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 !defined(VPX_MAX_ALLOCABLE_MEMORY)
20 #if SIZE_MAX > (1ULL << 40)
21 #define VPX_MAX_ALLOCABLE_MEMORY (1ULL << 40)
22 #else
23 // For 32-bit targets keep this below INT_MAX to avoid valgrind warnings.
24 #define VPX_MAX_ALLOCABLE_MEMORY ((1ULL << 31) - (1 << 16))
25 #endif
26 #endif
27
28 // Returns 0 in case of overflow of nmemb * size.
check_size_argument_overflow(uint64_t nmemb,uint64_t size)29 static int check_size_argument_overflow(uint64_t nmemb, uint64_t size) {
30 const uint64_t total_size = nmemb * size;
31 if (nmemb == 0) return 1;
32 if (size > VPX_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
33 if (total_size != (size_t)total_size) return 0;
34
35 return 1;
36 }
37
get_malloc_address_location(void * const mem)38 static size_t *get_malloc_address_location(void *const mem) {
39 return ((size_t *)mem) - 1;
40 }
41
get_aligned_malloc_size(size_t size,size_t align)42 static uint64_t get_aligned_malloc_size(size_t size, size_t align) {
43 return (uint64_t)size + align - 1 + ADDRESS_STORAGE_SIZE;
44 }
45
set_actual_malloc_address(void * const mem,const void * const malloc_addr)46 static void set_actual_malloc_address(void *const mem,
47 const void *const malloc_addr) {
48 size_t *const malloc_addr_location = get_malloc_address_location(mem);
49 *malloc_addr_location = (size_t)malloc_addr;
50 }
51
get_actual_malloc_address(void * const mem)52 static void *get_actual_malloc_address(void *const mem) {
53 size_t *const malloc_addr_location = get_malloc_address_location(mem);
54 return (void *)(*malloc_addr_location);
55 }
56
vpx_memalign(size_t align,size_t size)57 void *vpx_memalign(size_t align, size_t size) {
58 void *x = NULL, *addr;
59 const uint64_t aligned_size = get_aligned_malloc_size(size, align);
60 if (!check_size_argument_overflow(1, aligned_size)) return NULL;
61
62 addr = malloc((size_t)aligned_size);
63 if (addr) {
64 x = align_addr((unsigned char *)addr + ADDRESS_STORAGE_SIZE, align);
65 set_actual_malloc_address(x, addr);
66 }
67 return x;
68 }
69
vpx_malloc(size_t size)70 void *vpx_malloc(size_t size) { return vpx_memalign(DEFAULT_ALIGNMENT, size); }
71
vpx_calloc(size_t num,size_t size)72 void *vpx_calloc(size_t num, size_t size) {
73 void *x;
74 if (!check_size_argument_overflow(num, size)) return NULL;
75
76 x = vpx_malloc(num * size);
77 if (x) memset(x, 0, num * size);
78 return x;
79 }
80
vpx_free(void * memblk)81 void vpx_free(void *memblk) {
82 if (memblk) {
83 void *addr = get_actual_malloc_address(memblk);
84 free(addr);
85 }
86 }
87