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.

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.
 

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 ();
+      result = lll_wait_tid (pd->tid, abstime);
-
-      if (abstime != NULL)
-	result = lll_timedwait_tid (pd->tid, abstime);
-      else
-	lll_wait_tid (pd->tid);
-
-      CANCEL_RESET (oldtype);
 
       pthread_cleanup_pop (0);
     }

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);
+      err = lll_futex_wait_cancel (futex, 0, LLL_SHARED);
-
-      /* Disable asynchronous cancellation.  */
-      __pthread_disable_asynccancel (oldtype);
     }
   while (err == 0 || err == -EWOULDBLOCK);
 

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, \
+	    if (cancel)							      \
-					  timeout, FUTEX_PRIVATE);	      \
+	      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)					      \

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, \
+	    if (cancel)							      \
-					  timeout, FUTEX_PRIVATE);	      \
+	      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)					      \

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.  */
+   operations for futex wake-up when the clone terminates.
-#define lll_wait_tid(tid)				\
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
-  do {							\
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
-    __typeof (tid) __tid;				\
+   The futex operation are issues with cancellable versions.  */
-    /* We need acquire MO here so that we synchronize	\
+#define lll_wait_tid(tid, abstime)					\
-       with the kernel's store to 0 when the clone	\
+  ({									\
-       terminates. (see above)  */			\
+    int __res = 0;							\
-    while ((__tid = atomic_load_acquire (&(tid))) != 0)	\
+    __typeof (tid) __tid;						\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);	\
+    if (abstime != NULL)						\
-  } while (0)
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
-
+    else								\
-extern int __lll_timedwait_tid (int *, const struct timespec *)
+      /* We need acquire MO here so that we synchronize with the 	\
-     attribute_hidden;
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
-
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
-/* As lll_wait_tid, but with a timeout.  If the timeout occurs then return
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
-   ETIMEDOUT.  If ABSTIME is invalid, return EINVAL.  */
+    __res;								\
-#define lll_timedwait_tid(tid, abstime) \
-  ({							\
-    int __res = 0;					\
-    if ((tid) != 0)					\
-      __res = __lll_timedwait_tid (&(tid), (abstime));	\
-    __res;						\
   })
 
 

sysdeps/posix/open64.c

@@ -34,16 +34,8 @@ __libc_open64 (const char *file, int oflag, ...)
       va_end (arg);
     }
 
-  if (SINGLE_THREAD_P)
+  /* __libc_open should be a cancellation point.  */
-    return __libc_open (file, oflag | O_LARGEFILE, mode);
+  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;
 }
 weak_alias (__libc_open64, __open64)
 libc_hidden_weak (__open64)

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)
+  /* __sigsuspend should be a cancellation point.  */
-    return do_sigwait (set, sig);
+  return do_sigitid (idtype, id, infop, options);
-
-  int oldtype = LIBC_CANCEL_ASYNC ();
-
-  int result = do_sigwait (set, sig);
-
-  LIBC_CANCEL_RESET (oldtype);
-
-  return result;
 }
 libc_hidden_def (__sigwait)
 weak_alias (__sigwait, sigwait)

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)
+  /* __waitpid should be a cancellation point.  */
-    return do_waitid (idtype, id, infop, options);
+  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;
 }
 weak_alias (__waitid, waitid)
 strong_alias (__waitid, __libc_waitid)

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)
+  /* If the call is interrupted by a signal handler or encounters an error,
-    r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req, rem);
+     it returns a positive value similar to errno.  */
-  else
+  INTERNAL_SYSCALL_DECL (err);
-    {
+  int r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, flags,
-      int oldstate = LIBC_CANCEL_ASYNC ();
+				   req, rem);
-
-      r = INTERNAL_SYSCALL (clock_nanosleep, err, 4, clock_id, flags, req,
-			    rem);
-
-      LIBC_CANCEL_RESET (oldstate);
-    }
-
   return (INTERNAL_SYSCALL_ERROR_P (r, err)
 	  ? INTERNAL_SYSCALL_ERRNO (r, err) : 0);
 }

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:

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.  */
+   operations for futex wake-up when the clone terminates.
-#define lll_wait_tid(tid) \
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
-  do {					\
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
-    __typeof (tid) __tid;		\
+   The futex operation are issues with cancellable versions.  */
-    while ((__tid = (tid)) != 0)	\
+#define lll_wait_tid(tid, abstime)					\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);\
+  ({									\
-  } while (0)
+    int __res = 0;							\
-
+    __typeof (tid) __tid;						\
-extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime)
+    if (abstime != NULL)						\
-     __attribute__ ((regparm (2))) attribute_hidden;
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
-
+    else								\
-/* As lll_wait_tid, but with a timeout.  If the timeout occurs then return
+      /* We need acquire MO here so that we synchronize with the 	\
-   ETIMEDOUT.  If ABSTIME is invalid, return EINVAL.
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
-   XXX Note that this differs from the generic version in that we do the
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
-   error checking here and not in __lll_timedwait_tid.  */
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
-#define lll_timedwait_tid(tid, abstime) \
+    __res;								\
-  ({									      \
+  })
-    int __result = 0;							      \
-    if ((tid) != 0)							      \
-      __result = __lll_timedwait_tid (&(tid), (abstime));		      \
-    __result; })
-
 
 extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
   attribute_hidden;

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 */

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) \
+/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
-  ({							\
+   wake-up when the clone terminates.  The memory location contains the
-    int __res = 0;					\
+   thread ID while the clone is running and is reset to zero by the kernel
-    if ((tid) != 0)					\
+   afterwards.  The kernel up to version 3.16.3 does not use the private futex
-      __res = __lll_timedwait_tid (&(tid), (abstime));	\
+   operations for futex wake-up when the clone terminates.
-    __res;						\
+   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 */

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.  */
+   operations for futex wake-up when the clone terminates.
-#define lll_wait_tid(tid) \
+   If ABSTIME is not NULL, is used a timeout for futex call.  If the timeout
-  do {					\
+   occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL.
-    __typeof (tid) __tid;		\
+   The futex operation are issues with cancellable versions.  */
-    while ((__tid = (tid)) != 0)	\
+#define lll_wait_tid(tid, abstime)					\
-      lll_futex_wait (&(tid), __tid, LLL_SHARED);\
+  ({									\
-  } while (0)
+    int __res = 0;							\
-
+    __typeof (tid) __tid;						\
-extern int __lll_timedwait_tid (int *, const struct timespec *)
+    if (abstime != NULL)						\
-     attribute_hidden;
+      __res = __lll_timedwait_tid (&(tid), (abstime));			\
-
+    else								\
-/* As lll_wait_tid, but with a timeout.  If the timeout occurs then return
+      /* We need acquire MO here so that we synchronize with the 	\
-   ETIMEDOUT.  If ABSTIME is invalid, return EINVAL.
+	 kernel's store to 0 when the clone terminates. (see above)  */	\
-   XXX Note that this differs from the generic version in that we do the
+      while ((__tid = atomic_load_acquire (&(tid))) != 0)		\
-   error checking here and not in __lll_timedwait_tid.  */
+        lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED);		\
-#define lll_timedwait_tid(tid, abstime) \
+    __res;								\
-  ({									      \
+  })
-    int __result = 0;							      \
-    if ((tid) != 0)							      \
-      __result = __lll_timedwait_tid (&(tid), (abstime));		      \
-    __result; })
 
 extern int __lll_lock_elision (int *futex, short *adapt_count, int private)
   attribute_hidden;