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 <dlfcn.h>
18 #include <link.h>
19 #include <stdlib.h>
20 #include <android/dlext.h>
21
22 // These functions are exported by the loader
23 // TODO(dimitry): replace these with reference to libc.so
24
25 extern "C" {
26
27 __attribute__((__weak__, visibility("default")))
28 void __loader_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size);
29
30 __attribute__((__weak__, visibility("default")))
31 void* __loader_dlopen(const char* filename, int flags, const void* caller_addr);
32
33 __attribute__((__weak__, visibility("default")))
34 char* __loader_dlerror();
35
36 __attribute__((__weak__, visibility("default")))
37 void* __loader_dlsym(void* handle, const char* symbol, const void* caller_addr);
38
39 __attribute__((__weak__, visibility("default")))
40 void* __loader_dlvsym(void* handle,
41 const char* symbol,
42 const char* version,
43 const void* caller_addr);
44
45 __attribute__((__weak__, visibility("default")))
46 int __loader_dladdr(const void* addr, Dl_info* info);
47
48 __attribute__((__weak__, visibility("default")))
49 int __loader_dlclose(void* handle);
50
51 #if defined(__arm__)
52 __attribute__((__weak__, visibility("default")))
53 _Unwind_Ptr __loader_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount);
54 #endif
55
56 __attribute__((__weak__, visibility("default")))
57 int __loader_dl_iterate_phdr(int (*cb)(struct dl_phdr_info* info, size_t size, void* data),
58 void* data);
59
60 __attribute__((__weak__, visibility("default")))
61 void __loader_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size);
62
63 __attribute__((__weak__, visibility("default")))
64 void __loader_android_update_LD_LIBRARY_PATH(const char* ld_library_path);
65
66 __attribute__((__weak__, visibility("default")))
67 void* __loader_android_dlopen_ext(const char* filename,
68 int flag,
69 const android_dlextinfo* extinfo,
70 const void* caller_addr);
71
72 __attribute__((__weak__, visibility("default")))
73 int __loader_android_get_application_target_sdk_version();
74
75 // Proxy calls to bionic loader
76 __attribute__((__weak__))
android_get_LD_LIBRARY_PATH(char * buffer,size_t buffer_size)77 void android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
78 __loader_android_get_LD_LIBRARY_PATH(buffer, buffer_size);
79 }
80
81 __attribute__((__weak__))
dlopen(const char * filename,int flag)82 void* dlopen(const char* filename, int flag) {
83 const void* caller_addr = __builtin_return_address(0);
84 return __loader_dlopen(filename, flag, caller_addr);
85 }
86
87 __attribute__((__weak__))
dlerror()88 char* dlerror() {
89 return __loader_dlerror();
90 }
91
92 __attribute__((__weak__))
dlsym(void * handle,const char * symbol)93 void* dlsym(void* handle, const char* symbol) {
94 const void* caller_addr = __builtin_return_address(0);
95 return __loader_dlsym(handle, symbol, caller_addr);
96 }
97
98 __attribute__((__weak__))
dlvsym(void * handle,const char * symbol,const char * version)99 void* dlvsym(void* handle, const char* symbol, const char* version) {
100 const void* caller_addr = __builtin_return_address(0);
101 return __loader_dlvsym(handle, symbol, version, caller_addr);
102 }
103
104 __attribute__((__weak__))
dladdr(const void * addr,Dl_info * info)105 int dladdr(const void* addr, Dl_info* info) {
106 return __loader_dladdr(addr, info);
107 }
108
109 __attribute__((__weak__))
dlclose(void * handle)110 int dlclose(void* handle) {
111 return __loader_dlclose(handle);
112 }
113
114 #if defined(__arm__)
115 __attribute__((__weak__))
dl_unwind_find_exidx(_Unwind_Ptr pc,int * pcount)116 _Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
117 return __loader_dl_unwind_find_exidx(pc, pcount);
118 }
119 #endif
120
121 /*
122 * This needs to be defined as weak because it is also defined in libc.a.
123 * Without this, static executables will have a multiple definition error.
124 */
125 __attribute__((__weak__))
dl_iterate_phdr(int (* cb)(struct dl_phdr_info * info,size_t size,void * data),void * data)126 int dl_iterate_phdr(int (*cb)(struct dl_phdr_info* info, size_t size, void* data), void* data) {
127 return __loader_dl_iterate_phdr(cb, data);
128 }
129
130 __attribute__((__weak__))
android_dlopen_ext(const char * filename,int flag,const android_dlextinfo * extinfo)131 void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo) {
132 const void* caller_addr = __builtin_return_address(0);
133 return __loader_android_dlopen_ext(filename, flag, extinfo, caller_addr);
134 }
135
136 __attribute__((__weak__))
android_get_application_target_sdk_version()137 int android_get_application_target_sdk_version() {
138 return __loader_android_get_application_target_sdk_version();
139 }
140
141 #if defined(__arm__)
142 // An arm32 unwinding table has an R_ARM_NONE relocation to
143 // __aeabi_unwind_cpp_pr0. This shared library will never invoke the unwinder,
144 // so it doesn't actually need the routine. Define a dummy version here,
145 // because the real version calls libc functions (e.g. memcpy, abort), which
146 // would create a dependency cycle with libc.so.
147 __attribute__((visibility("hidden")))
__aeabi_unwind_cpp_pr0()148 void __aeabi_unwind_cpp_pr0() {
149 __builtin_trap();
150 }
151 #endif
152
153 } // extern "C"
154