[GIT pull] locking updates for 4.13

[Thomas Gleixner]

Linus,

please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
locking-urgent-for-linus

Two fixlets for the locking code:

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

  - Add a missing include to qspinlocks.

Thanks,

        tglx

------------------>
Kirill Tkhai (1):
      locking/rwsem-spinlock: Fix EINTR branch in __down_write_common()

Stafford Horne (1):
      locking/qspinlock: Explicitly include asm/prefetch.h


 kernel/locking/qspinlock.c      | 1 +
 kernel/locking/rwsem-spinlock.c | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index b2caec7315af..fd24153e8a48 100644
--- a/kernel/locking/qspinlock.c
+++ b/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>
 
diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c
index c65f7989f850..20819df98125 100644
--- a/kernel/locking/rwsem-spinlock.c
+++ b/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;