xref: /titanic_52/usr/src/lib/libc/port/sys/sigstack.c (revision 7257d1b4d25bfac0c802847390e98a464fd787ac)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5f841f6adSraf  * Common Development and Distribution License (the "License").
6f841f6adSraf  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
21e8031f0aSraf 
227c478bd9Sstevel@tonic-gate /*
23*7257d1b4Sraf  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
287c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
297c478bd9Sstevel@tonic-gate 
307c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
317c478bd9Sstevel@tonic-gate 
32*7257d1b4Sraf #include "lint.h"
337c478bd9Sstevel@tonic-gate #include <sys/types.h>
347c478bd9Sstevel@tonic-gate #include <sys/ucontext.h>
357c478bd9Sstevel@tonic-gate #include <signal.h>
367c478bd9Sstevel@tonic-gate #include <errno.h>
377c478bd9Sstevel@tonic-gate 
387c478bd9Sstevel@tonic-gate int
39e8031f0aSraf sigstack(struct sigstack *nss, struct sigstack *oss)
407c478bd9Sstevel@tonic-gate {
417c478bd9Sstevel@tonic-gate 	struct sigaltstack nalt;
427c478bd9Sstevel@tonic-gate 	struct sigaltstack oalt;
437c478bd9Sstevel@tonic-gate 	struct sigaltstack *naltp;
447c478bd9Sstevel@tonic-gate 
457c478bd9Sstevel@tonic-gate 	if (nss) {
467c478bd9Sstevel@tonic-gate 		/* Assumes stack growth is down */
477c478bd9Sstevel@tonic-gate 		nalt.ss_sp = (char *)nss->ss_sp - SIGSTKSZ;
487c478bd9Sstevel@tonic-gate 		nalt.ss_size = SIGSTKSZ;
497c478bd9Sstevel@tonic-gate 		nalt.ss_flags = 0;
507c478bd9Sstevel@tonic-gate 		naltp = &nalt;
517c478bd9Sstevel@tonic-gate 	} else
527c478bd9Sstevel@tonic-gate 		naltp = (struct sigaltstack *)0;
537c478bd9Sstevel@tonic-gate 
547c478bd9Sstevel@tonic-gate 	if (sigaltstack(naltp, &oalt) < 0)
557c478bd9Sstevel@tonic-gate 		return (-1);
567c478bd9Sstevel@tonic-gate 
577c478bd9Sstevel@tonic-gate 	if (oss) {
587c478bd9Sstevel@tonic-gate 		/* Assumes stack growth is down */
597c478bd9Sstevel@tonic-gate 		oss->ss_sp = (char *)oalt.ss_sp + oalt.ss_size;
607c478bd9Sstevel@tonic-gate 		oss->ss_onstack = ((oalt.ss_flags & SS_ONSTACK) != 0);
617c478bd9Sstevel@tonic-gate 	}
627c478bd9Sstevel@tonic-gate 	return (0);
637c478bd9Sstevel@tonic-gate }
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