platform_bionic/libc/unistd/abort.c
Andy McFadden 5f32207a3d Wrap ARM abort() to improve stack trace.
The code generated for Thumb and Thumb2 targets has different handling
for abort().  Because abort() is "noreturn", it doesn't need to preserve
the callee-save registers.  The Thumb2 version trashes LR and makes it
impossible to figure out who called abort().

This inserts a trivial stub function; net effect is stack traces are
reasonable after an abort().

For bug 2191452.
2009-10-15 16:29:22 -07:00

130 lines
4.2 KiB
C

/* $OpenBSD: abort.c,v 1.14 2005/08/08 08:05:36 espie Exp $ */
/*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "thread_private.h"
#include "atexit.h"
/* temporary, for bug hunting */
#include "logd.h"
#define debug_log(format, ...) \
__libc_android_log_print(ANDROID_LOG_DEBUG, "libc-abort", (format), ##__VA_ARGS__ )
#ifdef __arm__
void
__libc_android_abort(void)
#else
void
abort(void)
#endif
{
struct atexit *p = __atexit;
static int cleanup_called = 0;
sigset_t mask;
sigfillset(&mask);
/*
* don't block SIGABRT to give any handler a chance; we ignore
* any errors -- X311J doesn't allow abort to return anyway.
*/
sigdelset(&mask, SIGABRT);
/* temporary, so deliberate seg fault can be caught by debuggerd */
sigdelset(&mask, SIGSEGV);
/* -- */
(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
/*
* POSIX requires we flush stdio buffers on abort
*/
if (cleanup_called == 0) {
while (p != NULL && p->next != NULL)
p = p->next;
/* the check for fn_dso == NULL is mostly paranoia */
if (p != NULL && p->fns[0].fn_dso == NULL &&
p->fns[0].fn_ptr.std_func != NULL) {
cleanup_called = 1;
(*p->fns[0].fn_ptr.std_func)();
}
}
/* temporary, for bug hunting */
/* seg fault seems to produce better debuggerd results than SIGABRT */
*((char*)0xdeadbaad) = 39;
/* -- */
(void)kill(getpid(), SIGABRT);
/*
* if SIGABRT ignored, or caught and the handler returns, do
* it again, only harder.
*/
{
struct sigaction sa;
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_RESTART;
sigemptyset(&sa.sa_mask);
(void)sigaction( SIGABRT, &sa, &sa );
}
(void)sigprocmask(SIG_SETMASK, &mask, (sigset_t *)NULL);
(void)kill(getpid(), SIGABRT);
_exit(1);
}
#ifdef __arm__
/*
* abort() does not return, which gcc interprets to mean that it doesn't
* need to preserve any of the callee-save registers. Unfortunately this
* includes the link register, so if LR is used there is no way to determine
* which function called abort().
*
* We work around this by inserting a trivial stub that doesn't alter
* any of the "interesting" registers and thus doesn't need to save them.
* We can't just call __libc_android_abort from C because gcc uses "bl"
* without first saving LR, so we use an asm statement. This also has
* the side-effect of replacing abort() with __libc_android_abort() in
* the stack trace.
*
* Ideally __libc_android_abort would be static, but I haven't figured out
* how to tell gcc to call a static function from an asm statement.
*/
void
abort(void)
{
asm ("b __libc_android_abort");
_exit(1); /* suppress gcc noreturn warnings */
}
#endif