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/* $OpenBSD: stack_protector.c,v 1.23 2016/03/21 22:41:28 bluhm Exp $ */ |
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/* |
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* Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat. |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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* DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, |
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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*/ |
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#include <signal.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <syslog.h> |
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#include <unistd.h> |
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/* |
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* Note: test below is for PIC not __PIC__. This code must only be included |
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* in the shared library and not in libc.a, but __PIC__ is set for libc.a |
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* objects where PIE is supported |
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* |
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* XXX would this work? #if defined(__PIC__) && !defined(__PIE__) |
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* XXX any archs which are always PIC (like mips64) but don't have PIE? |
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*/ |
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#ifdef PIC |
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#include <../csu/os-note-elf.h> |
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long __guard_local __dso_hidden __attribute__((section(".openbsd.randomdata"))); |
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#endif /* PIC */ |
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void |
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__stack_smash_handler(const char func[], int damaged) |
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{ |
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struct sigaction sa; |
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sigset_t mask; |
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char buf[1024]; |
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/* Immediately block all signal handlers from running code */ |
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sigfillset(&mask); |
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sigdelset(&mask, SIGABRT); |
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sigprocmask(SIG_SETMASK, &mask, NULL); |
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/* <10> is LOG_CRIT */ |
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strlcpy(buf, "<10>", sizeof buf); |
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/* Make sure progname does not fill the whole buffer */ |
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strlcat(buf, __progname, sizeof(buf) / 2 ); |
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strlcat(buf, ": stack overflow in function ", sizeof buf); |
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strlcat(buf, func, sizeof buf); |
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sendsyslog(buf, strlen(buf), LOG_CONS); |
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memset(&sa, 0, sizeof(sa)); |
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sigemptyset(&sa.sa_mask); |
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sa.sa_flags = 0; |
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sa.sa_handler = SIG_DFL; |
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sigaction(SIGABRT, &sa, NULL); |
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thrkill(0, SIGABRT, NULL); |
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_exit(127); |
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} |
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DEF_STRONG(__stack_smash_handler); |