h63xx: tsc2101 alsa sound support

[linux-2.6-omap-h63xx.git] / kernel / futex.c

diff --git a/kernel/futex.c b/kernel/futex.c
index aca8d10704f675cbdf35267d49bb984669c49f44..5efa2f978032d1f20955c5f99eb24bf0e1051c51 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -201,21 +201,6 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
         * from swap.  But that's a lot of code to duplicate here
         * for a rare case, so we simply fetch the page.
         */
-
-       /*
-        * Do a quick atomic lookup first - this is the fastpath.
-        */
-       page = follow_page(mm, uaddr, FOLL_TOUCH|FOLL_GET);
-       if (likely(page != NULL)) {
-               key->shared.pgoff =
-                       page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
-               put_page(page);
-               return 0;
-       }
-
-       /*
-        * Do it the general way.
-        */
        err = get_user_pages(current, mm, uaddr, 1, 0, 0, &page, NULL);
        if (err >= 0) {
                key->shared.pgoff =
@@ -285,7 +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;
 }
 
@@ -365,6 +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;