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 | http://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
24 #ifdef USE_MMAP
25
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <sys/mman.h>
31
32 #if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
33 # define MAP_ANONYMOUS MAP_ANON
34 #endif
35 #if defined(MAP_ALIGNED_SUPER)
36 # define MAP_HUGETLB MAP_ALIGNED_SUPER
37 #endif
38
create_segments(size_t requested_size,zend_shared_segment *** shared_segments_p,int * shared_segments_count,char ** error_in)39 static int create_segments(size_t requested_size, zend_shared_segment ***shared_segments_p, int *shared_segments_count, char **error_in)
40 {
41 zend_shared_segment *shared_segment;
42 int flags = PROT_READ | PROT_WRITE;
43 void *p;
44 #ifdef PROT_MPROTECT
45 flags |= PROT_MPROTECT(PROT_EXEC);
46 #endif
47 #ifdef PROT_MAX
48 flags |= PROT_MAX(PROT_READ | PROT_WRITE | PROT_EXEC);
49 #endif
50 #ifdef MAP_HUGETLB
51 size_t huge_page_size = 2 * 1024 * 1024;
52
53 /* Try to allocate huge pages first to reduce dTLB misses.
54 * OSes has to be configured properly
55 * on Linux
56 * (e.g. https://wiki.debian.org/Hugepages#Enabling_HugeTlbPage)
57 * You may verify huge page usage with the following command:
58 * `grep "Huge" /proc/meminfo`
59 * on FreeBSD
60 * sysctl vm.pmap.pg_ps_enabled entry
61 * (boot time config only, but enabled by default on most arches).
62 */
63 if (requested_size >= huge_page_size && requested_size % huge_page_size == 0) {
64 # if defined(__x86_64__) && defined(MAP_32BIT)
65 /* to got HUGE PAGES in low 32-bit address we have to reserve address
66 space and then remap it using MAP_HUGETLB */
67
68 p = mmap(NULL, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT, -1, 0);
69 if (p != MAP_FAILED) {
70 munmap(p, requested_size);
71 p = (void*)(ZEND_MM_ALIGNED_SIZE_EX((ptrdiff_t)p, huge_page_size));
72 p = mmap(p, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT|MAP_HUGETLB|MAP_FIXED, -1, 0);
73 if (p != MAP_FAILED) {
74 goto success;
75 } else {
76 p = mmap(NULL, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT, -1, 0);
77 if (p != MAP_FAILED) {
78 goto success;
79 }
80 }
81 }
82 # endif
83 p = mmap(0, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0);
84 if (p != MAP_FAILED) {
85 goto success;
86 }
87 }
88 #elif defined(PREFER_MAP_32BIT) && defined(__x86_64__) && defined(MAP_32BIT)
89 p = mmap(NULL, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS|MAP_32BIT, -1, 0);
90 if (p != MAP_FAILED) {
91 goto success;
92 }
93 #endif
94
95 p = mmap(0, requested_size, flags, MAP_SHARED|MAP_ANONYMOUS, -1, 0);
96 if (p == MAP_FAILED) {
97 *error_in = "mmap";
98 return ALLOC_FAILURE;
99 }
100
101 success: ZEND_ATTRIBUTE_UNUSED;
102 *shared_segments_count = 1;
103 *shared_segments_p = (zend_shared_segment **) calloc(1, sizeof(zend_shared_segment) + sizeof(void *));
104 if (!*shared_segments_p) {
105 munmap(p, requested_size);
106 *error_in = "calloc";
107 return ALLOC_FAILURE;
108 }
109 shared_segment = (zend_shared_segment *)((char *)(*shared_segments_p) + sizeof(void *));
110 (*shared_segments_p)[0] = shared_segment;
111
112 shared_segment->p = p;
113 shared_segment->pos = 0;
114 shared_segment->size = requested_size;
115
116 return ALLOC_SUCCESS;
117 }
118
detach_segment(zend_shared_segment * shared_segment)119 static int detach_segment(zend_shared_segment *shared_segment)
120 {
121 munmap(shared_segment->p, shared_segment->size);
122 return 0;
123 }
124
segment_type_size(void)125 static size_t segment_type_size(void)
126 {
127 return sizeof(zend_shared_segment);
128 }
129
130 zend_shared_memory_handlers zend_alloc_mmap_handlers = {
131 create_segments,
132 detach_segment,
133 segment_type_size
134 };
135
136 #endif /* USE_MMAP */
137
