vfork.S revision 1849
11849Swollman/*- 21849Swollman * Copyright (c) 1990 The Regents of the University of California. 31849Swollman * All rights reserved. 41849Swollman * 51849Swollman * This code is derived from software contributed to Berkeley by 61849Swollman * William Jolitz. 71849Swollman * 81849Swollman * Redistribution and use in source and binary forms, with or without 91849Swollman * modification, are permitted provided that the following conditions 101849Swollman * are met: 111849Swollman * 1. Redistributions of source code must retain the above copyright 121849Swollman * notice, this list of conditions and the following disclaimer. 131849Swollman * 2. Redistributions in binary form must reproduce the above copyright 141849Swollman * notice, this list of conditions and the following disclaimer in the 151849Swollman * documentation and/or other materials provided with the distribution. 161849Swollman * 3. All advertising materials mentioning features or use of this software 171849Swollman * must display the following acknowledgement: 181849Swollman * This product includes software developed by the University of 191849Swollman * California, Berkeley and its contributors. 201849Swollman * 4. Neither the name of the University nor the names of its contributors 211849Swollman * may be used to endorse or promote products derived from this software 221849Swollman * without specific prior written permission. 231849Swollman * 241849Swollman * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251849Swollman * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261849Swollman * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271849Swollman * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281849Swollman * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291849Swollman * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301849Swollman * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311849Swollman * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321849Swollman * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331849Swollman * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341849Swollman * SUCH DAMAGE. 351849Swollman * 361849Swollman * $Id: Ovfork.S,v 1.3 1994/02/21 05:19:08 rgrimes Exp $ 371849Swollman */ 381849Swollman 391849Swollman#if defined(SYSLIBC_SCCS) && !defined(lint) 401849Swollman .asciz "@(#)Ovfork.s 5.1 (Berkeley) 4/23/90" 411849Swollman#endif /* SYSLIBC_SCCS and not lint */ 421849Swollman 431849Swollman#include "SYS.h" 441849Swollman 451849Swollman/* 461849Swollman * pid = vfork(); 471849Swollman * 481849Swollman * %edx == 0 in parent process, %edx == 1 in child process. 491849Swollman * %eax == pid of child in parent, %eax == pid of parent in child. 501849Swollman * 511849Swollman */ 521849Swollman .set vfork,66 531849Swollman.globl _vfork 541849Swollman.type _vfork,@function 551849Swollman 561849Swollman_vfork: 571849Swollman popl %ecx /* my rta into ecx */ 581849Swollman movl $vfork, %eax 591849Swollman LCALL(7,0) 601849Swollman jb verror 611849Swollmanvforkok: 621849Swollman cmpl $0,%edx /* child process? */ 631849Swollman jne child /* yes */ 641849Swollman jmp parent 651849Swollman.globl _errno 661849Swollmanverror: 671849Swollman#ifdef PIC 681849Swollman PIC_PROLOGUE 691849Swollman movl PIC_GOT(_errno), %edx 701849Swollman movl %eax,(%edx) 711849Swollman PIC_EPILOGUE 721849Swollman#else 731849Swollman movl %eax,_errno 741849Swollman#endif 751849Swollman movl $-1,%eax 761849Swollman jmp %ecx 771849Swollmanchild: 781849Swollman movl $0,%eax 791849Swollmanparent: 801849Swollman jmp %ecx 81