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sigstackalign.c revision 1.4
      1  1.4  mellon /*	$NetBSD: sigstackalign.c,v 1.4 2011/05/18 19:45:05 mellon Exp $       */
      2  1.2  itojun 
      3  1.2  itojun /*-
      4  1.2  itojun  * Copyright (c) 2001 The NetBSD Foundation, Inc.
      5  1.2  itojun  * All rights reserved.
      6  1.2  itojun  *
      7  1.2  itojun  * Redistribution and use in source and binary forms, with or without
      8  1.2  itojun  * modification, are permitted provided that the following conditions
      9  1.2  itojun  * are met:
     10  1.2  itojun  * 1. Redistributions of source code must retain the above copyright
     11  1.2  itojun  *    notice, this list of conditions and the following disclaimer.
     12  1.2  itojun  * 2. Redistributions in binary form must reproduce the above copyright
     13  1.2  itojun  *    notice, this list of conditions and the following disclaimer in the
     14  1.2  itojun  *    documentation and/or other materials provided with the distribution.
     15  1.2  itojun  *
     16  1.2  itojun  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  1.2  itojun  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  1.2  itojun  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  1.2  itojun  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  1.2  itojun  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  1.2  itojun  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  1.2  itojun  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  1.2  itojun  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  1.2  itojun  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  1.2  itojun  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  1.2  itojun  * POSSIBILITY OF SUCH DAMAGE.
     27  1.2  itojun  */
     28  1.1   bjh21 
     29  1.1   bjh21 #include <sys/types.h>
     30  1.1   bjh21 
     31  1.4  mellon __RCSID("$NetBSD: sigstackalign.c,v 1.4 2011/05/18 19:45:05 mellon Exp $");
     32  1.1   bjh21 
     33  1.1   bjh21 #include <signal.h>
     34  1.1   bjh21 #include <stdio.h>
     35  1.1   bjh21 #include <stdlib.h>
     36  1.4  mellon #include <err.h>
     37  1.4  mellon #include <unistd.h>
     38  1.1   bjh21 
     39  1.1   bjh21 #define RANGE 16
     40  1.1   bjh21 #define STACKALIGN 8
     41  1.1   bjh21 #define BLOCKSIZE (MINSIGSTKSZ + RANGE)
     42  1.1   bjh21 
     43  1.1   bjh21 extern void getstackptr(int);
     44  1.1   bjh21 
     45  1.1   bjh21 void *stackptr;
     46  1.1   bjh21 
     47  1.1   bjh21 int
     48  1.1   bjh21 main(int argc, char **argv)
     49  1.1   bjh21 {
     50  1.1   bjh21 	char *stackblock;
     51  1.1   bjh21 	int i, ret;
     52  1.1   bjh21 	struct sigaction sa;
     53  1.1   bjh21 	stack_t ss;
     54  1.1   bjh21 
     55  1.1   bjh21 	ret = 0;
     56  1.1   bjh21 
     57  1.1   bjh21 	sa.sa_handler = getstackptr;
     58  1.1   bjh21 	sigemptyset(&sa.sa_mask);
     59  1.1   bjh21 	sa.sa_flags = SA_ONSTACK;
     60  1.1   bjh21 	if (sigaction(SIGUSR1, &sa, NULL) != 0)
     61  1.1   bjh21 		err(1, "sigaction");
     62  1.1   bjh21 
     63  1.1   bjh21 	stackblock = malloc(BLOCKSIZE);
     64  1.1   bjh21 	for (i = 0; i < RANGE; i++) {
     65  1.1   bjh21 		ss.ss_sp = stackblock;
     66  1.1   bjh21 		ss.ss_size = MINSIGSTKSZ + i;
     67  1.1   bjh21 		ss.ss_flags = 0;
     68  1.1   bjh21 		if (sigaltstack(&ss, NULL) != 0)
     69  1.1   bjh21 			err(1, "sigaltstack");
     70  1.1   bjh21 		kill(getpid(), SIGUSR1);
     71  1.1   bjh21 		if ((u_int)stackptr % STACKALIGN != 0) {
     72  1.1   bjh21 			fprintf(stderr, "Bad stack pointer %p\n", stackptr);
     73  1.1   bjh21 			ret = 1;
     74  1.1   bjh21 		}
     75  1.1   bjh21 #if 0
     76  1.1   bjh21 		printf("i = %d, stackptr = %p\n", i, stackptr);
     77  1.1   bjh21 #endif
     78  1.1   bjh21 	}
     79  1.1   bjh21 
     80  1.1   bjh21 	return ret;
     81  1.1   bjh21 }
     82  1.1   bjh21 
     83