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(DebugData* debug, const Config& config) 40 : OptionData(debug), 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(const Header* header, const uint8_t* pointer) { 46 error_log(LOG_DIVIDER); 47 error_log("+++ ALLOCATION %p USED AFTER FREE", pointer); 48 uint8_t fill_free_value = debug_->config().fill_free_value(); 49 for (size_t i = 0; i < header->usable_size; i++) { 50 if (pointer[i] != fill_free_value) { 51 error_log(" allocation[%zu] = 0x%02x (expected 0x%02x)", i, pointer[i], fill_free_value); 52 } 53 } 54 auto back_iter = backtraces_.find(header); 55 if (back_iter != backtraces_.end()) { 56 const BacktraceHeader* back_header = back_iter->second; 57 error_log("Backtrace at time of free:"); 58 backtrace_log(&back_header->frames[0], back_header->num_frames); 59 } 60 error_log(LOG_DIVIDER); 61 } 62 63 void FreeTrackData::VerifyAndFree(const Header* header) { 64 const void* pointer = debug_->GetPointer(header); 65 if (header->tag != DEBUG_FREE_TAG) { 66 error_log(LOG_DIVIDER); 67 error_log("+++ ALLOCATION %p HAS CORRUPTED HEADER TAG 0x%x AFTER FREE", pointer, header->tag); 68 error_log(LOG_DIVIDER); 69 } else { 70 const uint8_t* memory = reinterpret_cast<const uint8_t*>(pointer); 71 size_t bytes = header->usable_size; 72 bytes = (bytes < debug_->config().fill_on_free_bytes()) ? bytes 73 : debug_->config().fill_on_free_bytes(); 74 while (bytes > 0) { 75 size_t bytes_to_cmp = (bytes < cmp_mem_.size()) ? bytes : cmp_mem_.size(); 76 if (memcmp(memory, cmp_mem_.data(), bytes_to_cmp) != 0) { 77 LogFreeError(header, reinterpret_cast<const uint8_t*>(pointer)); 78 break; 79 } 80 bytes -= bytes_to_cmp; 81 memory = &memory[bytes_to_cmp]; 82 } 83 } 84 85 auto back_iter = backtraces_.find(header); 86 if (back_iter != backtraces_.end()) { 87 g_dispatch->free(reinterpret_cast<void*>(back_iter->second)); 88 backtraces_.erase(header); 89 } 90 g_dispatch->free(header->orig_pointer); 91 } 92 93 void FreeTrackData::Add(const Header* header) { 94 pthread_mutex_lock(&mutex_); 95 if (list_.size() == debug_->config().free_track_allocations()) { 96 const Header* old_header = list_.back(); 97 VerifyAndFree(old_header); 98 list_.pop_back(); 99 } 100 101 if (backtrace_num_frames_ > 0) { 102 BacktraceHeader* back_header = reinterpret_cast<BacktraceHeader*>( 103 g_dispatch->malloc(sizeof(BacktraceHeader) + backtrace_num_frames_ * sizeof(uintptr_t))); 104 if (back_header) { 105 back_header->num_frames = backtrace_get(&back_header->frames[0], backtrace_num_frames_); 106 backtraces_[header] = back_header; 107 } 108 } 109 list_.push_front(header); 110 111 pthread_mutex_unlock(&mutex_); 112 } 113 114 void FreeTrackData::VerifyAll() { 115 for (const auto& header : list_) { 116 VerifyAndFree(header); 117 } 118 list_.clear(); 119 } 120 121 void FreeTrackData::LogBacktrace(const Header* header) { 122 auto back_iter = backtraces_.find(header); 123 if (back_iter == backtraces_.end()) { 124 return; 125 } 126 127 error_log("Backtrace of original free:"); 128 backtrace_log(&back_iter->second->frames[0], back_iter->second->num_frames); 129 } 130
