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Re: [PATCH] [BZ #20985] robust mutexes: Fix broken x86 assembly by removing it


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 <triegel@redhat.com>
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 <jakub@redhat.com>, 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
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <sysdep.h>
-#include <lowlevellock.h>
-#include <sys/time.h>
-#include <pthreadP.h>
-#include <kernel-features.h>
-
-
-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 <stddef.h>
-#include <pthreadP.h>
-
---
-
-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 <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 <lowlevellock.h>
-#include <lowlevelrobustlock.h>
-#include <kernel-features.h>
-
-	.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 <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 <lowlevellock.h>
-#include <lowlevelrobustlock.h>
-#include <kernel-features.h>
-
-	.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

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