blob: f4126e34bd2618576269c7ed1cacf93185da813a [file] [log] [blame]
/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include "aom_mem.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "include/aom_mem_intrnl.h"
#include "aom/aom_integer.h"
static size_t GetAllocationPaddingSize(size_t align) {
assert(align > 0);
assert(align < SIZE_MAX - ADDRESS_STORAGE_SIZE);
return align - 1 + ADDRESS_STORAGE_SIZE;
}
// Returns 0 in case of overflow of nmemb * size.
static int check_size_argument_overflow(size_t nmemb, size_t size,
size_t align) {
if (nmemb == 0) return 1;
const size_t alloc_padding = GetAllocationPaddingSize(align);
#if defined(AOM_MAX_ALLOCABLE_MEMORY)
assert(AOM_MAX_ALLOCABLE_MEMORY >= alloc_padding);
assert(AOM_MAX_ALLOCABLE_MEMORY <= SIZE_MAX);
if (size > (AOM_MAX_ALLOCABLE_MEMORY - alloc_padding) / nmemb) return 0;
#else
if (size > (SIZE_MAX - alloc_padding) / nmemb) return 0;
#endif
return 1;
}
static size_t *GetMallocAddressLocation(void *const mem) {
return ((size_t *)mem) - 1;
}
static void SetActualMallocAddress(void *const mem,
const void *const malloc_addr) {
size_t *const malloc_addr_location = GetMallocAddressLocation(mem);
*malloc_addr_location = (size_t)malloc_addr;
}
static void *GetActualMallocAddress(void *const mem) {
const size_t *const malloc_addr_location = GetMallocAddressLocation(mem);
return (void *)(*malloc_addr_location);
}
void *aom_memalign(size_t align, size_t size) {
void *x = NULL;
if (!check_size_argument_overflow(1, size, align)) return NULL;
const size_t aligned_size = size + GetAllocationPaddingSize(align);
void *const addr = malloc(aligned_size);
if (addr) {
x = aom_align_addr((unsigned char *)addr + ADDRESS_STORAGE_SIZE, align);
SetActualMallocAddress(x, addr);
}
return x;
}
void *aom_malloc(size_t size) { return aom_memalign(DEFAULT_ALIGNMENT, size); }
void *aom_calloc(size_t num, size_t size) {
if (!check_size_argument_overflow(num, size, DEFAULT_ALIGNMENT)) return NULL;
const size_t total_size = num * size;
void *const x = aom_malloc(total_size);
if (x) memset(x, 0, total_size);
return x;
}
void aom_free(void *memblk) {
if (memblk) {
void *addr = GetActualMallocAddress(memblk);
free(addr);
}
}