1 /*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <inttypes.h>
18 #include <stdint.h>
19 #include <stdlib.h>
20 #include <sys/types.h>
21 #include <ucontext.h>
22
23 #include <string>
24
25 #include <base/stringprintf.h>
26
27 #include <backtrace/Backtrace.h>
28 #include <backtrace/BacktraceMap.h>
29
30 #include <cutils/threads.h>
31
32 #include "BacktraceLog.h"
33 #include "thread_utils.h"
34 #include "UnwindCurrent.h"
35 #include "UnwindPtrace.h"
36
37 using android::base::StringPrintf;
38
39 //-------------------------------------------------------------------------
40 // Backtrace functions.
41 //-------------------------------------------------------------------------
Backtrace(pid_t pid,pid_t tid,BacktraceMap * map)42 Backtrace::Backtrace(pid_t pid, pid_t tid, BacktraceMap* map)
43 : pid_(pid), tid_(tid), map_(map), map_shared_(true) {
44 if (map_ == nullptr) {
45 map_ = BacktraceMap::Create(pid);
46 map_shared_ = false;
47 }
48 }
49
~Backtrace()50 Backtrace::~Backtrace() {
51 if (map_ && !map_shared_) {
52 delete map_;
53 map_ = nullptr;
54 }
55 }
56
GetFunctionName(uintptr_t pc,uintptr_t * offset)57 std::string Backtrace::GetFunctionName(uintptr_t pc, uintptr_t* offset) {
58 std::string func_name = GetFunctionNameRaw(pc, offset);
59 return func_name;
60 }
61
VerifyReadWordArgs(uintptr_t ptr,word_t * out_value)62 bool Backtrace::VerifyReadWordArgs(uintptr_t ptr, word_t* out_value) {
63 if (ptr & (sizeof(word_t)-1)) {
64 BACK_LOGW("invalid pointer %p", reinterpret_cast<void*>(ptr));
65 *out_value = static_cast<word_t>(-1);
66 return false;
67 }
68 return true;
69 }
70
FormatFrameData(size_t frame_num)71 std::string Backtrace::FormatFrameData(size_t frame_num) {
72 if (frame_num >= frames_.size()) {
73 return "";
74 }
75 return FormatFrameData(&frames_[frame_num]);
76 }
77
FormatFrameData(const backtrace_frame_data_t * frame)78 std::string Backtrace::FormatFrameData(const backtrace_frame_data_t* frame) {
79 const char* map_name;
80 if (BacktraceMap::IsValid(frame->map) && !frame->map.name.empty()) {
81 map_name = frame->map.name.c_str();
82 } else {
83 map_name = "<unknown>";
84 }
85
86 uintptr_t relative_pc = BacktraceMap::GetRelativePc(frame->map, frame->pc);
87
88 std::string line(StringPrintf("#%02zu pc %" PRIPTR " %s", frame->num, relative_pc, map_name));
89 // Special handling for non-zero offset maps, we need to print that
90 // information.
91 if (frame->map.offset != 0) {
92 line += " (offset " + StringPrintf("0x%" PRIxPTR, frame->map.offset) + ")";
93 }
94 if (!frame->func_name.empty()) {
95 line += " (" + frame->func_name;
96 if (frame->func_offset) {
97 line += StringPrintf("+%" PRIuPTR, frame->func_offset);
98 }
99 line += ')';
100 }
101
102 return line;
103 }
104
FillInMap(uintptr_t pc,backtrace_map_t * map)105 void Backtrace::FillInMap(uintptr_t pc, backtrace_map_t* map) {
106 if (map_ != nullptr) {
107 map_->FillIn(pc, map);
108 }
109 }
110
Create(pid_t pid,pid_t tid,BacktraceMap * map)111 Backtrace* Backtrace::Create(pid_t pid, pid_t tid, BacktraceMap* map) {
112 if (pid == BACKTRACE_CURRENT_PROCESS) {
113 pid = getpid();
114 if (tid == BACKTRACE_CURRENT_THREAD) {
115 tid = gettid();
116 }
117 } else if (tid == BACKTRACE_CURRENT_THREAD) {
118 tid = pid;
119 }
120
121 if (pid == getpid()) {
122 return new UnwindCurrent(pid, tid, map);
123 } else {
124 return new UnwindPtrace(pid, tid, map);
125 }
126 }
127