Merge branch 'linux-linaro-lsk-v3.10/be/32/core-20140413' of git://git.linaro.org/people/victor.kamensky/linux-linaro-tracking-be into lsk-v3.10-bev3.10/topic/old-arm64-bev3.10/topic/be

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 04c1b2d9b775..840604ed0235 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -729,9 +729,18 @@ void gnttab_request_free_callback(struct gnttab_free_callback *callback,
 				  void (*fn)(void *), void *arg, u16 count)
 {
 	unsigned long flags;
+	struct gnttab_free_callback *cb;
+
 	spin_lock_irqsave(&gnttab_list_lock, flags);
-	if (callback->next)
-		goto out;
+
+	/* Check if the callback is already on the list */
+	cb = gnttab_free_callback_list;
+	while (cb) {
+		if (cb == callback)
+			goto out;
+		cb = cb->next;
+	}
+
 	callback->fn = fn;
 	callback->arg = arg;
 	callback->count = count;
@@ -911,9 +920,10 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
 				       &kmap_ops[i] : NULL);
 		if (ret)
-			return ret;
+			goto out;
 	}
 
+ out:
 	if (lazy)
 		arch_leave_lazy_mmu_mode();
 
@@ -944,9 +954,10 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 		ret = m2p_remove_override(pages[i], kmap_ops ?
 				       &kmap_ops[i] : NULL);
 		if (ret)
-			return ret;
+			goto out;
 	}
 
+ out:
 	if (lazy)
 		arch_leave_lazy_mmu_mode();