/src/php-src/ext/opcache/shared_alloc_mmap.c

Source
/*
   +----------------------------------------------------------------------+
   | Zend OPcache                                                         |
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@php.net>                                 |
   |          Zeev Suraski <zeev@php.net>                                 |
   |          Stanislav Malyshev <stas@zend.com>                          |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/

#include "zend_shared_alloc.h"
#ifdef HAVE_JIT
# include "jit/zend_jit.h"
#endif

#ifdef USE_MMAP

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>

#ifdef __APPLE__
#include <mach/vm_statistics.h>
#endif

#include "zend_execute.h"
#ifdef HAVE_PROCCTL
#include <sys/procctl.h>
#endif

#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
# define MAP_ANONYMOUS MAP_ANON
#endif
#if defined(MAP_ALIGNED_SUPER)
# include <sys/types.h>
# include <sys/sysctl.h>
# include <sys/user.h>
# define MAP_HUGETLB MAP_ALIGNED_SUPER
#endif

#if defined(HAVE_JIT) && (defined(__linux__) || defined(__FreeBSD__)) && (defined(__x86_64__) || defined (__aarch64__)) && !defined(__SANITIZE_ADDRESS__)
static void *find_preferred_mmap_base(size_t requested_size)
{
  size_t huge_page_size = 2 * 1024 * 1024;
  uintptr_t last_free_addr = huge_page_size;
  uintptr_t last_candidate = (uintptr_t)MAP_FAILED;
  uintptr_t start, end, text_start = 0;
#if defined(__linux__)
  FILE *f;
  char buffer[MAXPATHLEN];

  f = fopen("/proc/self/maps", "r");
  if (!f) {
    return MAP_FAILED;
  }

  while (fgets(buffer, MAXPATHLEN, f) && sscanf(buffer, "%lx-%lx", &start, &end) == 2) {
    /* Don't place the segment directly before or after the heap segment. Due to an selinux bug,
     * a segment directly preceding or following the heap is interpreted as heap memory, which
     * will result in an execheap violation for the JIT.
     * See https://bugzilla.kernel.org/show_bug.cgi?id=218258. */
    bool heap_segment = strstr(buffer, "[heap]") != NULL;
    if (heap_segment) {
      uintptr_t start_base = start & ~(huge_page_size - 1);
      if (last_free_addr + requested_size >= start_base) {
        last_free_addr = ZEND_MM_ALIGNED_SIZE_EX(end + huge_page_size, huge_page_size);
        continue;
      }
    }
    if ((uintptr_t)execute_ex >= start) {
      /* the current segment lays before PHP .text segment or PHP .text segment itself */
      /*Search for candidates at the end of the free segment near the .text segment
        to prevent candidates from being missed due to large hole*/
      if (last_free_addr + requested_size <= start) {
        last_candidate = ZEND_MM_ALIGNED_SIZE_EX(start - requested_size, huge_page_size);
        if (last_candidate + requested_size > start) {
          last_candidate -= huge_page_size;
        }
      }
      if ((uintptr_t)execute_ex < end) {
        /* the current segment is PHP .text segment itself */
        if (last_candidate != (uintptr_t)MAP_FAILED) {
          if (end - last_candidate < UINT32_MAX) {
            /* we have found a big enough hole before the text segment */
            break;
          }
          last_candidate = (uintptr_t)MAP_FAILED;
        }
        text_start = start;
      }
    } else {
      /* the current segment lays after PHP .text segment */
      if (last_free_addr + requested_size - text_start > UINT32_MAX) {
        /* the current segment and the following segments lay too far from PHP .text segment */
        break;
      }
      if (last_free_addr + requested_size <= start) {
        last_candidate = last_free_addr;
        break;
      }
    }
    last_free_addr = ZEND_MM_ALIGNED_SIZE_EX(end, huge_page_size);
    if (heap_segment) {
      last_free_addr += huge_page_size;
    }
  }
  fclose(f);
#elif defined(__FreeBSD__)
  size_t s = 0;
  int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, getpid()};
  if (sysctl(mib, 4, NULL, &s, NULL, 0) == 0) {
    s = s * 4 / 3;
    void *addr = mmap(NULL, s, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
    if (addr != MAP_FAILED) {
      if (sysctl(mib, 4, addr, &s, NULL, 0) == 0) {
        start = (uintptr_t)addr;
        end = start + s;
        while (start < end) {
          struct kinfo_vmentry *entry = (struct kinfo_vmentry *)start;
          size_t sz = entry->kve_structsize;
          if (sz == 0) {
            break;
          }
          uintptr_t e_start = entry->kve_start;
          uintptr_t e_end = entry->kve_end;
          if ((uintptr_t)execute_ex >= e_start) {
            /* the current segment lays before PHP .text segment or PHP .text segment itself */
            if (last_free_addr + requested_size <= e_start) {
              last_candidate = ZEND_MM_ALIGNED_SIZE_EX(e_start - requested_size, huge_page_size);
              if (last_candidate + requested_size > e_start) {
                last_candidate -= huge_page_size;
              }
            }
            if ((uintptr_t)execute_ex < e_end) {
              /* the current segment is PHP .text segment itself */
              if (last_candidate != (uintptr_t)MAP_FAILED) {
                if (e_end - last_candidate < UINT32_MAX) {
                  /* we have found a big enough hole before the text segment */
                  break;
                }
                last_candidate = (uintptr_t)MAP_FAILED;
              }
              text_start = e_start;
            }
          } else {
            /* the current segment lays after PHP .text segment */
            if (last_free_addr + requested_size - text_start > UINT32_MAX) {
              /* the current segment and the following segments lay too far from PHP .text segment */
              break;
            }
            if (last_free_addr + requested_size <= e_start) {
              last_candidate = last_free_addr;
              break;
            }
          }
          last_free_addr = ZEND_MM_ALIGNED_SIZE_EX(e_end, huge_page_size);
          start += sz;
        }
      }
      munmap(addr, s);
    }
  }
#endif

  return (void*)last_candidate;
}
#endif

static int create_segments(size_t requested_size, zend_shared_segment ***shared_segments_p, int *shared_segments_count, const char **error_in)
{
  zend_shared_segment *shared_segment;
  int flags = PROT_READ | PROT_WRITE, fd = -1;
  void *p;
#if defined(HAVE_PROCCTL) && defined(PROC_WXMAP_CTL)
  int enable_wxmap = PROC_WX_MAPPINGS_PERMIT;
  if (procctl(P_PID, getpid(), PROC_WXMAP_CTL, &enable_wxmap) == -1) {
    return ALLOC_FAILURE;
  }
#endif
#ifdef PROT_MPROTECT
  flags |= PROT_MPROTECT(PROT_EXEC);
#endif
#ifdef VM_MAKE_TAG
  /* allows tracking segments via tools such as vmmap */
  fd = VM_MAKE_TAG(251U);
#endif
#ifdef PROT_MAX
  flags |= PROT_MAX(PROT_READ | PROT_WRITE | PROT_EXEC);
#endif
#if defined(HAVE_JIT) && (defined(__linux__) || defined(__FreeBSD__)) && (defined(__x86_64__) || defined (__aarch64__)) && !defined(__SANITIZE_ADDRESS__)
  void *hint;
  if (JIT_G(enabled) && JIT_G(buffer_size)
      && zend_jit_check_support() == SUCCESS) {
    hint = find_preferred_mmap_base(requested_size);
  } else {
    /* Do not use a hint if JIT is not enabled, as this profits only JIT and
     * this is potentially unsafe when the only suitable candidate is just
     * after the heap (e.g. in non-PIE builds) (GH-13775). */
    hint = MAP_FAILED;
  }
  if (hint != MAP_FAILED) {
# ifdef MAP_HUGETLB
    size_t huge_page_size = 2 * 1024 * 1024;
    if (requested_size >= huge_page_size && requested_size % huge_page_size == 0) {
      p = mmap(hint, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_HUGETLB|MAP_FIXED, -1, 0);
      if (p != MAP_FAILED) {
        goto success;
      }
    }
#endif
    p = mmap(hint, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_FIXED, -1, 0);
    if (p != MAP_FAILED) {
      goto success;
    }
  }
#endif
#ifdef MAP_HUGETLB
  size_t huge_page_size = 2 * 1024 * 1024;

  /* Try to allocate huge pages first to reduce dTLB misses.
   * OSes has to be configured properly
   * on Linux
   * (e.g. https://wiki.debian.org/Hugepages#Enabling_HugeTlbPage)
   * You may verify huge page usage with the following command:
   * `grep "Huge" /proc/meminfo`
   * on FreeBSD
   * sysctl vm.pmap.pg_ps_enabled entry
   * (boot time config only, but enabled by default on most arches).
   */
  if (requested_size >= huge_page_size && requested_size % huge_page_size == 0) {
# if defined(__x86_64__) && defined(MAP_32BIT)
    /* to got HUGE PAGES in low 32-bit address we have to reserve address
       space and then remap it using MAP_HUGETLB */

    p = mmap(NULL, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT, fd, 0);
    if (p != MAP_FAILED) {
      munmap(p, requested_size);
      p = (void*)(ZEND_MM_ALIGNED_SIZE_EX((ptrdiff_t)p, huge_page_size));
      p = mmap(p, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT|MAP_HUGETLB|MAP_FIXED, -1, 0);
      if (p != MAP_FAILED) {
        goto success;
      } else {
        p = mmap(NULL, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT, fd, 0);
        if (p != MAP_FAILED) {
          goto success;
        }
      }
    }
# endif
    p = mmap(0, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_HUGETLB, fd, 0);
    if (p != MAP_FAILED) {
      goto success;
    }
  }
#elif defined(PREFER_MAP_32BIT) && defined(__x86_64__) && defined(MAP_32BIT)
  p = mmap(NULL, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT, fd, 0);
  if (p != MAP_FAILED) {
    goto success;
  }
#endif

  p = mmap(0, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS, fd, 0);
  if (p == MAP_FAILED) {
    *error_in = "mmap";
    return ALLOC_FAILURE;
  }

success: ZEND_ATTRIBUTE_UNUSED;
  *shared_segments_count = 1;
  *shared_segments_p = (zend_shared_segment **) calloc(1, sizeof(zend_shared_segment) + sizeof(void *));
  if (!*shared_segments_p) {
    munmap(p, requested_size);
    *error_in = "calloc";
    return ALLOC_FAILURE;
  }
  shared_segment = (zend_shared_segment *)((char *)(*shared_segments_p) + sizeof(void *));
  (*shared_segments_p)[0] = shared_segment;

  shared_segment->p = p;
  shared_segment->pos = 0;
  shared_segment->size = requested_size;

  return ALLOC_SUCCESS;
}

static int detach_segment(zend_shared_segment *shared_segment)
{
  munmap(shared_segment->p, shared_segment->size);
  return 0;
}

static size_t segment_type_size(void)
{
  return sizeof(zend_shared_segment);
}

const zend_shared_memory_handlers zend_alloc_mmap_handlers = {
  create_segments,
  detach_segment,
  segment_type_size
};

#endif /* USE_MMAP */

Coverage Report

Created: 2025-09-27 06:26

Line	Count	Source
1		/*
2		+----------------------------------------------------------------------+
3		\| Zend OPcache \|
4		+----------------------------------------------------------------------+
5		\| Copyright (c) The PHP Group \|
6		+----------------------------------------------------------------------+
7		\| This source file is subject to version 3.01 of the PHP license, \|
8		\| that is bundled with this package in the file LICENSE, and is \|
9		\| available through the world-wide-web at the following url: \|
10		\| https://www.php.net/license/3_01.txt \|
11		\| If you did not receive a copy of the PHP license and are unable to \|
12		\| obtain it through the world-wide-web, please send a note to \|
13		\| license@php.net so we can mail you a copy immediately. \|
14		+----------------------------------------------------------------------+
15		\| Authors: Andi Gutmans <andi@php.net> \|
16		\| Zeev Suraski <zeev@php.net> \|
17		\| Stanislav Malyshev <stas@zend.com> \|
18		\| Dmitry Stogov <dmitry@php.net> \|
19		+----------------------------------------------------------------------+
20		*/
21
22		#include "zend_shared_alloc.h"
23		#ifdef HAVE_JIT
24		# include "jit/zend_jit.h"
25		#endif
26
27		#ifdef USE_MMAP
28
29		#include <sys/types.h>
30		#include <sys/stat.h>
31		#include <stdio.h>
32		#include <stdlib.h>
33		#include <sys/mman.h>
34
35		#ifdef __APPLE__
36		#include <mach/vm_statistics.h>
37		#endif
38
39		#include "zend_execute.h"
40		#ifdef HAVE_PROCCTL
41		#include <sys/procctl.h>
42		#endif
43
44		#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
45		# define MAP_ANONYMOUS MAP_ANON
46		#endif
47		#if defined(MAP_ALIGNED_SUPER)
48		# include <sys/types.h>
49		# include <sys/sysctl.h>
50		# include <sys/user.h>
51		# define MAP_HUGETLB MAP_ALIGNED_SUPER
52		#endif
53
54		#if defined(HAVE_JIT) && (defined(__linux__) \|\| defined(__FreeBSD__)) && (defined(__x86_64__) \|\| defined (__aarch64__)) && !defined(__SANITIZE_ADDRESS__)
55		static void *find_preferred_mmap_base(size_t requested_size)
56	0	{
57	0	size_t huge_page_size = 2 * 1024 * 1024;
58	0	uintptr_t last_free_addr = huge_page_size;
59	0	uintptr_t last_candidate = (uintptr_t)MAP_FAILED;
60	0	uintptr_t start, end, text_start = 0;
61	0	#if defined(__linux__)
62	0	FILE *f;
63	0	char buffer[MAXPATHLEN];
64
65	0	f = fopen("/proc/self/maps", "r");
66	0	if (!f) {
67	0	return MAP_FAILED;
68	0	}
69
70	0	while (fgets(buffer, MAXPATHLEN, f) && sscanf(buffer, "%lx-%lx", &start, &end) == 2) {
71		/* Don't place the segment directly before or after the heap segment. Due to an selinux bug,
72		* a segment directly preceding or following the heap is interpreted as heap memory, which
73		* will result in an execheap violation for the JIT.
74		* See https://bugzilla.kernel.org/show_bug.cgi?id=218258. */
75	0	bool heap_segment = strstr(buffer, "[heap]") != NULL;
76	0	if (heap_segment) {
77	0	uintptr_t start_base = start & ~(huge_page_size - 1);
78	0	if (last_free_addr + requested_size >= start_base) {
79	0	last_free_addr = ZEND_MM_ALIGNED_SIZE_EX(end + huge_page_size, huge_page_size);
80	0	continue;
81	0	}
82	0	}
83	0	if ((uintptr_t)execute_ex >= start) {
84		/* the current segment lays before PHP .text segment or PHP .text segment itself */
85		/*Search for candidates at the end of the free segment near the .text segment
86		to prevent candidates from being missed due to large hole*/
87	0	if (last_free_addr + requested_size <= start) {
88	0	last_candidate = ZEND_MM_ALIGNED_SIZE_EX(start - requested_size, huge_page_size);
89	0	if (last_candidate + requested_size > start) {
90	0	last_candidate -= huge_page_size;
91	0	}
92	0	}
93	0	if ((uintptr_t)execute_ex < end) {
94		/* the current segment is PHP .text segment itself */
95	0	if (last_candidate != (uintptr_t)MAP_FAILED) {
96	0	if (end - last_candidate < UINT32_MAX) {
97		/* we have found a big enough hole before the text segment */
98	0	break;
99	0	}
100	0	last_candidate = (uintptr_t)MAP_FAILED;
101	0	}
102	0	text_start = start;
103	0	}
104	0	} else {
105		/* the current segment lays after PHP .text segment */
106	0	if (last_free_addr + requested_size - text_start > UINT32_MAX) {
107		/* the current segment and the following segments lay too far from PHP .text segment */
108	0	break;
109	0	}
110	0	if (last_free_addr + requested_size <= start) {
111	0	last_candidate = last_free_addr;
112	0	break;
113	0	}
114	0	}
115	0	last_free_addr = ZEND_MM_ALIGNED_SIZE_EX(end, huge_page_size);
116	0	if (heap_segment) {
117	0	last_free_addr += huge_page_size;
118	0	}
119	0	}
120	0	fclose(f);
121		#elif defined(__FreeBSD__)
122		size_t s = 0;
123		int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, getpid()};
124		if (sysctl(mib, 4, NULL, &s, NULL, 0) == 0) {
125		s = s * 4 / 3;
126		void *addr = mmap(NULL, s, PROT_READ \| PROT_WRITE, MAP_SHARED \| MAP_ANON, -1, 0);
127		if (addr != MAP_FAILED) {
128		if (sysctl(mib, 4, addr, &s, NULL, 0) == 0) {
129		start = (uintptr_t)addr;
130		end = start + s;
131		while (start < end) {
132		struct kinfo_vmentry entry = (struct kinfo_vmentry )start;
133		size_t sz = entry->kve_structsize;
134		if (sz == 0) {
135		break;
136		}
137		uintptr_t e_start = entry->kve_start;
138		uintptr_t e_end = entry->kve_end;
139		if ((uintptr_t)execute_ex >= e_start) {
140		/* the current segment lays before PHP .text segment or PHP .text segment itself */
141		if (last_free_addr + requested_size <= e_start) {
142		last_candidate = ZEND_MM_ALIGNED_SIZE_EX(e_start - requested_size, huge_page_size);
143		if (last_candidate + requested_size > e_start) {
144		last_candidate -= huge_page_size;
145		}
146		}
147		if ((uintptr_t)execute_ex < e_end) {
148		/* the current segment is PHP .text segment itself */
149		if (last_candidate != (uintptr_t)MAP_FAILED) {
150		if (e_end - last_candidate < UINT32_MAX) {
151		/* we have found a big enough hole before the text segment */
152		break;
153		}
154		last_candidate = (uintptr_t)MAP_FAILED;
155		}
156		text_start = e_start;
157		}
158		} else {
159		/* the current segment lays after PHP .text segment */
160		if (last_free_addr + requested_size - text_start > UINT32_MAX) {
161		/* the current segment and the following segments lay too far from PHP .text segment */
162		break;
163		}
164		if (last_free_addr + requested_size <= e_start) {
165		last_candidate = last_free_addr;
166		break;
167		}
168		}
169		last_free_addr = ZEND_MM_ALIGNED_SIZE_EX(e_end, huge_page_size);
170		start += sz;
171		}
172		}
173		munmap(addr, s);
174		}
175		}
176		#endif
177
178	0	return (void*)last_candidate;
179	0	}
180		#endif
181
182		static int create_segments(size_t requested_size, zend_shared_segment **shared_segments_p, int shared_segments_count, const char **error_in)
183	16	{
184	16	zend_shared_segment *shared_segment;
185	16	int flags = PROT_READ \| PROT_WRITE, fd = -1;
186	16	void *p;
187		#if defined(HAVE_PROCCTL) && defined(PROC_WXMAP_CTL)
188		int enable_wxmap = PROC_WX_MAPPINGS_PERMIT;
189		if (procctl(P_PID, getpid(), PROC_WXMAP_CTL, &enable_wxmap) == -1) {
190		return ALLOC_FAILURE;
191		}
192		#endif
193		#ifdef PROT_MPROTECT
194		flags \|= PROT_MPROTECT(PROT_EXEC);
195		#endif
196		#ifdef VM_MAKE_TAG
197		/* allows tracking segments via tools such as vmmap */
198		fd = VM_MAKE_TAG(251U);
199		#endif
200		#ifdef PROT_MAX
201		flags \|= PROT_MAX(PROT_READ \| PROT_WRITE \| PROT_EXEC);
202		#endif
203	16	#if defined(HAVE_JIT) && (defined(__linux__) \|\| defined(__FreeBSD__)) && (defined(__x86_64__) \|\| defined (__aarch64__)) && !defined(__SANITIZE_ADDRESS__)
204	16	void *hint;
205	16	if (JIT_G(enabled) && JIT_G(buffer_size)
206	0	&& zend_jit_check_support() == SUCCESS) {
207	0	hint = find_preferred_mmap_base(requested_size);
208	16	} else {
209		/* Do not use a hint if JIT is not enabled, as this profits only JIT and
210		* this is potentially unsafe when the only suitable candidate is just
211		* after the heap (e.g. in non-PIE builds) (GH-13775). */
212	16	hint = MAP_FAILED;
213	16	}
214	16	if (hint != MAP_FAILED) {
215	0	# ifdef MAP_HUGETLB
216	0	size_t huge_page_size = 2 * 1024 * 1024;
217	0	if (requested_size >= huge_page_size && requested_size % huge_page_size == 0) {
218	0	p = mmap(hint, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_HUGETLB\|MAP_FIXED, -1, 0);
219	0	if (p != MAP_FAILED) {
220	0	goto success;
221	0	}
222	0	}
223	0	#endif
224	0	p = mmap(hint, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_FIXED, -1, 0);
225	0	if (p != MAP_FAILED) {
226	0	goto success;
227	0	}
228	0	}
229	16	#endif
230	16	#ifdef MAP_HUGETLB
231	16	size_t huge_page_size = 2 * 1024 * 1024;
232
233		/* Try to allocate huge pages first to reduce dTLB misses.
234		* OSes has to be configured properly
235		* on Linux
236		* (e.g. https://wiki.debian.org/Hugepages#Enabling_HugeTlbPage)
237		* You may verify huge page usage with the following command:
238		* `grep "Huge" /proc/meminfo`
239		* on FreeBSD
240		* sysctl vm.pmap.pg_ps_enabled entry
241		* (boot time config only, but enabled by default on most arches).
242		*/
243	16	if (requested_size >= huge_page_size && requested_size % huge_page_size == 0) {
244	16	# if defined(__x86_64__) && defined(MAP_32BIT)
245		/* to got HUGE PAGES in low 32-bit address we have to reserve address
246		space and then remap it using MAP_HUGETLB */
247
248	16	p = mmap(NULL, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_32BIT, fd, 0);
249	16	if (p != MAP_FAILED) {
250	14	munmap(p, requested_size);
251	14	p = (void*)(ZEND_MM_ALIGNED_SIZE_EX((ptrdiff_t)p, huge_page_size));
252	14	p = mmap(p, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_32BIT\|MAP_HUGETLB\|MAP_FIXED, -1, 0);
253	14	if (p != MAP_FAILED) {
254	0	goto success;
255	14	} else {
256	14	p = mmap(NULL, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_32BIT, fd, 0);
257	14	if (p != MAP_FAILED) {
258	14	goto success;
259	14	}
260	14	}
261	14	}
262	2	# endif
263	2	p = mmap(0, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_HUGETLB, fd, 0);
264	2	if (p != MAP_FAILED) {
265	0	goto success;
266	0	}
267	2	}
268		#elif defined(PREFER_MAP_32BIT) && defined(__x86_64__) && defined(MAP_32BIT)
269		p = mmap(NULL, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS\|MAP_32BIT, fd, 0);
270		if (p != MAP_FAILED) {
271		goto success;
272		}
273		#endif
274
275	2	p = mmap(0, requested_size, flags, MAP_SHARED\|MAP_ANONYMOUS, fd, 0);
276	2	if (p == MAP_FAILED) {
277	0	*error_in = "mmap";
278	0	return ALLOC_FAILURE;
279	0	}
280
281	16	success: ZEND_ATTRIBUTE_UNUSED;
282	16	*shared_segments_count = 1;
283	16	shared_segments_p = (zend_shared_segment ) calloc(1, sizeof(zend_shared_segment) + sizeof(void ));
284	16	if (!*shared_segments_p) {
285	0	munmap(p, requested_size);
286	0	*error_in = "calloc";
287	0	return ALLOC_FAILURE;
288	0	}
289	16	shared_segment = (zend_shared_segment )((char )(shared_segments_p) + sizeof(void ));
290	16	(*shared_segments_p)[0] = shared_segment;
291
292	16	shared_segment->p = p;
293	16	shared_segment->pos = 0;
294	16	shared_segment->size = requested_size;
295
296	16	return ALLOC_SUCCESS;
297	16	}
298
299		static int detach_segment(zend_shared_segment *shared_segment)
300	0	{
301	0	munmap(shared_segment->p, shared_segment->size);
302	0	return 0;
303	0	}
304
305		static size_t segment_type_size(void)
306	32	{
307	32	return sizeof(zend_shared_segment);
308	32	}
309
310		const zend_shared_memory_handlers zend_alloc_mmap_handlers = {
311		create_segments,
312		detach_segment,
313		segment_type_size
314		};
315
316		#endif /* USE_MMAP */