__vfork14.S revision 1.7
1 /* $NetBSD: __vfork14.S,v 1.7 2000/12/02 17:03:06 scw 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 1.7 2000/12/02 17:03:06 scw 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@+,%a1 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 %a1@ 74 err: 75 #ifdef _REENTRANT 76 .globl _C_LABEL(__errno) 77 movl %a1,%sp@- 78 movl %d0,%sp@- 79 #if defined(PIC) && !defined(__ELF__) 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 PIC_PLT(_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 #ifdef __ELF__ 98 lea %pc@(_GLOBAL_OFFSET_TABLE_@GOTPC),%a1 99 movl %a1@(_C_LABEL(errno)@GOT:w),%a1 100 #else 101 movl #_C_LABEL(_GLOBAL_OFFSET_TABLE_),%a1 102 lea %pc@(0,a1:l),%a1 103 movl %a1@(_C_LABEL(errno):w),%a1 104 #endif 105 movl %d0,%a1@ 106 #else 107 movl %d0,_C_LABEL(errno) 108 #endif /* PIC */ 109 #endif /* _REENTRANT */ 110 moveq #-1,%d0 111 jmp %a0@ 112
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