1 /*
2  * Copyright (C) 2018 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 <sys/mman.h>
19 #include <sys/stat.h>
20 #include <sys/types.h>
21 #include <unistd.h>
22 
23 #include <memory>
24 
25 #define LOG_TAG "unwind"
26 #include <log/log.h>
27 
28 #include <android-base/unique_fd.h>
29 #include <art_api/dex_file_support.h>
30 
31 #include <unwindstack/MapInfo.h>
32 #include <unwindstack/Memory.h>
33 
34 #include "DexFile.h"
35 
36 namespace unwindstack {
37 
CheckDexSupport()38 static bool CheckDexSupport() {
39   if (std::string err_msg; !art_api::dex::TryLoadLibdexfileExternal(&err_msg)) {
40     ALOGW("Failed to initialize DEX file support: %s", err_msg.c_str());
41     return false;
42   }
43   return true;
44 }
45 
HasDexSupport()46 static bool HasDexSupport() {
47   static bool has_dex_support = CheckDexSupport();
48   return has_dex_support;
49 }
50 
Create(uint64_t dex_file_offset_in_memory,Memory * memory,MapInfo * info)51 std::unique_ptr<DexFile> DexFile::Create(uint64_t dex_file_offset_in_memory, Memory* memory,
52                                          MapInfo* info) {
53   if (UNLIKELY(!HasDexSupport())) {
54     return nullptr;
55   }
56 
57   size_t max_size = info->end - dex_file_offset_in_memory;
58   if (memory->IsLocal()) {
59     size_t size = max_size;
60 
61     std::string err_msg;
62     std::unique_ptr<art_api::dex::DexFile> art_dex_file = DexFile::OpenFromMemory(
63         reinterpret_cast<void const*>(dex_file_offset_in_memory), &size, info->name, &err_msg);
64     if (art_dex_file != nullptr && size <= max_size) {
65       return std::unique_ptr<DexFile>(new DexFile(art_dex_file));
66     }
67   }
68 
69   if (!info->name.empty()) {
70     std::unique_ptr<DexFile> dex_file =
71         DexFileFromFile::Create(dex_file_offset_in_memory - info->start + info->offset, info->name);
72     if (dex_file) {
73       return dex_file;
74     }
75   }
76   return DexFileFromMemory::Create(dex_file_offset_in_memory, memory, info->name, max_size);
77 }
78 
GetMethodInformation(uint64_t dex_offset,std::string * method_name,uint64_t * method_offset)79 bool DexFile::GetMethodInformation(uint64_t dex_offset, std::string* method_name,
80                                    uint64_t* method_offset) {
81   art_api::dex::MethodInfo method_info = GetMethodInfoForOffset(dex_offset, false);
82   if (method_info.offset == 0) {
83     return false;
84   }
85   *method_name = method_info.name;
86   *method_offset = dex_offset - method_info.offset;
87   return true;
88 }
89 
Create(uint64_t dex_file_offset_in_file,const std::string & file)90 std::unique_ptr<DexFileFromFile> DexFileFromFile::Create(uint64_t dex_file_offset_in_file,
91                                                          const std::string& file) {
92   if (UNLIKELY(!HasDexSupport())) {
93     return nullptr;
94   }
95 
96   android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(file.c_str(), O_RDONLY | O_CLOEXEC)));
97   if (fd == -1) {
98     return nullptr;
99   }
100 
101   std::string error_msg;
102   std::unique_ptr<art_api::dex::DexFile> art_dex_file =
103       OpenFromFd(fd, dex_file_offset_in_file, file, &error_msg);
104   if (art_dex_file == nullptr) {
105     return nullptr;
106   }
107 
108   return std::unique_ptr<DexFileFromFile>(new DexFileFromFile(art_dex_file));
109 }
110 
Create(uint64_t dex_file_offset_in_memory,Memory * memory,const std::string & name,size_t max_size)111 std::unique_ptr<DexFileFromMemory> DexFileFromMemory::Create(uint64_t dex_file_offset_in_memory,
112                                                              Memory* memory,
113                                                              const std::string& name,
114                                                              size_t max_size) {
115   if (UNLIKELY(!HasDexSupport())) {
116     return nullptr;
117   }
118 
119   std::vector<uint8_t> backing_memory;
120 
121   for (size_t size = 0;;) {
122     std::string error_msg;
123     std::unique_ptr<art_api::dex::DexFile> art_dex_file =
124         OpenFromMemory(backing_memory.data(), &size, name, &error_msg);
125     if (size > max_size) {
126       return nullptr;
127     }
128 
129     if (art_dex_file != nullptr) {
130       return std::unique_ptr<DexFileFromMemory>(
131           new DexFileFromMemory(art_dex_file, std::move(backing_memory)));
132     }
133 
134     if (!error_msg.empty()) {
135       return nullptr;
136     }
137 
138     backing_memory.resize(size);
139     if (!memory->ReadFully(dex_file_offset_in_memory, backing_memory.data(),
140                            backing_memory.size())) {
141       return nullptr;
142     }
143   }
144 }
145 
146 }  // namespace unwindstack
147