Thu Dec 8 02:27:14 2011 UTC ()
Use a constant array for the MIB. Newer LLVM decided that mib[] warranted
stack protections, with the obvious crash after the setup was done.
As a positive side effect, code size shrinks a bit.


(joerg)
diff -r1.6 -r1.7 src/lib/libc/misc/stack_protector.c
cvs diff -r1.6 -r1.7 src/lib/libc/misc/stack_protector.c (switch to unified diff)

--- src/lib/libc/misc/stack_protector.c 2011/09/16 16:05:59 1.6
+++ src/lib/libc/misc/stack_protector.c 2011/12/08 02:27:14 1.7
@@ -1,126 +1,123 @@ @@ -1,126 +1,123 @@
1/* $NetBSD: stack_protector.c,v 1.6 2011/09/16 16:05:59 joerg Exp $ */ 1/* $NetBSD: stack_protector.c,v 1.7 2011/12/08 02:27:14 joerg Exp $ */
2/* $OpenBSD: stack_protector.c,v 1.10 2006/03/31 05:34:44 deraadt Exp $ */ 2/* $OpenBSD: stack_protector.c,v 1.10 2006/03/31 05:34:44 deraadt Exp $ */
3 3
4/* 4/*
5 * Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat. 5 * Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat.
6 * All rights reserved. 6 * All rights reserved.
7 * 7 *
8 * Redistribution and use in source and binary forms, with or without 8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions 9 * modification, are permitted provided that the following conditions
10 * are met: 10 * are met:
11 * 1. Redistributions of source code must retain the above copyright 11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer. 12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright 13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the 14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution. 15 * documentation and/or other materials provided with the distribution.
16 * 16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, 20 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT,
21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
26 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE. 27 * POSSIBILITY OF SUCH DAMAGE.
28 * 28 *
29 */ 29 */
30#include <sys/cdefs.h> 30#include <sys/cdefs.h>
31__RCSID("$NetBSD: stack_protector.c,v 1.6 2011/09/16 16:05:59 joerg Exp $"); 31__RCSID("$NetBSD: stack_protector.c,v 1.7 2011/12/08 02:27:14 joerg Exp $");
32 32
33#ifdef _LIBC 33#ifdef _LIBC
34#include "namespace.h" 34#include "namespace.h"
35#endif 35#endif
36#include <sys/param.h> 36#include <sys/param.h>
37#include <sys/sysctl.h> 37#include <sys/sysctl.h>
38#include <ssp/ssp.h> 38#include <ssp/ssp.h>
39#include <signal.h> 39#include <signal.h>
40#include <string.h> 40#include <string.h>
41#include <unistd.h> 41#include <unistd.h>
42#ifdef _LIBC 42#ifdef _LIBC
43#include <syslog.h> 43#include <syslog.h>
44#include "extern.h" 44#include "extern.h"
45#else 45#else
46#define __sysctl sysctl 46#define __sysctl sysctl
47void xprintf(const char *fmt, ...); 47void xprintf(const char *fmt, ...);
48#include <stdlib.h> 48#include <stdlib.h>
49#endif 49#endif
50 50
51long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 51long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
52static void __fail(const char *) __attribute__((__noreturn__)); 52static void __fail(const char *) __attribute__((__noreturn__));
53__dead void __stack_chk_fail_local(void); 53__dead void __stack_chk_fail_local(void);
54void __guard_setup(void); 54void __guard_setup(void);
55 55
56void 56void
57__guard_setup(void) 57__guard_setup(void)
58{ 58{
59 int mib[2]; 59 static const int mib[2] = { CTL_KERN, KERN_ARND };
60 size_t len; 60 size_t len;
61 61
62 if (__stack_chk_guard[0] != 0) 62 if (__stack_chk_guard[0] != 0)
63 return; 63 return;
64 64
65 mib[0] = CTL_KERN; 
66 mib[1] = KERN_ARND; 
67 
68 len = sizeof(__stack_chk_guard); 65 len = sizeof(__stack_chk_guard);
69 if (__sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 66 if (__sysctl(mib, __arraycount(mib), __stack_chk_guard, &len, NULL, 0) == -1 ||
70 len != sizeof(__stack_chk_guard)) { 67 len != sizeof(__stack_chk_guard)) {
71 /* If sysctl was unsuccessful, use the "terminator canary". */ 68 /* If sysctl was unsuccessful, use the "terminator canary". */
72 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 69 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
73 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 70 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
74 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 71 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
75 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 72 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255;
76 } 73 }
77} 74}
78 75
79/*ARGSUSED*/ 76/*ARGSUSED*/
80static void 77static void
81__fail(const char *msg) 78__fail(const char *msg)
82{ 79{
83#ifdef _LIBC 80#ifdef _LIBC
84 struct syslog_data sdata = SYSLOG_DATA_INIT; 81 struct syslog_data sdata = SYSLOG_DATA_INIT;
85#endif 82#endif
86 struct sigaction sa; 83 struct sigaction sa;
87 sigset_t mask; 84 sigset_t mask;
88 85
89 /* Immediately block all signal handlers from running code */ 86 /* Immediately block all signal handlers from running code */
90 (void)sigfillset(&mask); 87 (void)sigfillset(&mask);
91 (void)sigdelset(&mask, SIGABRT); 88 (void)sigdelset(&mask, SIGABRT);
92 (void)sigprocmask(SIG_BLOCK, &mask, NULL); 89 (void)sigprocmask(SIG_BLOCK, &mask, NULL);
93 90
94#ifdef _LIBC 91#ifdef _LIBC
95 /* This may fail on a chroot jail... */ 92 /* This may fail on a chroot jail... */
96 syslog_ss(LOG_CRIT, &sdata, "%s", msg); 93 syslog_ss(LOG_CRIT, &sdata, "%s", msg);
97#else 94#else
98 xprintf("%s: %s\n", getprogname(), msg); 95 xprintf("%s: %s\n", getprogname(), msg);
99#endif 96#endif
100 97
101 (void)memset(&sa, 0, sizeof(sa)); 98 (void)memset(&sa, 0, sizeof(sa));
102 (void)sigemptyset(&sa.sa_mask); 99 (void)sigemptyset(&sa.sa_mask);
103 sa.sa_flags = 0; 100 sa.sa_flags = 0;
104 sa.sa_handler = SIG_DFL; 101 sa.sa_handler = SIG_DFL;
105 (void)sigaction(SIGABRT, &sa, NULL); 102 (void)sigaction(SIGABRT, &sa, NULL);
106 (void)raise(SIGABRT); 103 (void)raise(SIGABRT);
107 _exit(127); 104 _exit(127);
108} 105}
109 106
110void 107void
111__stack_chk_fail(void) 108__stack_chk_fail(void)
112{ 109{
113 __fail("stack overflow detected; terminated"); 110 __fail("stack overflow detected; terminated");
114} 111}
115 112
116void 113void
117__chk_fail(void) 114__chk_fail(void)
118{ 115{
119 __fail("buffer overflow detected; terminated"); 116 __fail("buffer overflow detected; terminated");
120} 117}
121 118
122void 119void
123__stack_chk_fail_local(void) 120__stack_chk_fail_local(void)
124{ 121{
125 __stack_chk_fail(); 122 __stack_chk_fail();
126} 123}