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[glibc.git] / stdlib / abort.c
blob9f59d228d350ef00f9d3093f4dd8abdfc5567667
1 /* Copyright (C) 1991,1993,1995-1998,2001,2002,2009,2011
2 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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
7 License as published by the Free Software Foundation; either
8 version 2.1 of the 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/>. */
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 #include <libio/libioP.h>
35 #define fflush(s) _IO_flush_all_lockp (0)
37 /* Exported variable to locate abort message in core files etc. */
38 struct abort_msg_s *__abort_msg __attribute__ ((nocommon));
39 libc_hidden_def (__abort_msg)
41 /* We must avoid to run in circles. Therefore we remember how far we
42 already got. */
43 static int stage;
45 /* We should be prepared for multiple threads trying to run abort. */
46 __libc_lock_define_initialized_recursive (static, lock);
49 /* Cause an abnormal program termination with core-dump. */
50 void
51 abort (void)
53 struct sigaction act;
54 sigset_t sigs;
56 /* First acquire the lock. */
57 __libc_lock_lock_recursive (lock);
59 /* Now it's for sure we are alone. But recursive calls are possible. */
61 /* Unlock SIGABRT. */
62 if (stage == 0)
64 ++stage;
65 if (__sigemptyset (&sigs) == 0 &&
66 __sigaddset (&sigs, SIGABRT) == 0)
67 __sigprocmask (SIG_UNBLOCK, &sigs, (sigset_t *) NULL);
70 /* Flush all streams. We cannot close them now because the user
71 might have registered a handler for SIGABRT. */
72 if (stage == 1)
74 ++stage;
75 fflush (NULL);
78 /* Send signal which possibly calls a user handler. */
79 if (stage == 2)
81 /* This stage is special: we must allow repeated calls of
82 `abort' when a user defined handler for SIGABRT is installed.
83 This is risky since the `raise' implementation might also
84 fail but I don't see another possibility. */
85 int save_stage = stage;
87 stage = 0;
88 __libc_lock_unlock_recursive (lock);
90 raise (SIGABRT);
92 __libc_lock_lock_recursive (lock);
93 stage = save_stage + 1;
96 /* There was a handler installed. Now remove it. */
97 if (stage == 3)
99 ++stage;
100 memset (&act, '\0', sizeof (struct sigaction));
101 act.sa_handler = SIG_DFL;
102 __sigfillset (&act.sa_mask);
103 act.sa_flags = 0;
104 __sigaction (SIGABRT, &act, NULL);
107 /* Now close the streams which also flushes the output the user
108 defined handler might has produced. */
109 if (stage == 4)
111 ++stage;
112 __fcloseall ();
115 /* Try again. */
116 if (stage == 5)
118 ++stage;
119 raise (SIGABRT);
122 /* Now try to abort using the system specific command. */
123 if (stage == 6)
125 ++stage;
126 ABORT_INSTRUCTION;
129 /* If we can't signal ourselves and the abort instruction failed, exit. */
130 if (stage == 7)
132 ++stage;
133 _exit (127);
136 /* If even this fails try to use the provided instruction to crash
137 or otherwise make sure we never return. */
138 while (1)
139 /* Try for ever and ever. */
140 ABORT_INSTRUCTION;
142 libc_hidden_def (abort)