1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <stdint.h> 30 31 #include "backtrace.h" 32 #include "Config.h" 33 #include "DebugData.h" 34 #include "debug_disable.h" 35 #include "debug_log.h" 36 #include "FreeTrackData.h" 37 #include "malloc_debug.h" 38 39 FreeTrackData::FreeTrackData(const Config& config) 40 : backtrace_num_frames_(config.free_track_backtrace_num_frames) { 41 cmp_mem_.resize(4096); 42 memset(cmp_mem_.data(), config.fill_free_value, cmp_mem_.size()); 43 } 44 45 void FreeTrackData::LogFreeError(DebugData& debug, const Header* header, 46 const uint8_t* pointer) { 47 ScopedDisableDebugCalls disable; 48 49 error_log(LOG_DIVIDER); 50 error_log("+++ ALLOCATION %p USED AFTER FREE", pointer); 51 uint8_t fill_free_value = debug.config().fill_free_value; 52 for (size_t i = 0; i < header->usable_size; i++) { 53 if (pointer[i] != fill_free_value) { 54 error_log(" allocation[%zu] = 0x%02x (expected 0x%02x)", i, pointer[i], fill_free_value); 55 } 56 } 57 auto back_iter = backtraces_.find(header); 58 if (back_iter != backtraces_.end()) { 59 const BacktraceHeader* back_header = back_iter->second; 60 error_log("Backtrace at time of free:"); 61 backtrace_log(&back_header->frames[0], back_header->num_frames); 62 } 63 error_log(LOG_DIVIDER); 64 } 65 66 void FreeTrackData::VerifyAndFree(DebugData& debug, const Header* header, 67 const void* pointer) { 68 ScopedDisableDebugCalls disable; 69 70 if (header->tag != DEBUG_FREE_TAG) { 71 error_log(LOG_DIVIDER); 72 error_log("+++ ALLOCATION %p HAS CORRUPTED HEADER TAG 0x%x AFTER FREE", pointer, header->tag); 73 error_log(LOG_DIVIDER); 74 } else { 75 const uint8_t* memory = reinterpret_cast<const uint8_t*>(pointer); 76 size_t bytes = header->usable_size; 77 bytes = (bytes < debug.config().fill_on_free_bytes) ? bytes : debug.config().fill_on_free_bytes; 78 while (bytes > 0) { 79 size_t bytes_to_cmp = (bytes < cmp_mem_.size()) ? bytes : cmp_mem_.size(); 80 if (memcmp(memory, cmp_mem_.data(), bytes_to_cmp) != 0) { 81 LogFreeError(debug, header, reinterpret_cast<const uint8_t*>(pointer)); 82 break; 83 } 84 bytes -= bytes_to_cmp; 85 memory = &memory[bytes_to_cmp]; 86 } 87 } 88 89 auto back_iter = backtraces_.find(header); 90 if (back_iter != backtraces_.end()) { 91 g_dispatch->free(reinterpret_cast<void*>(back_iter->second)); 92 backtraces_.erase(header); 93 } 94 g_dispatch->free(header->orig_pointer); 95 } 96 97 void FreeTrackData::Add(DebugData& debug, const Header* header) { 98 // Make sure the stl calls below don't call the debug_XXX functions. 99 ScopedDisableDebugCalls disable; 100 101 pthread_mutex_lock(&mutex_); 102 if (list_.size() == debug.config().free_track_allocations) { 103 const Header* old_header = list_.back(); 104 VerifyAndFree(debug, old_header, debug.GetPointer(old_header)); 105 list_.pop_back(); 106 } 107 108 if (backtrace_num_frames_ > 0) { 109 BacktraceHeader* back_header = reinterpret_cast<BacktraceHeader*>( 110 g_dispatch->malloc(sizeof(BacktraceHeader) + backtrace_num_frames_ * sizeof(uintptr_t))); 111 if (back_header) { 112 back_header->num_frames = backtrace_get(&back_header->frames[0], backtrace_num_frames_); 113 backtraces_[header] = back_header; 114 } 115 } 116 list_.push_front(header); 117 118 pthread_mutex_unlock(&mutex_); 119 } 120 121 void FreeTrackData::VerifyAll(DebugData& debug) { 122 // Make sure the stl calls below don't call the debug_XXX functions. 123 ScopedDisableDebugCalls disable; 124 125 for (const auto& header : list_) { 126 VerifyAndFree(debug, header, debug.GetPointer(header)); 127 } 128 list_.clear(); 129 } 130 131 void FreeTrackData::LogBacktrace(const Header* header) { 132 ScopedDisableDebugCalls disable; 133 134 auto back_iter = backtraces_.find(header); 135 if (back_iter == backtraces_.end()) { 136 return; 137 } 138 139 error_log("Backtrace of original free:"); 140 backtrace_log(&back_iter->second->frames[0], back_iter->second->num_frames); 141 } 142
