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 <unistd.h>
18 
19 #include "native_bridge_support/vdso/vdso.h"
20 
21 extern "C" void __loader_add_thread_local_dtor(void* dso_handle) __attribute__((weak));
22 extern "C" void __loader_remove_thread_local_dtor(void* dso_handle) __attribute__((weak));
23 
24 struct WrappedArg {
25   typedef void (*thread_atexit_fn_t)(void*);
26   thread_atexit_fn_t fn;
27   void* arg;
28   void* dso_handle;
29 };
30 
WrappedFn(void * arg)31 static void WrappedFn(void* arg) {
32   WrappedArg* wrapped_arg = static_cast<WrappedArg*>(arg);
33   WrappedArg::thread_atexit_fn_t origin_fn = wrapped_arg->fn;
34   void* origin_arg = wrapped_arg->arg;
35   void* dso_handle = wrapped_arg->dso_handle;
36 
37   delete wrapped_arg;
38 
39   origin_fn(origin_arg);
40 
41   if (__loader_remove_thread_local_dtor != nullptr) {
42     __loader_remove_thread_local_dtor(dso_handle);
43   }
44 }
45 
__cxa_thread_atexit_impl(void (* func)(void *),void * arg,void * dso_handle)46 extern "C" int __cxa_thread_atexit_impl(void (*func)(void*), void* arg, void* dso_handle) {
47   WrappedArg* wrapped_arg = new WrappedArg();
48   wrapped_arg->fn = func;
49   wrapped_arg->arg = arg;
50   wrapped_arg->dso_handle = dso_handle;
51 
52   if (__loader_add_thread_local_dtor != nullptr) {
53     __loader_add_thread_local_dtor(dso_handle);
54   }
55 
56   typedef decltype(__cxa_thread_atexit_impl)* fn_t;
57   static fn_t __host_cxa_thread_atexit_impl = reinterpret_cast<fn_t>(
58       native_bridge_find_proxy_library_symbol("libc.so", "__cxa_thread_atexit_impl"));
59 
60   return __host_cxa_thread_atexit_impl(WrappedFn, wrapped_arg, dso_handle);
61 }
62