kern_ssp.c revision 1.2.6.2 1 1.2.6.2 yamt /* $NetBSD: kern_ssp.c,v 1.2.6.2 2009/05/04 08:13:47 yamt Exp $ */
2 1.2.6.2 yamt
3 1.2.6.2 yamt /*-
4 1.2.6.2 yamt * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 1.2.6.2 yamt * All rights reserved.
6 1.2.6.2 yamt *
7 1.2.6.2 yamt * Redistribution and use in source and binary forms, with or without
8 1.2.6.2 yamt * modification, are permitted provided that the following conditions
9 1.2.6.2 yamt * are met:
10 1.2.6.2 yamt * 1. Redistributions of source code must retain the above copyright
11 1.2.6.2 yamt * notice, this list of conditions and the following disclaimer.
12 1.2.6.2 yamt * 2. Redistributions in binary form must reproduce the above copyright
13 1.2.6.2 yamt * notice, this list of conditions and the following disclaimer in the
14 1.2.6.2 yamt * documentation and/or other materials provided with the distribution.
15 1.2.6.2 yamt *
16 1.2.6.2 yamt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 1.2.6.2 yamt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 1.2.6.2 yamt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 1.2.6.2 yamt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 1.2.6.2 yamt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 1.2.6.2 yamt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 1.2.6.2 yamt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 1.2.6.2 yamt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 1.2.6.2 yamt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 1.2.6.2 yamt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 1.2.6.2 yamt * POSSIBILITY OF SUCH DAMAGE.
27 1.2.6.2 yamt */
28 1.2.6.2 yamt
29 1.2.6.2 yamt #include <sys/cdefs.h>
30 1.2.6.2 yamt __KERNEL_RCSID(0, "$NetBSD: kern_ssp.c,v 1.2.6.2 2009/05/04 08:13:47 yamt Exp $");
31 1.2.6.2 yamt
32 1.2.6.2 yamt #include <sys/param.h>
33 1.2.6.2 yamt #include <sys/systm.h>
34 1.2.6.2 yamt #include <sys/intr.h>
35 1.2.6.2 yamt
36 1.2.6.2 yamt #if defined(__SSP__) || defined(__SSP_ALL__)
37 1.2.6.2 yamt long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
38 1.2.6.2 yamt void __stack_chk_fail(void);
39 1.2.6.2 yamt
40 1.2.6.2 yamt void
41 1.2.6.2 yamt __stack_chk_fail(void)
42 1.2.6.2 yamt {
43 1.2.6.2 yamt panic("stack overflow detected; terminated");
44 1.2.6.2 yamt }
45 1.2.6.2 yamt
46 1.2.6.2 yamt void
47 1.2.6.2 yamt ssp_init(void)
48 1.2.6.2 yamt {
49 1.2.6.2 yamt int s;
50 1.2.6.2 yamt
51 1.2.6.2 yamt #ifdef DIAGNOSTIC
52 1.2.6.2 yamt printf("Initializing SSP:");
53 1.2.6.2 yamt #endif
54 1.2.6.2 yamt /*
55 1.2.6.2 yamt * We initialize ssp here carefully:
56 1.2.6.2 yamt * 1. after we got some entropy
57 1.2.6.2 yamt * 2. without calling a function
58 1.2.6.2 yamt */
59 1.2.6.2 yamt size_t i;
60 1.2.6.2 yamt long guard[__arraycount(__stack_chk_guard)];
61 1.2.6.2 yamt
62 1.2.6.2 yamt arc4randbytes(guard, sizeof(guard));
63 1.2.6.2 yamt s = splhigh();
64 1.2.6.2 yamt for (i = 0; i < __arraycount(guard); i++)
65 1.2.6.2 yamt __stack_chk_guard[i] = guard[i];
66 1.2.6.2 yamt splx(s);
67 1.2.6.2 yamt #ifdef DIAGNOSTIC
68 1.2.6.2 yamt for (i = 0; i < __arraycount(guard); i++)
69 1.2.6.2 yamt printf("%lx ", guard[i]);
70 1.2.6.2 yamt printf("\n");
71 1.2.6.2 yamt #endif
72 1.2.6.2 yamt }
73 1.2.6.2 yamt #else
74 1.2.6.2 yamt void
75 1.2.6.2 yamt ssp_init(void)
76 1.2.6.2 yamt {
77 1.2.6.2 yamt }
78 1.2.6.2 yamt #endif
79