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authorad <ad@NetBSD.org>2007-11-13 15:21:19 +0000
committerad <ad@NetBSD.org>2007-11-13 15:21:19 +0000
commitec4d182d4ad675e79ae635d3f612ed6ab98bbfcd (patch)
tree1fc36afe7e42552ed224ca4f6a8a2be8fa0fbd6f /lib/libc/misc/stack_protector.c
parentac0bd149f2595bde7cca53005d6abcfde0702a0e (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.c128
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();
+}