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 #include <stdint.h>
18 #include <stdlib.h>
19 #include <sys/types.h>
20
21 #include <string>
22 #include <vector>
23
24 #include <backtrace/BacktraceMap.h>
25 #include <unwindstack/Elf.h>
26 #include <unwindstack/MapInfo.h>
27 #include <unwindstack/Maps.h>
28 #include <unwindstack/Regs.h>
29
30 #include "UnwindStackMap.h"
31
32 //-------------------------------------------------------------------------
UnwindStackMap(pid_t pid)33 UnwindStackMap::UnwindStackMap(pid_t pid) : BacktraceMap(pid) {}
34
Build()35 bool UnwindStackMap::Build() {
36 if (pid_ == 0) {
37 pid_ = getpid();
38 stack_maps_.reset(new unwindstack::LocalMaps);
39 } else {
40 stack_maps_.reset(new unwindstack::RemoteMaps(pid_));
41 }
42
43 // Create the process memory object.
44 process_memory_ = unwindstack::Memory::CreateProcessMemory(pid_);
45
46 if (arch_ == unwindstack::ARCH_UNKNOWN) {
47 if (pid_ == getpid()) {
48 arch_ = unwindstack::Regs::CurrentArch();
49 } else {
50 // Create a remote regs, to figure out the architecture.
51 std::unique_ptr<unwindstack::Regs> regs(unwindstack::Regs::RemoteGet(pid_));
52 if (regs.get() != nullptr) {
53 arch_ = regs->Arch();
54 }
55 }
56 }
57
58 // Create a JitDebug object for getting jit unwind information.
59 if (arch_ != unwindstack::ARCH_UNKNOWN) {
60 std::vector<std::string> search_libs_{"libart.so", "libartd.so"};
61 jit_debug_ = CreateJitDebug(arch_, process_memory_, search_libs_);
62 #if !defined(NO_LIBDEXFILE_SUPPORT)
63 dex_files_ = CreateDexFiles(arch_, process_memory_, search_libs_);
64 #endif
65 }
66
67 if (!stack_maps_->Parse()) {
68 return false;
69 }
70
71 // Iterate through the maps and fill in the backtrace_map_t structure.
72 for (const auto& map_info : *stack_maps_) {
73 backtrace_map_t map;
74 map.start = map_info->start();
75 map.end = map_info->end();
76 map.offset = map_info->offset();
77 // Set to -1 so that it is demand loaded.
78 map.load_bias = static_cast<uint64_t>(-1);
79 map.flags = map_info->flags();
80 map.name = map_info->name();
81
82 maps_.push_back(map);
83 }
84
85 return true;
86 }
87
FillIn(uint64_t addr,backtrace_map_t * map)88 void UnwindStackMap::FillIn(uint64_t addr, backtrace_map_t* map) {
89 BacktraceMap::FillIn(addr, map);
90 if (map->load_bias != static_cast<uint64_t>(-1)) {
91 return;
92 }
93
94 // Fill in the load_bias.
95 std::shared_ptr<unwindstack::MapInfo> map_info = stack_maps_->Find(addr);
96 if (map_info == nullptr) {
97 return;
98 }
99 map->load_bias = map_info->GetLoadBias(process_memory_);
100 }
101
GetBuildId(uint64_t addr)102 std::string UnwindStackMap::GetBuildId(uint64_t addr) {
103 auto map_info = stack_maps_->Find(addr);
104 return map_info == nullptr ? std::string() : map_info->GetPrintableBuildID();
105 }
106
GetLoadBias(size_t index)107 uint64_t UnwindStackMap::GetLoadBias(size_t index) {
108 if (index >= stack_maps_->Total()) {
109 return 0;
110 }
111
112 std::shared_ptr<unwindstack::MapInfo> map_info = stack_maps_->Get(index);
113 if (map_info == nullptr) {
114 return 0;
115 }
116 return map_info->GetLoadBias(process_memory_);
117 }
118
GetFunctionName(uint64_t pc,uint64_t * offset)119 std::string UnwindStackMap::GetFunctionName(uint64_t pc, uint64_t* offset) {
120 *offset = 0;
121 unwindstack::Maps* maps = stack_maps();
122
123 // Get the map for this
124 auto map_info = maps->Find(pc);
125 if (map_info == nullptr || map_info->flags() & PROT_DEVICE_MAP) {
126 return "";
127 }
128
129 if (arch_ == unwindstack::ARCH_UNKNOWN) {
130 if (pid_ == getpid()) {
131 arch_ = unwindstack::Regs::CurrentArch();
132 } else {
133 // Create a remote regs, to figure out the architecture.
134 std::unique_ptr<unwindstack::Regs> regs(unwindstack::Regs::RemoteGet(pid_));
135 arch_ = regs->Arch();
136 }
137 }
138
139 unwindstack::Elf* elf = map_info->GetElf(process_memory(), arch_);
140
141 unwindstack::SharedString name;
142 uint64_t func_offset;
143 if (!elf->GetFunctionName(elf->GetRelPc(pc, map_info.get()), &name, &func_offset)) {
144 return "";
145 }
146 *offset = func_offset;
147 return name;
148 }
149
GetProcessMemory()150 std::shared_ptr<unwindstack::Memory> UnwindStackMap::GetProcessMemory() {
151 return process_memory_;
152 }
153
154 //-------------------------------------------------------------------------
155 // BacktraceMap create function.
156 //-------------------------------------------------------------------------
Create(pid_t pid,bool uncached)157 BacktraceMap* BacktraceMap::Create(pid_t pid, bool uncached) {
158 BacktraceMap* map;
159
160 if (uncached) {
161 // Force use of the base class to parse the maps when this call is made.
162 map = new BacktraceMap(pid);
163 } else if (pid == getpid()) {
164 map = new UnwindStackMap(0);
165 } else {
166 map = new UnwindStackMap(pid);
167 }
168 if (!map->Build()) {
169 delete map;
170 return nullptr;
171 }
172 return map;
173 }
174