/src/haproxy/src/debug.c

Source (jump to first uncovered line)
/*
 * Process debugging functions.
 *
 * Copyright 2000-2019 Willy Tarreau <willy@haproxy.org>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */


#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#ifdef USE_EPOLL
#include <sys/epoll.h>
#endif

#include <haproxy/api.h>
#include <haproxy/applet.h>
#include <haproxy/buf.h>
#include <haproxy/cli.h>
#include <haproxy/clock.h>
#include <haproxy/debug.h>
#include <haproxy/fd.h>
#include <haproxy/global.h>
#include <haproxy/hlua.h>
#include <haproxy/http_ana.h>
#include <haproxy/log.h>
#include <haproxy/net_helper.h>
#include <haproxy/sc_strm.h>
#include <haproxy/stconn.h>
#include <haproxy/task.h>
#include <haproxy/thread.h>
#include <haproxy/time.h>
#include <haproxy/tools.h>
#include <import/ist.h>


/* The dump state is made of:
 *   - num_thread on the lowest 15 bits
 *   - a SYNC flag on bit 15 (waiting for sync start)
 *   - number of participating threads on bits 16-30
 * Initiating a dump consists in setting it to SYNC and incrementing the
 * num_thread part when entering the function. The first thread periodically
 * recounts active threads and compares it to the ready ones, and clears SYNC
 * and sets the number of participants to the value found, which serves as a
 * start signal. A thread finished dumping looks up the TID of the next active
 * thread after it and writes it in the lowest part. If there's none, it sets
 * the thread counter to the number of participants and resets that part,
 * which serves as an end-of-dump signal. All threads decrement the num_thread
 * part. Then all threads wait for the value to reach zero. Only used when
 * USE_THREAD_DUMP is set.
 */
#define THREAD_DUMP_TMASK     0x00007FFFU
#define THREAD_DUMP_FSYNC     0x00008000U
#define THREAD_DUMP_PMASK     0x7FFF0000U

volatile unsigned int thread_dump_state = 0;
unsigned int panic_started = 0;
unsigned int debug_commands_issued = 0;

/* dumps a backtrace of the current thread that is appended to buffer <buf>.
 * Lines are prefixed with the string <prefix> which may be empty (used for
 * indenting). It is recommended to use this at a function's tail so that
 * the function does not appear in the call stack. The <dump> argument
 * indicates what dump state to start from, and should usually be zero. It
 * may be among the following values:
 *   - 0: search usual callers before step 1, or directly jump to 2
 *   - 1: skip usual callers before step 2
 *   - 2: dump until polling loop, scheduler, or main() (excluded)
 *   - 3: end
 *   - 4-7: like 0 but stops *after* main.
 */
void ha_dump_backtrace(struct buffer *buf, const char *prefix, int dump)
{
  struct buffer bak;
  char pfx2[100];
  void *callers[100];
  int j, nptrs;
  const void *addr;

  nptrs = my_backtrace(callers, sizeof(callers)/sizeof(*callers));
  if (!nptrs)
    return;

  if (snprintf(pfx2, sizeof(pfx2), "%s| ", prefix) > sizeof(pfx2))
    pfx2[0] = 0;

  /* The call backtrace_symbols_fd(callers, nptrs, STDOUT_FILENO would
   * produce similar output to the following:
   */
  chunk_appendf(buf, "%scall trace(%d):\n", prefix, nptrs);
  for (j = 0; (j < nptrs || (dump & 3) < 2); j++) {
    if (j == nptrs && !(dump & 3)) {
      /* we failed to spot the starting point of the
       * dump, let's start over dumping everything we
       * have.
       */
      dump += 2;
      j = 0;
    }
    bak = *buf;
    dump_addr_and_bytes(buf, pfx2, callers[j], 8);
    addr = resolve_sym_name(buf, ": ", callers[j]);
    if ((dump & 3) == 0) {
      /* dump not started, will start *after*
       * ha_thread_dump_all_to_trash, ha_panic and ha_backtrace_to_stderr
       */
      if (addr == ha_thread_dump_all_to_trash || addr == ha_panic ||
          addr == ha_backtrace_to_stderr)
        dump++;
      *buf = bak;
      continue;
    }

    if ((dump & 3) == 1) {
      /* starting */
      if (addr == ha_thread_dump_all_to_trash || addr == ha_panic ||
          addr == ha_backtrace_to_stderr) {
        *buf = bak;
        continue;
      }
      dump++;
    }

    if ((dump & 3) == 2) {
      /* still dumping */
      if (dump == 6) {
        /* we only stop *after* main and we must send the LF */
        if (addr == main) {
          j = nptrs;
          dump++;
        }
      }
      else if (addr == run_poll_loop || addr == main || addr == run_tasks_from_lists) {
        dump++;
        *buf = bak;
        break;
      }
    }
    /* OK, line dumped */
    chunk_appendf(buf, "\n");
  }
}

/* dump a backtrace of current thread's stack to stderr. */
void ha_backtrace_to_stderr(void)
{
  char area[2048];
  struct buffer b = b_make(area, sizeof(area), 0, 0);

  ha_dump_backtrace(&b, "  ", 4);
  if (b.data)
    DISGUISE(write(2, b.area, b.data));
}

/* Dumps to the buffer some known information for the desired thread, and
 * optionally extra info for the current thread. The dump will be appended to
 * the buffer, so the caller is responsible for preliminary initializing it.
 * The calling thread ID needs to be passed in <calling_tid> to display a star
 * in front of the calling thread's line (usually it's tid). Any stuck thread
 * is also prefixed with a '>'.
 * It must be called under thread isolation.
 */
void ha_thread_dump(struct buffer *buf, int thr, int calling_tid)
{
  unsigned long thr_bit = ha_thread_info[thr].ltid_bit;
  unsigned long long p = ha_thread_ctx[thr].prev_cpu_time;
  unsigned long long n = now_cpu_time_thread(thr);
  int stuck = !!(ha_thread_ctx[thr].flags & TH_FL_STUCK);
  int tgrp  = ha_thread_info[thr].tgid;

  chunk_appendf(buf,
                "%c%cThread %-2u: id=0x%llx act=%d glob=%d wq=%d rq=%d tl=%d tlsz=%d rqsz=%d\n"
                "     %2u/%-2u   stuck=%d prof=%d",
                (thr == calling_tid) ? '*' : ' ', stuck ? '>' : ' ', thr + 1,
          ha_get_pthread_id(thr),
          thread_has_tasks(),
                !eb_is_empty(&ha_thread_ctx[thr].rqueue_shared),
                !eb_is_empty(&ha_thread_ctx[thr].timers),
                !eb_is_empty(&ha_thread_ctx[thr].rqueue),
                !(LIST_ISEMPTY(&ha_thread_ctx[thr].tasklets[TL_URGENT]) &&
      LIST_ISEMPTY(&ha_thread_ctx[thr].tasklets[TL_NORMAL]) &&
      LIST_ISEMPTY(&ha_thread_ctx[thr].tasklets[TL_BULK]) &&
      MT_LIST_ISEMPTY(&ha_thread_ctx[thr].shared_tasklet_list)),
                ha_thread_ctx[thr].tasks_in_list,
                ha_thread_ctx[thr].rq_total,
          ha_thread_info[thr].tgid, ha_thread_info[thr].ltid + 1,
                stuck,
                !!(th_ctx->flags & TH_FL_TASK_PROFILING));

  chunk_appendf(buf,
                " harmless=%d wantrdv=%d",
                !!(_HA_ATOMIC_LOAD(&ha_tgroup_ctx[tgrp-1].threads_harmless) & thr_bit),
                !!(th_ctx->flags & TH_FL_TASK_PROFILING));

  chunk_appendf(buf, "\n");
  chunk_appendf(buf, "             cpu_ns: poll=%llu now=%llu diff=%llu\n", p, n, n-p);

  /* this is the end of what we can dump from outside the current thread */

  if (thr != tid)
    return;

  chunk_appendf(buf, "             curr_task=");
  ha_task_dump(buf, th_ctx->current, "             ");

  if (stuck) {
    /* We only emit the backtrace for stuck threads in order not to
     * waste precious output buffer space with non-interesting data.
     * Please leave this as the last instruction in this function
     * so that the compiler uses tail merging and the current
     * function does not appear in the stack.
     */
    ha_dump_backtrace(buf, "             ", 0);
  }
}


/* dumps into the buffer some information related to task <task> (which may
 * either be a task or a tasklet, and prepend each line except the first one
 * with <pfx>. The buffer is only appended and the first output starts by the
 * pointer itself. The caller is responsible for making sure the task is not
 * going to vanish during the dump.
 */
void ha_task_dump(struct buffer *buf, const struct task *task, const char *pfx)
{
  const struct stream *s = NULL;
  const struct appctx __maybe_unused *appctx = NULL;
  struct hlua __maybe_unused *hlua = NULL;
  const struct stconn *sc;

  if (!task) {
    chunk_appendf(buf, "0\n");
    return;
  }

  if (TASK_IS_TASKLET(task))
    chunk_appendf(buf,
                  "%p (tasklet) calls=%u\n",
                  task,
                  task->calls);
  else
    chunk_appendf(buf,
                  "%p (task) calls=%u last=%llu%s\n",
                  task,
                  task->calls,
                  task->wake_date ? (unsigned long long)(now_mono_time() - task->wake_date) : 0,
                  task->wake_date ? " ns ago" : "");

  chunk_appendf(buf, "%s  fct=%p(", pfx, task->process);
  resolve_sym_name(buf, NULL, task->process);
  chunk_appendf(buf,") ctx=%p", task->context);

  if (task->process == task_run_applet && (appctx = task->context))
    chunk_appendf(buf, "(%s)\n", appctx->applet->name);
  else
    chunk_appendf(buf, "\n");

  if (task->process == process_stream && task->context)
    s = (struct stream *)task->context;
  else if (task->process == task_run_applet && task->context && (sc = appctx_sc((struct appctx *)task->context)))
    s = sc_strm(sc);
  else if (task->process == sc_conn_io_cb && task->context)
    s = sc_strm(((struct stconn *)task->context));

  if (s)
    stream_dump(buf, s, pfx, '\n');

#ifdef USE_LUA
  hlua = NULL;
  if (s && (hlua = s->hlua)) {
    chunk_appendf(buf, "%sCurrent executing Lua from a stream analyser -- ", pfx);
  }
  else if (task->process == hlua_process_task && (hlua = task->context)) {
    chunk_appendf(buf, "%sCurrent executing a Lua task -- ", pfx);
  }
  else if (task->process == task_run_applet && (appctx = task->context) &&
     (appctx->applet->fct == hlua_applet_tcp_fct)) {
    chunk_appendf(buf, "%sCurrent executing a Lua TCP service -- ", pfx);
  }
  else if (task->process == task_run_applet && (appctx = task->context) &&
     (appctx->applet->fct == hlua_applet_http_fct)) {
    chunk_appendf(buf, "%sCurrent executing a Lua HTTP service -- ", pfx);
  }

  if (hlua && hlua->T) {
    chunk_appendf(buf, "stack traceback:\n    ");
    append_prefixed_str(buf, hlua_traceback(hlua->T, "\n    "), pfx, '\n', 0);
    b_putchr(buf, '\n');
  }
  else
    b_putchr(buf, '\n');
#endif
}

/* This function dumps all profiling settings. It returns 0 if the output
 * buffer is full and it needs to be called again, otherwise non-zero.
 */
static int cli_io_handler_show_threads(struct appctx *appctx)
{
  struct stconn *sc = appctx_sc(appctx);
  int thr;

  if (unlikely(sc_ic(sc)->flags & CF_SHUTW))
    return 1;

  if (appctx->st0)
    thr = appctx->st1;
  else
    thr = 0;

  chunk_reset(&trash);
  ha_thread_dump_all_to_trash();

  if (applet_putchk(appctx, &trash) == -1) {
    /* failed, try again */
    appctx->st1 = thr;
    return 0;
  }
  return 1;
}

#if defined(HA_HAVE_DUMP_LIBS)
/* parse a "show libs" command. It returns 1 if it emits anything otherwise zero. */
static int debug_parse_cli_show_libs(char **args, char *payload, struct appctx *appctx, void *private)
{
  if (!cli_has_level(appctx, ACCESS_LVL_OPER))
    return 1;

  chunk_reset(&trash);
  if (dump_libs(&trash, 1))
    return cli_msg(appctx, LOG_INFO, trash.area);
  else
    return 0;
}
#endif

/* dumps a state of all threads into the trash and on fd #2, then aborts. */
void ha_panic()
{
  if (HA_ATOMIC_FETCH_ADD(&panic_started, 1) != 0) {
    /* a panic dump is already in progress, let's not disturb it,
     * we'll be called via signal DEBUGSIG. By returning we may be
     * able to leave a current signal handler (e.g. WDT) so that
     * this will ensure more reliable signal delivery.
     */
    return;
  }
  chunk_reset(&trash);
  chunk_appendf(&trash, "Thread %u is about to kill the process.\n", tid + 1);
  ha_thread_dump_all_to_trash();
  DISGUISE(write(2, trash.area, trash.data));
  for (;;)
    abort();
}

/* Complain with message <msg> on stderr. If <counter> is not NULL, it is
 * atomically incremented, and the message is only printed when the counter
 * was zero, so that the message is only printed once. <taint> is only checked
 * on bit 1, and will taint the process either for a bug (2) or warn (0).
 */
void complain(int *counter, const char *msg, int taint)
{
  if (counter && _HA_ATOMIC_FETCH_ADD(counter, 1))
    return;
  DISGUISE(write(2, msg, strlen(msg)));
  if (taint & 2)
    mark_tainted(TAINTED_BUG);
  else
    mark_tainted(TAINTED_WARN);
}

/* parse a "debug dev exit" command. It always returns 1, though it should never return. */
static int debug_parse_cli_exit(char **args, char *payload, struct appctx *appctx, void *private)
{
  int code = atoi(args[3]);

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  exit(code);
  return 1;
}

/* parse a "debug dev bug" command. It always returns 1, though it should never return.
 * Note: we make sure not to make the function static so that it appears in the trace.
 */
int debug_parse_cli_bug(char **args, char *payload, struct appctx *appctx, void *private)
{
  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  BUG_ON(one > zero);
  return 1;
}

/* parse a "debug dev warn" command. It always returns 1.
 * Note: we make sure not to make the function static so that it appears in the trace.
 */
int debug_parse_cli_warn(char **args, char *payload, struct appctx *appctx, void *private)
{
  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  WARN_ON(one > zero);
  return 1;
}

/* parse a "debug dev check" command. It always returns 1.
 * Note: we make sure not to make the function static so that it appears in the trace.
 */
int debug_parse_cli_check(char **args, char *payload, struct appctx *appctx, void *private)
{
  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  CHECK_IF(one > zero);
  return 1;
}

/* parse a "debug dev close" command. It always returns 1. */
static int debug_parse_cli_close(char **args, char *payload, struct appctx *appctx, void *private)
{
  int fd;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  if (!*args[3])
    return cli_err(appctx, "Missing file descriptor number.\n");

  fd = atoi(args[3]);
  if (fd < 0 || fd >= global.maxsock)
    return cli_err(appctx, "File descriptor out of range.\n");

  if (!fdtab[fd].owner)
    return cli_msg(appctx, LOG_INFO, "File descriptor was already closed.\n");

  _HA_ATOMIC_INC(&debug_commands_issued);
  fd_delete(fd);
  return 1;
}

/* this is meant to cause a deadlock when more than one task is running it or when run twice */
static struct task *debug_run_cli_deadlock(struct task *task, void *ctx, unsigned int state)
{
  static HA_SPINLOCK_T lock __maybe_unused;

  HA_SPIN_LOCK(OTHER_LOCK, &lock);
  return NULL;
}

/* parse a "debug dev deadlock" command. It always returns 1. */
static int debug_parse_cli_deadlock(char **args, char *payload, struct appctx *appctx, void *private)
{
  int tasks;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  for (tasks = atoi(args[3]); tasks > 0; tasks--) {
    struct task *t = task_new_on(tasks % global.nbthread);
    if (!t)
      continue;
    t->process = debug_run_cli_deadlock;
    t->context = NULL;
    task_wakeup(t, TASK_WOKEN_INIT);
  }

  return 1;
}

/* parse a "debug dev delay" command. It always returns 1. */
static int debug_parse_cli_delay(char **args, char *payload, struct appctx *appctx, void *private)
{
  int delay = atoi(args[3]);

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  usleep((long)delay * 1000);
  return 1;
}

/* parse a "debug dev log" command. It always returns 1. */
static int debug_parse_cli_log(char **args, char *payload, struct appctx *appctx, void *private)
{
  int arg;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  chunk_reset(&trash);
  for (arg = 3; *args[arg]; arg++) {
    if (arg > 3)
      chunk_strcat(&trash, " ");
    chunk_strcat(&trash, args[arg]);
  }

  send_log(NULL, LOG_INFO, "%s\n", trash.area);
  return 1;
}

/* parse a "debug dev loop" command. It always returns 1. */
static int debug_parse_cli_loop(char **args, char *payload, struct appctx *appctx, void *private)
{
  struct timeval deadline, curr;
  int loop = atoi(args[3]);

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  gettimeofday(&curr, NULL);
  tv_ms_add(&deadline, &curr, loop);

  while (tv_ms_cmp(&curr, &deadline) < 0)
    gettimeofday(&curr, NULL);

  return 1;
}

/* parse a "debug dev panic" command. It always returns 1, though it should never return. */
static int debug_parse_cli_panic(char **args, char *payload, struct appctx *appctx, void *private)
{
  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  ha_panic();
  return 1;
}

/* parse a "debug dev exec" command. It always returns 1. */
#if defined(DEBUG_DEV)
static int debug_parse_cli_exec(char **args, char *payload, struct appctx *appctx, void *private)
{
  int pipefd[2];
  int arg;
  int pid;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  _HA_ATOMIC_INC(&debug_commands_issued);
  chunk_reset(&trash);
  for (arg = 3; *args[arg]; arg++) {
    if (arg > 3)
      chunk_strcat(&trash, " ");
    chunk_strcat(&trash, args[arg]);
  }

  thread_isolate();
  if (pipe(pipefd) < 0)
    goto fail_pipe;

  if (fd_set_cloexec(pipefd[0]) == -1)
    goto fail_fcntl;

  if (fd_set_cloexec(pipefd[1]) == -1)
    goto fail_fcntl;

  pid = fork();

  if (pid < 0)
    goto fail_fork;
  else if (pid == 0) {
    /* child */
    char *cmd[4] = { "/bin/sh", "-c", 0, 0 };

    close(0);
    dup2(pipefd[1], 1);
    dup2(pipefd[1], 2);

    cmd[2] = trash.area;
    execvp(cmd[0], cmd);
    printf("execvp() failed\n");
    exit(1);
  }

  /* parent */
  thread_release();
  close(pipefd[1]);
  chunk_reset(&trash);
  while (1) {
    size_t ret = read(pipefd[0], trash.area + trash.data, trash.size - 20 - trash.data);
    if (ret <= 0)
      break;
    trash.data += ret;
    if (trash.data + 20 == trash.size) {
      chunk_strcat(&trash, "\n[[[TRUNCATED]]]\n");
      break;
    }
  }
  close(pipefd[0]);
  waitpid(pid, NULL, WNOHANG);
  trash.area[trash.data] = 0;
  return cli_msg(appctx, LOG_INFO, trash.area);

 fail_fork:
 fail_fcntl:
  close(pipefd[0]);
  close(pipefd[1]);
 fail_pipe:
  thread_release();
  return cli_err(appctx, "Failed to execute command.\n");
}

/* handles SIGRTMAX to inject random delays on the receiving thread in order
 * to try to increase the likelihood to reproduce inter-thread races. The
 * signal is periodically sent by a task initiated by "debug dev delay-inj".
 */
void debug_delay_inj_sighandler(int sig, siginfo_t *si, void *arg)
{
  volatile int i = statistical_prng_range(10000);

  while (i--)
    __ha_cpu_relax();
}
#endif

/* parse a "debug dev hex" command. It always returns 1. */
static int debug_parse_cli_hex(char **args, char *payload, struct appctx *appctx, void *private)
{
  unsigned long start, len;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  if (!*args[3])
    return cli_err(appctx, "Missing memory address to dump from.\n");

  start = strtoul(args[3], NULL, 0);
  if (!start)
    return cli_err(appctx, "Will not dump from NULL address.\n");

  _HA_ATOMIC_INC(&debug_commands_issued);

  /* by default, dump ~128 till next block of 16 */
  len = strtoul(args[4], NULL, 0);
  if (!len)
    len = ((start + 128) & -16) - start;

  chunk_reset(&trash);
  dump_hex(&trash, "  ", (const void *)start, len, 1);
  trash.area[trash.data] = 0;
  return cli_msg(appctx, LOG_INFO, trash.area);
}

/* parse a "debug dev sym <addr>" command. It always returns 1. */
static int debug_parse_cli_sym(char **args, char *payload, struct appctx *appctx, void *private)
{
  unsigned long addr;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  if (!*args[3])
    return cli_err(appctx, "Missing memory address to be resolved.\n");

  _HA_ATOMIC_INC(&debug_commands_issued);

  addr = strtoul(args[3], NULL, 0);
  chunk_printf(&trash, "%#lx resolves to ", addr);
  resolve_sym_name(&trash, NULL, (const void *)addr);
  chunk_appendf(&trash, "\n");

  return cli_msg(appctx, LOG_INFO, trash.area);
}

/* parse a "debug dev tkill" command. It always returns 1. */
static int debug_parse_cli_tkill(char **args, char *payload, struct appctx *appctx, void *private)
{
  int thr = 0;
  int sig = SIGABRT;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  if (*args[3])
    thr = atoi(args[3]);

  if (thr < 0 || thr > global.nbthread)
    return cli_err(appctx, "Thread number out of range (use 0 for current).\n");

  if (*args[4])
    sig = atoi(args[4]);

  _HA_ATOMIC_INC(&debug_commands_issued);
  if (thr)
    ha_tkill(thr - 1, sig);
  else
    raise(sig);
  return 1;
}

/* hashes 'word' in "debug dev hash 'word' ". */
static int debug_parse_cli_hash(char **args, char *payload, struct appctx *appctx, void *private)
{
  char *msg = NULL;

  cli_dynmsg(appctx, LOG_INFO, memprintf(&msg, "%s\n", HA_ANON_CLI(args[3])));
  return 1;
}

/* parse a "debug dev write" command. It always returns 1. */
static int debug_parse_cli_write(char **args, char *payload, struct appctx *appctx, void *private)
{
  unsigned long len;

  if (!*args[3])
    return cli_err(appctx, "Missing output size.\n");

  len = strtoul(args[3], NULL, 0);
  if (len >= trash.size)
    return cli_err(appctx, "Output too large, must be <tune.bufsize.\n");

  _HA_ATOMIC_INC(&debug_commands_issued);

  chunk_reset(&trash);
  trash.data = len;
  memset(trash.area, '.', trash.data);
  trash.area[trash.data] = 0;
  for (len = 64; len < trash.data; len += 64)
    trash.area[len] = '\n';
  return cli_msg(appctx, LOG_INFO, trash.area);
}

/* parse a "debug dev stream" command */
/*
 *  debug dev stream [strm=<ptr>] [strm.f[{+-=}<flags>]] [txn.f[{+-=}<flags>]] \
 *                   [req.f[{+-=}<flags>]] [res.f[{+-=}<flags>]]               \
 *                   [sif.f[{+-=<flags>]] [sib.f[{+-=<flags>]]                 \
 *                   [sif.s[=<state>]] [sib.s[=<state>]]
 */
static int debug_parse_cli_stream(char **args, char *payload, struct appctx *appctx, void *private)
{
  struct stream *s = appctx_strm(appctx);
  int arg;
  void *ptr;
  int size;
  const char *word, *end;
  struct ist name;
  char *msg = NULL;
  char *endarg;
  unsigned long long old, new;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  ptr = NULL; size = 0;

  if (!*args[3]) {
    return cli_err(appctx,
             "Usage: debug dev stream { <obj> <op> <value> | wake }*\n"
             "     <obj>   = {strm | strm.f | strm.x |\n"
             "                scf.s | scb.s |\n"
             "                txn.f | req.f | res.f}\n"
             "     <op>    = {'' (show) | '=' (assign) | '^' (xor) | '+' (or) | '-' (andnot)}\n"
             "     <value> = 'now' | 64-bit dec/hex integer (0x prefix supported)\n"
             "     'wake' wakes the stream asssigned to 'strm' (default: current)\n"
             );
  }

  _HA_ATOMIC_INC(&debug_commands_issued);
  for (arg = 3; *args[arg]; arg++) {
    old = 0;
    end = word = args[arg];
    while (*end && *end != '=' && *end != '^' && *end != '+' && *end != '-')
      end++;
    name = ist2(word, end - word);
    if (isteq(name, ist("strm"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s; size = sizeof(s);
    } else if (isteq(name, ist("strm.f"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->flags; size = sizeof(s->flags);
    } else if (isteq(name, ist("strm.x"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->conn_exp; size = sizeof(s->conn_exp);
    } else if (isteq(name, ist("txn.f"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->txn->flags; size = sizeof(s->txn->flags);
    } else if (isteq(name, ist("req.f"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->req.flags; size = sizeof(s->req.flags);
    } else if (isteq(name, ist("res.f"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->res.flags; size = sizeof(s->res.flags);
    } else if (isteq(name, ist("scf.s"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->scf->state; size = sizeof(s->scf->state);
    } else if (isteq(name, ist("scb.s"))) {
      ptr = (!s || !may_access(s)) ? NULL : &s->scf->state; size = sizeof(s->scb->state);
    } else if (isteq(name, ist("wake"))) {
      if (s && may_access(s) && may_access((void *)s + sizeof(*s) - 1))
        task_wakeup(s->task, TASK_WOKEN_TIMER|TASK_WOKEN_IO|TASK_WOKEN_MSG);
      continue;
    } else
      return cli_dynerr(appctx, memprintf(&msg, "Unsupported field name: '%s'.\n", word));

    /* read previous value */
    if ((s || ptr == &s) && ptr && may_access(ptr) && may_access(ptr + size - 1)) {
      if (size == 8)
        old = read_u64(ptr);
      else if (size == 4)
        old = read_u32(ptr);
      else if (size == 2)
        old = read_u16(ptr);
      else
        old = *(const uint8_t *)ptr;
    } else {
      memprintf(&msg,
          "%sSkipping inaccessible pointer %p for field '%.*s'.\n",
          msg ? msg : "", ptr, (int)(end - word), word);
      continue;
    }

    /* parse the new value . */
    new = strtoll(end + 1, &endarg, 0);
    if (end[1] && *endarg) {
      if (strcmp(end + 1, "now") == 0)
        new = now_ms;
      else {
        memprintf(&msg,
            "%sIgnoring unparsable value '%s' for field '%.*s'.\n",
            msg ? msg : "", end + 1, (int)(end - word), word);
        continue;
      }
    }

    switch (*end) {
    case '\0': /* show */
      memprintf(&msg, "%s%.*s=%#llx ", msg ? msg : "", (int)(end - word), word, old);
      new = old; // do not change the value
      break;

    case '=': /* set */
      break;

    case '^': /* XOR */
      new = old ^ new;
      break;

    case '+': /* OR */
      new = old | new;
      break;

    case '-': /* AND NOT */
      new = old & ~new;
      break;

    default:
      break;
    }

    /* write the new value */
    if (new != old) {
      if (size == 8)
        write_u64(ptr, new);
      else if (size == 4)
        write_u32(ptr, new);
      else if (size == 2)
        write_u16(ptr, new);
      else
        *(uint8_t *)ptr = new;
    }
  }

  if (msg && *msg)
    return cli_dynmsg(appctx, LOG_INFO, msg);
  return 1;
}

#if defined(DEBUG_DEV)
static struct task *debug_delay_inj_task(struct task *t, void *ctx, unsigned int state)
{
  unsigned long *tctx = ctx; // [0] = interval, [1] = nbwakeups
  unsigned long inter = tctx[0];
  unsigned long count = tctx[1];
  unsigned long rnd;

  if (inter)
    t->expire = tick_add(now_ms, inter);
  else
    task_wakeup(t, TASK_WOKEN_MSG);

  /* wake a random thread */
  while (count--) {
    rnd = statistical_prng_range(global.nbthread);
    ha_tkill(rnd, SIGRTMAX);
  }
  return t;
}

/* parse a "debug dev delay-inj" command
 * debug dev delay-inj <inter> <count>
 */
static int debug_parse_delay_inj(char **args, char *payload, struct appctx *appctx, void *private)
{
  unsigned long *tctx; // [0] = inter, [2] = count
  struct task *task;

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  if (!*args[4])
    return cli_err(appctx,  "Usage: debug dev delay-inj <inter_ms> <count>*\n");

  _HA_ATOMIC_INC(&debug_commands_issued);

  tctx = calloc(sizeof(*tctx), 2);
  if (!tctx)
    goto fail;

  tctx[0] = atoi(args[3]);
  tctx[1] = atoi(args[4]);

  task = task_new_here/*anywhere*/();
  if (!task)
    goto fail;

  task->process = debug_delay_inj_task;
  task->context = tctx;
  task_wakeup(task, TASK_WOKEN_INIT);
  return 1;

 fail:
  free(tctx);
  return cli_err(appctx, "Not enough memory");
}
#endif // DEBUG_DEV

static struct task *debug_task_handler(struct task *t, void *ctx, unsigned int state)
{
  unsigned long *tctx = ctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }
  unsigned long inter = tctx[1];
  unsigned long rnd;

  t->expire = tick_add(now_ms, inter);

  /* half of the calls will wake up another entry */
  rnd = statistical_prng();
  if (rnd & 1) {
    rnd >>= 1;
    rnd %= tctx[0];
    rnd = tctx[rnd + 2];

    if (rnd & 1)
      task_wakeup((struct task *)(rnd - 1), TASK_WOKEN_MSG);
    else
      tasklet_wakeup((struct tasklet *)rnd);
  }
  return t;
}

static struct task *debug_tasklet_handler(struct task *t, void *ctx, unsigned int state)
{
  unsigned long *tctx = ctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }
  unsigned long rnd;
  int i;

  /* wake up two random entries */
  for (i = 0; i < 2; i++) {
    rnd = statistical_prng() % tctx[0];
    rnd = tctx[rnd + 2];

    if (rnd & 1)
      task_wakeup((struct task *)(rnd - 1), TASK_WOKEN_MSG);
    else
      tasklet_wakeup((struct tasklet *)rnd);
  }
  return t;
}

/* parse a "debug dev sched" command
 * debug dev sched {task|tasklet} [count=<count>] [mask=<mask>] [single=<single>] [inter=<inter>]
 */
static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appctx, void *private)
{
  int arg;
  void *ptr;
  int size;
  const char *word, *end;
  struct ist name;
  char *msg = NULL;
  char *endarg;
  unsigned long long new;
  unsigned long count = 0;
  unsigned long thrid = tid;
  unsigned int inter = 0;
  unsigned long i;
  int mode = 0; // 0 = tasklet; 1 = task
  unsigned long *tctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }

  if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
    return 1;

  ptr = NULL; size = 0;

  if (strcmp(args[3], "task") != 0 && strcmp(args[3], "tasklet") != 0) {
    return cli_err(appctx,
             "Usage: debug dev sched {task|tasklet} { <obj> = <value> }*\n"
             "     <obj>   = {count | tid | inter }\n"
             "     <value> = 64-bit dec/hex integer (0x prefix supported)\n"
             );
  }

  mode = strcmp(args[3], "task") == 0;

  _HA_ATOMIC_INC(&debug_commands_issued);
  for (arg = 4; *args[arg]; arg++) {
    end = word = args[arg];
    while (*end && *end != '=' && *end != '^' && *end != '+' && *end != '-')
      end++;
    name = ist2(word, end - word);
    if (isteq(name, ist("count"))) {
      ptr = &count; size = sizeof(count);
    } else if (isteq(name, ist("tid"))) {
      ptr = &thrid; size = sizeof(thrid);
    } else if (isteq(name, ist("inter"))) {
      ptr = &inter; size = sizeof(inter);
    } else
      return cli_dynerr(appctx, memprintf(&msg, "Unsupported setting: '%s'.\n", word));

    /* parse the new value . */
    new = strtoll(end + 1, &endarg, 0);
    if (end[1] && *endarg) {
      memprintf(&msg,
                "%sIgnoring unparsable value '%s' for field '%.*s'.\n",
                msg ? msg : "", end + 1, (int)(end - word), word);
      continue;
    }

    /* write the new value */
    if (size == 8)
      write_u64(ptr, new);
    else if (size == 4)
      write_u32(ptr, new);
    else if (size == 2)
      write_u16(ptr, new);
    else
      *(uint8_t *)ptr = new;
  }

  tctx = calloc(sizeof(*tctx), count + 2);
  if (!tctx)
    goto fail;

  tctx[0] = (unsigned long)count;
  tctx[1] = (unsigned long)inter;

  if (thrid >= global.nbthread)
    thrid = tid;

  for (i = 0; i < count; i++) {
    /* now, if poly or mask was set, tmask corresponds to the
     * valid thread mask to use, otherwise it remains zero.
     */
    //printf("%lu: mode=%d mask=%#lx\n", i, mode, tmask);
    if (mode == 0) {
      struct tasklet *tl = tasklet_new();

      if (!tl)
        goto fail;

      tl->tid = thrid;
      tl->process = debug_tasklet_handler;
      tl->context = tctx;
      tctx[i + 2] = (unsigned long)tl;
    } else {
      struct task *task = task_new_on(thrid);

      if (!task)
        goto fail;

      task->process = debug_task_handler;
      task->context = tctx;
      tctx[i + 2] = (unsigned long)task + 1;
    }
  }

  /* start the tasks and tasklets */
  for (i = 0; i < count; i++) {
    unsigned long ctx = tctx[i + 2];

    if (ctx & 1)
      task_wakeup((struct task *)(ctx - 1), TASK_WOKEN_INIT);
    else
      tasklet_wakeup((struct tasklet *)ctx);
  }

  if (msg && *msg)
    return cli_dynmsg(appctx, LOG_INFO, msg);
  return 1;

 fail:
  /* free partially allocated entries */
  for (i = 0; tctx && i < count; i++) {
    unsigned long ctx = tctx[i + 2];

    if (!ctx)
      break;

    if (ctx & 1)
      task_destroy((struct task *)(ctx - 1));
    else
      tasklet_free((struct tasklet *)ctx);
  }

  free(tctx);
  return cli_err(appctx, "Not enough memory");
}

/* CLI state for "debug dev fd" */
struct dev_fd_ctx {
  int start_fd;
};

/* CLI parser for the "debug dev fd" command. The current FD to restart from is
 * stored in a struct dev_fd_ctx pointed to by svcctx.
 */
static int debug_parse_cli_fd(char **args, char *payload, struct appctx *appctx, void *private)
{
  struct dev_fd_ctx *ctx = applet_reserve_svcctx(appctx, sizeof(*ctx));

  if (!cli_has_level(appctx, ACCESS_LVL_OPER))
    return 1;

  /* start at fd #0 */
  ctx->start_fd = 0;
  return 0;
}

/* CLI I/O handler for the "debug dev fd" command. Dumps all FDs that are
 * accessible from the process but not known from fdtab. The FD number to
 * restart from is stored in a struct dev_fd_ctx pointed to by svcctx.
 */
static int debug_iohandler_fd(struct appctx *appctx)
{
  struct dev_fd_ctx *ctx = appctx->svcctx;
  struct stconn *sc = appctx_sc(appctx);
  struct sockaddr_storage sa;
  struct stat statbuf;
  socklen_t salen, vlen;
  int ret1, ret2, port;
  char *addrstr;
  int ret = 1;
  int i, fd;

  if (unlikely(sc_ic(sc)->flags & CF_SHUTW))
    goto end;

  chunk_reset(&trash);

  thread_isolate();

  /* we have two inner loops here, one for the proxy, the other one for
   * the buffer.
   */
  for (fd = ctx->start_fd; fd < global.maxsock; fd++) {
    /* check for FD's existence */
    ret1 = fcntl(fd, F_GETFD, 0);
    if (ret1 == -1)
      continue; // not known to the process
    if (fdtab[fd].owner)
      continue; // well-known

    /* OK we're seeing an orphan let's try to retrieve as much
     * information as possible about it.
     */
    chunk_printf(&trash, "%5d", fd);

    if (fstat(fd, &statbuf) != -1) {
      chunk_appendf(&trash, " type=%s mod=%04o dev=%#llx siz=%#llx uid=%lld gid=%lld fs=%#llx ino=%#llx",
              isatty(fd)                ? "tty.":
              S_ISREG(statbuf.st_mode)  ? "file":
              S_ISDIR(statbuf.st_mode)  ? "dir.":
              S_ISCHR(statbuf.st_mode)  ? "chr.":
              S_ISBLK(statbuf.st_mode)  ? "blk.":
              S_ISFIFO(statbuf.st_mode) ? "pipe":
              S_ISLNK(statbuf.st_mode)  ? "link":
              S_ISSOCK(statbuf.st_mode) ? "sock":
#ifdef USE_EPOLL
              epoll_wait(fd, NULL, 0, 0) != -1 || errno != EBADF ? "epol":
#endif
              "????",
              (uint)statbuf.st_mode & 07777,

              (ullong)statbuf.st_rdev,
              (ullong)statbuf.st_size,
              (ullong)statbuf.st_uid,
              (ullong)statbuf.st_gid,

              (ullong)statbuf.st_dev,
              (ullong)statbuf.st_ino);
    }

    chunk_appendf(&trash, " getfd=%s+%#x",
           (ret1 & FD_CLOEXEC) ? "cloex" : "",
           ret1 &~ FD_CLOEXEC);

    /* FD options */
    ret2 = fcntl(fd, F_GETFL, 0);
    if (ret2) {
      chunk_appendf(&trash, " getfl=%s",
              (ret1 & 3) >= 2 ? "O_RDWR" :
              (ret1 & 1) ? "O_WRONLY" : "O_RDONLY");

      for (i = 2; i < 32; i++) {
        if (!(ret2 & (1UL << i)))
          continue;
        switch (1UL << i) {
        case O_CREAT:   chunk_appendf(&trash, ",O_CREAT");   break;
        case O_EXCL:    chunk_appendf(&trash, ",O_EXCL");    break;
        case O_NOCTTY:  chunk_appendf(&trash, ",O_NOCTTY");  break;
        case O_TRUNC:   chunk_appendf(&trash, ",O_TRUNC");   break;
        case O_APPEND:  chunk_appendf(&trash, ",O_APPEND");  break;
#ifdef O_ASYNC
        case O_ASYNC:   chunk_appendf(&trash, ",O_ASYNC");   break;
#endif
#ifdef O_DIRECT
        case O_DIRECT:  chunk_appendf(&trash, ",O_DIRECT");  break;
#endif
#ifdef O_NOATIME
        case O_NOATIME: chunk_appendf(&trash, ",O_NOATIME"); break;
#endif
        }
      }
    }

    vlen = sizeof(ret2);
    ret1 = getsockopt(fd, SOL_SOCKET, SO_TYPE, &ret2, &vlen);
    if (ret1 != -1)
      chunk_appendf(&trash, " so_type=%d", ret2);

    vlen = sizeof(ret2);
    ret1 = getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &ret2, &vlen);
    if (ret1 != -1)
      chunk_appendf(&trash, " so_accept=%d", ret2);

    vlen = sizeof(ret2);
    ret1 = getsockopt(fd, SOL_SOCKET, SO_ERROR, &ret2, &vlen);
    if (ret1 != -1)
      chunk_appendf(&trash, " so_error=%d", ret2);

    salen = sizeof(sa);
    if (getsockname(fd, (struct sockaddr *)&sa, &salen) != -1) {
      if (sa.ss_family == AF_INET)
        port = ntohs(((const struct sockaddr_in *)&sa)->sin_port);
      else if (sa.ss_family == AF_INET6)
        port = ntohs(((const struct sockaddr_in6 *)&sa)->sin6_port);
      else
        port = 0;
      addrstr = sa2str(&sa, port, 0);
      chunk_appendf(&trash, " laddr=%s", addrstr);
      free(addrstr);
    }

    salen = sizeof(sa);
    if (getpeername(fd, (struct sockaddr *)&sa, &salen) != -1) {
      if (sa.ss_family == AF_INET)
        port = ntohs(((const struct sockaddr_in *)&sa)->sin_port);
      else if (sa.ss_family == AF_INET6)
        port = ntohs(((const struct sockaddr_in6 *)&sa)->sin6_port);
      else
        port = 0;
      addrstr = sa2str(&sa, port, 0);
      chunk_appendf(&trash, " raddr=%s", addrstr);
      free(addrstr);
    }

    chunk_appendf(&trash, "\n");

    if (applet_putchk(appctx, &trash) == -1) {
      ctx->start_fd = fd;
      ret = 0;
      break;
    }
  }

  thread_release();
 end:
  return ret;
}

#if defined(DEBUG_MEM_STATS)

/* CLI state for "debug dev memstats" */
struct dev_mem_ctx {
  struct mem_stats *start, *stop; /* begin/end of dump */
  char *match;                    /* non-null if a name prefix is specified */
  int show_all;                   /* show all entries if non-null */
  int width;                      /* 1st column width */
  long tot_size;                  /* sum of alloc-free */
  ulong tot_calls;                /* sum of calls */
};

/* CLI parser for the "debug dev memstats" command. Sets a dev_mem_ctx shown above. */
static int debug_parse_cli_memstats(char **args, char *payload, struct appctx *appctx, void *private)
{
  struct dev_mem_ctx *ctx = applet_reserve_svcctx(appctx, sizeof(*ctx));
  int arg;

  extern __attribute__((__weak__)) struct mem_stats __start_mem_stats;
  extern __attribute__((__weak__)) struct mem_stats __stop_mem_stats;

  if (!cli_has_level(appctx, ACCESS_LVL_OPER))
    return 1;

  for (arg = 3; *args[arg]; arg++) {
    if (strcmp(args[arg], "reset") == 0) {
      struct mem_stats *ptr;

      if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
        return 1;

      for (ptr = &__start_mem_stats; ptr < &__stop_mem_stats; ptr++) {
        _HA_ATOMIC_STORE(&ptr->calls, 0);
        _HA_ATOMIC_STORE(&ptr->size, 0);
      }
      return 1;
    }
    else if (strcmp(args[arg], "all") == 0) {
      ctx->show_all = 1;
      continue;
    }
    else if (strcmp(args[arg], "match") == 0 && *args[arg + 1]) {
      ha_free(&ctx->match);
      ctx->match = strdup(args[arg + 1]);
      arg++;
      continue;
    }
    else
      return cli_err(appctx, "Expects either 'reset', 'all', or 'match <pfx>'.\n");
  }

  /* otherwise proceed with the dump from p0 to p1 */
  ctx->start = &__start_mem_stats;
  ctx->stop  = &__stop_mem_stats;
  ctx->width = 0;
  return 0;
}

/* CLI I/O handler for the "debug dev memstats" command using a dev_mem_ctx
 * found in appctx->svcctx. Dumps all mem_stats structs referenced by pointers
 * located between ->start and ->stop. Dumps all entries if ->show_all != 0,
 * otherwise only non-zero calls.
 */
static int debug_iohandler_memstats(struct appctx *appctx)
{
  struct dev_mem_ctx *ctx = appctx->svcctx;
  struct stconn *sc = appctx_sc(appctx);
  struct mem_stats *ptr;
  const char *pfx = ctx->match;
  int ret = 1;

  if (unlikely(sc_ic(sc)->flags & CF_SHUTW))
    goto end;

  if (!ctx->width) {
    /* we don't know the first column's width, let's compute it
     * now based on a first pass on printable entries and their
     * expected width (approximated).
     */
    for (ptr = ctx->start; ptr != ctx->stop; ptr++) {
      const char *p, *name;
      int w = 0;
      char tmp;

      if (!ptr->size && !ptr->calls && !ctx->show_all)
        continue;

      for (p = name = ptr->caller.file; *p; p++) {
        if (*p == '/')
          name = p + 1;
      }

      if (ctx->show_all)
        w = snprintf(&tmp, 0, "%s(%s:%d) ", ptr->caller.func, name, ptr->caller.line);
      else
        w = snprintf(&tmp, 0, "%s:%d ", name, ptr->caller.line);

      if (w > ctx->width)
        ctx->width = w;
    }
  }

  /* we have two inner loops here, one for the proxy, the other one for
   * the buffer.
   */
  for (ptr = ctx->start; ptr != ctx->stop; ptr++) {
    const char *type;
    const char *name;
    const char *p;
    const char *info = NULL;
    const char *func = NULL;
    int direction = 0; // neither alloc nor free (e.g. realloc)

    if (!ptr->size && !ptr->calls && !ctx->show_all)
      continue;

    /* basename only */
    for (p = name = ptr->caller.file; *p; p++) {
      if (*p == '/')
        name = p + 1;
    }

    func = ptr->caller.func;

    switch (ptr->caller.what) {
    case MEM_STATS_TYPE_CALLOC:  type = "CALLOC";  direction =  1; break;
    case MEM_STATS_TYPE_FREE:    type = "FREE";    direction = -1; break;
    case MEM_STATS_TYPE_MALLOC:  type = "MALLOC";  direction =  1; break;
    case MEM_STATS_TYPE_REALLOC: type = "REALLOC"; break;
    case MEM_STATS_TYPE_STRDUP:  type = "STRDUP";  direction =  1; break;
    case MEM_STATS_TYPE_P_ALLOC: type = "P_ALLOC"; direction =  1; if (ptr->extra) info = ((const struct pool_head *)ptr->extra)->name; break;
    case MEM_STATS_TYPE_P_FREE:  type = "P_FREE";  direction = -1; if (ptr->extra) info = ((const struct pool_head *)ptr->extra)->name; break;
    default:                     type = "UNSET";   break;
    }

    //chunk_printf(&trash,
    //       "%20s:%-5d %7s size: %12lu calls: %9lu size/call: %6lu\n",
    //       name, ptr->line, type,
    //       (unsigned long)ptr->size, (unsigned long)ptr->calls,
    //       (unsigned long)(ptr->calls ? (ptr->size / ptr->calls) : 0));

    /* only match requested prefixes */
    if (pfx && (!info || strncmp(info, pfx, strlen(pfx)) != 0))
      continue;

    chunk_reset(&trash);
    if (ctx->show_all)
      chunk_appendf(&trash, "%s(", func);

    chunk_appendf(&trash, "%s:%d", name, ptr->caller.line);

    if (ctx->show_all)
      chunk_appendf(&trash, ")");

    while (trash.data < ctx->width)
      trash.area[trash.data++] = ' ';

    chunk_appendf(&trash, "%7s  size: %12lu  calls: %9lu  size/call: %6lu %s\n",
           type,
           (unsigned long)ptr->size, (unsigned long)ptr->calls,
                 (unsigned long)(ptr->calls ? (ptr->size / ptr->calls) : 0),
           info ? info : "");

    if (applet_putchk(appctx, &trash) == -1) {
      ctx->start = ptr;
      ret = 0;
      goto end;
    }
    if (direction > 0) {
      ctx->tot_size  += (ulong)ptr->size;
      ctx->tot_calls += (ulong)ptr->calls;
    }
    else if (direction < 0) {
      ctx->tot_size  -= (ulong)ptr->size;
      ctx->tot_calls += (ulong)ptr->calls;
    }
  }

  /* now dump a summary */
  chunk_reset(&trash);
  chunk_appendf(&trash, "Total");
  while (trash.data < ctx->width)
    trash.area[trash.data++] = ' ';

  chunk_appendf(&trash, "%7s  size: %12ld  calls: %9lu  size/call: %6ld %s\n",
          "BALANCE",
          ctx->tot_size, ctx->tot_calls,
          (long)(ctx->tot_calls ? (ctx->tot_size / ctx->tot_calls) : 0),
          "(excl. realloc)");

  if (applet_putchk(appctx, &trash) == -1) {
    ctx->start = ptr;
    ret = 0;
    goto end;
  }
 end:
  return ret;
}

/* release the "show pools" context */
static void debug_release_memstats(struct appctx *appctx)
{
  struct dev_mem_ctx *ctx = appctx->svcctx;

  ha_free(&ctx->match);
}
#endif

#ifndef USE_THREAD_DUMP

/* This function dumps all threads' state to the trash. This version is the
 * most basic one, which doesn't inspect other threads.
 */
void ha_thread_dump_all_to_trash()
{
  unsigned int thr;

  for (thr = 0; thr < global.nbthread; thr++)
    ha_thread_dump(&trash, thr, tid);
}

#else /* below USE_THREAD_DUMP is set */

/* ID of the thread requesting the dump */
static unsigned int thread_dump_tid;

/* points to the buffer where the dump functions should write. It must
 * have already been initialized by the requester. Nothing is done if
 * it's NULL.
 */
struct buffer *thread_dump_buffer = NULL;

/* initiates a thread dump */
void ha_thread_dump_all_to_trash()
{
  unsigned int old;

  /* initiate a dump starting from first thread. Use a CAS so that we do
   * not wait if we're not the first one, but we wait for a previous dump
   * to finish.
   */
  while (1) {
    old = 0;
    if (HA_ATOMIC_CAS(&thread_dump_state, &old, THREAD_DUMP_FSYNC))
      break;
    ha_thread_relax();
  }
  thread_dump_buffer = &trash;
  thread_dump_tid = tid;
  ha_tkillall(DEBUGSIG);

  /* the call above contains a raise() so we're certain to return after
   * returning from the sighandler, hence when the dump is complete.
   */
}

/* handles DEBUGSIG to dump the state of the thread it's working on. This is
 * appended at the end of thread_dump_buffer which must be protected against
 * reentrance from different threads (a thread-local buffer works fine).
 */
void debug_handler(int sig, siginfo_t *si, void *arg)
{
  int harmless = is_thread_harmless();
  int running = 0;
  uint prev;
  uint next;

  /* first, let's check it's really for us and that we didn't just get
   * a spurious DEBUGSIG.
   */
  if (!_HA_ATOMIC_LOAD(&thread_dump_state))
    return;

  /* There are 5 phases in the dump process:
   *   1- wait for all threads to sync or the first one to start
   *   2- wait for our turn, i.e. when tid appears in lower bits.
   *   3- perform the action if our tid is there
   *   4- pass tid to the number of the next thread to dump or
   *      reset running counter if we're last one.
   *   5- wait for running to be zero and decrement the count
   */

  /* wait for all previous threads to finish first */
  if (!harmless)
    thread_harmless_now();

  if (HA_ATOMIC_FETCH_ADD(&thread_dump_state, 1) == THREAD_DUMP_FSYNC) {
    /* the first one which lands here is responsible for constantly
     * recounting the number of active theads and switching from
     * SYNC to DUMP.
     */
    while (1) {
      int first = -1; // first tid to dump
      int thr;

      running = 0;
      for (thr = 0; thr < global.nbthread; thr++) {
        if (ha_thread_info[thr].tg->threads_enabled & ha_thread_info[thr].ltid_bit) {
          running++;
          if (first < 0)
            first = thr;
        }
      }

      if ((HA_ATOMIC_LOAD(&thread_dump_state) & THREAD_DUMP_TMASK) == running) {
        /* all threads are there, let's try to start */
        prev = THREAD_DUMP_FSYNC | running;
        next = (running << 16) | first;
        if (HA_ATOMIC_CAS(&thread_dump_state, &prev, next))
          break;
        /* it failed! maybe a thread appeared late (e.g. during boot), let's
         * recount.
         */
      }
      ha_thread_relax();
    }
  }

  /* all threads: let's wait for the SYNC flag to disappear; tid is reset at
   * the same time to the first valid tid to dump and pmask will reflect the
   * number of participants.
   */
  while (HA_ATOMIC_LOAD(&thread_dump_state) & THREAD_DUMP_FSYNC)
    ha_thread_relax();

  /* wait for our turn */
  while ((HA_ATOMIC_LOAD(&thread_dump_state) & THREAD_DUMP_TMASK) != tid)
    ha_thread_relax();

  if (!harmless)
    thread_harmless_end_sig();

  /* dump if needed */
  if (thread_dump_buffer)
    ha_thread_dump(thread_dump_buffer, tid, thread_dump_tid);

  /* figure which is the next thread ID to dump among enabled ones. Note
   * that this relies on the fact that we're not creating new threads in
   * the middle of a dump, which is normally granted by the harmless bits
   * anyway.
   */
  for (next = tid + 1; next < global.nbthread; next++) {
    if (unlikely(next >= MAX_THREADS)) {
      /* just to please gcc 6.5 who guesses the ranges wrong. */
      continue;
    }

    if (ha_thread_info[next].tg &&
        ha_thread_info[next].tg->threads_enabled & ha_thread_info[next].ltid_bit)
      break;
  }

  /* if there are threads left to dump, we atomically set the next one,
   * otherwise we'll clear dump and set the thread part to the number of
   * threads that need to disappear.
   */
  if (next < global.nbthread) {
    next = (HA_ATOMIC_LOAD(&thread_dump_state) & THREAD_DUMP_PMASK) | next;
    HA_ATOMIC_STORE(&thread_dump_state, next);
  } else {
    thread_dump_buffer = NULL; // was the last one
    running = (HA_ATOMIC_LOAD(&thread_dump_state) & THREAD_DUMP_PMASK) >> 16;
    HA_ATOMIC_STORE(&thread_dump_state, running);
  }

  /* now wait for all others to finish dumping: the lowest part will turn
   * to zero. Then all others decrement the done part. We must not change
   * the harmless status anymore because one of the other threads might
   * have been interrupted in thread_isolate() waiting for all others to
   * become harmless, and changing the situation here would break that
   * promise.
   */

  /* wait for everyone to finish*/
  while (HA_ATOMIC_LOAD(&thread_dump_state) & THREAD_DUMP_PMASK)
    ha_thread_relax();

  /* we're gone. Past this point anything can happen including another
   * thread trying to re-trigger a dump, so thread_dump_buffer and
   * thread_dump_tid may become invalid immediately after this call.
   */
  HA_ATOMIC_SUB(&thread_dump_state, 1);

  /* mark the current thread as stuck to detect it upon next invocation
   * if it didn't move.
   */
  if (!harmless &&
      !(_HA_ATOMIC_LOAD(&th_ctx->flags) & TH_FL_SLEEPING))
    _HA_ATOMIC_OR(&th_ctx->flags, TH_FL_STUCK);
}

static int init_debug_per_thread()
{
  sigset_t set;

  /* unblock the DEBUGSIG signal we intend to use */
  sigemptyset(&set);
  sigaddset(&set, DEBUGSIG);
#if defined(DEBUG_DEV)
  sigaddset(&set, SIGRTMAX);
#endif
  ha_sigmask(SIG_UNBLOCK, &set, NULL);
  return 1;
}

static int init_debug()
{
  struct sigaction sa;
  void *callers[1];

  /* calling backtrace() will access libgcc at runtime. We don't want to
   * do it after the chroot, so let's perform a first call to have it
   * ready in memory for later use.
   */
  my_backtrace(callers, sizeof(callers)/sizeof(*callers));
  sa.sa_handler = NULL;
  sa.sa_sigaction = debug_handler;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = SA_SIGINFO;
  sigaction(DEBUGSIG, &sa, NULL);

#if defined(DEBUG_DEV)
  sa.sa_handler = NULL;
  sa.sa_sigaction = debug_delay_inj_sighandler;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = SA_SIGINFO;
  sigaction(SIGRTMAX, &sa, NULL);
#endif
  return ERR_NONE;
}

REGISTER_POST_CHECK(init_debug);
REGISTER_PER_THREAD_INIT(init_debug_per_thread);

#endif /* USE_THREAD_DUMP */

/* register cli keywords */
static struct cli_kw_list cli_kws = {{ },{
  {{ "debug", "dev", "bug", NULL },      "debug dev bug                           : call BUG_ON() and crash",                 debug_parse_cli_bug,   NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "check", NULL },    "debug dev check                         : call CHECK_IF() and possibly crash",      debug_parse_cli_check, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "close", NULL },    "debug dev close  <fd>                   : close this file descriptor",              debug_parse_cli_close, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "deadlock", NULL }, "debug dev deadlock [nbtask]             : deadlock between this number of tasks",   debug_parse_cli_deadlock, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "delay", NULL },    "debug dev delay  [ms]                   : sleep this long",                         debug_parse_cli_delay, NULL, NULL, NULL, ACCESS_EXPERT },
#if defined(DEBUG_DEV)
  {{ "debug", "dev", "delay-inj", NULL },"debug dev delay-inj <inter> <count>     : inject random delays into threads",       debug_parse_delay_inj, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "exec",  NULL },    "debug dev exec   [cmd] ...              : show this command's output",              debug_parse_cli_exec,  NULL, NULL, NULL, ACCESS_EXPERT },
#endif
  {{ "debug", "dev", "fd", NULL },       "debug dev fd                            : scan for rogue/unhandled FDs",            debug_parse_cli_fd,    debug_iohandler_fd, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "exit",  NULL },    "debug dev exit   [code]                 : immediately exit the process",            debug_parse_cli_exit,  NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "hash", NULL },     "debug dev hash   [msg]                  : return msg hashed if anon is set",        debug_parse_cli_hash,  NULL, NULL, NULL, 0 },
  {{ "debug", "dev", "hex",   NULL },    "debug dev hex    <addr> [len]           : dump a memory area",                      debug_parse_cli_hex,   NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "log",   NULL },    "debug dev log    [msg] ...              : send this msg to global logs",            debug_parse_cli_log,   NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "loop",  NULL },    "debug dev loop   [ms]                   : loop this long",                          debug_parse_cli_loop,  NULL, NULL, NULL, ACCESS_EXPERT },
#if defined(DEBUG_MEM_STATS)
  {{ "debug", "dev", "memstats", NULL }, "debug dev memstats [reset|all|match ...]: dump/reset memory statistics",            debug_parse_cli_memstats, debug_iohandler_memstats, debug_release_memstats, NULL, 0 },
#endif
  {{ "debug", "dev", "panic", NULL },    "debug dev panic                         : immediately trigger a panic",             debug_parse_cli_panic, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "sched", NULL },    "debug dev sched  {task|tasklet} [k=v]*  : stress the scheduler",                    debug_parse_cli_sched, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "stream",NULL },    "debug dev stream [k=v]*                 : show/manipulate stream flags",            debug_parse_cli_stream,NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "sym",   NULL },    "debug dev sym    <addr>                 : resolve symbol address",                  debug_parse_cli_sym,   NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "tkill", NULL },    "debug dev tkill  [thr] [sig]            : send signal to thread",                   debug_parse_cli_tkill, NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "warn",  NULL },    "debug dev warn                          : call WARN_ON() and possibly crash",       debug_parse_cli_warn,  NULL, NULL, NULL, ACCESS_EXPERT },
  {{ "debug", "dev", "write", NULL },    "debug dev write  [size]                 : write that many bytes in return",         debug_parse_cli_write, NULL, NULL, NULL, ACCESS_EXPERT },

#if defined(HA_HAVE_DUMP_LIBS)
  {{ "show", "libs", NULL, NULL },       "show libs                               : show loaded object files and libraries", debug_parse_cli_show_libs, NULL, NULL },
#endif
  {{ "show", "threads", NULL, NULL },    "show threads                            : show some threads debugging information", NULL, cli_io_handler_show_threads, NULL },
  {{},}
}};

INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);

Coverage Report

Created: 2023-03-26 06:06