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[glibc.git] / sysdeps / generic / abort.c
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1 /* Copyright (C) 1991, 93, 95, 96, 97, 98 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA. */
19 #include <bits/libc-lock.h>
20 #include <signal.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
26 /* Try to get a machine dependent instruction which will make the
27 program crash. This is used in case everything else fails. */
28 #include <abort-instr.h>
29 #ifndef ABORT_INSTRUCTION
30 /* No such instruction is available. */
31 # define ABORT_INSTRUCTION
32 #endif
34 #ifdef USE_IN_LIBIO
35 # include <libio/iolibio.h>
36 # define fflush(s) _IO_fflush (s)
37 #endif
39 /* We must avoid to run in circles. Therefore we remember how far we
40 already got. */
41 static int stage;
43 /* We should be prepared for multiple threads trying to run abort. */
44 __libc_lock_define_initialized_recursive (static, lock);
47 /* Cause an abnormal program termination with core-dump. */
48 void
49 abort (void)
51 struct sigaction act;
52 sigset_t sigs;
54 /* First acquire the lock. */
55 __libc_lock_lock_recursive (lock);
57 /* Now it's for sure we are alone. But recursive calls are possible. */
59 /* Unlock SIGABRT. */
60 if (stage == 0)
62 ++stage;
63 if (__sigemptyset (&sigs) == 0 &&
64 __sigaddset (&sigs, SIGABRT) == 0)
65 __sigprocmask (SIG_UNBLOCK, &sigs, (sigset_t *) NULL);
68 /* Flush all streams. We cannot close them now because the user
69 might have registered a handler for SIGABRT. */
70 if (stage == 1)
72 ++stage;
73 fflush (NULL);
76 /* Send signal which possibly calls a user handler. */
77 if (stage == 2)
79 /* This stage is special: we must allow repeated calls of
80 `abort' when a user defined handler for SIGABRT is installed.
81 This is risky since the `raise' implementation might also
82 fail but I don't see another possibility. */
83 int save_stage = stage;
85 stage = 0;
86 __libc_lock_unlock_recursive (lock);
88 raise (SIGABRT);
90 __libc_lock_lock_recursive (lock);
91 stage = save_stage + 1;
94 /* There was a handler installed. Now remove it. */
95 if (stage == 3)
97 ++stage;
98 memset (&act, '\0', sizeof (struct sigaction));
99 act.sa_handler = SIG_DFL;
100 __sigfillset (&act.sa_mask);
101 act.sa_flags = 0;
102 __sigaction (SIGABRT, &act, NULL);
105 /* Now close the streams which also flushes the output the user
106 defined handler might has produced. */
107 if (stage == 4)
109 ++stage;
110 __fcloseall ();
113 /* Try again. */
114 if (stage == 5)
116 ++stage;
117 raise (SIGABRT);
120 /* Now try to abort using the system specific command. */
121 if (stage == 6)
123 ++stage;
124 ABORT_INSTRUCTION;
127 /* If we can't signal ourselves and the abort instruction failed, exit. */
128 if (stage == 7)
130 ++stage;
131 _exit (127);
134 /* If even this fails try to use the provided instruction to crash
135 or otherwise make sure we never return. */
136 while (1)
137 /* Try for ever and ever. */
138 ABORT_INSTRUCTION;