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
39FreeTrackData::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
45void 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
66void 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
97void 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
121void 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
131void 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