/
lowlevellock.S
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/
lowlevellock.S
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/* Copyright (C) 2002-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <pthread-errnos.h>
#include <kernel-features.h>
#include <lowlevellock.h>
#include <stap-probe.h>
.text
#ifdef __ASSUME_PRIVATE_FUTEX
# define LOAD_PRIVATE_FUTEX_WAIT(reg) \
movl $(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg
# define LOAD_PRIVATE_FUTEX_WAKE(reg) \
movl $(FUTEX_WAKE | FUTEX_PRIVATE_FLAG), reg
# define LOAD_FUTEX_WAIT(reg) \
xorl $(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg
# define LOAD_FUTEX_WAIT_ABS(reg) \
xorl $(FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME), reg
# define LOAD_FUTEX_WAKE(reg) \
xorl $(FUTEX_WAKE | FUTEX_PRIVATE_FLAG), reg
#else
# if FUTEX_WAIT == 0
# define LOAD_PRIVATE_FUTEX_WAIT(reg) \
movl %fs:PRIVATE_FUTEX, reg
# else
# define LOAD_PRIVATE_FUTEX_WAIT(reg) \
movl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAIT, reg
# endif
# define LOAD_PRIVATE_FUTEX_WAKE(reg) \
movl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAKE, reg
# if FUTEX_WAIT == 0
# define LOAD_FUTEX_WAIT(reg) \
xorl $FUTEX_PRIVATE_FLAG, reg ; \
andl %fs:PRIVATE_FUTEX, reg
# else
# define LOAD_FUTEX_WAIT(reg) \
xorl $FUTEX_PRIVATE_FLAG, reg ; \
andl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAIT, reg
# endif
# define LOAD_FUTEX_WAIT_ABS(reg) \
xorl $FUTEX_PRIVATE_FLAG, reg ; \
andl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME, reg
# define LOAD_FUTEX_WAKE(reg) \
xorl $FUTEX_PRIVATE_FLAG, reg ; \
andl %fs:PRIVATE_FUTEX, reg ; \
orl $FUTEX_WAKE, reg
#endif
.globl __lll_lock_wait_private
.type __lll_lock_wait_private,@function
.hidden __lll_lock_wait_private
.align 16
__lll_lock_wait_private:
cfi_startproc
pushq %r10
cfi_adjust_cfa_offset(8)
pushq %rdx
cfi_adjust_cfa_offset(8)
cfi_offset(%r10, -16)
cfi_offset(%rdx, -24)
xorq %r10, %r10 /* No timeout. */
movl $2, %edx
LOAD_PRIVATE_FUTEX_WAIT (%esi)
cmpl %edx, %eax /* NB: %edx == 2 */
jne 2f
1: LIBC_PROBE (lll_lock_wait_private, 1, %rdi)
movl $SYS_futex, %eax
syscall
2: movl %edx, %eax
xchgl %eax, (%rdi) /* NB: lock is implied */
testl %eax, %eax
jnz 1b
popq %rdx
cfi_adjust_cfa_offset(-8)
cfi_restore(%rdx)
popq %r10
cfi_adjust_cfa_offset(-8)
cfi_restore(%r10)
retq
cfi_endproc
.size __lll_lock_wait_private,.-__lll_lock_wait_private
#if !IS_IN (libc)
.globl __lll_lock_wait
.type __lll_lock_wait,@function
.hidden __lll_lock_wait
.align 16
__lll_lock_wait:
cfi_startproc
pushq %r10
cfi_adjust_cfa_offset(8)
pushq %rdx
cfi_adjust_cfa_offset(8)
cfi_offset(%r10, -16)
cfi_offset(%rdx, -24)
xorq %r10, %r10 /* No timeout. */
movl $2, %edx
LOAD_FUTEX_WAIT (%esi)
cmpl %edx, %eax /* NB: %edx == 2 */
jne 2f
1: LIBC_PROBE (lll_lock_wait, 2, %rdi, %rsi)
movl $SYS_futex, %eax
syscall
2: movl %edx, %eax
xchgl %eax, (%rdi) /* NB: lock is implied */
testl %eax, %eax
jnz 1b
popq %rdx
cfi_adjust_cfa_offset(-8)
cfi_restore(%rdx)
popq %r10
cfi_adjust_cfa_offset(-8)
cfi_restore(%r10)
retq
cfi_endproc
.size __lll_lock_wait,.-__lll_lock_wait
/* %rdi: futex
%rsi: flags
%rdx: timeout
%eax: futex value
*/
.globl __lll_timedlock_wait
.type __lll_timedlock_wait,@function
.hidden __lll_timedlock_wait
.align 16
__lll_timedlock_wait:
cfi_startproc
# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
# ifdef PIC
cmpl $0, __have_futex_clock_realtime(%rip)
# else
cmpl $0, __have_futex_clock_realtime
# endif
je .Lreltmo
# endif
cmpq $0, (%rdx)
js 5f
pushq %r9
cfi_adjust_cfa_offset(8)
cfi_rel_offset(%r9, 0)
movq %rdx, %r10
movl $0xffffffff, %r9d
LOAD_FUTEX_WAIT_ABS (%esi)
movl $2, %edx
cmpl %edx, %eax
jne 2f
1: movl $SYS_futex, %eax
movl $2, %edx
syscall
2: xchgl %edx, (%rdi) /* NB: lock is implied */
testl %edx, %edx
jz 3f
cmpl $-ETIMEDOUT, %eax
je 4f
cmpl $-EINVAL, %eax
jne 1b
4: movl %eax, %edx
negl %edx
3: movl %edx, %eax
popq %r9
cfi_adjust_cfa_offset(-8)
cfi_restore(%r9)
retq
5: movl $ETIMEDOUT, %eax
retq
# ifndef __ASSUME_FUTEX_CLOCK_REALTIME
.Lreltmo:
/* Check for a valid timeout value. */
cmpq $1000000000, 8(%rdx)
jae 3f
pushq %r8
cfi_adjust_cfa_offset(8)
pushq %r9
cfi_adjust_cfa_offset(8)
pushq %r12
cfi_adjust_cfa_offset(8)
pushq %r13
cfi_adjust_cfa_offset(8)
pushq %r14
cfi_adjust_cfa_offset(8)
cfi_offset(%r8, -16)
cfi_offset(%r9, -24)
cfi_offset(%r12, -32)
cfi_offset(%r13, -40)
cfi_offset(%r14, -48)
pushq %rsi
cfi_adjust_cfa_offset(8)
/* Stack frame for the timespec and timeval structs. */
subq $24, %rsp
cfi_adjust_cfa_offset(24)
movq %rdi, %r12
movq %rdx, %r13
movl $2, %edx
xchgl %edx, (%r12)
testl %edx, %edx
je 6f
1:
/* Get current time. */
movq %rsp, %rdi
xorl %esi, %esi
/* This call works because we directly jump to a system call entry
which preserves all the registers. */
call JUMPTARGET(__gettimeofday)
/* Compute relative timeout. */
movq 8(%rsp), %rax
movl $1000, %edi
mul %rdi /* Milli seconds to nano seconds. */
movq (%r13), %rdi
movq 8(%r13), %rsi
subq (%rsp), %rdi
subq %rax, %rsi
jns 4f
addq $1000000000, %rsi
decq %rdi
4: testq %rdi, %rdi
js 2f /* Time is already up. */
/* Store relative timeout. */
movq %rdi, (%rsp)
movq %rsi, 8(%rsp)
/* Futex call. */
movl $2, %edx
movl $1, %eax
movq %rsp, %r10
movl 24(%rsp), %esi
LOAD_FUTEX_WAIT (%esi)
movq %r12, %rdi
movl $SYS_futex, %eax
syscall
/* NB: %edx == 2 */
xchgl %edx, (%r12)
testl %edx, %edx
je 6f
cmpl $-ETIMEDOUT, %eax
jne 1b
2: movl $ETIMEDOUT, %edx
6: addq $32, %rsp
cfi_adjust_cfa_offset(-32)
popq %r14
cfi_adjust_cfa_offset(-8)
cfi_restore(%r14)
popq %r13
cfi_adjust_cfa_offset(-8)
cfi_restore(%r13)
popq %r12
cfi_adjust_cfa_offset(-8)
cfi_restore(%r12)
popq %r9
cfi_adjust_cfa_offset(-8)
cfi_restore(%r9)
popq %r8
cfi_adjust_cfa_offset(-8)
cfi_restore(%r8)
movl %edx, %eax
retq
3: movl $EINVAL, %eax
retq
# endif
cfi_endproc
.size __lll_timedlock_wait,.-__lll_timedlock_wait
#endif
.globl __lll_unlock_wake_private
.type __lll_unlock_wake_private,@function
.hidden __lll_unlock_wake_private
.align 16
__lll_unlock_wake_private:
cfi_startproc
pushq %rsi
cfi_adjust_cfa_offset(8)
pushq %rdx
cfi_adjust_cfa_offset(8)
cfi_offset(%rsi, -16)
cfi_offset(%rdx, -24)
movl $0, (%rdi)
LOAD_PRIVATE_FUTEX_WAKE (%esi)
movl $1, %edx /* Wake one thread. */
movl $SYS_futex, %eax
syscall
popq %rdx
cfi_adjust_cfa_offset(-8)
cfi_restore(%rdx)
popq %rsi
cfi_adjust_cfa_offset(-8)
cfi_restore(%rsi)
retq
cfi_endproc
.size __lll_unlock_wake_private,.-__lll_unlock_wake_private
#if !IS_IN (libc)
.globl __lll_unlock_wake
.type __lll_unlock_wake,@function
.hidden __lll_unlock_wake
.align 16
__lll_unlock_wake:
cfi_startproc
pushq %rsi
cfi_adjust_cfa_offset(8)
pushq %rdx
cfi_adjust_cfa_offset(8)
cfi_offset(%rsi, -16)
cfi_offset(%rdx, -24)
movl $0, (%rdi)
LOAD_FUTEX_WAKE (%esi)
movl $1, %edx /* Wake one thread. */
movl $SYS_futex, %eax
syscall
popq %rdx
cfi_adjust_cfa_offset(-8)
cfi_restore(%rdx)
popq %rsi
cfi_adjust_cfa_offset(-8)
cfi_restore(%rsi)
retq
cfi_endproc
.size __lll_unlock_wake,.-__lll_unlock_wake
.globl __lll_timedwait_tid
.type __lll_timedwait_tid,@function
.hidden __lll_timedwait_tid
.align 16
__lll_timedwait_tid:
cfi_startproc
pushq %r12
cfi_adjust_cfa_offset(8)
pushq %r13
cfi_adjust_cfa_offset(8)
cfi_offset(%r12, -16)
cfi_offset(%r13, -24)
movq %rdi, %r12
movq %rsi, %r13
/* Align stack to 16 bytes when calling __gettimeofday. */
subq $24, %rsp
cfi_adjust_cfa_offset(24)
/* Get current time. */
2: movq %rsp, %rdi
xorl %esi, %esi
/* This call works because we directly jump to a system call entry
which preserves all the registers. */
call JUMPTARGET(__gettimeofday)
/* Compute relative timeout. */
movq 8(%rsp), %rax
movl $1000, %edi
mul %rdi /* Milli seconds to nano seconds. */
movq (%r13), %rdi
movq 8(%r13), %rsi
subq (%rsp), %rdi
subq %rax, %rsi
jns 5f
addq $1000000000, %rsi
decq %rdi
5: testq %rdi, %rdi
js 6f /* Time is already up. */
movq %rdi, (%rsp) /* Store relative timeout. */
movq %rsi, 8(%rsp)
movl (%r12), %edx
testl %edx, %edx
jz 4f
movq %rsp, %r10
/* XXX The kernel so far uses global futex for the wakeup at
all times. */
#if FUTEX_WAIT == 0
xorl %esi, %esi
#else
movl $FUTEX_WAIT, %esi
#endif
movq %r12, %rdi
movl $SYS_futex, %eax
syscall
cmpl $0, (%rdi)
jne 1f
4: xorl %eax, %eax
8: addq $24, %rsp
cfi_adjust_cfa_offset(-24)
popq %r13
cfi_adjust_cfa_offset(-8)
cfi_restore(%r13)
popq %r12
cfi_adjust_cfa_offset(-8)
cfi_restore(%r12)
retq
cfi_adjust_cfa_offset(32)
1: cmpq $-ETIMEDOUT, %rax
jne 2b
6: movl $ETIMEDOUT, %eax
jmp 8b
cfi_endproc
.size __lll_timedwait_tid,.-__lll_timedwait_tid
#endif