mm: kmemleak: factor object reference updating out of scan_block()

scan_block() updates the number of references (pointers) to objects,
adding them to the gray_list when object->min_count is reached.  The
patch factors out this functionality into a separate update_refs()
function.

Link: http://lkml.kernel.org/r/1495726937-23557-3-git-send-email-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 964b12eba2c1b58fd9aad9f897d82d1f8162ed8a..266482f460c228e4faee71a7b33a75eee84a61f0 100644 (file)
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1187,6 +1187,30 @@ static bool update_checksum(struct kmemleak_object *object)
        return object->checksum != old_csum;
 }
 
+/*
+ * Update an object's references. object->lock must be held by the caller.
+ */
+static void update_refs(struct kmemleak_object *object)
+{
+       if (!color_white(object)) {
+               /* non-orphan, ignored or new */
+               return;
+       }
+
+       /*
+        * Increase the object's reference count (number of pointers to the
+        * memory block). If this count reaches the required minimum, the
+        * object's color will become gray and it will be added to the
+        * gray_list.
+        */
+       object->count++;
+       if (color_gray(object)) {
+               /* put_object() called when removing from gray_list */
+               WARN_ON(!get_object(object));
+               list_add_tail(&object->gray_list, &gray_list);
+       }
+}
+
 /*
  * Memory scanning is a long process and it needs to be interruptable. This
  * function checks whether such interrupt condition occurred.
@@ -1259,24 +1283,7 @@ static void scan_block(void *_start, void *_end,
                 * enclosed by scan_mutex.
                 */
                spin_lock_nested(&object->lock, SINGLE_DEPTH_NESTING);
-               if (!color_white(object)) {
-                       /* non-orphan, ignored or new */
-                       spin_unlock(&object->lock);
-                       continue;
-               }
-
-               /*
-                * Increase the object's reference count (number of pointers
-                * to the memory block). If this count reaches the required
-                * minimum, the object's color will become gray and it will be
-                * added to the gray_list.
-                */
-               object->count++;
-               if (color_gray(object)) {
-                       /* put_object() called when removing from gray_list */
-                       WARN_ON(!get_object(object));
-                       list_add_tail(&object->gray_list, &gray_list);
-               }
+               update_refs(object);
                spin_unlock(&object->lock);
        }
        read_unlock_irqrestore(&kmemleak_lock, flags);