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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 | /* * 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@ */ #include "SYS.h" #if defined(__i386__) .data .private_extern __current_pid L__current_pid_addr: __current_pid: .long 0 #if defined(__DYNAMIC__) #define GET_CURRENT_PID \ call 0f ; \ 0: ; \ popl %ecx ; \ leal L__current_pid_addr-0b(%ecx), %ecx #define __current_pid (%ecx) #else #define GET_CURRENT_PID #endif /* * If __current_pid is > 0, return it, else make syscall. * If __current_pid is 0, cache result of syscall. */ TEXT LEAF(___getpid, 0) GET_CURRENT_PID movl __current_pid, %eax testl %eax, %eax jle 1f ret 1: UNIX_SYSCALL_NONAME(getpid, 0, cerror_nocancel) movl %eax, %edx xorl %eax, %eax GET_CURRENT_PID lock cmpxchgl %edx, __current_pid movl %edx, %eax ret #elif defined(__x86_64__) .data .private_extern __current_pid __current_pid: .long 0 /* * If __current_pid is > 0, return it, else make syscall. * If __current_pid is 0, cache result of syscall. */ TEXT LEAF(___getpid, 0) movl __current_pid(%rip), %eax testl %eax, %eax jle 1f ret 1: UNIX_SYSCALL_NONAME(getpid, 0, cerror_nocancel) movl %eax, %edx xorl %eax, %eax leaq __current_pid(%rip), %rcx lock cmpxchgl %edx, (%rcx) movl %edx, %eax ret UNWIND_EPILOGUE #elif defined(__arm__) #include <arm/arch.h> .data .globl __current_pid .align 2 __current_pid: /* Cached pid. Possible values: * 0: no value cached * > 0: cached PID of current process * < 0: negative number of vforks in progress * INT_MIN: for pre-ARMv6, "looking" value (0x80000000) */ .long 0 MI_ENTRY_POINT(___getpid) ldr r3, L__current_pid L1: add r3, pc, r3 // r3 = &__current_pid ldr r0, [r3] // get the cached pid cmp r0, #0 bxgt lr // if positive, return it SYSCALL_NONAME(getpid, 0, cerror_nocancel) #ifdef _ARM_ARCH_6 ldrex r2, [r3] // see if we can cache it cmp r2, #0 // we can't if there are any... bxlt lr // ...vforks in progress strex r2, r0, [r3] // ignore conflicts #else mov r1, #0x80000000 // load "looking" value swp r2, r1, [r3] // look at the value, lock others out cmp r2, r1 // anyone else trying to look? bxeq lr // yes, so return immediately/ cmp r2, #0 // see if we can cache it streq r0, [r3] // if zero, we can strne r2, [r3] // otherwise restore previous value #endif bx lr L__current_pid: .long __current_pid - (L1+8) #elif defined(__arm64__) .data .globl __current_pid .align 2 __current_pid: /* cached pid. possible values: * 0: no value cached * > 0: cached pid of current process * < 0: negative number of vforks in progress * int_min: for pre-armv6, "looking" value (0x80000000) */ .long 0 MI_ENTRY_POINT(___getpid) MI_GET_ADDRESS(x9, __current_pid) // Get address of cached value ldr w0, [x9] // Load it cmp w0, #0 // See if there's a cached value b.le L_notcached // If not, make syscall ret // Else, we're done L_notcached: SYSCALL_NONAME(getpid, 0, cerror_nocancel) ldxr w10, [x9] // Exclusive load cbnz w10, L_done // Unless unset, don't even try stxr wzr, w0, [x9] // Try to store, but don't care if we fail (someone will win, or not) L_done: ret // Done #else #error Unsupported architecture #endif |