FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_ssp.c

     /*      $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

Cache object: 3bc3c745c5243d6e3d26d13612a17964