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 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 73 main(int argc, char **argv) 74 { 75 for (;;) { 76 foo(); 77 } 78 79 return (0); 80 } 81