linker/dlfcn.cpp - platform/bionic - Git at Google

 /*
  * 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_debuggerd.h"
 #include "linker_dlwarning.h"
 #include "linker_globals.h"

 #include <link.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <android/api-level.h>

 #include <bionic/pthread_internal.h>
 #include "private/bionic_globals.h"
 #include "private/bionic_tls.h"
 #include "private/ScopedPthreadMutexLocker.h"

 #define __LINKER_PUBLIC__ __attribute__((visibility("default")))

 extern "C" {

 android_namespace_t* __loader_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) __LINKER_PUBLIC__;
 void* __loader_android_dlopen_ext(const char* filename,
                            int flags,
                            const android_dlextinfo* extinfo,
                            const void* caller_addr) __LINKER_PUBLIC__;
 void __loader_android_dlwarning(void* obj, void (*f)(void*, const char*)) __LINKER_PUBLIC__;
 int __loader_android_get_application_target_sdk_version() __LINKER_PUBLIC__;
 void __loader_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) __LINKER_PUBLIC__;
 android_namespace_t* __loader_android_get_exported_namespace(const char* name) __LINKER_PUBLIC__;
 bool __loader_android_init_anonymous_namespace(const char* shared_libs_sonames,
                                                const char* library_search_path) __LINKER_PUBLIC__;
 bool __loader_android_link_namespaces(android_namespace_t* namespace_from,
                                       android_namespace_t* namespace_to,
                                       const char* shared_libs_sonames) __LINKER_PUBLIC__;
 bool __loader_android_link_namespaces_all_libs(android_namespace_t* namespace_from,
                                                android_namespace_t* namespace_to) __LINKER_PUBLIC__;
 void __loader_android_set_application_target_sdk_version(int target) __LINKER_PUBLIC__;
 void __loader_android_update_LD_LIBRARY_PATH(const char* ld_library_path) __LINKER_PUBLIC__;
 void __loader_cfi_fail(uint64_t CallSiteTypeId,
                        void* Ptr,
                        void *DiagData,
                        void *CallerPc) __LINKER_PUBLIC__;
 int __loader_dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data),
                              void* data) __LINKER_PUBLIC__;
 int __loader_dladdr(const void* addr, Dl_info* info) __LINKER_PUBLIC__;
 int __loader_dlclose(void* handle) __LINKER_PUBLIC__;
 char* __loader_dlerror() __LINKER_PUBLIC__;
 void* __loader_dlopen(const char* filename, int flags, const void* caller_addr) __LINKER_PUBLIC__;
 void* __loader_dlsym(void* handle, const char* symbol, const void* caller_addr) __LINKER_PUBLIC__;
 void* __loader_dlvsym(void* handle,
                       const char* symbol,
                       const char* version,
                       const void* caller_addr) __LINKER_PUBLIC__;
 void __loader_add_thread_local_dtor(void* dso_handle) __LINKER_PUBLIC__;
 void __loader_remove_thread_local_dtor(void* dso_handle) __LINKER_PUBLIC__;
 void __loader_android_set_16kb_appcompat_mode(bool enable_app_compat) __LINKER_PUBLIC__;
 libc_shared_globals* __loader_shared_globals() __LINKER_PUBLIC__;
 #if defined(__arm__)
 _Unwind_Ptr __loader_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) __LINKER_PUBLIC__;
 #endif
 bool __loader_android_handle_signal(int signal_number, siginfo_t* info,
                                     void* context) __LINKER_PUBLIC__;
 }

 pthread_mutex_t g_dl_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;

 static char* __bionic_set_dlerror(char* new_value) {
   char* old_value = __get_thread()->current_dlerror;
   __get_thread()->current_dlerror = new_value;

   if (new_value != nullptr) LD_LOG(kLogErrors, "dlerror set to \"%s\"", 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* __loader_dlerror() {
   char* old_value = __bionic_set_dlerror(nullptr);
   return old_value;
 }

 void __loader_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 __loader_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* __loader_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* __loader_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* __loader_dlsym(void* handle, const char* symbol, const void* caller_addr) {
   return dlsym_impl(handle, symbol, nullptr, caller_addr);
 }

 void* __loader_dlvsym(void* handle, const char* symbol, const char* version, const void* caller_addr) {
   return dlsym_impl(handle, symbol, version, caller_addr);
 }

 int __loader_dladdr(const void* addr, Dl_info* info) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   return do_dladdr(addr, info);
 }

 int __loader_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;
 }

 int __loader_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 __loader_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   return do_dl_unwind_find_exidx(pc, pcount);
 }
 #endif

 void __loader_android_set_application_target_sdk_version(int target) {
   // lock to avoid modification in the middle of dlopen.
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   set_application_target_sdk_version(target);
 }

 int __loader_android_get_application_target_sdk_version() {
   return get_application_target_sdk_version();
 }

 void __loader_android_dlwarning(void* obj, void (*f)(void*, const char*)) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   get_dlwarning(obj, f);
 }

 bool __loader_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* __loader_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 __loader_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;
 }

 bool __loader_android_link_namespaces_all_libs(android_namespace_t* namespace_from,
                                                android_namespace_t* namespace_to) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);

   bool success = link_namespaces_all_libs(namespace_from, namespace_to);

   if (!success) {
     __bionic_format_dlerror("android_link_namespaces_all_libs failed", linker_get_error_buffer());
   }

   return success;
 }

 android_namespace_t* __loader_android_get_exported_namespace(const char* name) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   return get_exported_namespace(name);
 }

 void __loader_cfi_fail(uint64_t CallSiteTypeId, void* Ptr, void *DiagData, void *CallerPc) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   CFIShadowWriter::CfiFail(CallSiteTypeId, Ptr, DiagData, CallerPc);
 }

 void __loader_add_thread_local_dtor(void* dso_handle) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   increment_dso_handle_reference_counter(dso_handle);
 }

 void __loader_remove_thread_local_dtor(void* dso_handle) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   decrement_dso_handle_reference_counter(dso_handle);
 }

 void __loader_android_set_16kb_appcompat_mode(bool enable_app_compat) {
   ScopedPthreadMutexLocker locker(&g_dl_mutex);
   set_16kb_appcompat_mode(enable_app_compat);
 }

 libc_shared_globals* __loader_shared_globals() {
   return __libc_shared_globals();
 }

 bool __loader_android_handle_signal(int signal_number, siginfo_t* info, void* context) {
   return debuggerd_handle_signal(signal_number, info, context);
 }

 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 soinfo& linker_si) {
   CHECK((linker_si.flags_ & FLAG_GNU_HASH) != 0);

   if (__libdl_info == nullptr) {
     __libdl_info = new (__libdl_info_buf) soinfo(&g_default_namespace, nullptr, nullptr, 0, 0);
     __libdl_info->flags_ |= (FLAG_LINKED | FLAG_GNU_HASH);
     __libdl_info->strtab_ = linker_si.strtab_;
     __libdl_info->symtab_ = linker_si.symtab_;
     __libdl_info->load_bias = linker_si.load_bias;
     __libdl_info->phdr = linker_si.phdr;
     __libdl_info->phnum = linker_si.phnum;

     __libdl_info->gnu_nbucket_ = linker_si.gnu_nbucket_;
     __libdl_info->gnu_maskwords_ = linker_si.gnu_maskwords_;
     __libdl_info->gnu_shift2_ = linker_si.gnu_shift2_;
     __libdl_info->gnu_bloom_filter_ = linker_si.gnu_bloom_filter_;
     __libdl_info->gnu_bucket_ = linker_si.gnu_bucket_;
     __libdl_info->gnu_chain_ = linker_si.gnu_chain_;
     __libdl_info->memtag_dynamic_entries_ = linker_si.memtag_dynamic_entries_;

     __libdl_info->ref_count_ = 1;
     __libdl_info->strtab_size_ = linker_si.strtab_size_;
     __libdl_info->local_group_root_ = __libdl_info;
     __libdl_info->soname_ = linker_si.soname_;
     __libdl_info->target_sdk_version_ = __ANDROID_API__;
     __libdl_info->generate_handle();
 #if !defined(__LP64__)
     strlcpy(__libdl_info->old_name_, __libdl_info->soname_.c_str(),
             sizeof(__libdl_info->old_name_));
 #endif
   }

   return __libdl_info;
 }
	/*
	* 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_debuggerd.h"
	#include "linker_dlwarning.h"
	#include "linker_globals.h"

	#include <link.h>
	#include <pthread.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <android/api-level.h>

	#include <bionic/pthread_internal.h>
	#include "private/bionic_globals.h"
	#include "private/bionic_tls.h"
	#include "private/ScopedPthreadMutexLocker.h"

	#define __LINKER_PUBLIC__ __attribute__((visibility("default")))

	extern "C" {

	android_namespace_t* __loader_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) __LINKER_PUBLIC__;
	void* __loader_android_dlopen_ext(const char* filename,
	int flags,
	const android_dlextinfo* extinfo,
	const void* caller_addr) __LINKER_PUBLIC__;
	void __loader_android_dlwarning(void* obj, void (f)(void, const char*)) __LINKER_PUBLIC__;
	int __loader_android_get_application_target_sdk_version() __LINKER_PUBLIC__;
	void __loader_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) __LINKER_PUBLIC__;
	android_namespace_t* __loader_android_get_exported_namespace(const char* name) __LINKER_PUBLIC__;
	bool __loader_android_init_anonymous_namespace(const char* shared_libs_sonames,
	const char* library_search_path) __LINKER_PUBLIC__;
	bool __loader_android_link_namespaces(android_namespace_t* namespace_from,
	android_namespace_t* namespace_to,
	const char* shared_libs_sonames) __LINKER_PUBLIC__;
	bool __loader_android_link_namespaces_all_libs(android_namespace_t* namespace_from,
	android_namespace_t* namespace_to) __LINKER_PUBLIC__;
	void __loader_android_set_application_target_sdk_version(int target) __LINKER_PUBLIC__;
	void __loader_android_update_LD_LIBRARY_PATH(const char* ld_library_path) __LINKER_PUBLIC__;
	void __loader_cfi_fail(uint64_t CallSiteTypeId,
	void* Ptr,
	void *DiagData,
	void *CallerPc) __LINKER_PUBLIC__;
	int __loader_dl_iterate_phdr(int (cb)(dl_phdr_info info, size_t size, void* data),
	void* data) __LINKER_PUBLIC__;
	int __loader_dladdr(const void* addr, Dl_info* info) __LINKER_PUBLIC__;
	int __loader_dlclose(void* handle) __LINKER_PUBLIC__;
	char* __loader_dlerror() __LINKER_PUBLIC__;
	void* __loader_dlopen(const char* filename, int flags, const void* caller_addr) __LINKER_PUBLIC__;
	void* __loader_dlsym(void* handle, const char* symbol, const void* caller_addr) __LINKER_PUBLIC__;
	void* __loader_dlvsym(void* handle,
	const char* symbol,
	const char* version,
	const void* caller_addr) __LINKER_PUBLIC__;
	void __loader_add_thread_local_dtor(void* dso_handle) __LINKER_PUBLIC__;
	void __loader_remove_thread_local_dtor(void* dso_handle) __LINKER_PUBLIC__;
	void __loader_android_set_16kb_appcompat_mode(bool enable_app_compat) __LINKER_PUBLIC__;
	libc_shared_globals* __loader_shared_globals() __LINKER_PUBLIC__;
	#if defined(__arm__)
	_Unwind_Ptr __loader_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) __LINKER_PUBLIC__;
	#endif
	bool __loader_android_handle_signal(int signal_number, siginfo_t* info,
	void* context) __LINKER_PUBLIC__;
	}

	pthread_mutex_t g_dl_mutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;

	static char* __bionic_set_dlerror(char* new_value) {
	char* old_value = __get_thread()->current_dlerror;
	__get_thread()->current_dlerror = new_value;

	if (new_value != nullptr) LD_LOG(kLogErrors, "dlerror set to \"%s\"", 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* __loader_dlerror() {
	char* old_value = __bionic_set_dlerror(nullptr);
	return old_value;
	}

	void __loader_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 __loader_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* __loader_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* __loader_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* __loader_dlsym(void* handle, const char* symbol, const void* caller_addr) {
	return dlsym_impl(handle, symbol, nullptr, caller_addr);
	}

	void* __loader_dlvsym(void* handle, const char* symbol, const char* version, const void* caller_addr) {
	return dlsym_impl(handle, symbol, version, caller_addr);
	}

	int __loader_dladdr(const void* addr, Dl_info* info) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	return do_dladdr(addr, info);
	}

	int __loader_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;
	}

	int __loader_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 __loader_dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	return do_dl_unwind_find_exidx(pc, pcount);
	}
	#endif

	void __loader_android_set_application_target_sdk_version(int target) {
	// lock to avoid modification in the middle of dlopen.
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	set_application_target_sdk_version(target);
	}

	int __loader_android_get_application_target_sdk_version() {
	return get_application_target_sdk_version();
	}

	void __loader_android_dlwarning(void* obj, void (f)(void, const char*)) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	get_dlwarning(obj, f);
	}

	bool __loader_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* __loader_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 __loader_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;
	}

	bool __loader_android_link_namespaces_all_libs(android_namespace_t* namespace_from,
	android_namespace_t* namespace_to) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);

	bool success = link_namespaces_all_libs(namespace_from, namespace_to);

	if (!success) {
	__bionic_format_dlerror("android_link_namespaces_all_libs failed", linker_get_error_buffer());
	}

	return success;
	}

	android_namespace_t* __loader_android_get_exported_namespace(const char* name) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	return get_exported_namespace(name);
	}

	void __loader_cfi_fail(uint64_t CallSiteTypeId, void* Ptr, void DiagData, void CallerPc) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	CFIShadowWriter::CfiFail(CallSiteTypeId, Ptr, DiagData, CallerPc);
	}

	void __loader_add_thread_local_dtor(void* dso_handle) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	increment_dso_handle_reference_counter(dso_handle);
	}

	void __loader_remove_thread_local_dtor(void* dso_handle) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	decrement_dso_handle_reference_counter(dso_handle);
	}

	void __loader_android_set_16kb_appcompat_mode(bool enable_app_compat) {
	ScopedPthreadMutexLocker locker(&g_dl_mutex);
	set_16kb_appcompat_mode(enable_app_compat);
	}

	libc_shared_globals* __loader_shared_globals() {
	return __libc_shared_globals();
	}

	bool __loader_android_handle_signal(int signal_number, siginfo_t* info, void* context) {
	return debuggerd_handle_signal(signal_number, info, context);
	}

	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 soinfo& linker_si) {
	CHECK((linker_si.flags_ & FLAG_GNU_HASH) != 0);

	if (__libdl_info == nullptr) {
	__libdl_info = new (__libdl_info_buf) soinfo(&g_default_namespace, nullptr, nullptr, 0, 0);
	__libdl_info->flags_ \|= (FLAG_LINKED \| FLAG_GNU_HASH);
	__libdl_info->strtab_ = linker_si.strtab_;
	__libdl_info->symtab_ = linker_si.symtab_;
	__libdl_info->load_bias = linker_si.load_bias;
	__libdl_info->phdr = linker_si.phdr;
	__libdl_info->phnum = linker_si.phnum;

	__libdl_info->gnu_nbucket_ = linker_si.gnu_nbucket_;
	__libdl_info->gnu_maskwords_ = linker_si.gnu_maskwords_;
	__libdl_info->gnu_shift2_ = linker_si.gnu_shift2_;
	__libdl_info->gnu_bloom_filter_ = linker_si.gnu_bloom_filter_;
	__libdl_info->gnu_bucket_ = linker_si.gnu_bucket_;
	__libdl_info->gnu_chain_ = linker_si.gnu_chain_;
	__libdl_info->memtag_dynamic_entries_ = linker_si.memtag_dynamic_entries_;

	__libdl_info->ref_count_ = 1;
	__libdl_info->strtab_size_ = linker_si.strtab_size_;
	__libdl_info->local_group_root_ = __libdl_info;
	__libdl_info->soname_ = linker_si.soname_;
	__libdl_info->target_sdk_version_ = __ANDROID_API__;
	__libdl_info->generate_handle();
	#if !defined(__LP64__)
	strlcpy(__libdl_info->old_name_, __libdl_info->soname_.c_str(),
	sizeof(__libdl_info->old_name_));
	#endif
	}

	return __libdl_info;
	}