Fix semaphore destruction (bug 12674).

This commit fixes semaphore destruction by either using 64b atomic
operations (where available), or by using two separate fields when only
32b atomic operations are available.  In the latter case, we keep a
conservative estimate of whether there are any waiting threads in one
bit of the field that counts the number of available tokens, thus
allowing sem_post to atomically both add a token and determine whether
it needs to call futex_wake.

See:
https://sourceware.org/ml/libc-alpha/2014-12/msg00155.html

4 files changed, 0 insertions, 678 deletions

diff --git a/sysdeps/unix/sysv/linux/x86_64/sem_post.S b/sysdeps/unix/sysv/linux/x86_64/sem_post.S
deleted file mode 100644
index f5dfb0536e..0000000000
--- a/sysdeps/unix/sysv/linux/x86_64/sem_post.S
+++ /dev/null
@@ -1,75 +0,0 @@
-/* Copyright (C) 2002-2015 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 <lowlevellock.h>
-#include <shlib-compat.h>
-#include <pthread-errnos.h>
-#include <structsem.h>
-
-
-	.text
-
-	.globl	sem_post
-	.type	sem_post,@function
-	.align	16
-sem_post:
-#if VALUE == 0
-	movl	(%rdi), %eax
-#else
-	movl	VALUE(%rdi), %eax
-#endif
-0:	cmpl	$SEM_VALUE_MAX, %eax
-	je	3f
-	leal	1(%rax), %esi
-	LOCK
-#if VALUE == 0
-	cmpxchgl %esi, (%rdi)
-#else
-	cmpxchgl %esi, VALUE(%rdi)
-#endif
-	jnz	0b
-
-	LP_OP(cmp) $0, NWAITERS(%rdi)
-	je	2f
-
-	movl	$SYS_futex, %eax
-	movl	$FUTEX_WAKE, %esi
-	orl	PRIVATE(%rdi), %esi
-	movl	$1, %edx
-	syscall
-
-	testq	%rax, %rax
-	js	1f
-
-2:	xorl	%eax, %eax
-	retq
-
-1:
-	movl	$EINVAL, %eax
-	jmp	4f
-
-3:
-	movl	$EOVERFLOW, %eax
-
-4:
-	movq	errno@gottpoff(%rip), %rdx
-	movl	%eax, %fs:(%rdx)
-	orl	$-1, %eax
-	retq
-	.size	sem_post,.-sem_post
diff --git a/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S b/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S
deleted file mode 100644
index 091b2411b4..0000000000
--- a/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S
+++ /dev/null
@@ -1,380 +0,0 @@
-/* Copyright (C) 2002-2015 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 <kernel-features.h>
-#include <lowlevellock.h>
-#include <shlib-compat.h>
-#include <pthread-errnos.h>
-#include <structsem.h>
-
-	.text
-
-	.globl	sem_timedwait
-	.type	sem_timedwait,@function
-	.align	16
-sem_timedwait:
-.LSTARTCODE:
-	cfi_startproc
-#ifdef SHARED
-	cfi_personality(DW_EH_PE_pcrel | DW_EH_PE_sdata4 | DW_EH_PE_indirect,
-			DW.ref.__gcc_personality_v0)
-	cfi_lsda(DW_EH_PE_pcrel | DW_EH_PE_sdata4, .LexceptSTART)
-#else
-	cfi_personality(DW_EH_PE_udata4, __gcc_personality_v0)
-	cfi_lsda(DW_EH_PE_udata4, .LexceptSTART)
-#endif
-#if VALUE == 0
-	movl	(%rdi), %eax
-#else
-	movl	VALUE(%rdi), %eax
-#endif
-2:	testl	%eax, %eax
-	je	1f
-
-	leaq	-1(%rax), %rdx
-	LOCK
-#if VALUE == 0
-	cmpxchgl %edx, (%rdi)
-#else
-	cmpxchgl %edx, VALUE(%rdi)
-#endif
-	jne	2b
-
-	xorl	%eax, %eax
-	retq
-
-	/* Check whether the timeout value is valid.  */
-1:	cmpq	$1000000000, 8(%rsi)
-	jae	6f
-
-#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, (%rsi)
-	js	16f
-
-	/* This push is only needed to store the sem_t pointer for the
-	   exception handler.  */
-	pushq	%rdi
-	cfi_adjust_cfa_offset(8)
-
-	movq	%rsi, %r10
-
-	LOCK
-	LP_OP(add) $1, NWAITERS(%rdi)
-
-.LcleanupSTART:
-13:	call	__pthread_enable_asynccancel
-	movl	%eax, %r8d
-
-#if VALUE != 0
-	leaq	VALUE(%rdi), %rdi
-#endif
-	movl	$0xffffffff, %r9d
-	movl	$FUTEX_WAIT_BITSET|FUTEX_CLOCK_REALTIME, %esi
-	orl	PRIVATE(%rdi), %esi
-	movl	$SYS_futex, %eax
-	xorl	%edx, %edx
-	syscall
-	movq	%rax, %r9
-#if VALUE != 0
-	leaq	-VALUE(%rdi), %rdi
-#endif
-
-	xchgq	%r8, %rdi
-	call	__pthread_disable_asynccancel
-.LcleanupEND:
-	movq	%r8, %rdi
-
-	testq	%r9, %r9
-	je	11f
-	cmpq	$-EWOULDBLOCK, %r9
-	jne	3f
-
-11:
-#if VALUE == 0
-	movl	(%rdi), %eax
-#else
-	movl	VALUE(%rdi), %eax
-#endif
-14:	testl	%eax, %eax
-	je	13b
-
-	leaq	-1(%rax), %rcx
-	LOCK
-#if VALUE == 0
-	cmpxchgl %ecx, (%rdi)
-#else
-	cmpxchgl %ecx, VALUE(%rdi)
-#endif
-	jne	14b
-
-	xorl	%eax, %eax
-
-15:	LOCK
-	LP_OP(sub) $1, NWAITERS(%rdi)
-
-	leaq	8(%rsp), %rsp
-	cfi_adjust_cfa_offset(-8)
-	retq
-
-	cfi_adjust_cfa_offset(8)
-3:	negq	%r9
-	movq	errno@gottpoff(%rip), %rdx
-	movl	%r9d, %fs:(%rdx)
-
-	orl	$-1, %eax
-	jmp	15b
-
-	cfi_adjust_cfa_offset(-8)
-6:
-	movq	errno@gottpoff(%rip), %rdx
-	movl	$EINVAL, %fs:(%rdx)
-
-	orl	$-1, %eax
-
-	retq
-
-16:
-	movq	errno@gottpoff(%rip), %rdx
-	movl	$ETIMEDOUT, %fs:(%rdx)
-
-	orl	$-1, %eax
-
-	retq
-
-#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
-.Lreltmo:
-	pushq	%r12
-	cfi_adjust_cfa_offset(8)
-	cfi_rel_offset(%r12, 0)
-	pushq	%r13
-	cfi_adjust_cfa_offset(8)
-	cfi_rel_offset(%r13, 0)
-	pushq	%r14
-	cfi_adjust_cfa_offset(8)
-	cfi_rel_offset(%r14, 0)
-
-#ifdef __ASSUME_FUTEX_CLOCK_REALTIME
-# define STACKFRAME 8
-#else
-# define STACKFRAME 24
-#endif
-	subq	$STACKFRAME, %rsp
-	cfi_adjust_cfa_offset(STACKFRAME)
-
-	movq	%rdi, %r12
-	movq	%rsi, %r13
-
-	LOCK
-	LP_OP(add) $1, NWAITERS(%r12)
-
-7:	xorl	%esi, %esi
-	movq	%rsp,%rdi
-	/* 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
-	movl	$ETIMEDOUT, %r14d
-	js	36f		/* Time is already up.  */
-
-	movq	%rdi, (%rsp)	/* Store relative timeout.  */
-	movq	%rsi, 8(%rsp)
-
-.LcleanupSTART2:
-	call	__pthread_enable_asynccancel
-	movl	%eax, 16(%rsp)
-
-	movq	%rsp, %r10
-# if VALUE == 0
-	movq	%r12, %rdi
-# else
-	leaq	VALUE(%r12), %rdi
-# endif
-# if FUTEX_WAIT == 0
-	movl	PRIVATE(%rdi), %esi
-# else
-	movl	$FUTEX_WAIT, %esi
-	orl	PRIVATE(%rdi), %esi
-# endif
-	movl	$SYS_futex, %eax
-	xorl	%edx, %edx
-	syscall
-	movq	%rax, %r14
-
-	movl	16(%rsp), %edi
-	call	__pthread_disable_asynccancel
-.LcleanupEND2:
-
-	testq	%r14, %r14
-	je	9f
-	cmpq	$-EWOULDBLOCK, %r14
-	jne	33f
-
-9:
-# if VALUE == 0
-	movl	(%r12), %eax
-# else
-	movl	VALUE(%r12), %eax
-# endif
-8:	testl	%eax, %eax
-	je	7b
-
-	leaq	-1(%rax), %rcx
-	LOCK
-# if VALUE == 0
-	cmpxchgl %ecx, (%r12)
-# else
-	cmpxchgl %ecx, VALUE(%r12)
-# endif
-	jne	8b
-
-	xorl	%eax, %eax
-
-45:	LOCK
-	LP_OP(sub) $1, NWAITERS(%r12)
-
-	addq	$STACKFRAME, %rsp
-	cfi_adjust_cfa_offset(-STACKFRAME)
-	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)
-	retq
-
-	cfi_adjust_cfa_offset(STACKFRAME + 3 * 8)
-	cfi_rel_offset(%r12, STACKFRAME + 2 * 8)
-	cfi_rel_offset(%r13, STACKFRAME + 1 * 8)
-	cfi_rel_offset(%r14, STACKFRAME)
-33:	negq	%r14
-36:
-	movq	errno@gottpoff(%rip), %rdx
-	movl	%r14d, %fs:(%rdx)
-
-	orl	$-1, %eax
-	jmp	45b
-#endif
-	cfi_endproc
-	.size	sem_timedwait,.-sem_timedwait
-
-
-	.type	sem_timedwait_cleanup,@function
-sem_timedwait_cleanup:
-	cfi_startproc
-	cfi_adjust_cfa_offset(8)
-
-	movq	(%rsp), %rdi
-	LOCK
-	LP_OP(sub) $1, NWAITERS(%rdi)
-	movq	%rax, %rdi
-.LcallUR:
-	call	_Unwind_Resume@PLT
-	hlt
-.LENDCODE:
-	cfi_endproc
-	.size	sem_timedwait_cleanup,.-sem_timedwait_cleanup
-
-
-#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
-	.type	sem_timedwait_cleanup2,@function
-sem_timedwait_cleanup2:
-	cfi_startproc
-	cfi_adjust_cfa_offset(STACKFRAME + 3 * 8)
-	cfi_rel_offset(%r12, STACKFRAME + 2 * 8)
-	cfi_rel_offset(%r13, STACKFRAME + 1 * 8)
-	cfi_rel_offset(%r14, STACKFRAME)
-
-	LOCK
-	LP_OP(sub) $1, NWAITERS(%r12)
-	movq	%rax, %rdi
-	movq	STACKFRAME(%rsp), %r14
-	movq	STACKFRAME+8(%rsp), %r13
-	movq	STACKFRAME+16(%rsp), %r12
-.LcallUR2:
-	call	_Unwind_Resume@PLT
-	hlt
-.LENDCODE2:
-	cfi_endproc
-	.size	sem_timedwait_cleanup2,.-sem_timedwait_cleanup2
-#endif
-
-
-	.section .gcc_except_table,"a",@progbits
-.LexceptSTART:
-	.byte	DW_EH_PE_omit			# @LPStart format
-	.byte	DW_EH_PE_omit			# @TType format
-	.byte	DW_EH_PE_uleb128		# call-site format
-	.uleb128 .Lcstend-.Lcstbegin
-.Lcstbegin:
-	.uleb128 .LcleanupSTART-.LSTARTCODE
-	.uleb128 .LcleanupEND-.LcleanupSTART
-	.uleb128 sem_timedwait_cleanup-.LSTARTCODE
-	.uleb128  0
-#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
-	.uleb128 .LcleanupSTART2-.LSTARTCODE
-	.uleb128 .LcleanupEND2-.LcleanupSTART2
-	.uleb128 sem_timedwait_cleanup2-.LSTARTCODE
-	.uleb128  0
-#endif
-	.uleb128 .LcallUR-.LSTARTCODE
-	.uleb128 .LENDCODE-.LcallUR
-	.uleb128 0
-	.uleb128  0
-#ifndef __ASSUME_FUTEX_CLOCK_REALTIME
-	.uleb128 .LcallUR2-.LSTARTCODE
-	.uleb128 .LENDCODE2-.LcallUR2
-	.uleb128 0
-	.uleb128  0
-#endif
-.Lcstend:
-
-
-#ifdef SHARED
-	.hidden	DW.ref.__gcc_personality_v0
-	.weak	DW.ref.__gcc_personality_v0
-	.section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
-	.align	LP_SIZE
-	.type	DW.ref.__gcc_personality_v0, @object
-	.size	DW.ref.__gcc_personality_v0, LP_SIZE
-DW.ref.__gcc_personality_v0:
-	ASM_ADDR __gcc_personality_v0
-#endif
diff --git a/sysdeps/unix/sysv/linux/x86_64/sem_trywait.S b/sysdeps/unix/sysv/linux/x86_64/sem_trywait.S
deleted file mode 100644
index 1838e96223..0000000000
--- a/sysdeps/unix/sysv/linux/x86_64/sem_trywait.S
+++ /dev/null
@@ -1,47 +0,0 @@
-/* Copyright (C) 2002-2015 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 <lowlevellock.h>
-#include <shlib-compat.h>
-#include <pthread-errnos.h>
-
-	.text
-
-	.globl	sem_trywait
-	.type	sem_trywait,@function
-	.align	16
-sem_trywait:
-	movl	(%rdi), %eax
-2:	testl	%eax, %eax
-	jz	1f
-
-	leal	-1(%rax), %edx
-	LOCK
-	cmpxchgl %edx, (%rdi)
-	jne	2b
-
-	xorl	%eax, %eax
-	retq
-
-1:
-	movq	errno@gottpoff(%rip), %rdx
-	movl	$EAGAIN, %fs:(%rdx)
-	orl	$-1, %eax
-	retq
-	.size	sem_trywait,.-sem_trywait
diff --git a/sysdeps/unix/sysv/linux/x86_64/sem_wait.S b/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
deleted file mode 100644
index 2e7b131923..0000000000
--- a/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
+++ /dev/null
@@ -1,176 +0,0 @@
-/* Copyright (C) 2002-2015 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 <lowlevellock.h>
-#include <shlib-compat.h>
-#include <pthread-errnos.h>
-#include <structsem.h>
-
-
-	.text
-
-	.globl	sem_wait
-	.type	sem_wait,@function
-	.align	16
-sem_wait:
-.LSTARTCODE:
-	cfi_startproc
-#ifdef SHARED
-	cfi_personality(DW_EH_PE_pcrel | DW_EH_PE_sdata4 | DW_EH_PE_indirect,
-			DW.ref.__gcc_personality_v0)
-	cfi_lsda(DW_EH_PE_pcrel | DW_EH_PE_sdata4, .LexceptSTART)
-#else
-	cfi_personality(DW_EH_PE_udata4, __gcc_personality_v0)
-	cfi_lsda(DW_EH_PE_udata4, .LexceptSTART)
-#endif
-
-#if VALUE == 0
-	movl	(%rdi), %eax
-#else
-	movl	VALUE(%rdi), %eax
-#endif
-2:	testl	%eax, %eax
-	je	1f
-
-	leal	-1(%rax), %edx
-	LOCK
-#if VALUE == 0
-	cmpxchgl %edx, (%rdi)
-#else
-	cmpxchgl %edx, VALUE(%rdi)
-#endif
-	jne	2b
-
-	xorl	%eax, %eax
-	retq
-
-	/* This push is only needed to store the sem_t pointer for the
-	   exception handler.  */
-1:	pushq	%rdi
-	cfi_adjust_cfa_offset(8)
-
-	LOCK
-	LP_OP(add) $1, NWAITERS(%rdi)
-
-.LcleanupSTART:
-6:	call	__pthread_enable_asynccancel
-	movl	%eax, %r8d
-
-	xorq	%r10, %r10
-	movl	$SYS_futex, %eax
-#if FUTEX_WAIT == 0
-	movl	PRIVATE(%rdi), %esi
-#else
-	movl	$FUTEX_WAIT, %esi
-	orl	PRIVATE(%rdi), %esi
-#endif
-	xorl	%edx, %edx
-	syscall
-	movq	%rax, %rcx
-
-	xchgq	%r8, %rdi
-	call	__pthread_disable_asynccancel
-.LcleanupEND:
-	movq	%r8, %rdi
-
-	testq	%rcx, %rcx
-	je	3f
-	cmpq	$-EWOULDBLOCK, %rcx
-	jne	4f
-
-3:
-#if VALUE == 0
-	movl	(%rdi), %eax
-#else
-	movl	VALUE(%rdi), %eax
-#endif
-5:	testl	%eax, %eax
-	je	6b
-
-	leal	-1(%rax), %edx
-	LOCK
-#if VALUE == 0
-	cmpxchgl %edx, (%rdi)
-#else
-	cmpxchgl %edx, VALUE(%rdi)
-#endif
-	jne	5b
-
-	xorl	%eax, %eax
-
-9:	LOCK
-	LP_OP(sub) $1, NWAITERS(%rdi)
-
-	leaq	8(%rsp), %rsp
-	cfi_adjust_cfa_offset(-8)
-
-	retq
-
-	cfi_adjust_cfa_offset(8)
-4:	negq	%rcx
-	movq	errno@gottpoff(%rip), %rdx
-	movl	%ecx, %fs:(%rdx)
-	orl	$-1, %eax
-
-	jmp 9b
-	.size	sem_wait,.-sem_wait
-
-
-	.type	sem_wait_cleanup,@function
-sem_wait_cleanup:
-	movq	(%rsp), %rdi
-	LOCK
-	LP_OP(sub) $1, NWAITERS(%rdi)
-	movq	%rax, %rdi
-.LcallUR:
-	call	_Unwind_Resume@PLT
-	hlt
-.LENDCODE:
-	cfi_endproc
-	.size	sem_wait_cleanup,.-sem_wait_cleanup
-
-
-	.section .gcc_except_table,"a",@progbits
-.LexceptSTART:
-	.byte	DW_EH_PE_omit			# @LPStart format
-	.byte	DW_EH_PE_omit			# @TType format
-	.byte	DW_EH_PE_uleb128		# call-site format
-	.uleb128 .Lcstend-.Lcstbegin
-.Lcstbegin:
-	.uleb128 .LcleanupSTART-.LSTARTCODE
-	.uleb128 .LcleanupEND-.LcleanupSTART
-	.uleb128 sem_wait_cleanup-.LSTARTCODE
-	.uleb128  0
-	.uleb128 .LcallUR-.LSTARTCODE
-	.uleb128 .LENDCODE-.LcallUR
-	.uleb128 0
-	.uleb128  0
-.Lcstend:
-
-
-#ifdef SHARED
-	.hidden	DW.ref.__gcc_personality_v0
-	.weak	DW.ref.__gcc_personality_v0
-	.section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
-	.align	LP_SIZE
-	.type	DW.ref.__gcc_personality_v0, @object
-	.size	DW.ref.__gcc_personality_v0, LP_SIZE
-DW.ref.__gcc_personality_v0:
-	ASM_ADDR __gcc_personality_v0
-#endif