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 "art_api/dex_file_support.h"
18
19 #include <dlfcn.h>
20 #include <mutex>
21
22 #ifndef STATIC_LIB
23 // Not used in the static lib, so avoid a dependency on this header in
24 // libdexfile_support_static.
25 #include <log/log.h>
26 #endif
27
28 namespace art_api {
29 namespace dex {
30
31 #define FOR_ALL_DLFUNCS(MACRO) \
32 MACRO(DexString, ExtDexFileMakeString) \
33 MACRO(DexString, ExtDexFileGetString) \
34 MACRO(DexString, ExtDexFileFreeString) \
35 MACRO(DexFile, ExtDexFileOpenFromMemory) \
36 MACRO(DexFile, ExtDexFileOpenFromFd) \
37 MACRO(DexFile, ExtDexFileGetMethodInfoForOffset) \
38 MACRO(DexFile, ExtDexFileGetAllMethodInfos) \
39 MACRO(DexFile, ExtDexFileFree)
40
41 #ifdef STATIC_LIB
42 #define DEFINE_DLFUNC_PTR(CLASS, DLFUNC) decltype(DLFUNC)* CLASS::g_##DLFUNC = DLFUNC;
43 #else
44 #define DEFINE_DLFUNC_PTR(CLASS, DLFUNC) decltype(DLFUNC)* CLASS::g_##DLFUNC = nullptr;
45 #endif
FOR_ALL_DLFUNCS(DEFINE_DLFUNC_PTR)46 FOR_ALL_DLFUNCS(DEFINE_DLFUNC_PTR)
47 #undef DEFINE_DLFUNC_PTR
48
49 bool TryLoadLibdexfileExternal([[maybe_unused]] std::string* err_msg) {
50 #if defined(STATIC_LIB)
51 // Nothing to do here since all function pointers are initialised statically.
52 return true;
53 #elif defined(NO_DEXFILE_SUPPORT)
54 *err_msg = "Dex file support not available.";
55 return false;
56 #else
57 // Use a plain old mutex since we want to try again if loading fails (to set
58 // err_msg, if nothing else).
59 static std::mutex load_mutex;
60 static bool is_loaded = false;
61 std::lock_guard<std::mutex> lock(load_mutex);
62
63 if (!is_loaded) {
64 // Check which version is already loaded to avoid loading both debug and
65 // release builds. We might also be backtracing from separate process, in
66 // which case neither is loaded.
67 const char* so_name = "libdexfiled_external.so";
68 void* handle = dlopen(so_name, RTLD_NOLOAD | RTLD_NOW | RTLD_NODELETE);
69 if (handle == nullptr) {
70 so_name = "libdexfile_external.so";
71 handle = dlopen(so_name, RTLD_NOW | RTLD_GLOBAL | RTLD_NODELETE);
72 }
73 if (handle == nullptr) {
74 *err_msg = dlerror();
75 return false;
76 }
77
78 #define RESOLVE_DLFUNC_PTR(CLASS, DLFUNC) \
79 decltype(DLFUNC)* DLFUNC##_ptr = reinterpret_cast<decltype(DLFUNC)*>(dlsym(handle, #DLFUNC)); \
80 if ((DLFUNC) == nullptr) { \
81 *err_msg = dlerror(); \
82 return false; \
83 }
84 FOR_ALL_DLFUNCS(RESOLVE_DLFUNC_PTR);
85 #undef RESOLVE_DLFUNC_PTR
86
87 #define SET_DLFUNC_PTR(CLASS, DLFUNC) CLASS::g_##DLFUNC = DLFUNC##_ptr;
88 FOR_ALL_DLFUNCS(SET_DLFUNC_PTR);
89 #undef SET_DLFUNC_PTR
90
91 is_loaded = true;
92 }
93
94 return is_loaded;
95 #endif // !defined(NO_DEXFILE_SUPPORT) && !defined(STATIC_LIB)
96 }
97
LoadLibdexfileExternal()98 void LoadLibdexfileExternal() {
99 #ifndef STATIC_LIB
100 if (std::string err_msg; !TryLoadLibdexfileExternal(&err_msg)) {
101 LOG_ALWAYS_FATAL("%s", err_msg.c_str());
102 }
103 #endif
104 }
105
~DexFile()106 DexFile::~DexFile() { g_ExtDexFileFree(ext_dex_file_); }
107
AbsorbMethodInfo(const ExtDexFileMethodInfo & ext_method_info)108 MethodInfo DexFile::AbsorbMethodInfo(const ExtDexFileMethodInfo& ext_method_info) {
109 return {ext_method_info.offset, ext_method_info.len, DexString(ext_method_info.name)};
110 }
111
AddMethodInfoCallback(const ExtDexFileMethodInfo * ext_method_info,void * ctx)112 void DexFile::AddMethodInfoCallback(const ExtDexFileMethodInfo* ext_method_info, void* ctx) {
113 auto vect = static_cast<MethodInfoVector*>(ctx);
114 vect->emplace_back(AbsorbMethodInfo(*ext_method_info));
115 }
116
117 } // namespace dex
118 } // namespace art_api
119