/* * Copyright (c) 1999-2007 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_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. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * 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_OSREFERENCE_LICENSE_HEADER_END@ */ /* Copyright (c) 1998 Apple Computer, Inc. All rights reserved. * * File: libc/ppc/sys/vfork.s * * HISTORY * 23-Jun-1998 Umesh Vaishampayan (umeshv@apple.com) * Created from fork.s * */ #include "SYS.h" #if defined(__i386__) #if defined(__DYNAMIC__) #define GET_CURRENT_PID PICIFY(__current_pid) NON_LAZY_STUB(__current_pid) #define __current_pid (%edx) #else #define GET_CURRENT_PID #endif /* * If __current_pid >= 0, we want to put a -1 in there * otherwise we just decrement it */ LEAF(___vfork, 0) GET_CURRENT_PID movl __current_pid, %eax 0: xorl %ecx, %ecx testl %eax, %eax cmovs %eax, %ecx decl %ecx lock cmpxchgl %ecx, __current_pid jne 0b popl %ecx movl $(SYS_vfork), %eax // code for vfork -> eax UNIX_SYSCALL_TRAP // do the system call jnb L1 // jump if CF==0 GET_CURRENT_PID lock incl __current_pid pushl %ecx BRANCH_EXTERN(cerror) L1: testl %edx, %edx // CF=OF=0, ZF set if zero result jz L2 // parent, since r1 == 0 in parent, 1 in child xorl %eax, %eax // zero eax jmp *%ecx L2: GET_CURRENT_PID lock incl __current_pid jmp *%ecx #elif defined(__x86_64__) /* * If __current_pid >= 0, we want to put a -1 in there * otherwise we just decrement it */ LEAF(___vfork, 0) movq __current_pid@GOTPCREL(%rip), %rax movl (%rax), %eax 0: xorl %ecx, %ecx testl %eax, %eax cmovs %eax, %ecx subl $1, %ecx movq __current_pid@GOTPCREL(%rip), %rdx lock cmpxchgl %ecx, (%rdx) jne 0b popq %rdi // return address in %rdi movq $ SYSCALL_CONSTRUCT_UNIX(SYS_vfork), %rax // code for vfork -> rax UNIX_SYSCALL_TRAP // do the system call jnb L1 // jump if CF==0 pushq %rdi // put return address back on stack for cerror movq __current_pid@GOTPCREL(%rip), %rcx lock addq $1, (%rcx) movq (%rcx), %rdi BRANCH_EXTERN(cerror) L1: testl %edx, %edx // CF=OF=0, ZF set if zero result jz L2 // parent, since r1 == 0 in parent, 1 in child xorq %rax, %rax // zero rax jmp *%rdi L2: movq __current_pid@GOTPCREL(%rip), %rdx lock addq $1, (%rdx) jmp *%rdi #else #error Unsupported architecture #endif