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 34 baz(void) 35 { 36 return (8); 37 } 38 39 static int 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 75 main(int argc, char **argv) 76 { 77 for (;;) { 78 foo(); 79 } 80 81 return (0); 82 } 83