| 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 | |