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
baz(void)32 baz(void)
33 {
34 return (8);
35 }
36
37 static int
foo(void)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 uint8_t 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 uint8_t *fp = malloc(sizeof (instr));
53
54 /*
55 * Do our little relocation dance.
56 */
57 *((int *)&instr[4]) = (uintptr_t)baz - (uintptr_t)&fp[8];
58
59 /*
60 * Copy the code to the heap (it's a pain to build in ON with an
61 * executable stack).
62 */
63 bcopy(instr, fp, sizeof (instr));
64
65 (*(int (*)(void))fp)();
66
67 free(fp);
68
69 return (0);
70 }
71
72 int
main(int argc,char ** argv)73 main(int argc, char **argv)
74 {
75 for (;;) {
76 foo();
77 }
78
79 return (0);
80 }
81