nptl: Cleanup cancellation macros

This patch wraps all uses of *_{enable,disable}_asynccancel and
and *_CANCEL_{ASYNC,RESET} in either already provided macros
(lll_futex_timed_wait_cancel) or creates new ones if the
functionality is not provided (SYSCALL_CANCEL_NCS, lll_futex_wait_cancel,
and lll_futex_timed_wait_cancel).

Also for some generic implementations, the direct call of the macros
are removed since the underlying symbols are suppose to provide
cancellation support.

This is a priliminary patch intended to simplify the work required
for BZ#12683 fix.  It is a refactor change, no semantic changes are
expected.

Checked on x86_64-linux-gnu and i686-linux-gnu.

	* nptl/pthread_join_common.c (__pthread_timedjoin_ex): Use
	lll_wait_tid with timeout.
	* nptl/sem_wait.c (__old_sem_wait): Use lll_futex_wait_cancel.
	* sysdeps/nptl/aio_misc.h (AIO_MISC_WAIT): Use
	futex_reltimed_wait_cancelable for cancelabla mode.
	* sysdeps/nptl/gai_misc.h (GAI_MISC_WAIT): Likewise.
	* sysdeps/posix/open64.c (__libc_open64): Do not call cancelation
	macros.
	* sysdeps/posix/sigwait.c (__sigwait): Likewise.
	* sysdeps/posix/waitid.c (__sigwait): Likewise.
	* sysdeps/unix/sysdep.h (__SYSCALL_CANCEL_CALL,
	SYSCALL_CANCEL_NCS): New macro.
	* sysdeps/nptl/lowlevellock.h (lll_wait_tid): Add timeout argument.
	(lll_timedwait_tid): Remove macro.
	* sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_wait_tid):
	Likewise.
	(lll_timedwait_tid): Likewise.
	* sysdeps/unix/sysv/linux/sparc/lowlevellock.h (lll_wait_tid):
	Likewise.
	(lll_timedwait_tid): Likewise.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_wait_tid):
	Likewise.
	(lll_timedwait_tid): Likewise.
	* sysdeps/unix/sysv/linux/clock_nanosleep.c (__clock_nanosleep):
	Use INTERNAL_SYSCALL_CANCEL.
	* sysdeps/unix/sysv/linux/futex-internal.h
	(futex_reltimed_wait_cancelable): Use LIBC_CANCEL_{ASYNC,RESET}
	instead of __pthread_{enable,disable}_asynccancel.
	* sysdeps/unix/sysv/linux/lowlevellock-futex.h
	(lll_futex_wait_cancel): New macro.

15 files changed, 146 insertions, 164 deletions

diff --git a/ChangeLog b/ChangeLog
index 159808db85..c7b2feb21b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,36 @@
 2019-01-03  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
+	* nptl/pthread_join_common.c (__pthread_timedjoin_ex): Use
+	lll_wait_tid with timeout.
+	* nptl/sem_wait.c (__old_sem_wait): Use lll_futex_wait_cancel.
+	* sysdeps/nptl/aio_misc.h (AIO_MISC_WAIT): Use
+	futex_reltimed_wait_cancelable for cancelabla mode.
+	* sysdeps/nptl/gai_misc.h (GAI_MISC_WAIT): Likewise.
+	* sysdeps/posix/open64.c (__libc_open64): Do not call cancelation
+	macros.
+	* sysdeps/posix/sigwait.c (__sigwait): Likewise.
+	* sysdeps/posix/waitid.c (__sigwait): Likewise.
+	* sysdeps/unix/sysdep.h (__SYSCALL_CANCEL_CALL,
+	SYSCALL_CANCEL_NCS): New macro.
+	* sysdeps/nptl/lowlevellock.h (lll_wait_tid): Add timeout argument.
+	(lll_timedwait_tid): Remove macro.
+	* sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_wait_tid):
+	Likewise.
+	(lll_timedwait_tid): Likewise.
+	* sysdeps/unix/sysv/linux/sparc/lowlevellock.h (lll_wait_tid):
+	Likewise.
+	(lll_timedwait_tid): Likewise.
+	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_wait_tid):
+	Likewise.
+	(lll_timedwait_tid): Likewise.
+	* sysdeps/unix/sysv/linux/clock_nanosleep.c (__clock_nanosleep):
+	Use INTERNAL_SYSCALL_CANCEL.
+	* sysdeps/unix/sysv/linux/futex-internal.h
+	(futex_reltimed_wait_cancelable): Use LIBC_CANCEL_{ASYNC,RESET}
+	instead of __pthread_{enable,disable}_asynccancel.
+	* sysdeps/unix/sysv/linux/lowlevellock-futex.h
+	(lll_futex_wait_cancel): New macro.
+
 	* sysdeps/i386/nptl/tls.h (THREAD_ATOMIC_CMPXCHG_VAL,
 	THREAD_ATOMIC_AND, THREAD_ATOMIC_BIT_SET): Remove macros.
 
diff --git a/nptl/pthread_join_common.c b/nptl/pthread_join_common.c
index 260fed4cfb..ecb78ffba5 100644
--- a/nptl/pthread_join_common.c
+++ b/nptl/pthread_join_common.c
@@ -81,14 +81,7 @@ __pthread_timedjoin_ex (pthread_t threadid, void **thread_return,
 	 un-wait-ed for again.  */
       pthread_cleanup_push (cleanup, &pd->joinid);
 
-      int oldtype = CANCEL_ASYNC ();
-
-      if (abstime != NULL)
-	result = lll_timedwait_tid (pd->tid, abstime);
-      else
-	lll_wait_tid (pd->tid);
-
-      CANCEL_RESET (oldtype);
+      result = lll_wait_tid (pd->tid, abstime);
 
       pthread_cleanup_pop (0);
     }
diff --git a/nptl/sem_wait.c b/nptl/sem_wait.c
index 61bdd9bf4f..6a2d26bd1a 100644
--- a/nptl/sem_wait.c
+++ b/nptl/sem_wait.c
@@ -56,14 +56,8 @@ __old_sem_wait (sem_t *sem)
       if (atomic_decrement_if_positive (futex) > 0)
 	return 0;
 
-      /* Enable asynchronous cancellation.  Required by the standard.  */
-      int oldtype = __pthread_enable_asynccancel ();
-
       /* Always assume the semaphore is shared.  */
-      err = lll_futex_wait (futex, 0, LLL_SHARED);
-
-      /* Disable asynchronous cancellation.  */
-      __pthread_disable_asynccancel (oldtype);
+      err = lll_futex_wait_cancel (futex, 0, LLL_SHARED);
     }
   while (err == 0 || err == -EWOULDBLOCK);
 
diff --git a/sysdeps/nptl/aio_misc.h b/sysdeps/nptl/aio_misc.h
index 8c10021089..c5d829e47c 100644
--- a/sysdeps/nptl/aio_misc.h
+++ b/sysdeps/nptl/aio_misc.h
@@ -41,15 +41,15 @@
       {									      \
 	pthread_mutex_unlock (&__aio_requests_mutex);			      \
 									      \
-	int oldtype;							      \
-	if (cancel)							      \
-	  oldtype = LIBC_CANCEL_ASYNC ();				      \
-									      \
 	int status;							      \
 	do								      \
 	  {								      \
-	    status = futex_reltimed_wait ((unsigned int *) futexaddr, oldval, \
-					  timeout, FUTEX_PRIVATE);	      \
+	    if (cancel)							      \
+	      status = futex_reltimed_wait_cancelable (			      \
+		(unsigned int *) futexaddr, oldval, timeout, FUTEX_PRIVATE);  \
+	    else							      \
+	      status = futex_reltimed_wait ((unsigned int *) futexaddr,	      \
+		oldval, timeout, FUTEX_PRIVATE);	      		      \
 	    if (status != EAGAIN)					      \
 	      break;							      \
 									      \
@@ -57,9 +57,6 @@
 	  }								      \
 	while (oldval != 0);						      \
 									      \
-	if (cancel)							      \
-	  LIBC_CANCEL_RESET (oldtype);					      \
-									      \
 	if (status == EINTR)						      \
 	  result = EINTR;						      \
 	else if (status == ETIMEDOUT)					      \
diff --git a/sysdeps/nptl/gai_misc.h b/sysdeps/nptl/gai_misc.h
index 5632bad454..a3492c7c48 100644
--- a/sysdeps/nptl/gai_misc.h
+++ b/sysdeps/nptl/gai_misc.h
@@ -42,15 +42,15 @@
       {									      \
 	pthread_mutex_unlock (&__gai_requests_mutex);			      \
 									      \
-	int oldtype;							      \
-	if (cancel)							      \
-	  oldtype = LIBC_CANCEL_ASYNC ();				      \
-									      \
 	int status;							      \
 	do								      \
 	  {								      \
-	    status = futex_reltimed_wait ((unsigned int *) futexaddr, oldval, \
-					  timeout, FUTEX_PRIVATE);	      \
+	    if (cancel)							      \
+	      status = futex_reltimed_wait_cancelable (			      \
+		(unsigned int *) futexaddr, oldval, timeout, FUTEX_PRIVATE);  \
+	    else							      \
+	      status = futex_reltimed_wait ((unsigned int *) futexaddr,	      \
+		oldval, timeout, FUTEX_PRIVATE);	      		      \
 	    if (status != EAGAIN)					      \
 	      break;							      \
 									      \
@@ -58,9 +58,6 @@
 	  }								      \
 	while (oldval != 0);						      \
 									      \
-	if (cancel)							      \
-	  LIBC_CANCEL_RESET (oldtype);					      \
-									      \
 	if (status == EINTR)						      \
 	  result = EINTR;						      \
 	else if (status == ETIMEDOUT)					      \
diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h
index 45dc1ea470..36bbc472e7 100644
--- a/sysdeps/nptl/lowlevellock.h
+++ b/sysdeps/nptl/lowlevellock.h
@@ -175,33 +175,29 @@ extern int __lll_timedlock_wait (int *futex, const struct timespec *,
 #define LLL_LOCK_INITIALIZER		(0)
 #define LLL_LOCK_INITIALIZER_LOCKED	(1)
 
+extern int __lll_timedwait_tid (int *, const struct timespec *)
+     attribute_hidden;
 
 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
    wake-up when the clone terminates.  The memory location contains the
    thread ID while the clone is running and is reset to zero by the kernel
    afterwards.  The kernel up to version 3.16.3 does not use the private futex
-   operations for futex wake-up when the clone terminates.  */
-#define lll_wait_tid(tid)				\
-  do {							\
-    __typeof (tid) __tid;				\
-    /* We need acquire MO here so that we synchronize	\
-       with the kernel's store to 0 when the clone	\
-       terminates. (see above)  */			\
-    while ((__tid = atomic_load_acquire (&(tid))) != 0)	\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);	\
-  } while (0)
-
-extern int __lll_timedwait_tid (int *, const struct timespec *)
-     attribute_hidden;
-
-/* As lll_wait_tid, but with a timeout.  If the timeout occurs then return
-   ETIMEDOUT.  If ABSTIME is invalid, return EINVAL.  */
-#define lll_timedwait_tid(tid, abstime) \
-  ({							\
-    int __res = 0;					\
-    if ((tid) != 0)					\
-      __res = __lll_timedwait_tid (&(tid), (abstime));	\
-    __res;						\
+   operations for futex wake-up when the clone terminates.
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
+   The futex operation are issues with cancellable versions.  */
+#define lll_wait_tid(tid, abstime)					\
+  ({									\
+    int __res = 0;							\
+    __typeof (tid) __tid;						\
+    if (abstime != NULL)						\
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
+    else								\
+      /* We need acquire MO here so that we synchronize with the 	\
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
+    __res;								\
   })
 
 
diff --git a/sysdeps/posix/open64.c b/sysdeps/posix/open64.c
index b0bfd39abc..c84f4fa85a 100644
--- a/sysdeps/posix/open64.c
+++ b/sysdeps/posix/open64.c
@@ -34,16 +34,8 @@ __libc_open64 (const char *file, int oflag, ...)
       va_end (arg);
     }
 
-  if (SINGLE_THREAD_P)
-    return __libc_open (file, oflag | O_LARGEFILE, mode);
-
-  int oldtype = LIBC_CANCEL_ASYNC ();
-
-  int result = __libc_open (file, oflag | O_LARGEFILE, mode);
-
-  LIBC_CANCEL_RESET (oldtype);
-
-  return result;
+  /* __libc_open should be a cancellation point.  */
+  return __libc_open (file, oflag | O_LARGEFILE, mode);
 }
 weak_alias (__libc_open64, __open64)
 libc_hidden_weak (__open64)
diff --git a/sysdeps/posix/sigwait.c b/sysdeps/posix/sigwait.c
index 6f8678a09e..c157df80de 100644
--- a/sysdeps/posix/sigwait.c
+++ b/sysdeps/posix/sigwait.c
@@ -85,16 +85,8 @@ do_sigwait (const sigset_t *set, int *sig)
 int
 __sigwait (const sigset_t *set, int *sig)
 {
-  if (SINGLE_THREAD_P)
-    return do_sigwait (set, sig);
-
-  int oldtype = LIBC_CANCEL_ASYNC ();
-
-  int result = do_sigwait (set, sig);
-
-  LIBC_CANCEL_RESET (oldtype);
-
-  return result;
+  /* __sigsuspend should be a cancellation point.  */
+  return do_sigitid (idtype, id, infop, options);
 }
 libc_hidden_def (__sigwait)
 weak_alias (__sigwait, sigwait)
diff --git a/sysdeps/posix/waitid.c b/sysdeps/posix/waitid.c
index de82049c21..d49a2f7883 100644
--- a/sysdeps/posix/waitid.c
+++ b/sysdeps/posix/waitid.c
@@ -151,16 +151,8 @@ OUR_WAITID (idtype_t idtype, id_t id, siginfo_t *infop, int options)
 int
 __waitid (idtype_t idtype, id_t id, siginfo_t *infop, int options)
 {
-  if (SINGLE_THREAD_P)
-    return do_waitid (idtype, id, infop, options);
-
-  int oldtype = LIBC_CANCEL_ASYNC ();
-
-  int result = do_waitid (idtype, id, infop, options);
-
-  LIBC_CANCEL_RESET (oldtype);
-
-  return result;
+  /* __waitpid should be a cancellation point.  */
+  return do_waitid (idtype, id, infop, options);
 }
 weak_alias (__waitid, waitid)
 strong_alias (__waitid, __libc_waitid)
diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c b/sysdeps/unix/sysv/linux/clock_nanosleep.c
index 0f6dd5d359..0cb6614dc9 100644
--- a/sysdeps/unix/sysv/linux/clock_nanosleep.c
+++ b/sysdeps/unix/sysv/linux/clock_nanosleep.c
@@ -28,26 +28,16 @@ int
 __clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
 		   struct timespec *rem)
 {
-  INTERNAL_SYSCALL_DECL (err);
-  int r;
-
   if (clock_id == CLOCK_THREAD_CPUTIME_ID)
     return EINVAL;
   if (clock_id == CLOCK_PROCESS_CPUTIME_ID)
     clock_id = MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED);
 
-  if (SINGLE_THREAD_P)
-    r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req, rem);
-  else
-    {
-      int oldstate = LIBC_CANCEL_ASYNC ();
-
-      r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req,
-			    rem);
-
-      LIBC_CANCEL_RESET (oldstate);
-    }
-
+  /* If the call is interrupted by a signal handler or encounters an error,
+     it returns a positive value similar to errno.  */
+  INTERNAL_SYSCALL_DECL (err);
+  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
+				   req, rem);
   return (INTERNAL_SYSCALL_ERROR_P (r, err)
 	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
 }
diff --git a/sysdeps/unix/sysv/linux/futex-internal.h b/sysdeps/unix/sysv/linux/futex-internal.h
index 4620a5b31c..55f0fab77c 100644
--- a/sysdeps/unix/sysv/linux/futex-internal.h
+++ b/sysdeps/unix/sysv/linux/futex-internal.h
@@ -138,9 +138,9 @@ futex_reltimed_wait_cancelable (unsigned int *futex_word,
 			        const struct timespec *reltime, int private)
 {
   int oldtype;
-  oldtype = __pthread_enable_asynccancel ();
+  oldtype = LIBC_CANCEL_ASYNC ();
   int err = lll_futex_timed_wait (futex_word, expected, reltime, private);
-  __pthread_disable_asynccancel (oldtype);
+  LIBC_CANCEL_RESET (oldtype);
   switch (err)
     {
     case 0:
diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/sysdeps/unix/sysv/linux/i386/lowlevellock.h
index 6fef23d16d..63d58aef00 100644
--- a/sysdeps/unix/sysv/linux/i386/lowlevellock.h
+++ b/sysdeps/unix/sysv/linux/i386/lowlevellock.h
@@ -221,32 +221,30 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count,
 #define lll_islocked(futex) \
   (futex != LLL_LOCK_INITIALIZER)
 
+extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime)
+     __attribute__ ((regparm (2))) attribute_hidden;
+
 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
    wake-up when the clone terminates.  The memory location contains the
    thread ID while the clone is running and is reset to zero by the kernel
    afterwards.  The kernel up to version 3.16.3 does not use the private futex
-   operations for futex wake-up when the clone terminates.  */
-#define lll_wait_tid(tid) \
-  do {					\
-    __typeof (tid) __tid;		\
-    while ((__tid = (tid)) != 0)	\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);\
-  } while (0)
-
-extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime)
-     __attribute__ ((regparm (2))) attribute_hidden;
-
-/* As lll_wait_tid, but with a timeout.  If the timeout occurs then return
-   ETIMEDOUT.  If ABSTIME is invalid, return EINVAL.
-   XXX Note that this differs from the generic version in that we do the
-   error checking here and not in __lll_timedwait_tid.  */
-#define lll_timedwait_tid(tid, abstime) \
-  ({									      \
-    int __result = 0;							      \
-    if ((tid) != 0)							      \
-      __result = __lll_timedwait_tid (&(tid), (abstime));		      \
-    __result; })
-
+   operations for futex wake-up when the clone terminates.
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
+   The futex operation are issues with cancellable versions.  */
+#define lll_wait_tid(tid, abstime)					\
+  ({									\
+    int __res = 0;							\
+    __typeof (tid) __tid;						\
+    if (abstime != NULL)						\
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
+    else								\
+      /* We need acquire MO here so that we synchronize with the 	\
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
+    __res;								\
+  })
 
 extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
   attribute_hidden;
diff --git a/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
index 59e6fd3b8c..8ca3417aaa 100644
--- a/sysdeps/unix/sysv/linux/lowlevellock-futex.h
+++ b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
@@ -125,6 +125,17 @@
 					 private),                      \
 		     nr_wake, nr_move, mutex, val)
 
+
+/* Cancellable futex macros.  */
+#define lll_futex_wait_cancel(futexp, val, private) \
+  ({                                                                   \
+    int __oldtype = CANCEL_ASYNC ();				       \
+    long int __err = lll_futex_wait (futexp, val, LLL_SHARED);	       \
+    CANCEL_RESET (__oldtype);					       \
+    __err;							       \
+  })
+
+
 #endif  /* !__ASSEMBLER__  */
 
 #endif  /* lowlevellock-futex.h */
diff --git a/sysdeps/unix/sysv/linux/sparc/lowlevellock.h b/sysdeps/unix/sysv/linux/sparc/lowlevellock.h
index 47946c3eb5..5aed572d43 100644
--- a/sysdeps/unix/sysv/linux/sparc/lowlevellock.h
+++ b/sysdeps/unix/sysv/linux/sparc/lowlevellock.h
@@ -108,28 +108,29 @@ __lll_timedlock (int *futex, const struct timespec *abstime, int private)
 #define LLL_LOCK_INITIALIZER		(0)
 #define LLL_LOCK_INITIALIZER_LOCKED	(1)
 
-/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
-   wakeup when the clone terminates.  The memory location contains the
-   thread ID while the clone is running and is reset to zero
-   afterwards.	*/
-#define lll_wait_tid(tid) \
-  do							\
-    {							\
-      __typeof (tid) __tid;				\
-      while ((__tid = (tid)) != 0)			\
-	lll_futex_wait (&(tid), __tid, LLL_SHARED);	\
-    }							\
-  while (0)
-
 extern int __lll_timedwait_tid (int *, const struct timespec *)
      attribute_hidden;
 
-#define lll_timedwait_tid(tid, abstime) \
-  ({							\
-    int __res = 0;					\
-    if ((tid) != 0)					\
-      __res = __lll_timedwait_tid (&(tid), (abstime));	\
-    __res;						\
+/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
+   wake-up when the clone terminates.  The memory location contains the
+   thread ID while the clone is running and is reset to zero by the kernel
+   afterwards.  The kernel up to version 3.16.3 does not use the private futex
+   operations for futex wake-up when the clone terminates.
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
+   The futex operation are issues with cancellable versions.  */
+#define lll_wait_tid(tid, abstime)					\
+  ({									\
+    int __res = 0;							\
+    __typeof (tid) __tid;						\
+    if (abstime != NULL)						\
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
+    else								\
+      /* We need acquire MO here so that we synchronize with the 	\
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
+    __res;								\
   })
 
 #endif	/* lowlevellock.h */
diff --git a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
index e44a33f4c3..563b297655 100644
--- a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
+++ b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
@@ -224,32 +224,30 @@ extern int __lll_timedlock_elision (int *futex, short *adapt_count,
 #define lll_islocked(futex) \
   (futex != LLL_LOCK_INITIALIZER)
 
+extern int __lll_timedwait_tid (int *, const struct timespec *)
+     attribute_hidden;
 
 /* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
    wake-up when the clone terminates.  The memory location contains the
    thread ID while the clone is running and is reset to zero by the kernel
    afterwards.  The kernel up to version 3.16.3 does not use the private futex
-   operations for futex wake-up when the clone terminates.  */
-#define lll_wait_tid(tid) \
-  do {					\
-    __typeof (tid) __tid;		\
-    while ((__tid = (tid)) != 0)	\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);\
-  } while (0)
-
-extern int __lll_timedwait_tid (int *, const struct timespec *)
-     attribute_hidden;
-
-/* As lll_wait_tid, but with a timeout.  If the timeout occurs then return
-   ETIMEDOUT.  If ABSTIME is invalid, return EINVAL.
-   XXX Note that this differs from the generic version in that we do the
-   error checking here and not in __lll_timedwait_tid.  */
-#define lll_timedwait_tid(tid, abstime) \
-  ({									      \
-    int __result = 0;							      \
-    if ((tid) != 0)							      \
-      __result = __lll_timedwait_tid (&(tid), (abstime));		      \
-    __result; })
+   operations for futex wake-up when the clone terminates.
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
+   The futex operation are issues with cancellable versions.  */
+#define lll_wait_tid(tid, abstime)					\
+  ({									\
+    int __res = 0;							\
+    __typeof (tid) __tid;						\
+    if (abstime != NULL)						\
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
+    else								\
+      /* We need acquire MO here so that we synchronize with the 	\
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
+    __res;								\
+  })
 
 extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
   attribute_hidden;