xref: /illumos-gate/usr/src/cmd/dtrace/test/tst/sparc/ustack/tst.helper.c (revision 20a7641f9918de8574b8b3b47dbe35c4bfc78df1)
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 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <stdint.h>
28 #include <stdlib.h>
29 #include <strings.h>
30 
31 int
32 baz(void)
33 {
34 	return (8);
35 }
36 
37 static int
38 foo(void)
39 {
40 	/*
41 	 * In order to assure that our helper is properly employed to identify
42 	 * the frame, we're going to trampoline through data.
43 	 */
44 	uint32_t instr[] = {
45 	    0x9de3bfa0,		/* save %sp, -0x60, %sp	*/
46 	    0x40000000,		/* call baz		*/
47 	    0x01000000,		/* nop			*/
48 	    0x81c7e008,		/* ret			*/
49 	    0x81e80000		/* restore		*/
50 	};
51 	uint32_t *fp = malloc(sizeof (instr));
52 
53 	/*
54 	 * Do our little relocation dance.
55 	 */
56 	instr[1] |= ((uintptr_t)baz - (uintptr_t)&fp[1]) >> 2;
57 
58 	/*
59 	 * Copy the code to the heap (it's a pain to build in ON with an
60 	 * executable stack).
61 	 */
62 	bcopy(instr, fp, sizeof (instr));
63 
64 	(*(int (*)(void))fp)();
65 
66 	free(fp);
67 
68 	return (0);
69 }
70 
71 int
72 main(int argc, char **argv)
73 {
74 	for (;;) {
75 		foo();
76 	}
77 
78 	return (0);
79 }
80