xref: /illumos-gate/usr/src/lib/libc/sparc/gen/getctxt.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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) 1988 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 #include "lint.h"
31 #include "thr_uberdata.h"
32 #include <ucontext.h>
33 #include <sys/types.h>
34 #include "libc.h"
35 
36 #pragma weak _getcontext = getcontext
37 
38 int
39 getcontext(ucontext_t *ucp)
40 {
41 	greg_t *reg;
42 
43 	ucp->uc_flags = UC_ALL;
44 	if (__getcontext(ucp))
45 		return (-1);
46 
47 	/*
48 	 * Note that %o1 and %g1 are modified by the system call
49 	 * routine. ABI calling conventions specify that the caller
50 	 * cannot depend upon %o0 through %o5 nor %g1, so no effort is
51 	 * made to maintain these registers. %o0 is forced to reflect
52 	 * an affirmative return code.
53 	 */
54 	reg = ucp->uc_mcontext.gregs;
55 	reg[REG_SP] = getfp();
56 	reg[REG_O7] = caller();
57 	reg[REG_PC] = reg[REG_O7] + 8;
58 	reg[REG_nPC] = reg[REG_PC] + 4;
59 	reg[REG_O0] = 0;
60 
61 	return (0);
62 }
63