1 /* Copyright (C) 2003-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Jakub Jelinek <jakub@redhat.com>.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If
17 not, see <https://www.gnu.org/licenses/>. */
24 #include <gnu/lib-names.h>
25 #include <unwind-resume.h>
27 static void *libgcc_s_handle
;
28 void (*__libgcc_s_resume
) (struct _Unwind_Exception
*exc
)
29 attribute_hidden
__attribute__ ((noreturn
));
30 static _Unwind_Reason_Code (*libgcc_s_personality
) PERSONALITY_PROTO
;
31 static _Unwind_Reason_Code (*libgcc_s_forcedunwind
)
32 (struct _Unwind_Exception
*, _Unwind_Stop_Fn
, void *);
33 static _Unwind_Word (*libgcc_s_getcfa
) (struct _Unwind_Context
*);
36 __attribute_noinline__
37 pthread_cancel_init (void)
45 if (__glibc_likely (libgcc_s_handle
!= NULL
))
47 /* Force gcc to reload all values. */
48 asm volatile ("" ::: "memory");
52 /* See include/dlfcn.h. Use of __libc_dlopen requires RTLD_NOW. */
53 handle
= __libc_dlopen (LIBGCC_S_SO
);
56 || (resume
= __libc_dlsym (handle
, "_Unwind_Resume")) == NULL
57 || (personality
= __libc_dlsym (handle
, "__gcc_personality_v0")) == NULL
58 || (forcedunwind
= __libc_dlsym (handle
, "_Unwind_ForcedUnwind"))
60 || (getcfa
= __libc_dlsym (handle
, "_Unwind_GetCFA")) == NULL
61 #ifdef ARCH_CANCEL_INIT
62 || ARCH_CANCEL_INIT (handle
)
65 __libc_fatal (LIBGCC_S_SO
" must be installed for pthread_cancel to work\n");
68 __libgcc_s_resume
= resume
;
69 PTR_MANGLE (personality
);
70 libgcc_s_personality
= personality
;
71 PTR_MANGLE (forcedunwind
);
72 libgcc_s_forcedunwind
= forcedunwind
;
74 libgcc_s_getcfa
= getcfa
;
75 /* Make sure libgcc_s_handle is written last. Otherwise,
76 pthread_cancel_init might return early even when the pointer the
77 caller is interested in is not initialized yet. */
78 atomic_write_barrier ();
79 libgcc_s_handle
= handle
;
82 /* Register for cleanup in libpthread.so. */
84 __nptl_unwind_freeres (void)
86 void *handle
= libgcc_s_handle
;
89 libgcc_s_handle
= NULL
;
90 __libc_dlclose (handle
);
94 #if !HAVE_ARCH_UNWIND_RESUME
96 _Unwind_Resume (struct _Unwind_Exception
*exc
)
98 if (__glibc_unlikely (libgcc_s_handle
== NULL
))
99 pthread_cancel_init ();
101 atomic_read_barrier ();
103 void (*resume
) (struct _Unwind_Exception
*exc
) = __libgcc_s_resume
;
104 PTR_DEMANGLE (resume
);
110 __gcc_personality_v0 PERSONALITY_PROTO
112 if (__glibc_unlikely (libgcc_s_handle
== NULL
))
113 pthread_cancel_init ();
115 atomic_read_barrier ();
117 __typeof (libgcc_s_personality
) personality
= libgcc_s_personality
;
118 PTR_DEMANGLE (personality
);
119 return (*personality
) PERSONALITY_ARGS
;
123 _Unwind_ForcedUnwind (struct _Unwind_Exception
*exc
, _Unwind_Stop_Fn stop
,
126 if (__glibc_unlikely (libgcc_s_handle
== NULL
))
127 pthread_cancel_init ();
129 atomic_read_barrier ();
131 _Unwind_Reason_Code (*forcedunwind
)
132 (struct _Unwind_Exception
*, _Unwind_Stop_Fn
, void *)
133 = libgcc_s_forcedunwind
;
134 PTR_DEMANGLE (forcedunwind
);
135 return forcedunwind (exc
, stop
, stop_argument
);
139 _Unwind_GetCFA (struct _Unwind_Context
*context
)
141 if (__glibc_unlikely (libgcc_s_handle
== NULL
))
142 pthread_cancel_init ();
144 atomic_read_barrier ();
146 _Unwind_Word (*getcfa
) (struct _Unwind_Context
*) = libgcc_s_getcfa
;
147 PTR_DEMANGLE (getcfa
);
148 return getcfa (context
);