1 /*
2 * Copyright (C) 2007 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 <android/dlext.h>
18 #include <dlfcn.h>
19 #include <link.h>
20 #include <signal.h>
21 #include <stdlib.h>
22
23 // These functions are exported by the loader
24 // TODO(dimitry): replace these with reference to libc.so
25
26 extern "C" {
27
28 __attribute__((__weak__, visibility("default")))
29 void __loader_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size);
30
31 __attribute__((__weak__, visibility("default")))
32 void* __loader_dlopen(const char* filename, int flags, const void* caller_addr);
33
34 __attribute__((__weak__, visibility("default")))
35 char* __loader_dlerror();
36
37 __attribute__((__weak__, visibility("default")))
38 void* __loader_dlsym(void* handle, const char* symbol, const void* caller_addr);
39
40 __attribute__((__weak__, visibility("default")))
41 void* __loader_dlvsym(void* handle,
42 const char* symbol,
43 const char* version,
44 const void* caller_addr);
45
46 __attribute__((__weak__, visibility("default")))
47 int __loader_dladdr(const void* addr, Dl_info* info);
48
49 __attribute__((__weak__, visibility("default")))
50 int __loader_dlclose(void* handle);
51
52 #if defined(__arm__)
53 __attribute__((__weak__, visibility("default")))
54 _Unwind_Ptr __loader_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount);
55 #endif
56
57 __attribute__((__weak__, visibility("default")))
58 int __loader_dl_iterate_phdr(int (*cb)(struct dl_phdr_info* info, size_t size, void* data),
59 void* data);
60
61 __attribute__((__weak__, visibility("default")))
62 void __loader_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size);
63
64 __attribute__((__weak__, visibility("default")))
65 void __loader_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
66
67 __attribute__((__weak__, visibility("default")))
68 void* __loader_android_dlopen_ext(const char* filename,
69 int flag,
70 const android_dlextinfo* extinfo,
71 const void* caller_addr);
72
73 __attribute__((__weak__, visibility("default")))
74 int __loader_android_get_application_target_sdk_version();
75
76 __attribute__((__weak__, visibility("default"))) bool __loader_android_handle_signal(
77 int signal_number, siginfo_t* info, void* context);
78
79 // Proxy calls to bionic loader
80 __attribute__((__weak__))
android_get_LD_LIBRARY_PATH(char * buffer,size_t buffer_size)81 void android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
82 __loader_android_get_LD_LIBRARY_PATH(buffer, buffer_size);
83 }
84
85 __attribute__((__weak__))
dlopen(const char * filename,int flag)86 void* dlopen(const char* filename, int flag) {
87 const void* caller_addr = __builtin_return_address(0);
88 return __loader_dlopen(filename, flag, caller_addr);
89 }
90
91 __attribute__((__weak__))
dlerror()92 char* dlerror() {
93 return __loader_dlerror();
94 }
95
96 __attribute__((__weak__))
dlsym(void * handle,const char * symbol)97 void* dlsym(void* handle, const char* symbol) {
98 const void* caller_addr = __builtin_return_address(0);
99 return __loader_dlsym(handle, symbol, caller_addr);
100 }
101
102 __attribute__((__weak__))
dlvsym(void * handle,const char * symbol,const char * version)103 void* dlvsym(void* handle, const char* symbol, const char* version) {
104 const void* caller_addr = __builtin_return_address(0);
105 return __loader_dlvsym(handle, symbol, version, caller_addr);
106 }
107
108 __attribute__((__weak__))
dladdr(const void * addr,Dl_info * info)109 int dladdr(const void* addr, Dl_info* info) {
110 return __loader_dladdr(addr, info);
111 }
112
113 __attribute__((__weak__))
dlclose(void * handle)114 int dlclose(void* handle) {
115 return __loader_dlclose(handle);
116 }
117
118 #if defined(__arm__)
119 __attribute__((__weak__))
dl_unwind_find_exidx(_Unwind_Ptr pc,int * pcount)120 _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
121 return __loader_dl_unwind_find_exidx(pc, pcount);
122 }
123 #endif
124
125 /*
126 * This needs to be defined as weak because it is also defined in libc.a.
127 * Without this, static executables will have a multiple definition error.
128 */
129 __attribute__((__weak__))
dl_iterate_phdr(int (* cb)(struct dl_phdr_info * info,size_t size,void * data),void * data)130 int dl_iterate_phdr(int (*cb)(struct dl_phdr_info* info, size_t size, void* data), void* data) {
131 return __loader_dl_iterate_phdr(cb, data);
132 }
133
134 __attribute__((__weak__))
android_dlopen_ext(const char * filename,int flag,const android_dlextinfo * extinfo)135 void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo) {
136 const void* caller_addr = __builtin_return_address(0);
137 return __loader_android_dlopen_ext(filename, flag, extinfo, caller_addr);
138 }
139
140 __attribute__((__weak__))
android_get_application_target_sdk_version()141 int android_get_application_target_sdk_version() {
142 return __loader_android_get_application_target_sdk_version();
143 }
144
145 // Returns true if this function handled the signal, false if the caller should handle the signal
146 // itself. This function returns true if the sigchain handler should immediately return, which
147 // happens when the signal came from GWP-ASan, and we've dumped a debuggerd report and patched up
148 // the GWP-ASan allocator to recover from the fault, and regular execution of the program can
149 // continue.
android_handle_signal(int signal_number,siginfo_t * info,void * context)150 __attribute__((__weak__)) bool android_handle_signal(int signal_number, siginfo_t* info,
151 void* context) {
152 return __loader_android_handle_signal(signal_number, info, context);
153 }
154
155 } // extern "C"
156