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 #include <string.h>
31 
32 #include <vector>
33 
34 #include "backtrace.h"
35 #include "Config.h"
36 #include "debug_disable.h"
37 #include "debug_log.h"
38 #include "DebugData.h"
39 #include "malloc_debug.h"
40 #include "GuardData.h"
41 
GuardData(DebugData * debug_data,int init_value,size_t num_bytes)42 GuardData::GuardData(DebugData* debug_data, int init_value, size_t num_bytes)
43     : OptionData(debug_data) {
44   // Create a buffer for fast comparisons of the front guard.
45   cmp_mem_.resize(num_bytes);
46   memset(cmp_mem_.data(), init_value, cmp_mem_.size());
47 }
48 
LogFailure(const Header * header,const void * pointer,const void * data)49 void GuardData::LogFailure(const Header* header, const void* pointer, const void* data) {
50   error_log(LOG_DIVIDER);
51   error_log("+++ ALLOCATION %p SIZE %zu HAS A CORRUPTED %s GUARD", pointer,
52             header->real_size(), GetTypeName());
53 
54   // Log all of the failing bytes.
55   const uint8_t* expected = cmp_mem_.data();
56   int pointer_idx = reinterpret_cast<uintptr_t>(data) - reinterpret_cast<uintptr_t>(pointer);
57   const uint8_t* real = reinterpret_cast<const uint8_t*>(data);
58   for (size_t i = 0; i < cmp_mem_.size(); i++, pointer_idx++) {
59     if (real[i] != expected[i]) {
60       error_log("  allocation[%d] = 0x%02x (expected 0x%02x)", pointer_idx, real[i], expected[i]);
61     }
62   }
63 
64   error_log("Backtrace at time of failure:");
65   std::vector<uintptr_t> frames(64);
66   size_t frame_num = backtrace_get(frames.data(), frames.size());
67   frames.resize(frame_num);
68   backtrace_log(frames.data(), frames.size());
69   error_log(LOG_DIVIDER);
70 }
71 
FrontGuardData(DebugData * debug_data,const Config & config,size_t * offset)72 FrontGuardData::FrontGuardData(DebugData* debug_data, const Config& config, size_t* offset)
73    : GuardData(debug_data, config.front_guard_value, config.front_guard_bytes) {
74   // Create a buffer for fast comparisons of the front guard.
75   cmp_mem_.resize(config.front_guard_bytes);
76   memset(cmp_mem_.data(), config.front_guard_value, cmp_mem_.size());
77   // Assumes that front_bytes is a multiple of MINIMUM_ALIGNMENT_BYTES.
78   offset_ = *offset;
79   *offset += config.front_guard_bytes;
80 }
81 
Valid(const Header * header)82 bool FrontGuardData::Valid(const Header* header) {
83   return GuardData::Valid(debug_->GetFrontGuard(header));
84 }
85 
LogFailure(const Header * header)86 void FrontGuardData::LogFailure(const Header* header) {
87   GuardData::LogFailure(header, debug_->GetPointer(header), debug_->GetFrontGuard(header));
88 }
89 
RearGuardData(DebugData * debug_data,const Config & config)90 RearGuardData::RearGuardData(DebugData* debug_data, const Config& config)
91     : GuardData(debug_data, config.rear_guard_value, config.rear_guard_bytes) {
92 }
93 
Valid(const Header * header)94 bool RearGuardData::Valid(const Header* header) {
95   return GuardData::Valid(debug_->GetRearGuard(header));
96 }
97 
LogFailure(const Header * header)98 void RearGuardData::LogFailure(const Header* header) {
99   GuardData::LogFailure(header, debug_->GetPointer(header), debug_->GetRearGuard(header));
100 }
101