1/* $OpenBSD: Ovfork.S,v 1.7 2012/08/22 17:19:34 pascal Exp $ */ 2/*- 3 * Copyright (c) 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#include "SYS.h" 35 36/* 37 * pid = vfork(); 38 * 39 * %edx == 0 in parent process, %edx == 1 in child process. 40 * %eax == pid of child in parent, %eax == pid of parent in child. 41 * 42 */ 43SYSENTRY(vfork) 44 popl %ecx /* my rta into ecx */ 45 movl $(SYS_vfork),%eax 46 int $0x80 47 jc err 48 decl %edx 49 andl %edx,%eax 50 jmp *%ecx 51err: 52#ifdef __PIC__ 53 PIC_PROLOGUE 54 movl PIC_GOT(_C_LABEL(errno)),%edx 55 PIC_EPILOGUE 56 movl %eax,(%edx) 57#else 58 movl %eax,_C_LABEL(errno) 59#endif 60 movl $-1,%eax 61 jmp *%ecx 62