/*
* 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 popl %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
#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.ls 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