1 /* Copyright (C) 1991 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 
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.
8 
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.
13 
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
16 not, see <http://www.gnu.org/licenses/>.  */
17 
18 /* Hacked up for uClibc by Erik Andersen */
19 
20 #include <features.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 #include <signal.h>
26 #include <errno.h>
27 
28 
29 
30 /* Defeat compiler optimization which assumes function addresses are never NULL */
not_null_ptr(const void * p)31 static __always_inline int not_null_ptr(const void *p)
32 {
33 	const void *q;
34 	__asm__ (""
35 		: "=r" (q) /* output */
36 		: "0" (p) /* input */
37 	);
38 	return q != 0;
39 }
40 
41 /* Our last ditch effort to commit suicide */
42 #ifdef __UCLIBC_ABORT_INSTRUCTION__
43 # define ABORT_INSTRUCTION __asm__(__UCLIBC_ABORT_INSTRUCTION__)
44 #else
45 # define ABORT_INSTRUCTION
46 # warning "no abort instruction defined for your arch"
47 #endif
48 
49 static smallint been_there_done_that = 0;
50 
51 /* Be prepared in case multiple threads try to abort() */
52 #include <bits/uClibc_mutex.h>
53 __UCLIBC_MUTEX_STATIC(mylock, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP);
54 
55 /* Cause an abnormal program termination with core-dump */
abort(void)56 void abort(void)
57 {
58 	sigset_t sigs;
59 
60 	/* Make sure we acquire the lock before proceeding */
61 	__UCLIBC_MUTEX_LOCK_CANCEL_UNSAFE(mylock);
62 
63 	/* Unmask SIGABRT to be sure we can get it */
64 	__sigemptyset(&sigs);
65 	__sigaddset(&sigs, SIGABRT);
66 	sigprocmask(SIG_UNBLOCK, &sigs, NULL);
67 
68 	while (1) {
69 		/* Try to suicide with a SIGABRT */
70 		if (been_there_done_that == 0) {
71 			been_there_done_that++;
72 
73 #ifdef __UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT__
74 			/* If we are using stdio, try to shut it down.  At the very least,
75 			 * this will attempt to commit all buffered writes.  It may also
76 			 * unbuffer all writable files, or close them outright.
77 			 * Check the stdio routines for details. */
78 			if (not_null_ptr(_stdio_term)) {
79 				_stdio_term();
80 			}
81 #endif
82 
83 abort_it:
84 			__UCLIBC_MUTEX_UNLOCK_CANCEL_UNSAFE(mylock);
85 			raise(SIGABRT);
86 			__UCLIBC_MUTEX_LOCK_CANCEL_UNSAFE(mylock);
87 		}
88 
89 		/* Still here?  Try to remove any signal handlers */
90 		if (been_there_done_that == 1) {
91 			struct sigaction act;
92 
93 			been_there_done_that++;
94 			memset(&act, '\0', sizeof(struct sigaction));
95 			if (SIG_DFL) /* if it's constant zero, already done */
96 				act.sa_handler = SIG_DFL;
97 			__sigfillset(&act.sa_mask);
98 			sigaction(SIGABRT, &act, NULL);
99 
100 			goto abort_it;
101 		}
102 
103 		/* Still here?  Try to suicide with an illegal instruction */
104 		if (been_there_done_that == 2) {
105 			been_there_done_that++;
106 			ABORT_INSTRUCTION;
107 		}
108 
109 		/* Still here?  Try to at least exit */
110 		if (been_there_done_that == 3) {
111 			been_there_done_that++;
112 			_exit(127);
113 		}
114 
115 		/* Still here?  We're screwed.  Sleepy time.  Good night. */
116 		while (1)
117 			/* Try for ever and ever */
118 			ABORT_INSTRUCTION;
119 	}
120 }
121 libc_hidden_def(abort)
122