1 /****************************************************************************** 2 * 3 * Copyright 2014 Google, Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 #define LOG_TAG "bt_osi_allocation_tracker" 20 21 #include "osi/include/allocation_tracker.h" 22 23 #include <base/logging.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <mutex> 27 #include <unordered_map> 28 29 #include "osi/include/allocator.h" 30 #include "osi/include/log.h" 31 #include "osi/include/osi.h" 32 33 typedef struct { 34 uint8_t allocator_id; 35 void* ptr; 36 size_t size; 37 bool freed; 38 } allocation_t; 39 40 static const size_t canary_size = 8; 41 static char canary[canary_size]; 42 static std::unordered_map<void*, allocation_t*> allocations; 43 static std::mutex tracker_lock; 44 static bool enabled = false; 45 46 // Memory allocation statistics 47 static size_t alloc_counter = 0; 48 static size_t free_counter = 0; 49 static size_t alloc_total_size = 0; 50 static size_t free_total_size = 0; 51 52 void allocation_tracker_init(void) { 53 std::unique_lock<std::mutex> lock(tracker_lock); 54 if (enabled) return; 55 56 // randomize the canary contents 57 for (size_t i = 0; i < canary_size; i++) canary[i] = (char)osi_rand(); 58 59 LOG_DEBUG(LOG_TAG, "canary initialized"); 60 61 enabled = true; 62 } 63 64 // Test function only. Do not call in the normal course of operations. 65 void allocation_tracker_uninit(void) { 66 std::unique_lock<std::mutex> lock(tracker_lock); 67 if (!enabled) return; 68 69 allocations.clear(); 70 enabled = false; 71 } 72 73 void allocation_tracker_reset(void) { 74 std::unique_lock<std::mutex> lock(tracker_lock); 75 if (!enabled) return; 76 77 allocations.clear(); 78 } 79 80 size_t allocation_tracker_expect_no_allocations(void) { 81 std::unique_lock<std::mutex> lock(tracker_lock); 82 if (!enabled) return 0; 83 84 size_t unfreed_memory_size = 0; 85 86 for (const auto& entry : allocations) { 87 allocation_t* allocation = entry.second; 88 if (!allocation->freed) { 89 unfreed_memory_size += 90 allocation->size; // Report back the unfreed byte count 91 LOG_ERROR(LOG_TAG, 92 "%s found unfreed allocation. address: 0x%zx size: %zd bytes", 93 __func__, (uintptr_t)allocation->ptr, allocation->size); 94 } 95 } 96 97 return unfreed_memory_size; 98 } 99 100 void* allocation_tracker_notify_alloc(uint8_t allocator_id, void* ptr, 101 size_t requested_size) { 102 char* return_ptr; 103 { 104 std::unique_lock<std::mutex> lock(tracker_lock); 105 if (!enabled || !ptr) return ptr; 106 107 // Keep statistics 108 alloc_counter++; 109 alloc_total_size += allocation_tracker_resize_for_canary(requested_size); 110 111 return_ptr = ((char*)ptr) + canary_size; 112 113 auto map_entry = allocations.find(return_ptr); 114 allocation_t* allocation; 115 if (map_entry != allocations.end()) { 116 allocation = map_entry->second; 117 CHECK(allocation->freed); // Must have been freed before 118 } else { 119 allocation = (allocation_t*)calloc(1, sizeof(allocation_t)); 120 allocations[return_ptr] = allocation; 121 } 122 123 allocation->allocator_id = allocator_id; 124 allocation->freed = false; 125 allocation->size = requested_size; 126 allocation->ptr = return_ptr; 127 } 128 129 // Add the canary on both sides 130 memcpy(return_ptr - canary_size, canary, canary_size); 131 memcpy(return_ptr + requested_size, canary, canary_size); 132 133 return return_ptr; 134 } 135 136 void* allocation_tracker_notify_free(UNUSED_ATTR uint8_t allocator_id, 137 void* ptr) { 138 std::unique_lock<std::mutex> lock(tracker_lock); 139 140 if (!enabled || !ptr) return ptr; 141 142 auto map_entry = allocations.find(ptr); 143 CHECK(map_entry != allocations.end()); 144 allocation_t* allocation = map_entry->second; 145 CHECK(allocation); // Must have been tracked before 146 CHECK(!allocation->freed); // Must not be a double free 147 CHECK(allocation->allocator_id == 148 allocator_id); // Must be from the same allocator 149 150 // Keep statistics 151 free_counter++; 152 free_total_size += allocation_tracker_resize_for_canary(allocation->size); 153 154 allocation->freed = true; 155 156 UNUSED_ATTR const char* beginning_canary = ((char*)ptr) - canary_size; 157 UNUSED_ATTR const char* end_canary = ((char*)ptr) + allocation->size; 158 159 for (size_t i = 0; i < canary_size; i++) { 160 CHECK(beginning_canary[i] == canary[i]); 161 CHECK(end_canary[i] == canary[i]); 162 } 163 164 // Free the hash map entry to avoid unlimited memory usage growth. 165 // Double-free of memory is detected with "assert(allocation)" above 166 // as the allocation entry will not be present. 167 allocations.erase(ptr); 168 free(allocation); 169 170 return ((char*)ptr) - canary_size; 171 } 172 173 size_t allocation_tracker_resize_for_canary(size_t size) { 174 return (!enabled) ? size : size + (2 * canary_size); 175 } 176 177 void osi_allocator_debug_dump(int fd) { 178 dprintf(fd, "\nBluetooth Memory Allocation Statistics:\n"); 179 180 std::unique_lock<std::mutex> lock(tracker_lock); 181 182 dprintf(fd, " Total allocated/free/used counts : %zu / %zu / %zu\n", 183 alloc_counter, free_counter, alloc_counter - free_counter); 184 dprintf(fd, " Total allocated/free/used octets : %zu / %zu / %zu\n", 185 alloc_total_size, free_total_size, 186 alloc_total_size - free_total_size); 187 } 188
