1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. 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#if defined(SYSLIBC_SCCS) && !defined(lint) 35 /* .asciz "@(#)Ovfork.s 8.1 (Berkeley) 6/4/93" */ 36 .asciz "$NetBSD: __vfork14.S,v 1.4 2002/02/24 01:06:20 matt Exp $" 37#endif /* SYSLIBC_SCCS and not lint */ 38 39/* 40 * @(#)vfork.s 4.1 (Berkeley) 12/21/80 41 * C library -- vfork 42 */ 43 44#include "SYS.h" 45 46/* 47 * pid = vfork(); 48 * 49 * %r1 == 0 in parent process, %r1 == 1 in child process. 50 * %r0 == pid of child in parent, %r0 == pid of parent in child. 51 * 52 * trickery here, due to keith sklower, uses ret to clear the stack, 53 * and then returns with a jump indirect, since only one person can return 54 * with a ret off this stack... we do the ret before we vfork! 55 */ 56 57ENTRY(__vfork14, 0) 58 movl 16(%fp),%r2 # save return address before we smash it 59 movab here,16(%fp) 60 ret 61here: 62 chmk $ SYS___vfork14 63 bcs err # if failed, set errno and return -1 64 /* this next trick is Chris Torek's fault */ 65 mnegl %r1,%r1 # %r1 = 0xffffffff if child, 0 if parent 66 bicl2 %r1,%r0 # %r0 &= ~%r1, i.e., 0 if child, else unchanged 67 jmp (%r2) 68 69err: 70#ifdef _REENTRANT 71 pushr $0x5 72 calls $0,_C_LABEL(__errno) 73 movl (%sp)+,(%r0) 74 mnegl $1,%r0 75 rsb 76#else 77 movl %r0,_C_LABEL(errno) 78 mnegl $1,%r0 79 jmp (%r2) 80#endif 81