1/*	$OpenBSD: abort.c,v 1.14 2005/08/08 08:05:36 espie Exp $ */
2/*
3 * Copyright (c) 1985 Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <signal.h>
32#include <stdlib.h>
33#include <unistd.h>
34#include "thread_private.h"
35#include "atexit.h"
36
37/* temporary, for bug hunting */
38#include "logd.h"
39#define debug_log(format, ...)  \
40    __libc_android_log_print(ANDROID_LOG_DEBUG, "libc-abort", (format), ##__VA_ARGS__ )
41
42#ifdef __arm__
43void
44__libc_android_abort(void)
45#else
46void
47abort(void)
48#endif
49{
50	struct atexit *p = __atexit;
51	static int cleanup_called = 0;
52	sigset_t mask;
53
54
55	sigfillset(&mask);
56	/*
57	 * don't block SIGABRT to give any handler a chance; we ignore
58	 * any errors -- X311J doesn't allow abort to return anyway.
59	 */
60	sigdelset(&mask, SIGABRT);
61    /* temporary, so deliberate seg fault can be caught by debuggerd */
62	sigdelset(&mask, SIGSEGV);
63    /* -- */
64	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
65
66	/*
67	 * POSIX requires we flush stdio buffers on abort
68	 */
69	if (cleanup_called == 0) {
70		while (p != NULL && p->next != NULL)
71			p = p->next;
72		/* the check for fn_dso == NULL is mostly paranoia */
73		if (p != NULL && p->fns[0].fn_dso == NULL &&
74		    p->fns[0].fn_ptr.std_func != NULL) {
75			cleanup_called = 1;
76			(*p->fns[0].fn_ptr.std_func)();
77		}
78	}
79
80    /* temporary, for bug hunting */
81    /* seg fault seems to produce better debuggerd results than SIGABRT */
82    *((char*)0xdeadbaad) = 39;
83    /* -- */
84
85	(void)kill(getpid(), SIGABRT);
86
87	/*
88	 * if SIGABRT ignored, or caught and the handler returns, do
89	 * it again, only harder.
90	 */
91        {
92            struct sigaction sa;
93
94            sa.sa_handler = SIG_DFL;
95            sa.sa_flags   = SA_RESTART;
96            sigemptyset(&sa.sa_mask);
97
98            (void)sigaction( SIGABRT, &sa, &sa );
99        }
100
101	(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
102	(void)kill(getpid(), SIGABRT);
103	_exit(1);
104}
105
106#ifdef __arm__
107/*
108 * abort() does not return, which gcc interprets to mean that it doesn't
109 * need to preserve any of the callee-save registers.  Unfortunately this
110 * includes the link register, so if LR is used there is no way to determine
111 * which function called abort().
112 *
113 * We work around this by inserting a trivial stub that doesn't alter
114 * any of the "interesting" registers and thus doesn't need to save them.
115 * We can't just call __libc_android_abort from C because gcc uses "bl"
116 * without first saving LR, so we use an asm statement.  This also has
117 * the side-effect of replacing abort() with __libc_android_abort() in
118 * the stack trace.
119 *
120 * Ideally __libc_android_abort would be static, but I haven't figured out
121 * how to tell gcc to call a static function from an asm statement.
122 */
123void
124abort(void)
125{
126    asm ("b __libc_android_abort");
127    _exit(1);       /* suppress gcc noreturn warnings */
128}
129#endif
130
131