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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | /* * 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 |