1 /*
2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "vpx_mem.h"
12 #include <limits.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include "include/vpx_mem_intrnl.h"
17 #include "vpx/vpx_integer.h"
18
19 #if SIZE_MAX > (1ULL << 40)
20 #define VPX_MAX_ALLOCABLE_MEMORY (1ULL << 40)
21 #else
22 // For 32-bit targets keep this below INT_MAX to avoid valgrind warnings.
23 #define VPX_MAX_ALLOCABLE_MEMORY ((1ULL << 31) - (1 << 16))
24 #endif
25
26 // Returns 0 in case of overflow of nmemb * size.
check_size_argument_overflow(uint64_t nmemb,uint64_t size)27 static int check_size_argument_overflow(uint64_t nmemb, uint64_t size) {
28 const uint64_t total_size = nmemb * size;
29 if (nmemb == 0) return 1;
30 if (size > VPX_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
31 if (total_size != (size_t)total_size) return 0;
32
33 return 1;
34 }
35
get_malloc_address_location(void * const mem)36 static size_t *get_malloc_address_location(void *const mem) {
37 return ((size_t *)mem) - 1;
38 }
39
get_aligned_malloc_size(size_t size,size_t align)40 static uint64_t get_aligned_malloc_size(size_t size, size_t align) {
41 return (uint64_t)size + align - 1 + ADDRESS_STORAGE_SIZE;
42 }
43
set_actual_malloc_address(void * const mem,const void * const malloc_addr)44 static void set_actual_malloc_address(void *const mem,
45 const void *const malloc_addr) {
46 size_t *const malloc_addr_location = get_malloc_address_location(mem);
47 *malloc_addr_location = (size_t)malloc_addr;
48 }
49
get_actual_malloc_address(void * const mem)50 static void *get_actual_malloc_address(void *const mem) {
51 size_t *const malloc_addr_location = get_malloc_address_location(mem);
52 return (void *)(*malloc_addr_location);
53 }
54
vpx_memalign(size_t align,size_t size)55 void *vpx_memalign(size_t align, size_t size) {
56 void *x = NULL, *addr;
57 const uint64_t aligned_size = get_aligned_malloc_size(size, align);
58 if (!check_size_argument_overflow(1, aligned_size)) return NULL;
59
60 addr = malloc((size_t)aligned_size);
61 if (addr) {
62 x = align_addr((unsigned char *)addr + ADDRESS_STORAGE_SIZE, align);
63 set_actual_malloc_address(x, addr);
64 }
65 return x;
66 }
67
vpx_malloc(size_t size)68 void *vpx_malloc(size_t size) { return vpx_memalign(DEFAULT_ALIGNMENT, size); }
69
vpx_calloc(size_t num,size_t size)70 void *vpx_calloc(size_t num, size_t size) {
71 void *x;
72 if (!check_size_argument_overflow(num, size)) return NULL;
73
74 x = vpx_malloc(num * size);
75 if (x) memset(x, 0, num * size);
76 return x;
77 }
78
vpx_free(void * memblk)79 void vpx_free(void *memblk) {
80 if (memblk) {
81 void *addr = get_actual_malloc_address(memblk);
82 free(addr);
83 }
84 }
85