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__vfork14.S revision 1.4
      1 /*	$NetBSD: __vfork14.S,v 1.4 1999/05/02 20:52:03 kleink 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. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the University of
     22  *	California, Berkeley and its contributors.
     23  * 4. Neither the name of the University nor the names of its contributors
     24  *    may be used to endorse or promote products derived from this software
     25  *    without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  */
     39 
     40 #include "SYS.h"
     41 
     42 #if defined(LIBC_SCCS) && !defined(lint)
     43 #if 0
     44 	RCSID("from: @(#)Ovfork.s	5.1 (Berkeley) 5/12/90")
     45 #else
     46 	RCSID("$NetBSD: __vfork14.S,v 1.4 1999/05/02 20:52:03 kleink Exp $")
     47 #endif
     48 #endif /* LIBC_SCCS and not lint */
     49 
     50 /*
     51  * @(#)vfork.s	4.1 (Berkeley) 12/21/80
     52  * C library -- vfork
     53  */
     54 
     55 /*
     56  * pid = vfork();
     57  *
     58  * d1 == 0 in parent process, d1 == 1 in child process.
     59  * d0 == pid of child in parent, d0 == pid of parent in child.
     60  *
     61  * trickery here, due to keith sklower, uses ret to clear the stack,
     62  * and then returns with a jump indirect, since only one person can return
     63  * with a ret off this stack... we do the ret before we vfork!
     64  */
     65 
     66 ENTRY(__vfork14)
     67 	movl	sp@+,a0
     68 	movl	#SYS___vfork14,d0
     69 	trap	#0
     70 	jcs	err
     71 	subql	#1,d1	/* from 1 to 0 in child, 0 to -1 in parent */
     72 	andl	d1,d0
     73 	jmp	a0@
     74 err:
     75 #ifdef	_REENTRANT
     76 	.globl	_C_LABEL(__errno)
     77 	movl	a0,sp@-
     78 	movl	d0,sp@-
     79 #ifdef	PIC
     80 	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),a1
     81 	lea	pc@(0,a1:l),a1
     82 	movl	a1@(_C_LABEL(__errno):l),a1
     83 	jsr	a1@
     84 #else
     85 	jbsr	_C_LABEL(__errno)
     86 #endif	/* PIC */
     87 #ifdef	__SVR4_ABI__
     88 	movl	sp@+,a0@
     89 #else
     90 	movl	d0,a1
     91 	movl	sp@+,a1@
     92 #endif
     93 	movl	sp@+,a0
     94 #else
     95 	.globl	_C_LABEL(errno)
     96 #ifdef	PIC
     97 	movl	#_C_LABEL(_GLOBAL_OFFSET_TABLE_),a1
     98 	lea	pc@(0,a1:l),a1
     99 	movl	a1@(_C_LABEL(errno):w),a1
    100 	movl	d0,a1@
    101 #else
    102 	movl	d0,_C_LABEL(errno)
    103 #endif	/* PIC */
    104 #endif	/* _REENTRANT */
    105 	moveq	#-1,d0
    106 	jmp	a0@
    107