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Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:

 - Fix the EINTR logic in rwsem-spinlock to avoid double locking by a
   writer and a reader

 - Add a missing include to qspinlocks

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/qspinlock: Explicitly include asm/prefetch.h
  locking/rwsem-spinlock: Fix EINTR branch in __down_write_common()
Linus Torvalds 8 years ago
parent
commit
c8b2ba83fb
2 changed files with 3 additions and 2 deletions
  1. 1 0
      kernel/locking/qspinlock.c
  2. 2 2
      kernel/locking/rwsem-spinlock.c

+ 1 - 0
kernel/locking/qspinlock.c

@@ -28,6 +28,7 @@
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
 #include <linux/mutex.h>
+#include <linux/prefetch.h>
 #include <asm/byteorder.h>
 #include <asm/qspinlock.h>
 

+ 2 - 2
kernel/locking/rwsem-spinlock.c

@@ -231,8 +231,8 @@ int __sched __down_write_common(struct rw_semaphore *sem, int state)
 
 out_nolock:
 	list_del(&waiter.list);
-	if (!list_empty(&sem->wait_list))
-		__rwsem_do_wake(sem, 1);
+	if (!list_empty(&sem->wait_list) && sem->count >= 0)
+		__rwsem_do_wake(sem, 0);
 	raw_spin_unlock_irqrestore(&sem->wait_lock, flags);
 
 	return -EINTR;