1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/* Copyright (C) 2003-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <dlfcn.h>
#include <stdio.h>
#include <unwind.h>
#include <pthreadP.h>
#include <sysdep.h>
#include <gnu/lib-names.h>
static void *libgcc_s_handle;
static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
static _Unwind_Reason_Code (*libgcc_s_personality)
(int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *,
struct _Unwind_Context *);
static _Unwind_Reason_Code (*libgcc_s_forcedunwind)
(struct _Unwind_Exception *, _Unwind_Stop_Fn, void *);
static _Unwind_Word (*libgcc_s_getcfa) (struct _Unwind_Context *);
void
__attribute_noinline__
pthread_cancel_init (void)
{
void *resume;
void *personality;
void *forcedunwind;
void *getcfa;
void *handle;
if (__glibc_likely (libgcc_s_handle != NULL))
{
/* Force gcc to reload all values. */
asm volatile ("" ::: "memory");
return;
}
handle = __libc_dlopen (LIBGCC_S_SO);
if (handle == NULL
|| (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL
|| (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL
|| (forcedunwind = __libc_dlsym (handle, "_Unwind_ForcedUnwind"))
== NULL
|| (getcfa = __libc_dlsym (handle, "_Unwind_GetCFA")) == NULL
#ifdef ARCH_CANCEL_INIT
|| ARCH_CANCEL_INIT (handle)
#endif
)
__libc_fatal (LIBGCC_S_SO " must be installed for pthread_cancel to work\n");
PTR_MANGLE (resume);
libgcc_s_resume = resume;
PTR_MANGLE (personality);
libgcc_s_personality = personality;
PTR_MANGLE (forcedunwind);
libgcc_s_forcedunwind = forcedunwind;
PTR_MANGLE (getcfa);
libgcc_s_getcfa = getcfa;
/* Make sure libgcc_s_handle is written last. Otherwise,
pthread_cancel_init might return early even when the pointer the
caller is interested in is not initialized yet. */
atomic_write_barrier ();
libgcc_s_handle = handle;
}
void
__libc_freeres_fn_section
__unwind_freeres (void)
{
void *handle = libgcc_s_handle;
if (handle != NULL)
{
libgcc_s_handle = NULL;
__libc_dlclose (handle);
}
}
void
_Unwind_Resume (struct _Unwind_Exception *exc)
{
if (__glibc_unlikely (libgcc_s_handle == NULL))
pthread_cancel_init ();
else
atomic_read_barrier ();
void (*resume) (struct _Unwind_Exception *exc) = libgcc_s_resume;
PTR_DEMANGLE (resume);
resume (exc);
}
_Unwind_Reason_Code
__gcc_personality_v0 (int version, _Unwind_Action actions,
_Unwind_Exception_Class exception_class,
struct _Unwind_Exception *ue_header,
struct _Unwind_Context *context)
{
if (__glibc_unlikely (libgcc_s_handle == NULL))
pthread_cancel_init ();
else
atomic_read_barrier ();
_Unwind_Reason_Code (*personality)
(int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *,
struct _Unwind_Context *) = libgcc_s_personality;
PTR_DEMANGLE (personality);
return personality (version, actions, exception_class, ue_header, context);
}
_Unwind_Reason_Code
_Unwind_ForcedUnwind (struct _Unwind_Exception *exc, _Unwind_Stop_Fn stop,
void *stop_argument)
{
if (__glibc_unlikely (libgcc_s_handle == NULL))
pthread_cancel_init ();
else
atomic_read_barrier ();
_Unwind_Reason_Code (*forcedunwind)
(struct _Unwind_Exception *, _Unwind_Stop_Fn, void *)
= libgcc_s_forcedunwind;
PTR_DEMANGLE (forcedunwind);
return forcedunwind (exc, stop, stop_argument);
}
_Unwind_Word
_Unwind_GetCFA (struct _Unwind_Context *context)
{
if (__glibc_unlikely (libgcc_s_handle == NULL))
pthread_cancel_init ();
else
atomic_read_barrier ();
_Unwind_Word (*getcfa) (struct _Unwind_Context *) = libgcc_s_getcfa;
PTR_DEMANGLE (getcfa);
return getcfa (context);
}
|
