Pull up following revision(s) (requested by christos in ticket #458):
	sys/conf/Makefile.kern.inc: revision 1.121
	sys/conf/files: revision 1.940
	sys/kern/init_main.c: revision 1.381
	sys/kern/kern_ssp.c: revision 1.1
	sys/kern/subr_autoconf.c: revision 1.168
	sys/sys/device.h: revision 1.116
	sys/sys/systm.h: revision 1.233
Unbreak ssp kernels. The issue here that when the ssp_init() call was
deferred, it caused the return from the enclosing function to break, as
well as the ssp return on i386. To fix both issues, split configure in
two pieces the one before calling ssp_init and the one after, and move
the ssp_init() call back in main. Put ssp_init() in its own file, and
compile this new file with -fno-stack-protector. Tested on amd64.
XXX: If we want to have ssp kernels working on 5.0, this change needs to
be pulled up.


(snj)

/*	$NetBSD: kern_ssp.c,v 1.2.4.2 2009/03/15 19:43:48 snj 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 1.2.4.2 2009/03/15 19:43:48 snj Exp $");

#include <sys/systm.h>
#include <sys/intr.h>

#if defined(__SSP__) || defined(__SSP_ALL__)
long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
void __stack_chk_fail(void);

void
__stack_chk_fail(void)
{
	panic("stack overflow detected; terminated");
}

void
ssp_init(void)
{
	int s;

#ifdef DIAGNOSTIC
	printf("Initializing SSP:");
#endif
	/*
	 * 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)];

	arc4randbytes(guard, sizeof(guard));
	s = splhigh();
	for (i = 0; i < __arraycount(guard); i++)
		__stack_chk_guard[i] = guard[i];
	splx(s);
#ifdef DIAGNOSTIC
	for (i = 0; i < __arraycount(guard); i++)
		printf("%lx ", guard[i]);
	printf("\n");
#endif
}
#else
void
ssp_init(void)
{
}
#endif