/*
* 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;
}
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;