diff options
| author | ad <ad@NetBSD.org> | 2007-11-13 15:21:19 +0000 |
|---|---|---|
| committer | ad <ad@NetBSD.org> | 2007-11-13 15:21:19 +0000 |
| commit | ec4d182d4ad675e79ae635d3f612ed6ab98bbfcd (patch) | |
| tree | 1fc36afe7e42552ed224ca4f6a8a2be8fa0fbd6f /lib/libc/misc/stack_protector.c | |
| parent | ac0bd149f2595bde7cca53005d6abcfde0702a0e (diff) | |
- stack_protector.c doesn't really belong under sys/. Add a new directory
for misc support routines and put it there.
- Add a libc constructor. Use this to initialize threading and the
stack protector stuff. libpthread cannot be initialized safely using
its own constructor because libc and libpthread are deeply intertwined.
PR bin/37347
Diffstat (limited to 'lib/libc/misc/stack_protector.c')
| -rw-r--r-- | lib/libc/misc/stack_protector.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/lib/libc/misc/stack_protector.c b/lib/libc/misc/stack_protector.c new file mode 100644 index 00000000000..a404bfae463 --- /dev/null +++ b/lib/libc/misc/stack_protector.c @@ -0,0 +1,128 @@ +/* $NetBSD: stack_protector.c,v 1.1 2007/11/13 15:21:20 ad 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> +__RCSID("$NetBSD: stack_protector.c,v 1.1 2007/11/13 15:21:20 ad Exp $"); + +#ifdef _LIBC +#include "namespace.h" +#endif +#include <sys/param.h> +#include <sys/sysctl.h> +#include <ssp/ssp.h> +#include <signal.h> +#include <string.h> +#include <unistd.h> +#ifdef _LIBC +#include <syslog.h> +#include "extern.h" +#else +#define __sysctl sysctl +extern int xprintf(const char *fmt, ...); +#include <stdlib.h> +#endif + +long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; +static void __fail(const char *); +void __stack_chk_fail(void); +void __chk_fail(void); +void __stack_chk_fail_local(void); +void __guard_setup(void); + +void +__guard_setup(void) +{ + int mib[2]; + size_t len; + + if (__stack_chk_guard[0] != 0) + return; + + mib[0] = CTL_KERN; + mib[1] = KERN_ARND; + + len = sizeof(__stack_chk_guard); + if (__sysctl(mib, 2, __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; + } +} + +/*ARGSUSED*/ +static void +__fail(const char *msg) +{ +#ifdef _LIBC + struct syslog_data sdata = SYSLOG_DATA_INIT; +#endif + struct sigaction sa; + sigset_t mask; + + /* Immediately block all signal handlers from running code */ + (void)sigfillset(&mask); + (void)sigdelset(&mask, SIGABRT); + (void)sigprocmask(SIG_BLOCK, &mask, NULL); + +#ifdef _LIBC + /* This may fail on a chroot jail... */ + syslog_ss(LOG_CRIT, &sdata, msg); +#else + xprintf("%s: %s\n", getprogname(), msg); +#endif + + (void)memset(&sa, 0, sizeof(sa)); + (void)sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + sa.sa_handler = SIG_DFL; + (void)sigaction(SIGABRT, &sa, NULL); + (void)kill(getpid(), SIGABRT); + _exit(127); +} + +void +__stack_chk_fail(void) +{ + __fail("stack overflow detected; terminated"); +} + +void +__chk_fail(void) +{ + __fail("buffer overflow detected; terminated"); +} + +void +__stack_chk_fail_local(void) +{ + __stack_chk_fail(); +} |
