xref: /illumos-gate/usr/src/cmd/dtrace/test/tst/i386/ustack/tst.helper.c (revision 055d7c804dc8f1263f0b3166ba459c65996b8697)
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 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <stdint.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 	unsigned char instr[] = {
45 	    0x55,			/* pushl %ebp		*/
46 	    0x8b, 0xec,			/* movl  %esp, %ebp	*/
47 	    0xe8, 0x0, 0x0, 0x0, 0x0,	/* call  baz		*/
48 	    0x8b, 0xe5,			/* movl  %ebp, %esp	*/
49 	    0x5d,			/* popl  %ebp		*/
50 	    0xc3			/* ret			*/
51 	};
52 
53 	*((int *)&instr[4]) = (uintptr_t)baz - (uintptr_t)&instr[8];
54 	return ((*(int(*)(void))instr)() + 3);
55 }
56 
57 int
58 main(int argc, char **argv)
59 {
60 	for (;;) {
61 		foo();
62 	}
63 
64 	return (0);
65 }
66