ref: b9e44842fcaa97f336001564e7715d8a5f0496f0
dir: /vpx_mem/vpx_mem.c/
/* * Copyright (c) 2010 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include "vpx_mem.h" #include <limits.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include "include/vpx_mem_intrnl.h" #include "vpx/vpx_integer.h" #if SIZE_MAX > (1ULL << 40) #define VPX_MAX_ALLOCABLE_MEMORY (1ULL << 40) #else // For 32-bit targets keep this below INT_MAX to avoid valgrind warnings. #define VPX_MAX_ALLOCABLE_MEMORY ((1ULL << 31) - (1 << 16)) #endif // Returns 0 in case of overflow of nmemb * size. static int check_size_argument_overflow(uint64_t nmemb, uint64_t size) { const uint64_t total_size = nmemb * size; if (nmemb == 0) return 1; if (size > VPX_MAX_ALLOCABLE_MEMORY / nmemb) return 0; if (total_size != (size_t)total_size) return 0; return 1; } static size_t *get_malloc_address_location(void *const mem) { return ((size_t *)mem) - 1; } static uint64_t get_aligned_malloc_size(size_t size, size_t align) { return (uint64_t)size + align - 1 + ADDRESS_STORAGE_SIZE; } static void set_actual_malloc_address(void *const mem, const void *const malloc_addr) { size_t *const malloc_addr_location = get_malloc_address_location(mem); *malloc_addr_location = (size_t)malloc_addr; } static void *get_actual_malloc_address(void *const mem) { size_t *const malloc_addr_location = get_malloc_address_location(mem); return (void *)(*malloc_addr_location); } void *vpx_memalign(size_t align, size_t size) { void *x = NULL, *addr; const uint64_t aligned_size = get_aligned_malloc_size(size, align); if (!check_size_argument_overflow(1, aligned_size)) return NULL; addr = malloc((size_t)aligned_size); if (addr) { x = align_addr((unsigned char *)addr + ADDRESS_STORAGE_SIZE, align); set_actual_malloc_address(x, addr); } return x; } void *vpx_malloc(size_t size) { return vpx_memalign(DEFAULT_ALIGNMENT, size); } void *vpx_calloc(size_t num, size_t size) { void *x; if (!check_size_argument_overflow(num, size)) return NULL; x = vpx_malloc(num * size); if (x) memset(x, 0, num * size); return x; } void vpx_free(void *memblk) { if (memblk) { void *addr = get_actual_malloc_address(memblk); free(addr); } }