__clone.S revision 1.1 
1/*	$NetBSD: __clone.S,v 1.1 2001/07/19 21:50:46 scw Exp $	*/
2
3/*-
4 * Copyright (c) 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Steve C. Woodford.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *        This product includes software developed by the NetBSD
21 *        Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#include <sys/errno.h>
40#include "SYS.h"
41
42#ifdef WEAK_ALIAS
43WEAK_ALIAS(clone, __clone)
44#endif
45
46/*
47 * int clone(int (*fn)(void *), void *stack, int flags, void *arg);
48 */
49ENTRY(__clone)
50	movl	%sp@(4),%d0	/* NULL function pointer? */
51	jeq	2f		/* Yup, bomb out */
52	movl	%d0,%a1
53	movl	%sp@(8),%d0	/* NULL stack? */
54	jeq	2f		/* Yup, bomb out */
55	movl	%d0,%a0
56	movl	%sp@(16),%a0@-	/* Push clone's `arg' on its new stack */
57	movl	%a0,%sp@-	/* Syscall arg: stack */
58	movl	%sp@(16),%sp@-	/* Syscall arg: flags */
59	clrl	%sp@-		/* Fake return address */
60	SYSTRAP(__clone)	/* Note: `fn' in a1@ is preserved */
61	lea	%sp@(12),%sp	/* Zap syscall args */
62	jcs	3f		/* Punt if syscall failed */
63	tstl	%d0
64	jne	1f		/* We're the parent, just return. */
65	jsr	%a1@		/* We're the clone, call the function */
66	movl	%d0,%sp@-	/* If clone returns, invoke _exit(3) */
67	jbsr	PIC_PLT(_C_LABEL(_exit))
68	/* NOTREACHED */
691:	rts
702:	movl	#EINVAL,%d0
713:	jra	PIC_PLT(CERROR)
72