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
FreeTrackData(const Config & config)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
LogFreeError(DebugData & debug,const Header * header,const uint8_t * pointer)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
VerifyAndFree(DebugData & debug,const Header * header,const void * pointer)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
Add(DebugData & debug,const Header * header)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
VerifyAll(DebugData & debug)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
LogBacktrace(const Header * header)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