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 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <stdint.h>
30 #include <stdlib.h>
31 #include <strings.h>
32
33 int
baz(void)34 baz(void)
35 {
36 return (8);
37 }
38
39 static int
foo(void)40 foo(void)
41 {
42 /*
43 * In order to assure that our helper is properly employed to identify
44 * the frame, we're going to trampoline through data.
45 */
46 uint8_t instr[] = {
47 0x55, /* pushl %ebp */
48 0x8b, 0xec, /* movl %esp, %ebp */
49 0xe8, 0x0, 0x0, 0x0, 0x0, /* call baz */
50 0x8b, 0xe5, /* movl %ebp, %esp */
51 0x5d, /* popl %ebp */
52 0xc3 /* ret */
53 };
54 uint8_t *fp = malloc(sizeof (instr));
55
56 /*
57 * Do our little relocation dance.
58 */
59 *((int *)&instr[4]) = (uintptr_t)baz - (uintptr_t)&fp[8];
60
61 /*
62 * Copy the code to the heap (it's a pain to build in ON with an
63 * executable stack).
64 */
65 bcopy(instr, fp, sizeof (instr));
66
67 (*(int (*)(void))fp)();
68
69 free(fp);
70
71 return (0);
72 }
73
74 int
main(int argc,char ** argv)75 main(int argc, char **argv)
76 {
77 for (;;) {
78 foo();
79 }
80
81 return (0);
82 }
83