/*      $NetBSD: sigstackalign.c,v 1.4 2011/05/18 19:45:05 mellon Exp $       */

/*-
* Copyright (c) 2001 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/types.h>

__RCSID("$NetBSD: sigstackalign.c,v 1.4 2011/05/18 19:45:05 mellon Exp $");

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <err.h>
#include <unistd.h>

#define RANGE 16
#define STACKALIGN 8
#define BLOCKSIZE (MINSIGSTKSZ + RANGE)

extern void getstackptr(int);

void *stackptr;

int
main(int argc, char **argv)
{
       char *stackblock;
       int i, ret;
       struct sigaction sa;
       stack_t ss;

       ret = 0;

       sa.sa_handler = getstackptr;
       sigemptyset(&sa.sa_mask);
       sa.sa_flags = SA_ONSTACK;
       if (sigaction(SIGUSR1, &sa, NULL) != 0)
               err(1, "sigaction");

       stackblock = malloc(BLOCKSIZE);
       for (i = 0; i < RANGE; i++) {
               ss.ss_sp = stackblock;
               ss.ss_size = MINSIGSTKSZ + i;
               ss.ss_flags = 0;
               if (sigaltstack(&ss, NULL) != 0)
                       err(1, "sigaltstack");
               kill(getpid(), SIGUSR1);
               if ((u_int)stackptr % STACKALIGN != 0) {
                       fprintf(stderr, "Bad stack pointer %p\n", stackptr);
                       ret = 1;
               }
#if 0
               printf("i = %d, stackptr = %p\n", i, stackptr);
#endif
       }

       return ret;
}