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/* $OpenBSD: stack_protector.c,v 1.24 2017/11/29 05:13:57 guenther Exp $ */
/*
* Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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 <string.h>
#include <syslog.h>
#include <unistd.h>
/*
* Note: test below is for PIC not __PIC__. This code must only be included
* in the shared library and not in libc.a, but __PIC__ is set for libc.a
* objects where PIE is supported
*
* XXX would this work? #if defined(__PIC__) && !defined(__PIE__)
* XXX any archs which are always PIC (like mips64) but don't have PIE?
*/
#ifdef PIC
#include <../csu/os-note-elf.h>
long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata")));
#endif /* PIC */
void
__stack_smash_handler(const char func[], int damaged)
{
struct sigaction sa;
sigset_t mask;
char buf[1024];
/* Immediately block all signal handlers from running code */
sigfillset(&mask);
sigdelset(&mask, SIGABRT);
sigprocmask(SIG_SETMASK, &mask, NULL);
/* <10> is LOG_CRIT */
strlcpy(buf, "<10>", sizeof buf);
/* Make sure progname does not fill the whole buffer */
strlcat(buf, __progname, sizeof(buf) / 2 );
strlcat(buf, ": stack overflow in function ", sizeof buf);
strlcat(buf, func, sizeof buf);
sendsyslog(buf, strlen(buf), LOG_CONS);
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = SIG_DFL;
sigaction(SIGABRT, &sa, NULL);
thrkill(0, SIGABRT, NULL);
_exit(127);
}
DEF_BUILTIN(__stack_smash_handler);
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