1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27/* Copyright (c) 1988 AT&T */ 28/* All Rights Reserved */ 29 30#pragma ident "%Z%%M% %I% %E% SMI" 31 32 .file "%M%" 33 34#include "SYS.h" 35#include <assym.h> 36 37/* 38 * pid = vforkx(flags); 39 * syscall trap: forksys(2, flags) 40 * 41 * pid = vfork(); 42 * syscall trap: forksys(2, 0) 43 * 44 * From the syscall: 45 * %o1 == 0 in parent process, %o1 == 1 in child process. 46 * %o0 == pid of child in parent, %o0 == pid of parent in child. 47 * 48 * The child gets a zero return value. 49 * The parent gets the pid of the child. 50 */ 51 52/* 53 * Note that since the SPARC architecture maintains stack maintence 54 * information (return pc, sp, fp) in the register windows, both parent 55 * and child can execute in a common address space without conflict. 56 * 57 * We block all blockable signals while performing the vfork() system call 58 * trap. This enables us to set curthread->ul_vfork safely, so that we 59 * don't end up in a signal handler with curthread->ul_vfork set wrong. 60 */ 61 62 ENTRY_NP(vforkx) 63 ba 0f 64 mov %o0, %o3 /* flags */ 65 ENTRY_NP(vfork) 66 clr %o3 /* flags = 0 */ 670: 68 mov SIG_SETMASK, %o0 /* block all signals */ 69 set MASKSET0, %o1 70 set MASKSET1, %o2 71 SYSTRAP_2RVALS(lwp_sigmask) 72 73 mov %o3, %o1 /* flags */ 74 mov 2, %o0 75 SYSTRAP_2RVALS(forksys) /* vforkx(flags) */ 76 bcc,a,pt %icc, 1f 77 tst %o1 78 79 mov %o0, %o3 /* save the vfork() error number */ 80 81 mov SIG_SETMASK, %o0 /* reinstate signals */ 82 ld [%g7 + UL_SIGMASK], %o1 83 ld [%g7 + UL_SIGMASK + 4], %o2 84 SYSTRAP_2RVALS(lwp_sigmask) 85 86 ba __cerror 87 mov %o3, %o0 /* restore the vfork() error number */ 88 891: 90 /* 91 * To determine if we are (still) a child of vfork(), the child 92 * increments curthread->ul_vfork by one and the parent decrements 93 * it by one. If the result is zero, then we are not a child of 94 * vfork(), else we are. We do this to deal with the case of 95 * a vfork() child calling vfork(). 96 */ 97 bnz,pt %icc, 2f 98 ld [%g7 + UL_VFORK], %g1 99 brnz,a,pt %g1, 3f /* don't let it go negative */ 100 sub %g1, 1, %g1 /* curthread->ul_vfork--; */ 101 ba,a 3f 1022: 103 clr %o0 /* zero the return value in the child */ 104 add %g1, 1, %g1 /* curthread->ul_vfork++; */ 1053: 106 st %g1, [%g7 + UL_VFORK] 107 /* 108 * Clear the schedctl interface in both parent and child. 109 * (The child might have modified the parent.) 110 */ 111 stn %g0, [%g7 + UL_SCHEDCTL] 112 stn %g0, [%g7 + UL_SCHEDCTL_CALLED] 113 mov %o0, %o3 /* save the vfork() return value */ 114 115 mov SIG_SETMASK, %o0 /* reinstate signals */ 116 ld [%g7 + UL_SIGMASK], %o1 117 ld [%g7 + UL_SIGMASK + 4], %o2 118 SYSTRAP_2RVALS(lwp_sigmask) 119 120 retl 121 mov %o3, %o0 /* restore the vfork() return value */ 122 SET_SIZE(vfork) 123 SET_SIZE(vforkx) 124