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
|
/* Copyright (C) 2003, 2005 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,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <dlfcn.h>
#include <string.h>
#include <unwind.h>
#include <unistd.h>
#include <pthreadP.h>
#define __libc_dlopen(x) dlopen(x, (RTLD_LOCAL | RTLD_LAZY))
#define __libc_dlsym dlsym
static void (*libgcc_s_resume) (struct _Unwind_Exception *exc);
static _Unwind_Reason_Code (*libgcc_s_personality)
(_Unwind_State, 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
pthread_cancel_init (void)
{
void *resume, *personality, *forcedunwind, *getcfa;
void *handle;
if (__builtin_expect (libgcc_s_getcfa != NULL, 1))
return;
handle = __libc_dlopen ("libgcc_s.so.1");
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
)
{
# define STR_N_LEN(str) str, strlen (str)
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL (write, err, 3, STDERR_FILENO,
STR_N_LEN ("libgcc_s.so.1 must be installed for pthread_cancel to work\n"));
abort ();
}
libgcc_s_resume = resume;
libgcc_s_personality = personality;
libgcc_s_forcedunwind = forcedunwind;
libgcc_s_getcfa = getcfa;
}
/* It's vitally important that _Unwind_Resume not have a stack frame; the
ARM unwinder relies on register state at entrance. So we write this in
assembly. */
asm (
#ifdef __thumb__
" .code 32"
#endif
" .globl _Unwind_Resume\n"
" .type _Unwind_Resume, %function\n"
"_Unwind_Resume:\n"
" stmfd sp!, {r4, r5, r6, lr}\n"
" ldr r4, 1f\n"
" ldr r5, 2f\n"
"3: add r4, pc, r4\n"
" ldr r3, [r4, r5]\n"
" mov r6, r0\n"
" cmp r3, #0\n"
" beq 4f\n"
"5: mov r0, r6\n"
" ldmfd sp!, {r4, r5, r6, lr}\n"
" bx r3\n"
"4: bl pthread_cancel_init\n"
" ldr r3, [r4, r5]\n"
" b 5b\n"
"1: .word _GLOBAL_OFFSET_TABLE_ - 3b - 8\n"
"2: .word libgcc_s_resume(GOTOFF)\n"
" .size _Unwind_Resume, .-_Unwind_Resume\n"
#ifdef __thumb__
" .code 16"
#endif
);
_Unwind_Reason_Code
__gcc_personality_v0 (_Unwind_State state,
struct _Unwind_Exception *ue_header,
struct _Unwind_Context *context)
{
if (__builtin_expect (libgcc_s_personality == NULL, 0))
pthread_cancel_init ();
return libgcc_s_personality (state, ue_header, context);
}
_Unwind_Reason_Code
_Unwind_ForcedUnwind (struct _Unwind_Exception *exc, _Unwind_Stop_Fn stop,
void *stop_argument)
{
if (__builtin_expect (libgcc_s_forcedunwind == NULL, 0))
pthread_cancel_init ();
return libgcc_s_forcedunwind (exc, stop, stop_argument);
}
_Unwind_Word
_Unwind_GetCFA (struct _Unwind_Context *context)
{
if (__builtin_expect (libgcc_s_getcfa == NULL, 0))
pthread_cancel_init ();
return libgcc_s_getcfa (context);
}
|