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      1 /*	$NetBSD: sigstackalign.c,v 1.4 2011/05/18 19:45:05 mellon Exp $       */
      2 
      3 /*-
      4  * Copyright (c) 2001 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/types.h>
     30 
     31 __RCSID("$NetBSD: sigstackalign.c,v 1.4 2011/05/18 19:45:05 mellon Exp $");
     32 
     33 #include <signal.h>
     34 #include <stdio.h>
     35 #include <stdlib.h>
     36 #include <err.h>
     37 #include <unistd.h>
     38 
     39 #define RANGE 16
     40 #define STACKALIGN 8
     41 #define BLOCKSIZE (MINSIGSTKSZ + RANGE)
     42 
     43 extern void getstackptr(int);
     44 
     45 void *stackptr;
     46 
     47 int
     48 main(int argc, char **argv)
     49 {
     50 	char *stackblock;
     51 	int i, ret;
     52 	struct sigaction sa;
     53 	stack_t ss;
     54 
     55 	ret = 0;
     56 
     57 	sa.sa_handler = getstackptr;
     58 	sigemptyset(&sa.sa_mask);
     59 	sa.sa_flags = SA_ONSTACK;
     60 	if (sigaction(SIGUSR1, &sa, NULL) != 0)
     61 		err(1, "sigaction");
     62 
     63 	stackblock = malloc(BLOCKSIZE);
     64 	for (i = 0; i < RANGE; i++) {
     65 		ss.ss_sp = stackblock;
     66 		ss.ss_size = MINSIGSTKSZ + i;
     67 		ss.ss_flags = 0;
     68 		if (sigaltstack(&ss, NULL) != 0)
     69 			err(1, "sigaltstack");
     70 		kill(getpid(), SIGUSR1);
     71 		if ((u_int)stackptr % STACKALIGN != 0) {
     72 			fprintf(stderr, "Bad stack pointer %p\n", stackptr);
     73 			ret = 1;
     74 		}
     75 #if 0
     76 		printf("i = %d, stackptr = %p\n", i, stackptr);
     77 #endif
     78 	}
     79 
     80 	return ret;
     81 }
     82 
     83