1/* $NetBSD: compat_Ovfork.S,v 1.1 2006/03/09 16:20:55 christos Exp $ */ 2 3/*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Systems Programming Group of the University of Utah Computer 9 * Science Department. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include "SYS.h" 37 38#if defined(LIBC_SCCS) && !defined(lint) 39#if 0 40 RCSID("from: @(#)Ovfork.s 5.1 (Berkeley) 5/12/90") 41#else 42 RCSID("$NetBSD: compat_Ovfork.S,v 1.1 2006/03/09 16:20:55 christos Exp $") 43#endif 44#endif /* LIBC_SCCS and not lint */ 45 46/* 47 * @(#)vfork.s 4.1 (Berkeley) 12/21/80 48 * C library -- vfork 49 */ 50 51WARN_REFERENCES(vfork, \ 52 "warning: reference to compatibility vfork(); include <unistd.h> for correct reference") 53 54/* 55 * pid = vfork(); 56 * 57 * d1 == 0 in parent process, d1 == 1 in child process. 58 * d0 == pid of child in parent, d0 == pid of parent in child. 59 * 60 * trickery here, due to keith sklower, uses ret to clear the stack, 61 * and then returns with a jump indirect, since only one person can return 62 * with a ret off this stack... we do the ret before we vfork! 63 */ 64 65ENTRY(vfork) 66 movl %sp@+,%a1 67 movl #SYS_vfork,%d0 68 trap #0 69 jcs err 70 subql #1,%d1 /* from 1 to 0 in child, 0 to -1 in parent */ 71 andl %d1,%d0 72 jmp %a1@ 73err: 74#ifdef _REENTRANT 75 .globl _C_LABEL(__errno) 76 movl %a1,%sp@- 77 movl %d0,%sp@- 78#if defined(PIC) && !defined(__ELF__) 79 movl #_C_LABEL(_GLOBAL_OFFSET_TABLE_),%a1 80 lea %pc@(0,a1:l),%a1 81 movl %a1@(_C_LABEL(__errno):l),%a1 82 jsr %a1@ 83#else 84 jbsr PIC_PLT(_C_LABEL(__errno)) 85#endif /* PIC */ 86#ifdef __SVR4_ABI__ 87 movl %sp@+,%a0@ 88#else 89 movl %d0,%a1 90 movl %sp@+,%a1@ 91#endif /* __SVR4_ABI__ */ 92 movl %sp@+,%a1 93#else 94 .globl _C_LABEL(errno) 95#ifdef PIC 96#ifdef __ELF__ 97 lea %pc@(_GLOBAL_OFFSET_TABLE_@GOTPC),%a0 98 movl %a0@(_C_LABEL(errno)@GOT:w),%a0 99#else 100 movl #_C_LABEL(_GLOBAL_OFFSET_TABLE_),%a0 101 lea %pc@(0,a0:l),%a0 102 movl %a0@(_C_LABEL(errno):w),%a0 103#endif 104 movl %d0,%a0@ 105#else 106 movl %d0,_C_LABEL(errno) 107#endif /* PIC */ 108#endif /* _REENTRANT */ 109 moveq #-1,%d0 110 jmp %a1@ 111