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. 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 38 static size_t *get_malloc_address_location(void *const mem) { 39 return ((size_t *)mem) - 1; 40 } 41 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 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 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 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 70 void *vpx_malloc(size_t size) { return vpx_memalign(DEFAULT_ALIGNMENT, size); } 71 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 81 void vpx_free(void *memblk) { 82 if (memblk) { 83 void *addr = get_actual_malloc_address(memblk); 84 free(addr); 85 } 86 } 87
