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 // Create a JitDebug object for getting jit unwind information.
47 std::vector<std::string> search_libs_{"libart.so", "libartd.so"};
48 jit_debug_.reset(new unwindstack::JitDebug(process_memory_, search_libs_));
49 #if !defined(NO_LIBDEXFILE_SUPPORT)
50 dex_files_.reset(new unwindstack::DexFiles(process_memory_, search_libs_));
51 #endif
52
53 if (!stack_maps_->Parse()) {
54 return false;
55 }
56
57 // Iterate through the maps and fill in the backtrace_map_t structure.
58 for (const auto& map_info : *stack_maps_) {
59 backtrace_map_t map;
60 map.start = map_info->start;
61 map.end = map_info->end;
62 map.offset = map_info->offset;
63 // Set to -1 so that it is demand loaded.
64 map.load_bias = static_cast<uint64_t>(-1);
65 map.flags = map_info->flags;
66 map.name = map_info->name;
67
68 maps_.push_back(map);
69 }
70
71 return true;
72 }
73
FillIn(uint64_t addr,backtrace_map_t * map)74 void UnwindStackMap::FillIn(uint64_t addr, backtrace_map_t* map) {
75 BacktraceMap::FillIn(addr, map);
76 if (map->load_bias != static_cast<uint64_t>(-1)) {
77 return;
78 }
79
80 // Fill in the load_bias.
81 unwindstack::MapInfo* map_info = stack_maps_->Find(addr);
82 if (map_info == nullptr) {
83 return;
84 }
85 map->load_bias = map_info->GetLoadBias(process_memory_);
86 }
87
GetLoadBias(size_t index)88 uint64_t UnwindStackMap::GetLoadBias(size_t index) {
89 if (index >= stack_maps_->Total()) {
90 return 0;
91 }
92
93 unwindstack::MapInfo* map_info = stack_maps_->Get(index);
94 if (map_info == nullptr) {
95 return 0;
96 }
97 return map_info->GetLoadBias(process_memory_);
98 }
99
GetFunctionName(uint64_t pc,uint64_t * offset)100 std::string UnwindStackMap::GetFunctionName(uint64_t pc, uint64_t* offset) {
101 *offset = 0;
102 unwindstack::Maps* maps = stack_maps();
103
104 // Get the map for this
105 unwindstack::MapInfo* map_info = maps->Find(pc);
106 if (map_info == nullptr || map_info->flags & PROT_DEVICE_MAP) {
107 return "";
108 }
109
110 if (arch_ == unwindstack::ARCH_UNKNOWN) {
111 if (pid_ == getpid()) {
112 arch_ = unwindstack::Regs::CurrentArch();
113 } else {
114 // Create a remote regs, to figure out the architecture.
115 std::unique_ptr<unwindstack::Regs> regs(unwindstack::Regs::RemoteGet(pid_));
116 arch_ = regs->Arch();
117 }
118 }
119
120 unwindstack::Elf* elf = map_info->GetElf(process_memory(), arch_);
121
122 std::string name;
123 uint64_t func_offset;
124 if (!elf->GetFunctionName(elf->GetRelPc(pc, map_info), &name, &func_offset)) {
125 return "";
126 }
127 *offset = func_offset;
128 return name;
129 }
130
GetProcessMemory()131 std::shared_ptr<unwindstack::Memory> UnwindStackMap::GetProcessMemory() {
132 return process_memory_;
133 }
134
135 //-------------------------------------------------------------------------
136 // BacktraceMap create function.
137 //-------------------------------------------------------------------------
Create(pid_t pid,bool uncached)138 BacktraceMap* BacktraceMap::Create(pid_t pid, bool uncached) {
139 BacktraceMap* map;
140
141 if (uncached) {
142 // Force use of the base class to parse the maps when this call is made.
143 map = new BacktraceMap(pid);
144 } else if (pid == getpid()) {
145 map = new UnwindStackMap(0);
146 } else {
147 map = new UnwindStackMap(pid);
148 }
149 if (!map->Build()) {
150 delete map;
151 return nullptr;
152 }
153 return map;
154 }
155