From patchwork Fri Jan 13 11:20:56 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Torvald Riegel X-Patchwork-Id: 91313 Delivered-To: patch@linaro.org Received: by 10.140.20.99 with SMTP id 90csp139703qgi; Fri, 13 Jan 2017 03:21:28 -0800 (PST) X-Received: by 10.98.204.216 with SMTP id j85mr14449570pfk.130.1484306488276; Fri, 13 Jan 2017 03:21:28 -0800 (PST) Return-Path: Received: from sourceware.org (server1.sourceware.org. [209.132.180.131]) by mx.google.com with ESMTPS id b62si12421689pgc.225.2017.01.13.03.21.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 13 Jan 2017 03:21:28 -0800 (PST) Received-SPF: pass (google.com: domain of libc-alpha-return-76761-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Authentication-Results: mx.google.com; dkim=pass header.i=@sourceware.org; spf=pass (google.com: domain of libc-alpha-return-76761-patch=linaro.org@sourceware.org designates 209.132.180.131 as permitted sender) smtp.mailfrom=libc-alpha-return-76761-patch=linaro.org@sourceware.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:message-id:subject:from:to:cc:date:in-reply-to :references:content-type:mime-version; q=dns; s=default; b=DXueD dQINsdlh88xcpoASZIc3xYFRRl8Jlp8tfGxw3i8LutnfVNzDCnVEhCROXGnTrPGD hxF/gKu6ThUdSOS8ZOoVCGnlOaAR8plDfIeOha6TUO3jcYfSqsBVxx6PaPIg89vx uJiaF/zYaGkCUljDyxDuFcAovpJYoN6ahAT5NI= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:message-id:subject:from:to:cc:date:in-reply-to :references:content-type:mime-version; s=default; bh=dtBpVxDzxXP whK0uYIknwqVvut4=; b=V2u9FqVOaZpGNRAuEP9mOjdwPyaB8ESbSr+ufC1HYDD hWwZxsgz53EaOlfvOQGdv6EigIPJVahpT2DFFiVIrsUWVQc95Zg8V2YGKwB7EzcR xQknrSa6yibGa0uqIgJWsB24efy/bBXcrft2JWUU4yNAA80vFoGSvK/dICzyDrWA = Received: (qmail 8098 invoked by alias); 13 Jan 2017 11:21:13 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 8073 invoked by uid 89); 13 Jan 2017 11:21:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=BAYES_00, KAM_LAZY_DOMAIN_SECURITY, LOTS_OF_MONEY, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=1516, cmpq, Adapt, $1000 X-HELO: mx1.redhat.com Message-ID: <1484306456.5606.284.camel@redhat.com> Subject: Re: [PATCH] [BZ #20985] robust mutexes: Fix broken x86 assembly by removing it From: Torvald Riegel To: Florian Weimer Cc: GLIBC Devel , "Carlos O'Donell" Date: Fri, 13 Jan 2017 12:20:56 +0100 In-Reply-To: <64979bdf-abe9-aeca-c3f5-9f92414e7e35@redhat.com> References: <1482402167.14990.784.camel@redhat.com> <1482405798.14990.788.camel@redhat.com> <64979bdf-abe9-aeca-c3f5-9f92414e7e35@redhat.com> Mime-Version: 1.0 On Fri, 2017-01-13 at 11:01 +0100, Florian Weimer wrote: > On 12/22/2016 12:23 PM, Torvald Riegel wrote: > > On Thu, 2016-12-22 at 12:06 +0100, Florian Weimer wrote: > >> On 12/22/2016 11:22 AM, Torvald Riegel wrote: > >>> (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. > >> > >> This needs to be documented in the code. It seems the code always > >> defines it as 0, so it's not clear to me why it makes sense to define it > >> at all (twice even). > > > > This should be defined differently when pthread_mutex_cond_lock.c > > includes the file; I just noticed that it doesn't do that. > > > > Is the patch OK besides that (ie, so after fixing that oversight and > > adding a suitable comment to the definition of > > LLL_ROBUST_MUTEX_LOCK_MODIFIER?). > > Do we already have a test case which detects the bug you introduced? The bug I introduced, meaning the oversight in the previous definition? I don't think we need tests for mistakes that never made it into master. Additionally, I intend to get rid of the special handling of cond_lock eventually; it's not necessary anymore because the new condvar doesn't use futex-requeue. But that's a change for the next release. > Would you please post a consolidated patch rebased to current master? Attached. commit 0adf48803004a034e603c90494097807f05ccc94 Author: Torvald Riegel Date: Thu Dec 22 10:20:43 2016 +0100 robust mutexes: Fix broken x86 assembly by removing it lll_robust_unlock on i386 and x86_64 first sets the futex word to FUTEX_WAITERS|0 before calling __LLL_unlock_wake, which will set the futex word to 0. If the thread is killed between these steps, then the futex word will be FUTEX_WAITERS|0, and the kernel (at least current upstream) will not set it to FUTEX_OWNER_DIED|FUTEX_WAITERS because 0 is not equal to the TID of the crashed thread. The lll_robust_lock assembly code on i386 and x86_64 is not prepared to deal with this case because the fastpath tries to only CAS 0 to TID and not FUTEX_WAITERS|0 to TID; the slowpath simply waits until it can CAS 0 to TID or the futex_word has the FUTEX_OWNER_DIED bit set. This issue is fixed by removing the custom x86 assembly code and using the generic C code instead. However, instead of adding more duplicate code to the custom x86 lowlevellock.h, the code of the lll_robust* functions is inlined into the single call sites that exist for each of these functions in the pthread_mutex_* functions. The robust mutex paths in the latter have been slightly reorganized to make them simpler. [BZ #20985] * nptl/Makefile: Adapt. * nptl/pthread_mutex_cond_lock.c (LLL_ROBUST_MUTEX_LOCK): Remove. (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. * nptl/pthread_mutex_lock.c (LLL_ROBUST_MUTEX_LOCK): Remove. (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. (__pthread_mutex_lock_full): Inline lll_robust* functions and adapt. * nptl/pthread_mutex_timedlock.c (pthread_mutex_timedlock): Inline lll_robust* functions and adapt. * nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full): Likewise. * sysdeps/nptl/lowlevellock.h (__lll_robust_lock_wait, __lll_robust_lock, lll_robust_cond_lock, __lll_robust_timedlock_wait, __lll_robust_timedlock, __lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_robust_lock, lll_robust_cond_lock, lll_robust_timedlock, lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_robust_lock, lll_robust_cond_lock, lll_robust_timedlock, lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/sparc/lowlevellock.h (__lll_robust_lock_wait, __lll_robust_lock, lll_robust_cond_lock, __lll_robust_timedlock_wait, __lll_robust_timedlock, __lll_robust_unlock): Remove. * nptl/lowlevelrobustlock.c: Remove file. * nptl/lowlevelrobustlock.sym: Likewise. * sysdeps/unix/sysv/linux/i386/lowlevelrobustlock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S: Likewise. diff --git a/nptl/Makefile b/nptl/Makefile index 9d5738f..dcb5953 100644 --- a/nptl/Makefile +++ b/nptl/Makefile @@ -117,7 +117,7 @@ libpthread-routines = nptl-init vars events version pt-interp \ cleanup_defer_compat unwind \ pt-longjmp pt-cleanup\ cancellation \ - lowlevellock lowlevelrobustlock \ + lowlevellock \ lll_timedlock_wait lll_timedwait_tid \ pt-fork pt-vfork \ $(pthread-compat-wrappers) \ @@ -309,7 +309,7 @@ tests-nolibpthread = tst-unload gen-as-const-headers = pthread-errnos.sym \ unwindbuf.sym \ - lowlevelrobustlock.sym pthread-pi-defines.sym + pthread-pi-defines.sym gen-py-const-headers := nptl_lock_constants.pysym pretty-printers := nptl-printers.py diff --git a/nptl/lowlevelrobustlock.c b/nptl/lowlevelrobustlock.c deleted file mode 100644 index 3a91a6b..0000000 --- a/nptl/lowlevelrobustlock.c +++ /dev/null @@ -1,136 +0,0 @@ -/* Copyright (C) 2006-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Jakub Jelinek , 2006. - - 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 - . */ - -#include -#include -#include -#include -#include -#include - - -int -__lll_robust_lock_wait (int *futex, int private) -{ - int oldval = *futex; - int tid = THREAD_GETMEM (THREAD_SELF, tid); - - /* If the futex changed meanwhile try locking again. */ - if (oldval == 0) - goto try; - - do - { - /* If the owner died, return the present value of the futex. */ - if (__glibc_unlikely (oldval & FUTEX_OWNER_DIED)) - return oldval; - - /* Try to put the lock into state 'acquired, possibly with waiters'. */ - int newval = oldval | FUTEX_WAITERS; - if (oldval != newval - && atomic_compare_and_exchange_bool_acq (futex, newval, oldval)) - continue; - - /* If *futex == 2, wait until woken. */ - lll_futex_wait (futex, newval, private); - - try: - ; - } - while ((oldval = atomic_compare_and_exchange_val_acq (futex, - tid | FUTEX_WAITERS, - 0)) != 0); - return 0; -} - - -int -__lll_robust_timedlock_wait (int *futex, const struct timespec *abstime, - int private) -{ - /* Reject invalid timeouts. */ - if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) - return EINVAL; - - int tid = THREAD_GETMEM (THREAD_SELF, tid); - int oldval = *futex; - - /* If the futex changed meanwhile, try locking again. */ - if (oldval == 0) - goto try; - - /* Work around the fact that the kernel rejects negative timeout values - despite them being valid. */ - if (__glibc_unlikely (abstime->tv_sec < 0)) - return ETIMEDOUT; - - do - { -#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ - || !defined lll_futex_timed_wait_bitset) - struct timeval tv; - struct timespec rt; - - /* Get the current time. */ - (void) __gettimeofday (&tv, NULL); - - /* Compute relative timeout. */ - rt.tv_sec = abstime->tv_sec - tv.tv_sec; - rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; - if (rt.tv_nsec < 0) - { - rt.tv_nsec += 1000000000; - --rt.tv_sec; - } - - /* Already timed out? */ - if (rt.tv_sec < 0) - return ETIMEDOUT; -#endif - - /* If the owner died, return the present value of the futex. */ - if (__glibc_unlikely (oldval & FUTEX_OWNER_DIED)) - return oldval; - - /* Try to put the lock into state 'acquired, possibly with waiters'. */ - int newval = oldval | FUTEX_WAITERS; - if (oldval != newval - && atomic_compare_and_exchange_bool_acq (futex, newval, oldval)) - continue; - - /* If *futex == 2, wait until woken or timeout. */ -#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ - || !defined lll_futex_timed_wait_bitset) - lll_futex_timed_wait (futex, newval, &rt, private); -#else - int err = lll_futex_timed_wait_bitset (futex, newval, abstime, - FUTEX_CLOCK_REALTIME, private); - /* The futex call timed out. */ - if (err == -ETIMEDOUT) - return -err; -#endif - - try: - ; - } - while ((oldval = atomic_compare_and_exchange_val_acq (futex, - tid | FUTEX_WAITERS, - 0)) != 0); - - return 0; -} diff --git a/nptl/lowlevelrobustlock.sym b/nptl/lowlevelrobustlock.sym deleted file mode 100644 index 2f1e9da..0000000 --- a/nptl/lowlevelrobustlock.sym +++ /dev/null @@ -1,6 +0,0 @@ -#include -#include - --- - -TID offsetof (struct pthread, tid) diff --git a/nptl/pthread_mutex_cond_lock.c b/nptl/pthread_mutex_cond_lock.c index 2ac421f..bd7149e 100644 --- a/nptl/pthread_mutex_cond_lock.c +++ b/nptl/pthread_mutex_cond_lock.c @@ -11,9 +11,9 @@ lll_cond_trylock ((mutex)->__data.__lock) #define LLL_MUTEX_TRYLOCK_ELISION(mutex) LLL_MUTEX_TRYLOCK(mutex) -#define LLL_ROBUST_MUTEX_LOCK(mutex, id) \ - lll_robust_cond_lock ((mutex)->__data.__lock, id, \ - PTHREAD_ROBUST_MUTEX_PSHARED (mutex)) +/* We need to assume that there are other threads blocked on the futex. + See __pthread_mutex_lock_full for further details. */ +#define LLL_ROBUST_MUTEX_LOCK_MODIFIER FUTEX_WAITERS #define __pthread_mutex_lock internal_function __pthread_mutex_cond_lock #define __pthread_mutex_lock_full __pthread_mutex_cond_lock_full #define NO_INCR diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c index 1795cc1..9b81f88 100644 --- a/nptl/pthread_mutex_lock.c +++ b/nptl/pthread_mutex_lock.c @@ -36,14 +36,14 @@ #define lll_trylock_elision(a,t) lll_trylock(a) #endif +/* Some of the following definitions differ when pthread_mutex_cond_lock.c + includes this file. */ #ifndef LLL_MUTEX_LOCK # define LLL_MUTEX_LOCK(mutex) \ lll_lock ((mutex)->__data.__lock, PTHREAD_MUTEX_PSHARED (mutex)) # define LLL_MUTEX_TRYLOCK(mutex) \ lll_trylock ((mutex)->__data.__lock) -# define LLL_ROBUST_MUTEX_LOCK(mutex, id) \ - lll_robust_lock ((mutex)->__data.__lock, id, \ - PTHREAD_ROBUST_MUTEX_PSHARED (mutex)) +# define LLL_ROBUST_MUTEX_LOCK_MODIFIER 0 # define LLL_MUTEX_LOCK_ELISION(mutex) \ lll_lock_elision ((mutex)->__data.__lock, (mutex)->__data.__elision, \ PTHREAD_MUTEX_PSHARED (mutex)) @@ -185,11 +185,21 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex) /* This is set to FUTEX_WAITERS iff we might have shared the FUTEX_WAITERS flag with other threads, and therefore need to keep it set to avoid lost wake-ups. We have the same requirement in the - simple mutex algorithm. */ - unsigned int assume_other_futex_waiters = 0; - do + simple mutex algorithm. + We start with value zero for a normal mutex, and FUTEX_WAITERS if we + are building the special case mutexes for use from within condition + variables. */ + unsigned int assume_other_futex_waiters = LLL_ROBUST_MUTEX_LOCK_MODIFIER; + while (1) { - again: + /* Try to acquire the lock through a CAS from 0 (not acquired) to + our TID | assume_other_futex_waiters. */ + if (__glibc_likely ((oldval == 0) + && (atomic_compare_and_exchange_bool_acq + (&mutex->__data.__lock, + id | assume_other_futex_waiters, 0) == 0))) + break; + if ((oldval & FUTEX_OWNER_DIED) != 0) { /* The previous owner died. Try locking the mutex. */ @@ -209,7 +219,7 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex) if (newval != oldval) { oldval = newval; - goto again; + continue; } /* We got the mutex. */ @@ -260,24 +270,47 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex) } } - oldval = LLL_ROBUST_MUTEX_LOCK (mutex, - id | assume_other_futex_waiters); - /* See above. We set FUTEX_WAITERS and might have shared this flag - with other threads; thus, we need to preserve it. */ - assume_other_futex_waiters = FUTEX_WAITERS; - - if (__builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) + /* We cannot acquire the mutex nor has its owner died. Thus, try + to block using futexes. Set FUTEX_WAITERS if necessary so that + other threads are aware that there are potentially threads + blocked on the futex. Restart if oldval changed in the + meantime. */ + if ((oldval & FUTEX_WAITERS) == 0) { - /* This mutex is now not recoverable. */ - mutex->__data.__count = 0; - lll_unlock (mutex->__data.__lock, - PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - return ENOTRECOVERABLE; + if (atomic_compare_and_exchange_bool_acq (&mutex->__data.__lock, + oldval | FUTEX_WAITERS, + oldval) + != 0) + { + oldval = mutex->__data.__lock; + continue; + } + oldval |= FUTEX_WAITERS; } + + /* It is now possible that we share the FUTEX_WAITERS flag with + another thread; therefore, update assume_other_futex_waiters so + that we do not forget about this when handling other cases + above and thus do not cause lost wake-ups. */ + assume_other_futex_waiters |= FUTEX_WAITERS; + + /* Block using the futex and reload current lock value. */ + lll_futex_wait (&mutex->__data.__lock, oldval, + PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); + oldval = mutex->__data.__lock; + } + + /* We have acquired the mutex; check if it is still consistent. */ + if (__builtin_expect (mutex->__data.__owner + == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) + { + /* This mutex is now not recoverable. */ + mutex->__data.__count = 0; + int private = PTHREAD_ROBUST_MUTEX_PSHARED (mutex); + lll_unlock (mutex->__data.__lock, private); + THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); + return ENOTRECOVERABLE; } - while ((oldval & FUTEX_OWNER_DIED) != 0); mutex->__data.__count = 1; ENQUEUE_MUTEX (mutex); diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c index 6915e82..ddd46fe 100644 --- a/nptl/pthread_mutex_timedlock.c +++ b/nptl/pthread_mutex_timedlock.c @@ -147,9 +147,16 @@ pthread_mutex_timedlock (pthread_mutex_t *mutex, set to avoid lost wake-ups. We have the same requirement in the simple mutex algorithm. */ unsigned int assume_other_futex_waiters = 0; - do + while (1) { - again: + /* Try to acquire the lock through a CAS from 0 (not acquired) to + our TID | assume_other_futex_waiters. */ + if (__glibc_likely ((oldval == 0) + && (atomic_compare_and_exchange_bool_acq + (&mutex->__data.__lock, + id | assume_other_futex_waiters, 0) == 0))) + break; + if ((oldval & FUTEX_OWNER_DIED) != 0) { /* The previous owner died. Try locking the mutex. */ @@ -162,7 +169,7 @@ pthread_mutex_timedlock (pthread_mutex_t *mutex, if (newval != oldval) { oldval = newval; - goto again; + continue; } /* We got the mutex. */ @@ -209,30 +216,87 @@ pthread_mutex_timedlock (pthread_mutex_t *mutex, } } - result = lll_robust_timedlock (mutex->__data.__lock, abstime, - id | assume_other_futex_waiters, - PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); - /* See above. We set FUTEX_WAITERS and might have shared this flag - with other threads; thus, we need to preserve it. */ - assume_other_futex_waiters = FUTEX_WAITERS; + /* We are about to block; check whether the timeout is invalid. */ + if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) + return EINVAL; + /* Work around the fact that the kernel rejects negative timeout + values despite them being valid. */ + if (__glibc_unlikely (abstime->tv_sec < 0)) + return ETIMEDOUT; +#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ + || !defined lll_futex_timed_wait_bitset) + struct timeval tv; + struct timespec rt; + + /* Get the current time. */ + (void) __gettimeofday (&tv, NULL); + + /* Compute relative timeout. */ + rt.tv_sec = abstime->tv_sec - tv.tv_sec; + rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; + if (rt.tv_nsec < 0) + { + rt.tv_nsec += 1000000000; + --rt.tv_sec; + } + + /* Already timed out? */ + if (rt.tv_sec < 0) + return ETIMEDOUT; +#endif - if (__builtin_expect (mutex->__data.__owner - == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) + /* We cannot acquire the mutex nor has its owner died. Thus, try + to block using futexes. Set FUTEX_WAITERS if necessary so that + other threads are aware that there are potentially threads + blocked on the futex. Restart if oldval changed in the + meantime. */ + if ((oldval & FUTEX_WAITERS) == 0) { - /* This mutex is now not recoverable. */ - mutex->__data.__count = 0; - lll_unlock (mutex->__data.__lock, - PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); - THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); - return ENOTRECOVERABLE; + if (atomic_compare_and_exchange_bool_acq (&mutex->__data.__lock, + oldval | FUTEX_WAITERS, + oldval) + != 0) + { + oldval = mutex->__data.__lock; + continue; + } + oldval |= FUTEX_WAITERS; } - if (result == ETIMEDOUT || result == EINVAL) - goto out; + /* It is now possible that we share the FUTEX_WAITERS flag with + another thread; therefore, update assume_other_futex_waiters so + that we do not forget about this when handling other cases + above and thus do not cause lost wake-ups. */ + assume_other_futex_waiters |= FUTEX_WAITERS; + + /* Block using the futex. */ +#if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ + || !defined lll_futex_timed_wait_bitset) + lll_futex_timed wait (&mutex->__data.__lock, oldval, + &rt, PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); +#else + int err = lll_futex_timed_wait_bitset (&mutex->__data.__lock, + oldval, abstime, FUTEX_CLOCK_REALTIME, + PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); + /* The futex call timed out. */ + if (err == -ETIMEDOUT) + return -err; +#endif + /* Reload current lock value. */ + oldval = mutex->__data.__lock; + } - oldval = result; + /* We have acquired the mutex; check if it is still consistent. */ + if (__builtin_expect (mutex->__data.__owner + == PTHREAD_MUTEX_NOTRECOVERABLE, 0)) + { + /* This mutex is now not recoverable. */ + mutex->__data.__count = 0; + int private = PTHREAD_ROBUST_MUTEX_PSHARED (mutex); + lll_unlock (mutex->__data.__lock, private); + THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); + return ENOTRECOVERABLE; } - while ((oldval & FUTEX_OWNER_DIED) != 0); mutex->__data.__count = 1; ENQUEUE_MUTEX (mutex); diff --git a/nptl/pthread_mutex_unlock.c b/nptl/pthread_mutex_unlock.c index 130883c..d3b3990 100644 --- a/nptl/pthread_mutex_unlock.c +++ b/nptl/pthread_mutex_unlock.c @@ -96,6 +96,7 @@ internal_function __pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr) { int newowner = 0; + int private; switch (PTHREAD_MUTEX_TYPE (mutex)) { @@ -149,9 +150,14 @@ __pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr) /* One less user. */ --mutex->__data.__nusers; - /* Unlock. */ - lll_robust_unlock (mutex->__data.__lock, - PTHREAD_ROBUST_MUTEX_PSHARED (mutex)); + /* Unlock by setting the lock to 0 (not acquired); if the lock had + FUTEX_WAITERS set previously, then wake any waiters. + The unlock operation must be the last access to the mutex to not + violate the mutex destruction requirements (see __lll_unlock). */ + private = PTHREAD_ROBUST_MUTEX_PSHARED (mutex); + if (__glibc_unlikely ((atomic_exchange_rel (&mutex->__data.__lock, 0) + & FUTEX_WAITERS) != 0)) + lll_futex_wake (&mutex->__data.__lock, 1, private); THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL); break; @@ -234,9 +240,9 @@ __pthread_mutex_unlock_full (pthread_mutex_t *mutex, int decr) to not violate the mutex destruction requirements (see lll_unlock). */ int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP; - int private = (robust - ? PTHREAD_ROBUST_MUTEX_PSHARED (mutex) - : PTHREAD_MUTEX_PSHARED (mutex)); + private = (robust + ? PTHREAD_ROBUST_MUTEX_PSHARED (mutex) + : PTHREAD_MUTEX_PSHARED (mutex)); /* Unlock the mutex using a CAS unless there are futex waiters or our TID is not the value of __lock anymore, in which case we let the kernel take care of the situation. Use release MO in the CAS to diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h index 36a76fa..42d9658 100644 --- a/sysdeps/nptl/lowlevellock.h +++ b/sysdeps/nptl/lowlevellock.h @@ -74,7 +74,6 @@ extern void __lll_lock_wait_private (int *futex) attribute_hidden; extern void __lll_lock_wait (int *futex, int private) attribute_hidden; -extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; /* This is an expression rather than a statement even though its value is void, so that it can be used in a comma expression or as an expression @@ -103,28 +102,6 @@ extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; __lll_lock (&(futex), private) -/* If FUTEX is 0 (not acquired), set to ID (acquired with no waiters) and - return 0. Otherwise, ensure that it is set to FUTEX | FUTEX_WAITERS - (acquired, possibly with waiters) and block until we acquire the lock. - FUTEX will now be ID | FUTEX_WAITERS and we return 0. - If the previous owner of the lock dies before we acquire the lock then FUTEX - will be the value of id as set by the previous owner, with FUTEX_OWNER_DIED - set (FUTEX_WAITERS may or may not be set). We return this value to indicate - that the lock is not acquired. */ -#define __lll_robust_lock(futex, id, private) \ - ({ \ - int *__futex = (futex); \ - int __val = 0; \ - \ - if (__glibc_unlikely \ - (atomic_compare_and_exchange_bool_acq (__futex, id, 0))) \ - __val = __lll_robust_lock_wait (__futex, private); \ - __val; \ - }) -#define lll_robust_lock(futex, id, private) \ - __lll_robust_lock (&(futex), id, private) - - /* This is an expression rather than a statement even though its value is void, so that it can be used in a comma expression or as an expression that's cast to void. */ @@ -142,16 +119,8 @@ extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) -/* As __lll_robust_lock, but set to ID | FUTEX_WAITERS (acquired, possibly with - waiters) if FUTEX is 0. */ -#define lll_robust_cond_lock(futex, id, private) \ - __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private) - - extern int __lll_timedlock_wait (int *futex, const struct timespec *, int private) attribute_hidden; -extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, - int private) attribute_hidden; /* As __lll_lock, but with a timeout. If the timeout occurs then return @@ -170,22 +139,6 @@ extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, __lll_timedlock (&(futex), abstime, private) -/* As __lll_robust_lock, but with a timeout. If the timeout occurs then return - ETIMEDOUT. If ABSTIME is invalid, return EINVAL. */ -#define __lll_robust_timedlock(futex, abstime, id, private) \ - ({ \ - int *__futex = (futex); \ - int __val = 0; \ - \ - if (__glibc_unlikely \ - (atomic_compare_and_exchange_bool_acq (__futex, id, 0))) \ - __val = __lll_robust_timedlock_wait (__futex, abstime, private); \ - __val; \ - }) -#define lll_robust_timedlock(futex, abstime, id, private) \ - __lll_robust_timedlock (&(futex), abstime, id, private) - - /* This is an expression rather than a statement even though its value is void, so that it can be used in a comma expression or as an expression that's cast to void. */ @@ -211,27 +164,6 @@ extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, __lll_unlock (&(futex), private) -/* This is an expression rather than a statement even though its value is - void, so that it can be used in a comma expression or as an expression - that's cast to void. */ -/* Unconditionally set FUTEX to 0 (not acquired), releasing the lock. If FUTEX - had FUTEX_WAITERS set then wake any waiters. The waiter that acquires the - lock will set FUTEX_WAITERS. - Evaluate PRIVATE before releasing the lock so that we do not violate the - mutex destruction requirements (see __lll_unlock). */ -#define __lll_robust_unlock(futex, private) \ - ((void) \ - ({ \ - int *__futex = (futex); \ - int __private = (private); \ - int __oldval = atomic_exchange_rel (__futex, 0); \ - if (__glibc_unlikely (__oldval & FUTEX_WAITERS)) \ - lll_futex_wake (__futex, 1, __private); \ - })) -#define lll_robust_unlock(futex, private) \ - __lll_robust_unlock (&(futex), private) - - #define lll_islocked(futex) \ ((futex) != LLL_LOCK_INITIALIZER) diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/sysdeps/unix/sysv/linux/i386/lowlevellock.h index 31946a5..197bb1f 100644 --- a/sysdeps/unix/sysv/linux/i386/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -132,20 +132,6 @@ } \ }) -#define lll_robust_lock(futex, id, private) \ - ({ int result, ignore1, ignore2; \ - __asm __volatile (LOCK_INSTR "cmpxchgl %1, %2\n\t" \ - "jz 18f\n\t" \ - "1:\tleal %2, %%edx\n" \ - "0:\tmovl %7, %%ecx\n" \ - "2:\tcall __lll_robust_lock_wait\n" \ - "18:" \ - : "=a" (result), "=c" (ignore1), "=m" (futex), \ - "=&d" (ignore2) \ - : "0" (0), "1" (id), "m" (futex), "g" ((int) (private))\ - : "memory"); \ - result; }) - /* Special version of lll_lock which causes the unlock function to always wakeup waiters. */ @@ -165,22 +151,6 @@ }) -#define lll_robust_cond_lock(futex, id, private) \ - ({ int result, ignore1, ignore2; \ - __asm __volatile (LOCK_INSTR "cmpxchgl %1, %2\n\t" \ - "jz 18f\n\t" \ - "1:\tleal %2, %%edx\n" \ - "0:\tmovl %7, %%ecx\n" \ - "2:\tcall __lll_robust_lock_wait\n" \ - "18:" \ - : "=a" (result), "=c" (ignore1), "=m" (futex), \ - "=&d" (ignore2) \ - : "0" (0), "1" (id | FUTEX_WAITERS), "m" (futex), \ - "g" ((int) (private)) \ - : "memory"); \ - result; }) - - #define lll_timedlock(futex, timeout, private) \ ({ int result, ignore1, ignore2, ignore3; \ __asm __volatile (LOCK_INSTR "cmpxchgl %1, %3\n\t" \ @@ -203,21 +173,6 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count, #define lll_timedlock_elision(futex, adapt_count, timeout, private) \ __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private) -#define lll_robust_timedlock(futex, timeout, id, private) \ - ({ int result, ignore1, ignore2, ignore3; \ - __asm __volatile (LOCK_INSTR "cmpxchgl %1, %3\n\t" \ - "jz 18f\n\t" \ - "1:\tleal %3, %%ecx\n" \ - "0:\tmovl %8, %%edx\n" \ - "2:\tcall __lll_robust_timedlock_wait\n" \ - "18:" \ - : "=a" (result), "=c" (ignore1), "=&d" (ignore2), \ - "=m" (futex), "=S" (ignore3) \ - : "0" (0), "1" (id), "m" (futex), "m" (timeout), \ - "4" ((int) (private)) \ - : "memory"); \ - result; }) - #if !IS_IN (libc) || defined UP # define __lll_unlock_asm LOCK_INSTR "subl $1, %0\n\t" #else @@ -255,21 +210,6 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count, } \ }) -#define lll_robust_unlock(futex, private) \ - (void) \ - ({ int ignore, ignore2; \ - __asm __volatile (LOCK_INSTR "andl %3, %0\n\t" \ - "je 18f\n\t" \ - "1:\tleal %0, %%eax\n" \ - "0:\tmovl %5, %%ecx\n" \ - "2:\tcall __lll_unlock_wake\n" \ - "18:" \ - : "=m" (futex), "=&a" (ignore), "=&c" (ignore2) \ - : "i" (FUTEX_WAITERS), "m" (futex), \ - "g" ((int) (private)) \ - : "memory"); \ - }) - #define lll_islocked(futex) \ (futex != LLL_LOCK_INITIALIZER) diff --git a/sysdeps/unix/sysv/linux/i386/lowlevelrobustlock.S b/sysdeps/unix/sysv/linux/i386/lowlevelrobustlock.S deleted file mode 100644 index f3a68c0..0000000 --- a/sysdeps/unix/sysv/linux/i386/lowlevelrobustlock.S +++ /dev/null @@ -1,232 +0,0 @@ -/* Copyright (C) 2002-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper , 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 - . */ - -#include -#include -#include -#include -#include - - .text - -#define FUTEX_WAITERS 0x80000000 -#define FUTEX_OWNER_DIED 0x40000000 - -#ifdef __ASSUME_PRIVATE_FUTEX -# define LOAD_FUTEX_WAIT(reg) \ - xorl $(FUTEX_WAIT | FUTEX_PRIVATE_FLAG), reg -#else -# if FUTEX_WAIT == 0 -# define LOAD_FUTEX_WAIT(reg) \ - xorl $FUTEX_PRIVATE_FLAG, reg ; \ - andl %gs:PRIVATE_FUTEX, reg -# else -# define LOAD_FUTEX_WAIT(reg) \ - xorl $FUTEX_PRIVATE_FLAG, reg ; \ - andl %gs:PRIVATE_FUTEX, reg ; \ - orl $FUTEX_WAIT, reg -# endif -#endif - - .globl __lll_robust_lock_wait - .type __lll_robust_lock_wait,@function - .hidden __lll_robust_lock_wait - .align 16 -__lll_robust_lock_wait: - cfi_startproc - pushl %edx - cfi_adjust_cfa_offset(4) - pushl %ebx - cfi_adjust_cfa_offset(4) - pushl %esi - cfi_adjust_cfa_offset(4) - cfi_offset(%edx, -8) - cfi_offset(%ebx, -12) - cfi_offset(%esi, -16) - - movl %edx, %ebx - xorl %esi, %esi /* No timeout. */ - LOAD_FUTEX_WAIT (%ecx) - -4: movl %eax, %edx - orl $FUTEX_WAITERS, %edx - - testl $FUTEX_OWNER_DIED, %eax - jnz 3f - - cmpl %edx, %eax /* NB: %edx == 2 */ - je 1f - - LOCK - cmpxchgl %edx, (%ebx) - jnz 2f - -1: movl $SYS_futex, %eax - ENTER_KERNEL - - movl (%ebx), %eax - -2: test %eax, %eax - jne 4b - - movl %gs:TID, %edx - orl $FUTEX_WAITERS, %edx - LOCK - cmpxchgl %edx, (%ebx) - jnz 4b - /* NB: %eax == 0 */ - -3: popl %esi - cfi_adjust_cfa_offset(-4) - cfi_restore(%esi) - popl %ebx - cfi_adjust_cfa_offset(-4) - cfi_restore(%ebx) - popl %edx - cfi_adjust_cfa_offset(-4) - cfi_restore(%edx) - ret - cfi_endproc - .size __lll_robust_lock_wait,.-__lll_robust_lock_wait - - - .globl __lll_robust_timedlock_wait - .type __lll_robust_timedlock_wait,@function - .hidden __lll_robust_timedlock_wait - .align 16 -__lll_robust_timedlock_wait: - cfi_startproc - /* Check for a valid timeout value. */ - cmpl $1000000000, 4(%edx) - jae 3f - - pushl %edi - cfi_adjust_cfa_offset(4) - pushl %esi - cfi_adjust_cfa_offset(4) - pushl %ebx - cfi_adjust_cfa_offset(4) - pushl %ebp - cfi_adjust_cfa_offset(4) - cfi_offset(%edi, -8) - cfi_offset(%esi, -12) - cfi_offset(%ebx, -16) - cfi_offset(%ebp, -20) - - /* Stack frame for the timespec and timeval structs. */ - subl $12, %esp - cfi_adjust_cfa_offset(12) - - movl %ecx, %ebp - movl %edx, %edi - -1: movl %eax, 8(%esp) - - /* Get current time. */ - movl %esp, %ebx - xorl %ecx, %ecx - movl $__NR_gettimeofday, %eax - ENTER_KERNEL - - /* Compute relative timeout. */ - movl 4(%esp), %eax - movl $1000, %edx - mul %edx /* Milli seconds to nano seconds. */ - movl (%edi), %ecx - movl 4(%edi), %edx - subl (%esp), %ecx - subl %eax, %edx - jns 4f - addl $1000000000, %edx - subl $1, %ecx -4: testl %ecx, %ecx - js 8f /* Time is already up. */ - - /* Store relative timeout. */ - movl %ecx, (%esp) - movl %edx, 4(%esp) - - movl %ebp, %ebx - - movl 8(%esp), %edx - movl %edx, %eax - orl $FUTEX_WAITERS, %edx - - testl $FUTEX_OWNER_DIED, %eax - jnz 6f - - cmpl %eax, %edx - je 2f - - LOCK - cmpxchgl %edx, (%ebx) - movl $0, %ecx /* Must use mov to avoid changing cc. */ - jnz 5f - -2: - /* Futex call. */ - movl %esp, %esi - movl 20(%esp), %ecx - LOAD_FUTEX_WAIT (%ecx) - movl $SYS_futex, %eax - ENTER_KERNEL - movl %eax, %ecx - - movl (%ebx), %eax - -5: testl %eax, %eax - jne 7f - - movl %gs:TID, %edx - orl $FUTEX_WAITERS, %edx - LOCK - cmpxchgl %edx, (%ebx) - jnz 7f - -6: addl $12, %esp - cfi_adjust_cfa_offset(-12) - popl %ebp - cfi_adjust_cfa_offset(-4) - cfi_restore(%ebp) - popl %ebx - cfi_adjust_cfa_offset(-4) - cfi_restore(%ebx) - popl %esi - cfi_adjust_cfa_offset(-4) - cfi_restore(%esi) - popl %edi - cfi_adjust_cfa_offset(-4) - cfi_restore(%edi) - ret - -3: movl $EINVAL, %eax - ret - - cfi_adjust_cfa_offset(28) - cfi_offset(%edi, -8) - cfi_offset(%esi, -12) - cfi_offset(%ebx, -16) - cfi_offset(%ebp, -20) - /* Check whether the time expired. */ -7: cmpl $-ETIMEDOUT, %ecx - jne 1b - -8: movl $ETIMEDOUT, %eax - jmp 6b - cfi_endproc - .size __lll_robust_timedlock_wait,.-__lll_robust_timedlock_wait diff --git a/sysdeps/unix/sysv/linux/sparc/lowlevellock.h b/sysdeps/unix/sysv/linux/sparc/lowlevellock.h index a0c6f7e..e36fde6 100644 --- a/sysdeps/unix/sysv/linux/sparc/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/sparc/lowlevellock.h @@ -46,7 +46,6 @@ __lll_cond_trylock (int *futex) extern void __lll_lock_wait_private (int *futex) attribute_hidden; extern void __lll_lock_wait (int *futex, int private) attribute_hidden; -extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden; static inline void __attribute__ ((always_inline)) @@ -64,18 +63,6 @@ __lll_lock (int *futex, int private) } #define lll_lock(futex, private) __lll_lock (&(futex), private) -static inline int -__attribute__ ((always_inline)) -__lll_robust_lock (int *futex, int id, int private) -{ - int result = 0; - if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0) - result = __lll_robust_lock_wait (futex, private); - return result; -} -#define lll_robust_lock(futex, id, private) \ - __lll_robust_lock (&(futex), id, private) - static inline void __attribute__ ((always_inline)) __lll_cond_lock (int *futex, int private) @@ -87,14 +74,9 @@ __lll_cond_lock (int *futex, int private) } #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) -#define lll_robust_cond_lock(futex, id, private) \ - __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private) - extern int __lll_timedlock_wait (int *futex, const struct timespec *, int private) attribute_hidden; -extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *, - int private) attribute_hidden; static inline int __attribute__ ((always_inline)) @@ -110,19 +92,6 @@ __lll_timedlock (int *futex, const struct timespec *abstime, int private) #define lll_timedlock(futex, abstime, private) \ __lll_timedlock (&(futex), abstime, private) -static inline int -__attribute__ ((always_inline)) -__lll_robust_timedlock (int *futex, const struct timespec *abstime, - int id, int private) -{ - int result = 0; - if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0) - result = __lll_robust_timedlock_wait (futex, abstime, private); - return result; -} -#define lll_robust_timedlock(futex, abstime, id, private) \ - __lll_robust_timedlock (&(futex), abstime, id, private) - #define lll_unlock(lock, private) \ ((void) ({ \ int *__futex = &(lock); \ @@ -132,15 +101,6 @@ __lll_robust_timedlock (int *futex, const struct timespec *abstime, lll_futex_wake (__futex, 1, __private); \ })) -#define lll_robust_unlock(lock, private) \ - ((void) ({ \ - int *__futex = &(lock); \ - int __private = (private); \ - int __val = atomic_exchange_rel (__futex, 0); \ - if (__glibc_unlikely (__val & FUTEX_WAITERS)) \ - lll_futex_wake (__futex, 1, __private); \ - })) - #define lll_islocked(futex) \ (futex != 0) diff --git a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h index 70421ff..cbf6597 100644 --- a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h @@ -136,23 +136,6 @@ : "cx", "r11", "cc", "memory"); \ }) \ -#define lll_robust_lock(futex, id, private) \ - ({ int result, ignore1, ignore2; \ - __asm __volatile (LOCK_INSTR "cmpxchgl %4, %2\n\t" \ - "jz 24f\n" \ - "1:\tlea %2, %%" RDI_LP "\n" \ - "2:\tsub $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset 128\n" \ - "3:\tcallq __lll_robust_lock_wait\n" \ - "4:\tadd $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset -128\n" \ - "24:" \ - : "=S" (ignore1), "=D" (ignore2), "=m" (futex), \ - "=a" (result) \ - : "1" (id), "m" (futex), "3" (0), "0" (private) \ - : "cx", "r11", "cc", "memory"); \ - result; }) - #define lll_cond_lock(futex, private) \ (void) \ ({ int ignore1, ignore2, ignore3; \ @@ -171,24 +154,6 @@ : "cx", "r11", "cc", "memory"); \ }) -#define lll_robust_cond_lock(futex, id, private) \ - ({ int result, ignore1, ignore2; \ - __asm __volatile (LOCK_INSTR "cmpxchgl %4, %2\n\t" \ - "jz 24f\n" \ - "1:\tlea %2, %%" RDI_LP "\n" \ - "2:\tsub $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset 128\n" \ - "3:\tcallq __lll_robust_lock_wait\n" \ - "4:\tadd $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset -128\n" \ - "24:" \ - : "=S" (ignore1), "=D" (ignore2), "=m" (futex), \ - "=a" (result) \ - : "1" (id | FUTEX_WAITERS), "m" (futex), "3" (0), \ - "0" (private) \ - : "cx", "r11", "cc", "memory"); \ - result; }) - #define lll_timedlock(futex, timeout, private) \ ({ int result, ignore1, ignore2, ignore3; \ __asm __volatile (LOCK_INSTR "cmpxchgl %1, %4\n\t" \ @@ -215,25 +180,6 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count, #define lll_timedlock_elision(futex, adapt_count, timeout, private) \ __lll_timedlock_elision(&(futex), &(adapt_count), timeout, private) -#define lll_robust_timedlock(futex, timeout, id, private) \ - ({ int result, ignore1, ignore2, ignore3; \ - __asm __volatile (LOCK_INSTR "cmpxchgl %1, %4\n\t" \ - "jz 24f\n\t" \ - "1:\tlea %4, %%" RDI_LP "\n" \ - "0:\tmov %8, %%" RDX_LP "\n" \ - "2:\tsub $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset 128\n" \ - "3:\tcallq __lll_robust_timedlock_wait\n" \ - "4:\tadd $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset -128\n" \ - "24:" \ - : "=a" (result), "=D" (ignore1), "=S" (ignore2), \ - "=&d" (ignore3), "=m" (futex) \ - : "0" (0), "1" (id), "m" (futex), "m" (timeout), \ - "2" (private) \ - : "memory", "cx", "cc", "r10", "r11"); \ - result; }) - #if !IS_IN (libc) || defined UP # define __lll_unlock_asm_start LOCK_INSTR "decl %0\n\t" \ "je 24f\n\t" @@ -276,26 +222,6 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count, : "ax", "cx", "r11", "cc", "memory"); \ }) -#define lll_robust_unlock(futex, private) \ - do \ - { \ - int ignore; \ - __asm __volatile (LOCK_INSTR "andl %2, %0\n\t" \ - "je 24f\n\t" \ - "1:\tlea %0, %%" RDI_LP "\n" \ - "2:\tsub $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset 128\n" \ - "3:\tcallq __lll_unlock_wake\n" \ - "4:\tadd $128, %%" RSP_LP "\n" \ - ".cfi_adjust_cfa_offset -128\n" \ - "24:" \ - : "=m" (futex), "=&D" (ignore) \ - : "i" (FUTEX_WAITERS), "m" (futex), \ - "S" (private) \ - : "ax", "cx", "r11", "cc", "memory"); \ - } \ - while (0) - #define lll_islocked(futex) \ (futex != LLL_LOCK_INITIALIZER) diff --git a/sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S b/sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S deleted file mode 100644 index e901ec4..0000000 --- a/sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S +++ /dev/null @@ -1,306 +0,0 @@ -/* Copyright (C) 2002-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper , 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 - . */ - -#include -#include -#include -#include -#include - - .text - -#define FUTEX_WAITERS 0x80000000 -#define FUTEX_OWNER_DIED 0x40000000 - -#ifdef __ASSUME_PRIVATE_FUTEX -# 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 -#else -# 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 -#endif - - - .globl __lll_robust_lock_wait - .type __lll_robust_lock_wait,@function - .hidden __lll_robust_lock_wait - .align 16 -__lll_robust_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. */ - LOAD_FUTEX_WAIT (%esi) - -4: movl %eax, %edx - orl $FUTEX_WAITERS, %edx - - testl $FUTEX_OWNER_DIED, %eax - jnz 3f - - cmpl %edx, %eax - je 1f - - LOCK - cmpxchgl %edx, (%rdi) - jnz 2f - -1: movl $SYS_futex, %eax - syscall - - movl (%rdi), %eax - -2: testl %eax, %eax - jne 4b - - movl %fs:TID, %edx - orl $FUTEX_WAITERS, %edx - LOCK - cmpxchgl %edx, (%rdi) - jnz 4b - /* NB: %rax == 0 */ - -3: 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_robust_lock_wait,.-__lll_robust_lock_wait - - - .globl __lll_robust_timedlock_wait - .type __lll_robust_timedlock_wait,@function - .hidden __lll_robust_timedlock_wait - .align 16 -__lll_robust_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 7f - - pushq %r9 - cfi_adjust_cfa_offset(8) - cfi_rel_offset(%r9, 0) - movq %rdx, %r10 - movl $0xffffffff, %r9d - LOAD_FUTEX_WAIT_ABS (%esi) - -1: testl $FUTEX_OWNER_DIED, %eax - jnz 3f - - movl %eax, %edx - orl $FUTEX_WAITERS, %edx - - cmpl %eax, %edx - je 5f - - LOCK - cmpxchgl %edx, (%rdi) - movq $0, %rcx /* Must use mov to avoid changing cc. */ - jnz 6f - -5: movl $SYS_futex, %eax - syscall - movl %eax, %ecx - - movl (%rdi), %eax - -6: testl %eax, %eax - jne 2f - - movl %fs:TID, %edx - orl $FUTEX_WAITERS, %edx - LOCK - cmpxchgl %edx, (%rdi) - jnz 2f - -3: popq %r9 - cfi_adjust_cfa_offset(-8) - cfi_restore(%r9) - retq - - cfi_adjust_cfa_offset(8) - cfi_rel_offset(%r9, 0) - /* Check whether the time expired. */ -2: cmpl $-ETIMEDOUT, %ecx - je 4f - cmpl $-EINVAL, %ecx - jne 1b - -4: movl %ecx, %eax - negl %eax - jmp 3b - cfi_adjust_cfa_offset(-8) - cfi_restore(%r9) - -7: 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) - cfi_offset(%r8, -16) - cfi_offset(%r9, -24) - cfi_offset(%r12, -32) - cfi_offset(%r13, -40) - pushq %rsi - cfi_adjust_cfa_offset(8) - - /* Stack frame for the timespec and timeval structs. */ - subq $32, %rsp - cfi_adjust_cfa_offset(32) - - movq %rdi, %r12 - movq %rdx, %r13 - -1: movq %rax, 16(%rsp) - - /* 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 8f /* Time is already up. */ - - /* Futex call. */ - movq %rdi, (%rsp) /* Store relative timeout. */ - movq %rsi, 8(%rsp) - - movq 16(%rsp), %rdx - movl %edx, %eax - orl $FUTEX_WAITERS, %edx - - testl $FUTEX_OWNER_DIED, %eax - jnz 6f - - cmpl %eax, %edx - je 2f - - LOCK - cmpxchgl %edx, (%r12) - movq $0, %rcx /* Must use mov to avoid changing cc. */ - jnz 5f - -2: movq %rsp, %r10 - movl 32(%rsp), %esi - LOAD_FUTEX_WAIT (%esi) - movq %r12, %rdi - movl $SYS_futex, %eax - syscall - movq %rax, %rcx - - movl (%r12), %eax - -5: testl %eax, %eax - jne 7f - - movl %fs:TID, %edx - orl $FUTEX_WAITERS, %edx - LOCK - cmpxchgl %edx, (%r12) - jnz 7f - -6: addq $40, %rsp - cfi_adjust_cfa_offset(-40) - 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) - retq - -3: movl $EINVAL, %eax - retq - - cfi_adjust_cfa_offset(72) - cfi_offset(%r8, -16) - cfi_offset(%r9, -24) - cfi_offset(%r12, -32) - cfi_offset(%r13, -40) - /* Check whether the time expired. */ -7: cmpl $-ETIMEDOUT, %ecx - jne 1b - -8: movl $ETIMEDOUT, %eax - jmp 6b -#endif - cfi_endproc - .size __lll_robust_timedlock_wait,.-__lll_robust_timedlock_wait