/* * Copyright (C) 2007 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "linker.h" #include "linker_cfi.h" #include "linker_globals.h" #include "linker_dlwarning.h" #include #include #include #include #include #include #include "private/bionic_tls.h" #include "private/ScopedPthreadMutexLocker.h" static pthread_mutex_t g_dl_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; static char* __bionic_set_dlerror(char* new_value) { char** dlerror_slot = &reinterpret_cast(__get_tls())[TLS_SLOT_DLERROR]; char* old_value = *dlerror_slot; *dlerror_slot = new_value; LD_LOG(kLogErrors, "%s\n", new_value); return old_value; } static void __bionic_format_dlerror(const char* msg, const char* detail) { char* buffer = __get_thread()->dlerror_buffer; strlcpy(buffer, msg, __BIONIC_DLERROR_BUFFER_SIZE); if (detail != nullptr) { strlcat(buffer, ": ", __BIONIC_DLERROR_BUFFER_SIZE); strlcat(buffer, detail, __BIONIC_DLERROR_BUFFER_SIZE); } __bionic_set_dlerror(buffer); } char* __dlerror() { char* old_value = __bionic_set_dlerror(nullptr); return old_value; } void __android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) { ScopedPthreadMutexLocker locker(&g_dl_mutex); do_android_get_LD_LIBRARY_PATH(buffer, buffer_size); } void __android_update_LD_LIBRARY_PATH(const char* ld_library_path) { ScopedPthreadMutexLocker locker(&g_dl_mutex); do_android_update_LD_LIBRARY_PATH(ld_library_path); } static void* dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo, const void* caller_addr) { ScopedPthreadMutexLocker locker(&g_dl_mutex); g_linker_logger.ResetState(); void* result = do_dlopen(filename, flags, extinfo, caller_addr); if (result == nullptr) { __bionic_format_dlerror("dlopen failed", linker_get_error_buffer()); return nullptr; } return result; } void* __android_dlopen_ext(const char* filename, int flags, const android_dlextinfo* extinfo, const void* caller_addr) { return dlopen_ext(filename, flags, extinfo, caller_addr); } void* __dlopen(const char* filename, int flags, const void* caller_addr) { return dlopen_ext(filename, flags, nullptr, caller_addr); } void* dlsym_impl(void* handle, const char* symbol, const char* version, const void* caller_addr) { ScopedPthreadMutexLocker locker(&g_dl_mutex); g_linker_logger.ResetState(); void* result; if (!do_dlsym(handle, symbol, version, caller_addr, &result)) { __bionic_format_dlerror(linker_get_error_buffer(), nullptr); return nullptr; } return result; } void* __dlsym(void* handle, const char* symbol, const void* caller_addr) { return dlsym_impl(handle, symbol, nullptr, caller_addr); } void* __dlvsym(void* handle, const char* symbol, const char* version, const void* caller_addr) { return dlsym_impl(handle, symbol, version, caller_addr); } int __dladdr(const void* addr, Dl_info* info) { ScopedPthreadMutexLocker locker(&g_dl_mutex); return do_dladdr(addr, info); } int __dlclose(void* handle) { ScopedPthreadMutexLocker locker(&g_dl_mutex); int result = do_dlclose(handle); if (result != 0) { __bionic_format_dlerror("dlclose failed", linker_get_error_buffer()); } return result; } // This function is needed by libgcc.a (this is why there is no prefix for this one) int dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data) { ScopedPthreadMutexLocker locker(&g_dl_mutex); return do_dl_iterate_phdr(cb, data); } #if defined(__arm__) _Unwind_Ptr __dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) { ScopedPthreadMutexLocker locker(&g_dl_mutex); return do_dl_unwind_find_exidx(pc, pcount); } #endif void __android_set_application_target_sdk_version(uint32_t target) { // lock to avoid modification in the middle of dlopen. ScopedPthreadMutexLocker locker(&g_dl_mutex); set_application_target_sdk_version(target); } uint32_t __android_get_application_target_sdk_version() { return get_application_target_sdk_version(); } void __android_dlwarning(void* obj, void (*f)(void*, const char*)) { ScopedPthreadMutexLocker locker(&g_dl_mutex); get_dlwarning(obj, f); } bool __android_init_anonymous_namespace(const char* shared_libs_sonames, const char* library_search_path) { ScopedPthreadMutexLocker locker(&g_dl_mutex); bool success = init_anonymous_namespace(shared_libs_sonames, library_search_path); if (!success) { __bionic_format_dlerror("android_init_anonymous_namespace failed", linker_get_error_buffer()); } return success; } android_namespace_t* __android_create_namespace(const char* name, const char* ld_library_path, const char* default_library_path, uint64_t type, const char* permitted_when_isolated_path, android_namespace_t* parent_namespace, const void* caller_addr) { ScopedPthreadMutexLocker locker(&g_dl_mutex); android_namespace_t* result = create_namespace(caller_addr, name, ld_library_path, default_library_path, type, permitted_when_isolated_path, parent_namespace); if (result == nullptr) { __bionic_format_dlerror("android_create_namespace failed", linker_get_error_buffer()); } return result; } bool __android_link_namespaces(android_namespace_t* namespace_from, android_namespace_t* namespace_to, const char* shared_libs_sonames) { ScopedPthreadMutexLocker locker(&g_dl_mutex); bool success = link_namespaces(namespace_from, namespace_to, shared_libs_sonames); if (!success) { __bionic_format_dlerror("android_link_namespaces failed", linker_get_error_buffer()); } return success; } android_namespace_t* __android_get_exported_namespace(const char* name) { return get_exported_namespace(name); } void __cfi_fail(uint64_t CallSiteTypeId, void* Ptr, void *DiagData, void *CallerPc) { CFIShadowWriter::CfiFail(CallSiteTypeId, Ptr, DiagData, CallerPc); } // name_offset: starting index of the name in libdl_info.strtab #define ELF32_SYM_INITIALIZER(name_offset, value, shndx) \ { name_offset, \ reinterpret_cast(value), \ /* st_size */ 0, \ ((shndx) == 0) ? 0 : (STB_GLOBAL << 4), \ /* st_other */ 0, \ shndx, \ } #define ELF64_SYM_INITIALIZER(name_offset, value, shndx) \ { name_offset, \ ((shndx) == 0) ? 0 : (STB_GLOBAL << 4), \ /* st_other */ 0, \ shndx, \ reinterpret_cast(value), \ /* st_size */ 0, \ } static const char ANDROID_LIBDL_STRTAB[] = // 0000000000111111 11112222222222333 333333344444444 44555555555566666 6666677777777778 8888888889999999999 // 0123456789012345 67890123456789012 345678901234567 89012345678901234 5678901234567890 1234567890123456789 "__loader_dlopen\0__loader_dlclose\0__loader_dlsym\0__loader_dlerror\0__loader_dladdr\0__loader_android_up" // 1* // 000000000011111111112 2222222223333333333444444444455555555 5566666666667777777777888 88888889999999999 // 012345678901234567890 1234567890123456789012345678901234567 8901234567890123456789012 34567890123456789 "date_LD_LIBRARY_PATH\0__loader_android_get_LD_LIBRARY_PATH\0__loader_dl_iterate_phdr\0__loader_android_" // 2* // 00000000001 1111111112222222222333333333344444444445555555555666 6666666777777777788888888889999999999 // 01234567890 1234567890123456789012345678901234567890123456789012 3456789012345678901234567890123456789 "dlopen_ext\0__loader_android_set_application_target_sdk_version\0__loader_android_get_application_targ" // 3* // 000000000011111 111112222222222333333333344444444445555555 5556666666666777777777788888888889 999999999 // 012345678901234 567890123456789012345678901234567890123456 7890123456789012345678901234567890 123456789 "et_sdk_version\0__loader_android_init_anonymous_namespace\0__loader_android_create_namespace\0__loader_" // 4* // 0000000 000111111111122222222223333 333333444444444455 555555556666666666777777777788888 888889999999999 // 0123456 789012345678901234567890123 456789012345678901 234567890123456789012345678901234 567890123456789 "dlvsym\0__loader_android_dlwarning\0__loader_cfi_fail\0__loader_android_link_namespaces\0__loader_androi" // 5* // 0000000000111111111122222 22222 // 0123456789012345678901234 56789 "d_get_exported_namespace\0" #if defined(__arm__) // 525 "__loader_dl_unwind_find_exidx\0" #endif ; static ElfW(Sym) g_libdl_symtab[] = { // Total length of libdl_info.strtab, including trailing 0. // This is actually the STH_UNDEF entry. Technically, it's // supposed to have st_name == 0, but instead, it points to an index // in the strtab with a \0 to make iterating through the symtab easier. ELFW(SYM_INITIALIZER)(sizeof(ANDROID_LIBDL_STRTAB) - 1, nullptr, 0), ELFW(SYM_INITIALIZER)( 0, &__dlopen, 1), ELFW(SYM_INITIALIZER)( 16, &__dlclose, 1), ELFW(SYM_INITIALIZER)( 33, &__dlsym, 1), ELFW(SYM_INITIALIZER)( 48, &__dlerror, 1), ELFW(SYM_INITIALIZER)( 65, &__dladdr, 1), ELFW(SYM_INITIALIZER)( 81, &__android_update_LD_LIBRARY_PATH, 1), ELFW(SYM_INITIALIZER)(121, &__android_get_LD_LIBRARY_PATH, 1), ELFW(SYM_INITIALIZER)(158, &dl_iterate_phdr, 1), ELFW(SYM_INITIALIZER)(183, &__android_dlopen_ext, 1), ELFW(SYM_INITIALIZER)(211, &__android_set_application_target_sdk_version, 1), ELFW(SYM_INITIALIZER)(263, &__android_get_application_target_sdk_version, 1), ELFW(SYM_INITIALIZER)(315, &__android_init_anonymous_namespace, 1), ELFW(SYM_INITIALIZER)(357, &__android_create_namespace, 1), ELFW(SYM_INITIALIZER)(391, &__dlvsym, 1), ELFW(SYM_INITIALIZER)(407, &__android_dlwarning, 1), ELFW(SYM_INITIALIZER)(434, &__cfi_fail, 1), ELFW(SYM_INITIALIZER)(452, &__android_link_namespaces, 1), ELFW(SYM_INITIALIZER)(485, &__android_get_exported_namespace, 1), #if defined(__arm__) ELFW(SYM_INITIALIZER)(525, &__dl_unwind_find_exidx, 1), #endif }; // Fake out a hash table with a single bucket. // // A search of the hash table will look through g_libdl_symtab starting with index 1, then // use g_libdl_chains to find the next index to look at. g_libdl_chains should be set up to // walk through every element in g_libdl_symtab, and then end with 0 (sentinel value). // // That is, g_libdl_chains should look like { 0, 2, 3, ... N, 0 } where N is the number // of actual symbols, or nelems(g_libdl_symtab)-1 (since the first element of g_libdl_symtab is not // a real symbol). (See soinfo_elf_lookup().) // // Note that adding any new symbols here requires stubbing them out in libdl. static unsigned g_libdl_buckets[1] = { 1 }; #if defined(__arm__) static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 0 }; #else static unsigned g_libdl_chains[] = { 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 0 }; #endif static uint8_t __libdl_info_buf[sizeof(soinfo)] __attribute__((aligned(8))); static soinfo* __libdl_info = nullptr; // This is used by the dynamic linker. Every process gets these symbols for free. soinfo* get_libdl_info(const char* linker_path) { if (__libdl_info == nullptr) { __libdl_info = new (__libdl_info_buf) soinfo(&g_default_namespace, linker_path, nullptr, 0, 0); __libdl_info->flags_ |= FLAG_LINKED; __libdl_info->strtab_ = ANDROID_LIBDL_STRTAB; __libdl_info->symtab_ = g_libdl_symtab; __libdl_info->nbucket_ = sizeof(g_libdl_buckets)/sizeof(unsigned); __libdl_info->nchain_ = sizeof(g_libdl_chains)/sizeof(unsigned); __libdl_info->bucket_ = g_libdl_buckets; __libdl_info->chain_ = g_libdl_chains; __libdl_info->ref_count_ = 1; __libdl_info->strtab_size_ = sizeof(ANDROID_LIBDL_STRTAB); __libdl_info->local_group_root_ = __libdl_info; __libdl_info->soname_ = "ld-android.so"; __libdl_info->target_sdk_version_ = __ANDROID_API__; __libdl_info->generate_handle(); #if defined(__work_around_b_24465209__) strlcpy(__libdl_info->old_name_, __libdl_info->soname_, sizeof(__libdl_info->old_name_)); #endif } return __libdl_info; }