1/* 2 * Copyright (c) 1999-2007 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* Copyright (c) 1998 Apple Computer, Inc. All rights reserved. 29 * 30 * File: libc/ppc/sys/vfork.s 31 * 32 * HISTORY 33 * 23-Jun-1998 Umesh Vaishampayan (umeshv@apple.com) 34 * Created from fork.s 35 * 36 */ 37 38#include "SYS.h" 39 40#if defined(__i386__) 41 42#if defined(__DYNAMIC__) 43#define GET_CURRENT_PID PICIFY(__current_pid) 44 45 NON_LAZY_STUB(__current_pid) 46#define __current_pid (%edx) 47#else 48#define GET_CURRENT_PID 49#endif 50 51/* 52 * If __current_pid >= 0, we want to put a -1 in there 53 * otherwise we just decrement it 54 */ 55 56LEAF(___vfork, 0) 57 GET_CURRENT_PID 58 movl __current_pid, %eax 590: 60 xorl %ecx, %ecx 61 testl %eax, %eax 62 cmovs %eax, %ecx 63 decl %ecx 64 lock 65 cmpxchgl %ecx, __current_pid 66 jne 0b 67 popl %ecx 68 movl $(SYS_vfork), %eax // code for vfork -> eax 69 UNIX_SYSCALL_TRAP // do the system call 70 jnb L1 // jump if CF==0 71 GET_CURRENT_PID 72 lock 73 incl __current_pid 74 pushl %ecx 75 BRANCH_EXTERN(tramp_cerror) 76 77L1: 78 testl %edx, %edx // CF=OF=0, ZF set if zero result 79 jz L2 // parent, since r1 == 0 in parent, 1 in child 80 xorl %eax, %eax // zero eax 81 jmp *%ecx 82 83L2: 84 GET_CURRENT_PID 85 lock 86 incl __current_pid 87 jmp *%ecx 88 89#elif defined(__x86_64__) 90 91/* 92 * If __current_pid >= 0, we want to put a -1 in there 93 * otherwise we just decrement it 94 */ 95 96LEAF(___vfork, 0) 97 movq __current_pid@GOTPCREL(%rip), %rax 98 movl (%rax), %eax 990: 100 xorl %ecx, %ecx 101 testl %eax, %eax 102 cmovs %eax, %ecx 103 subl $1, %ecx 104 movq __current_pid@GOTPCREL(%rip), %rdx 105 lock 106 cmpxchgl %ecx, (%rdx) 107 jne 0b 108 popq %rdi // return address in %rdi 109 movq $ SYSCALL_CONSTRUCT_UNIX(SYS_vfork), %rax // code for vfork -> rax 110 UNIX_SYSCALL_TRAP // do the system call 111 jnb L1 // jump if CF==0 112 pushq %rdi // put return address back on stack for cerror 113 movq __current_pid@GOTPCREL(%rip), %rcx 114 lock 115 addq $1, (%rcx) 116 movq %rax, %rdi 117 BRANCH_EXTERN(_cerror) 118 119L1: 120 testl %edx, %edx // CF=OF=0, ZF set if zero result 121 jz L2 // parent, since r1 == 0 in parent, 1 in child 122 xorq %rax, %rax // zero rax 123 jmp *%rdi 124 125L2: 126 movq __current_pid@GOTPCREL(%rip), %rdx 127 lock 128 addq $1, (%rdx) 129 jmp *%rdi 130 131#else 132#error Unsupported architecture 133#endif 134