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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"
31
32#include "lint.h"
33#include <sys/types.h>
34#include <sys/ucontext.h>
35#include <signal.h>
36#include <errno.h>
37
38int
39sigstack(struct sigstack *nss, struct sigstack *oss)
40{
41	struct sigaltstack nalt;
42	struct sigaltstack oalt;
43	struct sigaltstack *naltp;
44
45	if (nss) {
46		/* Assumes stack growth is down */
47		nalt.ss_sp = (char *)nss->ss_sp - SIGSTKSZ;
48		nalt.ss_size = SIGSTKSZ;
49		nalt.ss_flags = 0;
50		naltp = &nalt;
51	} else
52		naltp = (struct sigaltstack *)0;
53
54	if (sigaltstack(naltp, &oalt) < 0)
55		return (-1);
56
57	if (oss) {
58		/* Assumes stack growth is down */
59		oss->ss_sp = (char *)oalt.ss_sp + oalt.ss_size;
60		oss->ss_onstack = ((oalt.ss_flags & SS_ONSTACK) != 0);
61	}
62	return (0);
63}
64