X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ffutex.c;h=5efa2f978032d1f20955c5f99eb24bf0e1051c51;hb=b28485acb930f67c014024bc3b9c01129124e566;hp=5872e3507f356bc61c71fa65c7e58d7866df316c;hpb=cc3327e7dfc16a9a3e164075234c869867a59e45;p=linux-2.6-omap-h63xx.git

diff --git a/kernel/futex.c b/kernel/futex.c
index 5872e3507f3..5efa2f97803 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -270,7 +270,13 @@ static void wake_futex(struct futex_q *q)
 	/*
 	 * The waiting task can free the futex_q as soon as this is written,
 	 * without taking any locks.  This must come last.
+	 *
+	 * A memory barrier is required here to prevent the following store
+	 * to lock_ptr from getting ahead of the wakeup. Clearing the lock
+	 * at the end of wake_up_all() does not prevent this store from
+	 * moving.
 	 */
+	wmb();
 	q->lock_ptr = NULL;
 }
 
@@ -350,6 +356,13 @@ retry:
 		if (bh1 != bh2)
 			spin_unlock(&bh2->lock);
 
+#ifndef CONFIG_MMU
+		/* we don't get EFAULT from MMU faults if we don't have an MMU,
+		 * but we might get them from range checking */
+		ret = op_ret;
+		goto out;
+#endif
+
 		if (unlikely(op_ret != -EFAULT)) {
 			ret = op_ret;
 			goto out;