__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