1/*        $NetBSD: __clone.S,v 1.3 2008/04/28 20:22:55 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 */
43LEAF(__clone, 4)
44          br        pv, 1f
451:        LDGP(pv)
46
47          /*
48           * Sanity checks: func and stack may not be NULL.
49           */
50          beq       a0, 9f
51          beq       a1, 9f
52
53          /*
54           * We need to be able to get at the func and arg arguments
55           * in the child.  Luckily, we have a convenient place to
56           * do this; the child's stack.
57           */
58          subq      a1, 16, a1
59          stq       a0, 0(a1)
60          stq       a3, 8(a1)
61
62          /*
63           * The system call expects (flags, stack).
64           */
65          mov       a2, a0
66          CALLSYS_ERROR(__clone)
67
68          beq       a4, 8f              /* a4 (rv[1]) == 0, parent, child pid in v0 */
69
70          /*
71           * Fetch the function and argument from the new stack, and
72           * pop it back.
73           */
74          ldq       pv, 0(sp)
75          ldq       a0, 8(sp)
76          addq      sp, 16, sp
77
78          /* Call the clone's entry point. */
79          CALL((pv))
80
81          /* Pass return value to _exit(). */
82          mov       v0, a0
83          CALL(_exit)
84
85          /* NOTREACHED */
86
878:        RET
88
899:        ldiq      v0, EINVAL
90          jmp       zero, __cerror
91          END(__clone)
92