Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Conflicts:
	drivers/net/ethernet/rocker/rocker.c

The rocker commit was two overlapping changes, one to rename
the ->vport member to ->pport, and another making the bitmask
expression use '1ULL' instead of plain '1'.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 2 deletions

diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 7052d3f..8d0f35d 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -274,7 +274,7 @@ bool try_wait_for_completion(struct completion *x)
 	 * first without taking the lock so we can
 	 * return early in the blocking case.
 	 */
-	if (!ACCESS_ONCE(x->done))
+	if (!READ_ONCE(x->done))
 		return 0;
 
 	spin_lock_irqsave(&x->wait.lock, flags);
@@ -297,6 +297,21 @@ EXPORT_SYMBOL(try_wait_for_completion);
  */
 bool completion_done(struct completion *x)
 {
-	return !!ACCESS_ONCE(x->done);
+	if (!READ_ONCE(x->done))
+		return false;
+
+	/*
+	 * If ->done, we need to wait for complete() to release ->wait.lock
+	 * otherwise we can end up freeing the completion before complete()
+	 * is done referencing it.
+	 *
+	 * The RMB pairs with complete()'s RELEASE of ->wait.lock and orders
+	 * the loads of ->done and ->wait.lock such that we cannot observe
+	 * the lock before complete() acquires it while observing the ->done
+	 * after it's acquired the lock.
+	 */
+	smp_rmb();
+	spin_unlock_wait(&x->wait.lock);
+	return true;
 }
 EXPORT_SYMBOL(completion_done);