diff -ur /home/alex/checkouts/linux-2.6-git/drivers/gpu/drm/drm_hashtab.c linux-2.6.38-rc1/drivers/gpu/drm/drm_hashtab.c
--- /home/alex/checkouts/linux-2.6-git/drivers/gpu/drm/drm_hashtab.c	2010-04-07 11:02:04.000000000 -0500
+++ linux-2.6.38-rc1/drivers/gpu/drm/drm_hashtab.c	2011-01-19 12:04:30.000000000 -0500
@@ -111,6 +111,9 @@
 	unsigned long key = item->key;
 
 	hashed_key = hash_long(key, ht->order);
+
+	BUG_ON(hashed_key >= ht->size);
+
 	h_list = &ht->table[hashed_key];
 	parent = NULL;
 	hlist_for_each(list, h_list) {
diff -ur /home/alex/checkouts/linux-2.6-git/drivers/gpu/drm/i915/i915_gem.c linux-2.6.38-rc1/drivers/gpu/drm/i915/i915_gem.c
--- /home/alex/checkouts/linux-2.6-git/drivers/gpu/drm/i915/i915_gem.c	2011-01-12 18:53:37.000000000 -0500
+++ linux-2.6.38-rc1/drivers/gpu/drm/i915/i915_gem.c	2011-01-19 11:57:54.000000000 -0500
@@ -1331,6 +1331,8 @@
 	struct drm_gem_mm *mm = dev->mm_private;
 	struct drm_map_list *list = &obj->base.map_list;
 
+	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
+
 	drm_ht_remove_item(&mm->offset_hash, &list->hash);
 	drm_mm_put_block(list->file_offset_node);
 	kfree(list->map);