1/* 2 * Copyright (c) 1999-2010 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) 1992 NeXT Computer, Inc. All rights reserved. 29 * 30 * File: libc/ppc/sys/fork.s 31 * 32 * HISTORY 33 * 18-Nov-92 Ben Fathi ([email protected]) 34 * Created from M88K sources 35 * 36 * 11-Jan-92 Peter King ([email protected]) 37 * Created from M68K sources 38 */ 39 40/* 41 * All of the asm stubs in this file have been adjusted so the pre/post 42 * fork handlers and dyld fixup are done in C inside Libc. As such, Libc 43 * expects the __fork asm to fix up the return code to be -1, 0 or pid 44 * and errno if needed. 45 */ 46 47#include "SYS.h" 48 49#if defined(__i386__) 50 51LEAF(___fork, 0) 52 subl $28, %esp // Align the stack, with 16 bytes of extra padding that we'll need 53 54 movl $ SYS_fork,%eax; // code for fork -> eax 55 UNIX_SYSCALL_TRAP // do the system call 56 jnc L1 // jump if CF==0 57 58 CALL_EXTERN(tramp_cerror) 59 movl $-1,%eax 60 addl $28, %esp // restore the stack 61 ret 62 63L1: 64 orl %edx,%edx // CF=OF=0, ZF set if zero result 65 jz L2 // parent, since r1 == 0 in parent, 1 in child 66 67 //child here... 68 xorl %eax,%eax // zero eax 69 REG_TO_EXTERN(%eax, __current_pid); 70L2: 71 addl $28, %esp // restore the stack 72 // parent ends up here skipping child portion 73 ret 74 75#elif defined(__x86_64__) 76 77LEAF(___fork, 0) 78 subq $24, %rsp // Align the stack, plus room for local storage 79 80 movl $ SYSCALL_CONSTRUCT_UNIX(SYS_fork),%eax; // code for fork -> rax 81 UNIX_SYSCALL_TRAP // do the system call 82 jnc L1 // jump if CF==0 83 84 movq %rax, %rdi 85 CALL_EXTERN(_cerror) 86 movq $-1, %rax 87 addq $24, %rsp // restore the stack 88 ret 89 90L1: 91 orl %edx,%edx // CF=OF=0, ZF set if zero result 92 jz L2 // parent, since r1 == 0 in parent, 1 in child 93 94 //child here... 95 xorq %rax, %rax 96 PICIFY(__current_pid) 97 movl %eax,(%r11) 98L2: 99 // parent ends up here skipping child portion 100 addq $24, %rsp // restore the stack 101 ret 102 UNWIND_EPILOGUE 103 104#elif defined(__arm__) 105 106MI_ENTRY_POINT(___fork) 107 stmfd sp!, {r4, r7, lr} 108 add r7, sp, #4 109 110 mov r1, #1 // prime results 111 mov r12, #SYS_fork 112 swi #SWI_SYSCALL // make the syscall 113 bcs Lbotch // error? 114 115 cmp r1, #0 // parent (r1=0) or child(r1=1) 116 beq Lparent 117 118 //child here... 119 MI_GET_ADDRESS(r3, __current_pid) 120 mov r0, #0 121 str r0, [r3] // clear cached pid in child 122 ldmfd sp!, {r4, r7, pc} 123 124Lbotch: 125 MI_CALL_EXTERNAL(_cerror) // jump here on error 126 mov r0,#-1 // set the error 127 // fall thru 128Lparent: 129 ldmfd sp!, {r4, r7, pc} // pop and return 130 131#elif defined(__arm64__) 132 133#include <mach/arm64/asm.h> 134 135MI_ENTRY_POINT(___fork) 136 ARM64_STACK_PROLOG 137 PUSH_FRAME 138 // ARM moves a 1 in to r1 here, but I can't see why. 139 mov x16, #SYS_fork // Syscall code 140 svc #SWI_SYSCALL // Trap to kernel 141 b.cs Lbotch // Carry bit indicates failure 142 cbz x1, Lparent // x1 == 0 indicates that we are the parent 143 144 // Child 145 MI_GET_ADDRESS(x9, __current_pid) // Get address of cached "current pid" 146 mov w0, #0 147 str w0, [x9] // Clear cached current pid 148 POP_FRAME // And done 149 ARM64_STACK_EPILOG 150 151Lbotch: 152 MI_CALL_EXTERNAL(_cerror) // Handle error 153 mov w0, #-1 // Return value is -1 154Lparent: 155 POP_FRAME // Return 156 ARM64_STACK_EPILOG 157 158#else 159#error Unsupported architecture 160#endif 161