1 /*
2 * Copyright (C) 2017 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 #define _GNU_SOURCE 1
18 #include <stdint.h>
19 #include <stdlib.h>
20 #include <string.h>
21
22 #include <memory>
23 #include <set>
24 #include <string>
25
26 #include <backtrace/Backtrace.h>
27 #include <unwindstack/Elf.h>
28 #include <unwindstack/MapInfo.h>
29 #include <unwindstack/Maps.h>
30 #include <unwindstack/Memory.h>
31 #include <unwindstack/Regs.h>
32 #include <unwindstack/RegsGetLocal.h>
33
34 #if !defined(NO_LIBDEXFILE_SUPPORT)
35 #include <unwindstack/DexFiles.h>
36 #endif
37 #include <unwindstack/Unwinder.h>
38
39 #include "BacktraceLog.h"
40 #include "UnwindStack.h"
41 #include "UnwindStackMap.h"
42
43 extern "C" char* __cxa_demangle(const char*, char*, size_t*, int*);
44
Unwind(unwindstack::Regs * regs,BacktraceMap * back_map,std::vector<backtrace_frame_data_t> * frames,size_t num_ignore_frames,std::vector<std::string> * skip_names,BacktraceUnwindError * error)45 bool Backtrace::Unwind(unwindstack::Regs* regs, BacktraceMap* back_map,
46 std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames,
47 std::vector<std::string>* skip_names, BacktraceUnwindError* error) {
48 UnwindStackMap* stack_map = reinterpret_cast<UnwindStackMap*>(back_map);
49 auto process_memory = stack_map->process_memory();
50 unwindstack::Unwinder unwinder(MAX_BACKTRACE_FRAMES + num_ignore_frames, stack_map->stack_maps(),
51 regs, stack_map->process_memory());
52 unwinder.SetResolveNames(stack_map->ResolveNames());
53 stack_map->SetArch(regs->Arch());
54 if (stack_map->GetJitDebug() != nullptr) {
55 unwinder.SetJitDebug(stack_map->GetJitDebug());
56 }
57 #if !defined(NO_LIBDEXFILE_SUPPORT)
58 if (stack_map->GetDexFiles() != nullptr) {
59 unwinder.SetDexFiles(stack_map->GetDexFiles());
60 }
61 #endif
62 unwinder.Unwind(skip_names, &stack_map->GetSuffixesToIgnore());
63 if (error != nullptr) {
64 switch (unwinder.LastErrorCode()) {
65 case unwindstack::ERROR_NONE:
66 error->error_code = BACKTRACE_UNWIND_NO_ERROR;
67 break;
68
69 case unwindstack::ERROR_MEMORY_INVALID:
70 error->error_code = BACKTRACE_UNWIND_ERROR_ACCESS_MEM_FAILED;
71 error->error_info.addr = unwinder.LastErrorAddress();
72 break;
73
74 case unwindstack::ERROR_UNWIND_INFO:
75 error->error_code = BACKTRACE_UNWIND_ERROR_UNWIND_INFO;
76 break;
77
78 case unwindstack::ERROR_UNSUPPORTED:
79 error->error_code = BACKTRACE_UNWIND_ERROR_UNSUPPORTED_OPERATION;
80 break;
81
82 case unwindstack::ERROR_INVALID_MAP:
83 error->error_code = BACKTRACE_UNWIND_ERROR_MAP_MISSING;
84 break;
85
86 case unwindstack::ERROR_MAX_FRAMES_EXCEEDED:
87 error->error_code = BACKTRACE_UNWIND_ERROR_EXCEED_MAX_FRAMES_LIMIT;
88 break;
89
90 case unwindstack::ERROR_REPEATED_FRAME:
91 error->error_code = BACKTRACE_UNWIND_ERROR_REPEATED_FRAME;
92 break;
93
94 case unwindstack::ERROR_INVALID_ELF:
95 error->error_code = BACKTRACE_UNWIND_ERROR_INVALID_ELF;
96 break;
97
98 case unwindstack::ERROR_THREAD_DOES_NOT_EXIST:
99 error->error_code = BACKTRACE_UNWIND_ERROR_THREAD_DOESNT_EXIST;
100 break;
101
102 case unwindstack::ERROR_THREAD_TIMEOUT:
103 error->error_code = BACKTRACE_UNWIND_ERROR_THREAD_TIMEOUT;
104 break;
105
106 case unwindstack::ERROR_SYSTEM_CALL:
107 case unwindstack::ERROR_MAPS_PARSE:
108 case unwindstack::ERROR_BAD_ARCH:
109 case unwindstack::ERROR_INVALID_PARAMETER:
110 error->error_code = BACKTRACE_UNWIND_ERROR_INTERNAL;
111 break;
112 }
113 }
114
115 if (num_ignore_frames >= unwinder.NumFrames()) {
116 frames->resize(0);
117 return true;
118 }
119
120 auto unwinder_frames = unwinder.frames();
121 frames->resize(unwinder.NumFrames() - num_ignore_frames);
122 size_t cur_frame = 0;
123 for (size_t i = num_ignore_frames; i < unwinder.NumFrames(); i++) {
124 auto frame = &unwinder_frames[i];
125
126 backtrace_frame_data_t* back_frame = &frames->at(cur_frame);
127
128 back_frame->num = cur_frame++;
129
130 back_frame->rel_pc = frame->rel_pc;
131 back_frame->pc = frame->pc;
132 back_frame->sp = frame->sp;
133
134 char* demangled_name = __cxa_demangle(frame->function_name.c_str(), nullptr, nullptr, nullptr);
135 if (demangled_name != nullptr) {
136 back_frame->func_name = demangled_name;
137 free(demangled_name);
138 } else {
139 back_frame->func_name = frame->function_name;
140 }
141 back_frame->func_offset = frame->function_offset;
142
143 if (frame->map_info != nullptr) {
144 back_frame->map.name = frame->map_info->name();
145 back_frame->map.start = frame->map_info->start();
146 back_frame->map.end = frame->map_info->end();
147 back_frame->map.offset = frame->map_info->elf_start_offset();
148 back_frame->map.load_bias = frame->map_info->load_bias();
149 back_frame->map.flags = frame->map_info->flags();
150 } else {
151 back_frame->map.start = 0;
152 back_frame->map.end = 0;
153 back_frame->map.offset = 0;
154 back_frame->map.load_bias = 0;
155 back_frame->map.flags = 0;
156 }
157 }
158
159 return true;
160 }
161
UnwindStackCurrent(pid_t pid,pid_t tid,BacktraceMap * map)162 UnwindStackCurrent::UnwindStackCurrent(pid_t pid, pid_t tid, BacktraceMap* map)
163 : BacktraceCurrent(pid, tid, map) {}
164
GetFunctionNameRaw(uint64_t pc,uint64_t * offset)165 std::string UnwindStackCurrent::GetFunctionNameRaw(uint64_t pc, uint64_t* offset) {
166 return GetMap()->GetFunctionName(pc, offset);
167 }
168
UnwindFromContext(size_t num_ignore_frames,void * ucontext)169 bool UnwindStackCurrent::UnwindFromContext(size_t num_ignore_frames, void* ucontext) {
170 std::unique_ptr<unwindstack::Regs> regs;
171 if (ucontext == nullptr) {
172 regs.reset(unwindstack::Regs::CreateFromLocal());
173 // Fill in the registers from this function. Do it here to avoid
174 // one extra function call appearing in the unwind.
175 unwindstack::RegsGetLocal(regs.get());
176 } else {
177 regs.reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), ucontext));
178 }
179
180 std::vector<std::string> skip_names{"libunwindstack.so", "libbacktrace.so"};
181 if (!skip_frames_) {
182 skip_names.clear();
183 }
184 return Backtrace::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames, &skip_names, &error_);
185 }
186
UnwindStackPtrace(pid_t pid,pid_t tid,BacktraceMap * map)187 UnwindStackPtrace::UnwindStackPtrace(pid_t pid, pid_t tid, BacktraceMap* map)
188 : BacktracePtrace(pid, tid, map), memory_(unwindstack::Memory::CreateProcessMemory(pid)) {}
189
GetFunctionNameRaw(uint64_t pc,uint64_t * offset)190 std::string UnwindStackPtrace::GetFunctionNameRaw(uint64_t pc, uint64_t* offset) {
191 return GetMap()->GetFunctionName(pc, offset);
192 }
193
Unwind(size_t num_ignore_frames,void * context)194 bool UnwindStackPtrace::Unwind(size_t num_ignore_frames, void* context) {
195 std::unique_ptr<unwindstack::Regs> regs;
196 if (context == nullptr) {
197 regs.reset(unwindstack::Regs::RemoteGet(Tid()));
198 } else {
199 regs.reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), context));
200 }
201
202 return Backtrace::Unwind(regs.get(), GetMap(), &frames_, num_ignore_frames, nullptr, &error_);
203 }
204
Read(uint64_t addr,uint8_t * buffer,size_t bytes)205 size_t UnwindStackPtrace::Read(uint64_t addr, uint8_t* buffer, size_t bytes) {
206 #if defined(__aarch64__)
207 // Tagged pointer after Android R would lead top byte to have random values
208 // https://source.android.com/devices/tech/debug/tagged-pointers
209 addr &= (1ULL << 56) - 1;
210 #endif
211 return memory_->Read(addr, buffer, bytes);
212 }
213