1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 extern void __cxa_finalize(void *);
30 extern void *__dso_handle;
31 
32 __attribute__((destructor))
__on_dlclose(void)33 static void __on_dlclose(void) {
34   __cxa_finalize(&__dso_handle);
35 }
36 
37 /* Define a weak stub function here that will be overridden if the solib uses
38  * emutls. The function needs to be a definition, not just a declaration,
39  * because gold has a bug where it outputs weak+hidden symbols into the .dynsym
40  * table. */
41 __attribute__((weak,visibility("hidden")))
__emutls_unregister_key(void)42 void __emutls_unregister_key(void) {
43 }
44 
45 /* Use a priority of 0 to run after any ordinary destructor function. The
46  * priority setting moves the function towards the front of the .fini_array
47  * section. */
48 __attribute__((destructor(0)))
__on_dlclose_late(void)49 static void __on_dlclose_late(void) {
50   __emutls_unregister_key();
51 }
52 
53 /* CRT_LEGACY_WORKAROUND should only be defined when building
54  * this file as part of the platform's C library.
55  *
56  * The C library already defines a function named 'atexit()'
57  * for backwards compatibility with older NDK-generated binaries.
58  *
59  * For newer ones, 'atexit' is actually embedded in the C
60  * runtime objects that are linked into the final ELF
61  * binary (shared library or executable), and will call
62  * __cxa_atexit() in order to un-register any atexit()
63  * handler when a library is unloaded.
64  *
65  * This function must be global *and* hidden. Only the
66  * code inside the same ELF binary should be able to access it.
67  */
68 
69 #ifdef CRT_LEGACY_WORKAROUND
70 # include "__dso_handle.h"
71 #else
72 # include "__dso_handle_so.h"
73 # include "atexit.h"
74 #endif
75 #include "pthread_atfork.h"
76 #ifdef __i386__
77 # include "../../arch-x86/bionic/__stack_chk_fail_local.h"
78 #endif
79