sigstack.c revision 1219:f89f56c2d9ac 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22
23/*
24 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25 * Use is subject to license terms.
26 */
27
28/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
29/*	  All Rights Reserved  	*/
30
31#pragma ident	"%Z%%M%	%I%	%E% SMI"
32
33#include "synonyms.h"
34#include <sys/types.h>
35#include <sys/ucontext.h>
36#include <signal.h>
37#include <errno.h>
38
39int
40sigstack(struct sigstack *nss, struct sigstack *oss)
41{
42	struct sigaltstack nalt;
43	struct sigaltstack oalt;
44	struct sigaltstack *naltp;
45
46	if (nss) {
47		/* Assumes stack growth is down */
48		nalt.ss_sp = (char *)nss->ss_sp - SIGSTKSZ;
49		nalt.ss_size = SIGSTKSZ;
50		nalt.ss_flags = 0;
51		naltp = &nalt;
52	} else
53		naltp = (struct sigaltstack *)0;
54
55	if (sigaltstack(naltp, &oalt) < 0)
56		return (-1);
57
58	if (oss) {
59		/* Assumes stack growth is down */
60		oss->ss_sp = (char *)oalt.ss_sp + oalt.ss_size;
61		oss->ss_onstack = ((oalt.ss_flags & SS_ONSTACK) != 0);
62	}
63	return (0);
64}
65