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lib/libc/secure/stack_protector.c
- This file was added.
| /* $NetBSD: stack_protector.c,v 1.4 2006/11/22 17:23:25 christos Exp $ */ | |||||
| /* $OpenBSD: stack_protector.c,v 1.10 2006/03/31 05:34:44 deraadt 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 <sys/cdefs.h> | |||||
| __FBSDID("$FreeBSD$"); | |||||
| #include <sys/param.h> | |||||
| #include <sys/sysctl.h> | |||||
| #include <sys/types.h> | |||||
| #include <secure/security.h> | |||||
| #include <link.h> | |||||
| #include "libc_private.h" | |||||
| extern int __sysctl(const int *name, u_int namelen, void *oldp, | |||||
| size_t *oldlenp, void *newp, size_t newlen); | |||||
| long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; | |||||
| static void __guard_setup(void) __attribute__((__constructor__, __used__)); | |||||
| void __stack_chk_fail(void) __dead2; | |||||
| /*LINTED used*/ | |||||
| static void | |||||
| __guard_setup(void) | |||||
| { | |||||
| static const int mib[2] = { CTL_KERN, KERN_ARND }; | |||||
| size_t len; | |||||
| int error; | |||||
| if (__stack_chk_guard[0] != 0) | |||||
| return; | |||||
| error = _elf_aux_info(AT_CANARY, __stack_chk_guard, | |||||
| sizeof(__stack_chk_guard)); | |||||
| if (error == 0 && __stack_chk_guard[0] != 0) | |||||
| return; | |||||
| len = sizeof(__stack_chk_guard); | |||||
| if (__sysctl(mib, nitems(mib), __stack_chk_guard, &len, NULL, 0) == | |||||
| -1 || len != sizeof(__stack_chk_guard)) { | |||||
| /* If sysctl was unsuccessful, use the "terminator canary". */ | |||||
| ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; | |||||
| ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; | |||||
| ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; | |||||
| ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; | |||||
| } | |||||
| } | |||||
| void | |||||
| __stack_chk_fail(void) | |||||
| { | |||||
| __secure_fail("stack overflow detected; terminated"); | |||||
| } | |||||
| void | |||||
| __chk_fail(void) | |||||
| { | |||||
| __secure_fail("buffer overflow detected; terminated"); | |||||
| } | |||||
| #ifndef PIC | |||||
| __weak_reference(__stack_chk_fail, __stack_chk_fail_local); | |||||
| #endif | |||||