/* * Copyright (c) 1999-2004 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* Copyright (c) 1992 NeXT Computer, Inc. All rights reserved. * * File: libc/ppc/sys/fork.s * * HISTORY * 18-Nov-92 Ben Fathi (benf@next.com) * Created from M88K sources * * 11-Jan-92 Peter King (king@next.com) * Created from M68K sources */ /* We use mode-independent "g" opcodes such as "srgi". These expand * into word operations when targeting __ppc__, and into doubleword * operations when targeting __ppc64__. */ #include <architecture/ppc/mode_independent_asm.h> #include "SYS.h" MI_ENTRY_POINT(_fork) MI_PUSH_STACK_FRAME MI_CALL_EXTERNAL(__cthread_fork_prepare) #if defined(__DYNAMIC__) .cstring LC1: .ascii "__dyld_fork_prepare\0" .text .align 2 mflr r0 bcl 20,31,1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC1-1b) addi r3,r3,lo16(LC1-1b) addi r4,r1,SF_LOCAL1 bl __dyld_func_lookup lg r3,SF_LOCAL1(r1) mtspr ctr,r3 bctrl #endif li r0,SYS_fork sc // do the fork b Lbotch // error return cmpwi r4,0 // parent (r4==0) or child (r4==1) ? beq Lparent // parent, since r4==0 /* Here if we are the child. */ #if defined(__DYNAMIC__) .cstring LC3: .ascii "__dyld_fork_child\0" .text .align 2 mflr r0 bcl 20,31,1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC3-1b) addi r3,r3,lo16(LC3-1b) addi r4,r1,SF_LOCAL1 bl __dyld_func_lookup lg r3,SF_LOCAL1(r1) mtspr ctr,r3 bctrl #endif li r9,0 MI_GET_ADDRESS(r8,__current_pid) stw r9,0(r8) // clear cached pid in child MI_CALL_EXTERNAL(__cthread_fork_child) #if defined(__DYNAMIC__) .cstring LC4: .ascii "__dyld_fork_child_final\0" .text .align 2 mflr r0 bcl 20,31,1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC4-1b) addi r3,r3,lo16(LC4-1b) addi r4,r1,SF_LOCAL1 bl __dyld_func_lookup lg r3,SF_LOCAL1(r1) mtspr ctr,r3 bctrl #endif li r3,0 // flag for "we are the child" b Lreturn /* Here if we are the parent, with: * r3 = child's pid */ Lparent: stg r3,SF_LOCAL2(r1) // save child pid in stack #if defined(__DYNAMIC__) mflr r0 bcl 20,31,1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC2-1b) addi r3,r3,lo16(LC2-1b) addi r4,r1,SF_LOCAL1 bl __dyld_func_lookup lg r3,SF_LOCAL1(r1) mtspr ctr,r3 bctrl #endif b Lparent_return // clean up and return child's pid /* Here if the fork() syscall failed. We're still the parent. */ Lbotch: #if defined(__DYNAMIC__) .cstring LC2: .ascii "__dyld_fork_parent\0" .text .align 2 stg r3,SF_LOCAL2(r1) // save error return in stack mflr r0 bcl 20,31,1f 1: mflr r3 mtlr r0 addis r3,r3,ha16(LC2-1b) addi r3,r3,lo16(LC2-1b) addi r4,r1,SF_LOCAL1 bl __dyld_func_lookup lg r3,SF_LOCAL1(r1) mtspr ctr,r3 bctrl lg r3,SF_LOCAL2(r1) // restore error code #endif MI_CALL_EXTERNAL(cerror) li r3,-1 // get an error return code stg r3,SF_LOCAL2(r1) // save return code in stack /* * We use cthread_fork_parent() to clean up after a fork error * (unlock cthreads and mailloc packages) so the parent * process can Malloc() after fork() errors without * deadlocking. */ Lparent_return: MI_CALL_EXTERNAL(__cthread_fork_parent) lg r3,SF_LOCAL2(r1) // return -1 on error, child's pid on success Lreturn: MI_POP_STACK_FRAME_AND_RETURN