock = NULL, *tpsock;
        struct list_head *head;
        int index = 0;
        static const struct strp_callbacks cb = {
                .rcv_msg = kcm_rcv_strparser,
                .parse_msg = kcm_parse_func_strparser,
                .read_sock_done = kcm_read_sock_done,
        };
        int err = 0;

        csk = csock->sk;
        if (!csk)
                return -EINVAL;

        lock_sock(csk);

        /* Only allow TCP sockets to be attached for now */
        if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) ||
            csk->sk_protocol != IPPROTO_TCP) {
                err = -EOPNOTSUPP;
                goto out;
        }

        /* Don't allow listeners or closed sockets */
        if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) {
                err = -EOPNOTSUPP;
                goto out;
        }

        psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL);
        if (!psock) {
                err = -ENOMEM;
                goto out;
        }

        psock->mux = mux;
        psock->sk = csk;
        psock->bpf_prog = prog;

        write_lock_bh(&csk->sk_callback_lock);

        /* Check if sk_user_data is already by KCM or someone else.
         * Must be done under lock to prevent race conditions.
         */
        if (csk->sk_user_data) {
                write_unlock_bh(&csk->sk_callback_lock);
                kmem_cache_free(kcm_psockp, psock);
                err = -EALREADY;
                goto out;
        }

        err = strp_init(&psock->strp, csk, &cb);
        if (err) {
                write_unlock_bh(&csk->sk_callback_lock);
                kmem_cache_free(kcm_psockp, psock);
                goto out;
        }

        psock->save_data_ready = csk->sk_data_ready;
        psock->save_write_space = csk->sk_write_space;
        psock->save_state_change = csk->sk_state_change;
        csk->sk_user_data = psock;
        csk->sk_data_ready = psock_data_ready;
        csk->sk_write_space = psock_write_space;
        csk->sk_state_change = psock_state_change;

        write_unlock_bh(&csk->sk_callback_lock);

        sock_hold(csk);

        /* Finished initialization, now add the psock to the MUX. */
        spin_lock_bh(&mux->lock);
        head = &mux->psocks;
        list_for_each_entry(tpsock, &mux->psocks, psock_list) {
                if (tpsock->index != index)
                        break;
                head = &tpsock->psock_list;
                index++;
        }

        list_add(&psock->psock_list, head);
        psock->index = index;

        KCM_STATS_INCR(mux->stats.psock_attach);
        mux->psocks_cnt++;
        psock_now_avail(psock);
        spin_unlock_bh(&mux->lock);

        /* Schedule RX work in case there are already bytes queued */
        strp_check_rcv(&psock->strp);

out:
        release_sock(csk);

        return err;
}

static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info)
{
        struct socket *csock;
        struct bpf_prog *prog;
        int err;

        csock = sockfd_lookup(info->fd, &err);
        if (!csock)
                return -ENOENT;

        prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER);
        if (IS_ERR(prog)) {
                err = PTR_ERR(prog);
                goto out;
        }

        err = kcm_attach(sock, csock, prog);
        if (err) {
                bpf_prog_put(prog);
                goto out;
        }

        /* Keep reference on file also */

        return 0;
out:
        sockfd_put(csock);
        return err;
}

static void kcm_unattach(struct kcm_psock *psock)
{
        struct sock *csk = psock->sk;
        struct kcm_mux *mux = psock->mux;

        lock_sock(csk);

        /* Stop getting callbacks from TCP socket. After this there should
         * be no way to reserve a kcm for this psock.
         */
        write_lock_bh(&csk->sk_callback_lock);
        csk->sk_user_data = NULL;
        csk->sk_data_ready = psock->save_data_ready;
        csk->sk_write_space = psock->save_write_space;
        csk->sk_state_change = psock->save_state_change;
        strp_stop(&psock->strp);

        if (WARN_ON(psock->rx_kcm)) {
                write_unlock_bh(&csk->sk_callback_lock);
                release_sock(csk);
                return;
        }

        spin_lock_bh(&mux->rx_lock);

        /* Stop receiver activities. After this point psock should not be
         * able to get onto ready list either through callbacks or work.
         */
        if (psock->ready_rx_msg) {
                list_del(&psock->psock_ready_list);
                kfree_skb(psock->ready_rx_msg);
                psock->ready_rx_msg = NULL;
                KCM_STATS_INCR(mux->stats.rx_ready_drops);
        }

        spin_unlock_bh(&mux->rx_lock);

        write_unlock_bh(&csk->sk_callback_lock);

        /* Call strp_done without sock lock */
        release_sock(csk);
        strp_done(&psock->strp);
        lock_sock(csk);

        bpf_prog_put(psock->bpf_prog);

        spin_lock_bh(&mux->lock);

        aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats);
        save_strp_stats(&psock->strp, &mux->aggregate_strp_stats);

        KCM_STATS_INCR(mux->stats.psock_unattach);

        if (psock->tx_kcm) {
                /* psock was reserved.  Just mark it finished and we will clean
                 * up in the kcm paths, we need kcm lock which can not be
                 * acquired here.
                 */
                KCM_STATS_INCR(mux->stats.psock_unattach_rsvd);
                spin_unlock_bh(&mux->lock);

                /* We are unattaching a socket that is reserved. Abort the
                 * socket since we may be out of sync in sending on it. We need
                 * to do this without the mux lock.
                 */
                kcm_abort_tx_psock(psock, EPIPE, false);

                spin_lock_bh(&mux->lock);
                if (!psock->tx_kcm) {
                        /* psock now unreserved in window mux was unlocked */
                        goto no_reserved;
                }
                psock->done = 1;

                /* Commit done before queuing work to process it */
                smp_mb();

                /* Queue tx work to make sure psock->done is handled */
                queue_work(kcm_wq, &psock->tx_kcm->tx_work);
                spin_unlock_bh(&mux->lock);
        } else {
no_reserved:
                if (!psock->tx_stopped)
                        list_del(&psock->psock_avail_list);
                list_del(&psock->psock_list);
                mux->psocks_cnt--;
                spin_unlock_bh(&mux->lock);

                sock_put(csk);
                fput(csk->sk_socket->file);
                kmem_cache_free(kcm_psockp, psock);
        }

        release_sock(csk);
}

static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info)
{
        struct kcm_sock *kcm = kcm_sk(sock->sk);
        struct kcm_mux *mux = kcm->mux;
        struct kcm_psock *psock;
        struct socket *csock;
        struct sock *csk;
        int err;

        csock = sockfd_lookup(info->fd, &err);
        if (!csock)
                return -ENOENT;

        csk = csock->sk;
        if (!csk) {
                err = -EINVAL;
                goto out;
        }

        err = -ENOENT;

        spin_lock_bh(&mux->lock);

        list_for_each_entry(psock, &mux->psocks, psock_list) {
                if (psock->sk != csk)
                        continue;

                /* Found the matching psock */

                if (psock->unattaching || WARN_ON(psock->done)) {
                        err = -EALREADY;
                        break;
                }

                psock->unattaching = 1;

                spin_unlock_bh(&mux->lock);

                /* Lower socket lock should already be held */
                kcm_unattach(psock);

                err = 0;
                goto out;
        }

        spin_unlock_bh(&mux->lock);

out:
        sockfd_put(csock);
        return err;
}

static struct proto kcm_proto = {
        .name        = "KCM",
        .owner        = THIS_MODULE,
        .obj_size = sizeof(struct kcm_sock),
};

/* Clone a kcm socket. */
static struct file *kcm_clone(struct socket *osock)
{
        struct socket *newsock;
        struct sock *newsk;

        newsock = sock_alloc();
        if (!newsock)
                return ERR_PTR(-ENFILE);

        newsock->type = osock->type;
        newsock->ops = osock->ops;

        __module_get(newsock->ops->owner);

        newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL,
                         &kcm_proto, false);
        if (!newsk) {
                sock_release(newsock);
                return ERR_PTR(-ENOMEM);
        }
        sock_init_data(newsock, newsk);
        init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux);

        return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name);
}

static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
        int err;

        switch (cmd) {
        case SIOCKCMATTACH: {
                struct kcm_attach info;

                if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
                        return -EFAULT;

                err = kcm_attach_ioctl(sock, &info);

                break;
        }
        case SIOCKCMUNATTACH: {
                struct kcm_unattach info;

                if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
                        return -EFAULT;

                err = kcm_unattach_ioctl(sock, &info);

                break;
        }
        case SIOCKCMCLONE: {
                struct kcm_clone info;
                struct file *file;

                info.fd = get_unused_fd_flags(0);
                if (unlikely(info.fd < 0))
                        return info.fd;

                file = kcm_clone(sock);
                if (IS_ERR(file)) {
                        put_unused_fd(info.fd);
                        return PTR_ERR(file);
                }
                if (copy_to_user((void __user *)arg, &info,
                                 sizeof(info))) {
                        put_unused_fd(info.fd);
                        fput(file);
                        return -EFAULT;
                }
                fd_install(info.fd, file);
                err = 0;
                break;
        }
        default:
                err = -ENOIOCTLCMD;
                break;
        }

        return err;
}

static void release_mux(struct kcm_mux *mux)
{
        struct kcm_net *knet = mux->knet;
        struct kcm_psock *psock, *tmp_psock;

        /* Release psocks */
        list_for_each_entry_safe(psock, tmp_psock,
                                 &mux->psocks, psock_list) {
                if (!WARN_ON(psock->unattaching))
                        kcm_unattach(psock);
        }

        if (WARN_ON(mux->psocks_cnt))
                return;

        __skb_queue_purge(&mux->rx_hold_queue);

        mutex_lock(&knet->mutex);
        aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats);
        aggregate_psock_stats(&mux->aggregate_psock_stats,
                              &knet->aggregate_psock_stats);
        aggregate_strp_stats(&mux->aggregate_strp_stats,
                             &knet->aggregate_strp_stats);
        list_del_rcu(&mux->kcm_mux_list);
        knet->count--;
        mutex_unlock(&knet->mutex);

        kfree_rcu(mux, rcu);
}

static void kcm_done(struct kcm_sock *kcm)
{
        struct kcm_mux *mux = kcm->mux;
        struct sock *sk = &kcm->sk;
        int socks_cnt;

        spin_lock_bh(&mux->rx_lock);
        if (kcm->rx_psock) {
                /* Cleanup in unreserve_rx_kcm */
                WARN_ON(kcm->done);
                kcm->rx_disabled = 1;
                kcm->done = 1;
                spin_unlock_bh(&mux->rx_lock);
                return;
        }

        if (kcm->rx_wait) {
                list_del(&kcm->wait_rx_list);
                /* paired with lockless reads in kcm_rfree() */
                WRITE_ONCE(kcm->rx_wait, false);
        }
        /* Move any pending receive messages to other kcm sockets */
        requeue_rx_msgs(mux, &sk->sk_receive_queue);

        spin_unlock_bh(&mux->rx_lock);

        if (WARN_ON(sk_rmem_alloc_get(sk)))
                return;

        /* Detach from MUX */
        spin_lock_bh(&mux->lock);

        list_del(&kcm->kcm_sock_list);
        mux->kcm_socks_cnt--;
        socks_cnt = mux->kcm_socks_cnt;

        spin_unlock_bh(&mux->lock);

        if (!socks_cnt) {
                /* We are done with the mux now. */
                release_mux(mux);
        }

        WARN_ON(kcm->rx_wait);

        sock_put(&kcm->sk);
}

/* Called by kcm_release to close a KCM socket.
 * If this is the last KCM socket on the MUX, destroy the MUX.
 */
static int kcm_release(struct socket *sock)
{
        struct sock *sk = sock->sk;
        struct kcm_sock *kcm;
        struct kcm_mux *mux;
        struct kcm_psock *psock;

        if (!sk)
                return 0;

        kcm = kcm_sk(sk);
        mux = kcm->mux;

        lock_sock(sk);
        sock_orphan(sk);
        kfree_skb(kcm->seq_skb);

        /* Purge queue under lock to avoid race condition with tx_work trying
         * to act when queue is nonempty. If tx_work runs after this point
         * it will just return.
         */
        __skb_queue_purge(&sk->sk_write_queue);

        release_sock(sk);

        spin_lock_bh(&mux->lock);
        if (kcm->tx_wait) {
                /* Take of tx_wait list, after this point there should be no way
                 * that a psock will be assigned to this kcm.
                 */
                list_del(&kcm->wait_psock_list);
                kcm->tx_wait = false;
        }
        spin_unlock_bh(&mux->lock);

        /* Cancel work. After this point there should be no outside references
         * to the kcm socket.
         */
        disable_work_sync(&kcm->tx_work);

        lock_sock(sk);
        psock = kcm->tx_psock;
        if (psock) {
                /* A psock was reserved, so we need to kill it since it
                 * may already have some bytes queued from a message. We
                 * need to do this after removing kcm from tx_wait list.
                 */
                kcm_abort_tx_psock(psock, EPIPE, false);
                unreserve_psock(kcm);
        }
        release_sock(sk);

        WARN_ON(kcm->tx_wait);
        WARN_ON(kcm->tx_psock);

        sock->sk = NULL;

        kcm_done(kcm);

        return 0;
}

static const struct proto_ops kcm_dgram_ops = {
        .family =        PF_KCM,
        .owner =        THIS_MODULE,
        .release =        kcm_release,
        .bind =                sock_no_bind,
        .connect =        sock_no_connect,
        .socketpair =        sock_no_socketpair,
        .accept =        sock_no_accept,
        .getname =        sock_no_getname,
        .poll =                datagram_poll,
        .ioctl =        kcm_ioctl,
        .listen =        sock_no_listen,
        .shutdown =        sock_no_shutdown,
        .setsockopt =        kcm_setsockopt,
        .getsockopt =        kcm_getsockopt,
        .sendmsg =        kcm_sendmsg,
        .recvmsg =        kcm_recvmsg,
        .mmap =                sock_no_mmap,
        .splice_eof =        kcm_splice_eof,
};

static const struct proto_ops kcm_seqpacket_ops = {
        .family =        PF_KCM,
        .owner =        THIS_MODULE,
        .release =        kcm_release,
        .bind =                sock_no_bind,
        .connect =        sock_no_connect,
        .socketpair =        sock_no_socketpair,
        .accept =        sock_no_accept,
        .getname =        sock_no_getname,
        .poll =                datagram_poll,
        .ioctl =        kcm_ioctl,
        .listen =        sock_no_listen,
        .shutdown =        sock_no_shutdown,
        .setsockopt =        kcm_setsockopt,
        .getsockopt =        kcm_getsockopt,
        .sendmsg =        kcm_sendmsg,
        .recvmsg =        kcm_recvmsg,
        .mmap =                sock_no_mmap,
        .splice_eof =        kcm_splice_eof,
        .splice_read =        kcm_splice_read,
};

/* Create proto operation for kcm sockets */
static int kcm_create(struct net *net, struct socket *sock,
                      int protocol, int kern)
{
        struct kcm_net *knet = net_generic(net, kcm_net_id);
        struct sock *sk;
        struct kcm_mux *mux;

        switch (sock->type) {
        case SOCK_DGRAM:
                sock->ops = &kcm_dgram_ops;
                break;
        case SOCK_SEQPACKET:
                sock->ops = &kcm_seqpacket_ops;
                break;
        default:
                return -ESOCKTNOSUPPORT;
        }

        if (protocol != KCMPROTO_CONNECTED)
                return -EPROTONOSUPPORT;

        sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern);
        if (!sk)
                return -ENOMEM;

        /* Allocate a kcm mux, shared between KCM sockets */
        mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL);
        if (!mux) {
                sk_free(sk);
                return -ENOMEM;
        }

        spin_lock_init(&mux->lock);
        spin_lock_init(&mux->rx_lock);
        INIT_LIST_HEAD(&mux->kcm_socks);
        INIT_LIST_HEAD(&mux->kcm_rx_waiters);
        INIT_LIST_HEAD(&mux->kcm_tx_waiters);

        INIT_LIST_HEAD(&mux->psocks);
        INIT_LIST_HEAD(&mux->psocks_ready);
        INIT_LIST_HEAD(&mux->psocks_avail);

        mux->knet = knet;

        /* Add new MUX to list */
        mutex_lock(&knet->mutex);
        list_add_rcu(&mux->kcm_mux_list, &knet->mux_list);
        knet->count++;
        mutex_unlock(&knet->mutex);

        skb_queue_head_init(&mux->rx_hold_queue);

        /* Init KCM socket */
        sock_init_data(sock, sk);
        init_kcm_sock(kcm_sk(sk), mux);

        return 0;
}

static const struct net_proto_family kcm_family_ops = {
        .family = PF_KCM,
        .create = kcm_create,
        .owner  = THIS_MODULE,
};

static __net_init int kcm_init_net(struct net *net)
{
        struct kcm_net *knet = net_generic(net, kcm_net_id);

        INIT_LIST_HEAD_RCU(&knet->mux_list);
        mutex_init(&knet->mutex);

        return 0;
}

static __net_exit void kcm_exit_net(struct net *net)
{
        struct kcm_net *knet = net_generic(net, kcm_net_id);

        /* All KCM sockets should be closed at this point, which should mean
         * that all multiplexors and psocks have been destroyed.
         */
        WARN_ON(!list_empty(&knet->mux_list));

        mutex_destroy(&knet->mutex);
}

static struct pernet_operations kcm_net_ops = {
        .init = kcm_init_net,
        .exit = kcm_exit_net,
        .id   = &kcm_net_id,
        .size = sizeof(struct kcm_net),
};

static int __init kcm_init(void)
{
        int err = -ENOMEM;

        kcm_muxp = KMEM_CACHE(kcm_mux, SLAB_HWCACHE_ALIGN);
        if (!kcm_muxp)
                goto fail;

        kcm_psockp = KMEM_CACHE(kcm_psock, SLAB_HWCACHE_ALIGN);
        if (!kcm_psockp)
                goto fail;

        kcm_wq = create_singlethread_workqueue("kkcmd");
        if (!kcm_wq)
                goto fail;

        err = proto_register(&kcm_proto, 1);
        if (err)
                goto fail;

        err = register_pernet_device(&kcm_net_ops);
        if (err)
                goto net_ops_fail;

        err = sock_register(&kcm_family_ops);
        if (err)
                goto sock_register_fail;

        err = kcm_proc_init();
        if (err)
                goto proc_init_fail;

        return 0;

proc_init_fail:
        sock_unregister(PF_KCM);

sock_register_fail:
        unregister_pernet_device(&kcm_net_ops);

net_ops_fail:
        proto_unregister(&kcm_proto);

fail:
        kmem_cache_destroy(kcm_muxp);
        kmem_cache_destroy(kcm_psockp);

        if (kcm_wq)
                destroy_workqueue(kcm_wq);

        return err;
}

static void __exit kcm_exit(void)
{
        kcm_proc_exit();
        sock_unregister(PF_KCM);
        unregister_pernet_device(&kcm_net_ops);
        proto_unregister(&kcm_proto);
        destroy_workqueue(kcm_wq);

        kmem_cache_destroy(kcm_muxp);
        kmem_cache_destroy(kcm_psockp);
}

module_init(kcm_init);
module_exit(kcm_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("KCM (Kernel Connection Multiplexor) sockets");
MODULE_ALIAS_NETPROTO(PF_KCM);


























































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   66 

   66 

   66 


















  318 







  310 
    8 






   80 

  240 











  259 



   46 

   14 










   93 






    1 


  295 


  317 













































   18 
    2 




   16 

    1 






























































 1958 





 1956 




  150 

   18 


  148 

   39 

  154 

   16 

  154 

    6 

   55 
  136 





















  379 









  378 








  379 




  375 









   15 

   15 
   15 





















  371 


  359 






   42 
    7 







  372 



















  406 

















  241 



  377 










  377 






  406 

  248 










  276 
   51 
















  401 
   11 









  408 

  408 


  408 
















  395 

   44 

   15 







  279 
  277 




  247 




  389 


   18 

















  409 



  242 
  282 

  376 
  158 




  407 




  405 










  405 

  409 



  404 
   67 


  266 
  371 









   47 














   56 
   56 

   56 







   96 







   16 
   47 








    8 




   14 

   14 

    4 
   11 


   13 
    2 

   14 




   71 







   79 

    4 




































   30 










   30 







   31 







   31 







   31 


   31 



















   31 




   31 
   31 











   28 
   12 






   31 








    4 



    4 



    2 



    2 



    2 
    4 






    4 








    4 


    4 









    4 



    4 































    2 





















  146 





  265 



  274 


























  156 




  303 
   20 






  311 











  241 









    7 
  238 
  236 
   10 

  240 






















    1 




    7 
    3 
    3 


















  174 
  124 
   23 






  196 





   53 
  166 


  171 

   11 








   67 
  151 

    2 






   22 
   12 













   90 
  150 












   10 
    6 
   61 










































   10 
  212 


















   49 




   30 







   30 




















  205 








   12 


   12 
   12 

















   60 



  104 


   50 










   24 

    4 




















   75 





   75 


   75 
















   75 


   74 
   75 


























   11 








   80 















   38 



   30 






































   25 









   20 




    7 






    5 














































































































   64 


   64 

   64 




























  218 





















































































































  197 


   12 


    3 



    6 













    1 

























  189 

    1 










  190 





    1 








    1 







   86 
  146 

  446 






  150 







   95 
  208 



  525 










  422 
  392 
  419 
   56 










  175 


   14 



    3 





   32 

   64 





















  217 












  216 


   43 

  218 







  218 
  173 



  203 

   12 






  206 


  205 

   43 







   79 
  196 



  196 





  168 




   14 
   80 





   31 
   49 



  176 
   75 


  188 










  186 








  196 







   74 

  192 


   92 
  197 


  191 
   15 


    6 
  196 


  110 



  257 
















  187 
  179 







    9 

   93 
  130 









   53 
  174 

  178 

  178 










   47 



   10 











   26 






    2 




   27 


    6 










   21 



    3 










   19 





   21 


















  217 







  197 

   60 






   41 




   40 























































  281 














  221 
   59 



  279 

    3 











  281 


   75 














   75 









  259 


















   15 
   17 







































    7 
   69 


    3 



















    3 


    3 














    3 


    3 

    3 








    3 

   19 















   20 









   20 
   19 


    2 




   20 




    3 





    3 









   46 







   46 


   47 





   47 





























   46 
    1 







   31 
   16 




   14 





   40 





   41 
    8 
   43 


   30 
   20 






   46 





   47 



























   47 


   45 



   47 








   47 




    5 



    1 

   27 








   13 
   23 

   13 
   25 










   24 












   24 
   24 



   24 




   24 


   22 







   11 


    1 










    1 


   24 


   24 




    4 
   20 

   13 
   24 



   24 
   24 











  356 



  104 



  368 

  368 







   61 









   61 






    5 


















   56 

   56 

   56 











    8 













    8 



    8 





    8 









   81 








    8 








   73 




   73 




   81 



















   65 


















    5 

   63 














   66 

   65 




   63 
    1 





    4 
   64 

































   66 






   66 




   66 





   66 















   66 



















   66 











  266 


























  266 






    2 

  267 
  267 

  266 

    1 
  264 
  267 






    1 





  267 
  266 




















  244 

   23 
















  243 
















  130 




  110 








   22 






   22 







    5 







    1 



   16 




   16 


    2 
   19 


   21 
    5 
   15 













   20 






    6 




  117 


  110 
   18 







  267 





















































    2 


  267 


   23 










  244 


  243 
  244 



  131 
  115 









  243 
    6 












   14 
   94 









   80 




   78 



   30 










   30 









   80 





   80 


   10 



    2 
   45 








  225 



























  225 
  224 













  112 
  138 














   24 















   24 






   24 
    8 
   24 























































































    4 






    4 





    4 






    4 





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