/* $NetBSD: kern_ssp.c,v 1.7 2016/12/06 02:55:42 christos Exp $ */ /*- * Copyright (c) 2008 The NetBSD Foundation, Inc. * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``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 FOUNDATION OR CONTRIBUTORS * 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> __KERNEL_RCSID(0, "$NetBSD: kern_ssp.c,v 1.7 2016/12/06 02:55:42 christos Exp $"); #include <sys/param.h> #include <sys/systm.h> #include <sys/intr.h> #include <sys/cprng.h> #if defined(__SSP__) || defined(__SSP_ALL__) # ifdef _RUMPKERNEL __weak_alias(__stack_chk_guard, stack_chk_guard) __weak_alias(__stack_chk_fail, stack_chk_fail) # define SSP_STATIC static __used # else # define stack_chk_guard __stack_chk_guard # define stack_chk_fail __stack_chk_fail # define SSP_STATIC #endif SSP_STATIC long stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0,}; SSP_STATIC void stack_chk_fail(void); SSP_STATIC void stack_chk_fail(void) { panic("stack overflow detected; terminated"); } void ssp_init(void) { int s; aprint_debug("Initializing SSP: "); /* * We initialize ssp here carefully: * 1. after we got some entropy * 2. without calling a function */ size_t i; long guard[__arraycount(stack_chk_guard)]; cprng_fast(guard, sizeof(guard)); s = splhigh(); for (i = 0; i < __arraycount(guard); i++) stack_chk_guard[i] = guard[i]; splx(s); for (i = 0; i < __arraycount(guard); i++) aprint_debug("%lx ", guard[i]); aprint_debug("\n"); } #else void ssp_init(void) { } #endif |