1 /* Copyright (C) 2003-2013 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. If not, see
17 <http://www.gnu.org/licenses/>. */
24 static void *libgcc_s_handle
;
25 static void (*libgcc_s_resume
) (struct _Unwind_Exception
*exc
);
26 static _Unwind_Reason_Code (*libgcc_s_personality
)
27 (_Unwind_State
, struct _Unwind_Exception
*, struct _Unwind_Context
*);
28 static _Unwind_Reason_Code (*libgcc_s_forcedunwind
)
29 (struct _Unwind_Exception
*, _Unwind_Stop_Fn
, void *);
30 static _Unwind_Word (*libgcc_s_getcfa
) (struct _Unwind_Context
*);
33 __attribute_noinline__
34 pthread_cancel_init (void)
36 void *resume
, *personality
, *forcedunwind
, *getcfa
;
39 if (__builtin_expect (libgcc_s_handle
!= NULL
, 1))
41 /* Force gcc to reload all values. */
42 asm volatile ("" ::: "memory");
46 handle
= __libc_dlopen ("libgcc_s.so.1");
49 || (resume
= __libc_dlsym (handle
, "_Unwind_Resume")) == NULL
50 || (personality
= __libc_dlsym (handle
, "__gcc_personality_v0")) == NULL
51 || (forcedunwind
= __libc_dlsym (handle
, "_Unwind_ForcedUnwind"))
53 || (getcfa
= __libc_dlsym (handle
, "_Unwind_GetCFA")) == NULL
54 #ifdef ARCH_CANCEL_INIT
55 || ARCH_CANCEL_INIT (handle
)
58 __libc_fatal ("libgcc_s.so.1 must be installed for pthread_cancel to work\n");
60 libgcc_s_resume
= resume
;
61 libgcc_s_personality
= personality
;
62 libgcc_s_forcedunwind
= forcedunwind
;
63 libgcc_s_getcfa
= getcfa
;
64 /* Make sure libgcc_s_getcfa is written last. Otherwise,
65 pthread_cancel_init might return early even when the pointer the
66 caller is interested in is not initialized yet. */
67 atomic_write_barrier ();
68 libgcc_s_handle
= handle
;
72 __libc_freeres_fn_section
73 __unwind_freeres (void)
75 void *handle
= libgcc_s_handle
;
78 libgcc_s_handle
= NULL
;
79 __libc_dlclose (handle
);
83 /* It's vitally important that _Unwind_Resume not have a stack frame; the
84 ARM unwinder relies on register state at entrance. So we write this in
88 " .globl _Unwind_Resume\n"
89 " .type _Unwind_Resume, %function\n"
91 " .cfi_sections .debug_frame\n"
92 " " CFI_STARTPROC
"\n"
93 " stmfd sp!, {r4, r5, r6, lr}\n"
94 " " CFI_ADJUST_CFA_OFFSET (16)" \n"
95 " " CFI_REL_OFFSET (r4
, 0) "\n"
96 " " CFI_REL_OFFSET (r5
, 4) "\n"
97 " " CFI_REL_OFFSET (r6
, 8) "\n"
98 " " CFI_REL_OFFSET (lr
, 12) "\n"
99 " " CFI_REMEMBER_STATE
"\n"
102 "3: add r4, pc, r4\n"
103 " ldr r3, [r4, r5]\n"
108 " ldmfd sp!, {r4, r5, r6, lr}\n"
109 " " CFI_ADJUST_CFA_OFFSET (-16) "\n"
110 " " CFI_RESTORE (r4
) "\n"
111 " " CFI_RESTORE (r5
) "\n"
112 " " CFI_RESTORE (r6
) "\n"
113 " " CFI_RESTORE (lr
) "\n"
115 " " CFI_RESTORE_STATE
"\n"
116 "4: bl pthread_cancel_init\n"
117 " ldr r3, [r4, r5]\n"
122 "1: .word _GLOBAL_OFFSET_TABLE_ - 3b - 4\n"
124 "1: .word _GLOBAL_OFFSET_TABLE_ - 3b - 8\n"
126 "2: .word libgcc_s_resume(GOTOFF)\n"
127 " .size _Unwind_Resume, .-_Unwind_Resume\n"
131 __gcc_personality_v0 (_Unwind_State state
,
132 struct _Unwind_Exception
*ue_header
,
133 struct _Unwind_Context
*context
)
135 if (__builtin_expect (libgcc_s_personality
== NULL
, 0))
136 pthread_cancel_init ();
138 return libgcc_s_personality (state
, ue_header
, context
);
142 _Unwind_ForcedUnwind (struct _Unwind_Exception
*exc
, _Unwind_Stop_Fn stop
,
145 if (__builtin_expect (libgcc_s_forcedunwind
== NULL
, 0))
146 pthread_cancel_init ();
148 return libgcc_s_forcedunwind (exc
, stop
, stop_argument
);
152 _Unwind_GetCFA (struct _Unwind_Context
*context
)
154 if (__builtin_expect (libgcc_s_getcfa
== NULL
, 0))
155 pthread_cancel_init ();
157 return libgcc_s_getcfa (context
);