xref: /netbsd-src/lib/libc/arch/sparc64/sys/__clone.S (revision ce099b40997c43048fb78bd578195f81d2456523)
1/*	$NetBSD: __clone.S,v 1.7 2008/04/28 20:22:57 martin 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 Jason R. Thorpe.
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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/errno.h>
33
34#include "SYS.h"
35
36#ifdef WEAK_ALIAS
37WEAK_ALIAS(clone, __clone)
38#endif
39
40/*
41 * int __clone(int (*fn)(void *), void *stack, int flags, void *arg);
42 */
43ENTRY(__clone)
44	save	%sp, -CC64FSZ, %sp
45
46	/*
47	 * Sanity checks: func and stack may not be NULL.
48	 */
49	brz,pn	%i0,8f		! func == NULL, bail
50	 orcc	%i1, %g0, %o1	! setup stack arg for syscall, test
51	bz,pn	%xcc, 8f	! stack == NULL, bail
52	 mov	%i2, %o0	! setup flags arg for syscall
53
54	/*
55	 * Allocate "caller's" frame in the child stack as ABI
56	 * requires.  Subtract BIAS - it will be 64-bit code.
57	 *
58	 * We pass the function and the argument to the child by
59	 * stashing them at the bottom of the frame.  There they are
60	 * safe from window spill would we need to take one as it's
61	 * below the window save area.
62	 */
63	sub	%o1, CC64FSZ+BIAS, %o1		! make space
64	stx	%i0, [%o1+CC64FSZ-16+BIAS]	! save func
65	stx	%i3, [%o1+CC64FSZ-8+BIAS]	! save arg
66
67	/*
68	 * Args are now set up for system call as (flags, stack).
69	 */
70	mov	SYS___clone, %g1
71	t	ST_SYSCALL
72	bcs,pn	%xcc, 9f
73	 tst	%o1		! %o1 (rv[1]) == 0 in parent
74	bz	%xcc, 2f	! yes, parent
75	 ldx	[%sp+CC64FSZ-16+BIAS], %l0	! grab the function...
76	call	%l0 		! Call the clone's entry point.
77	 ldx	[%sp+CC64FSZ-8+BIAS], %o0	! ...and the argument
78
79	JUMP(_exit)
80	/* NOTREACHED */
81
822:	ret
83	 restore %g0, %o0, %o0
84
858:	restore %g0, EINVAL, %o0
86	ERROR()
87	/* NOTREACHED */
88
899:	restore %o0, %g0, %o0
90	ERROR()
91	/* NOTREACHED */
92