1 | /* $NetBSD: kern_ssp.c,v 1.6 2011/11/19 22:51:25 tls Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2008 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
28 | |
29 | #include <sys/cdefs.h> |
30 | __KERNEL_RCSID(0, "$NetBSD: kern_ssp.c,v 1.6 2011/11/19 22:51:25 tls Exp $" ); |
31 | |
32 | #include <sys/param.h> |
33 | #include <sys/systm.h> |
34 | #include <sys/intr.h> |
35 | #include <sys/cprng.h> |
36 | |
37 | #if defined(__SSP__) || defined(__SSP_ALL__) |
38 | long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; |
39 | void __stack_chk_fail(void); |
40 | |
41 | void |
42 | __stack_chk_fail(void) |
43 | { |
44 | panic("stack overflow detected; terminated" ); |
45 | } |
46 | |
47 | void |
48 | ssp_init(void) |
49 | { |
50 | int s; |
51 | |
52 | aprint_debug("Initializing SSP: " ); |
53 | /* |
54 | * We initialize ssp here carefully: |
55 | * 1. after we got some entropy |
56 | * 2. without calling a function |
57 | */ |
58 | size_t i; |
59 | long guard[__arraycount(__stack_chk_guard)]; |
60 | |
61 | cprng_fast(guard, sizeof(guard)); |
62 | s = splhigh(); |
63 | for (i = 0; i < __arraycount(guard); i++) |
64 | __stack_chk_guard[i] = guard[i]; |
65 | splx(s); |
66 | for (i = 0; i < __arraycount(guard); i++) |
67 | aprint_debug("%lx " , guard[i]); |
68 | aprint_debug("\n" ); |
69 | } |
70 | #else |
71 | void |
72 | ssp_init(void) |
73 | { |
74 | } |
75 | #endif |
76 | |