2 files changed, 67 insertions, 3 deletions

diff --git a/include/linux/debugobjects.h b/include/linux/debugobjects.h
index 8c243aaa86a7..597692f1fc8d 100644
--- a/include/linux/debugobjects.h
+++ b/include/linux/debugobjects.h
@@ -20,12 +20,14 @@ struct debug_obj_descr;
  * struct debug_obj - representaion of an tracked object
  * @node:       hlist node to link the object into the tracker list
  * @state:      tracked object state
+ * @astate:     current active state
  * @object:     pointer to the real object
  * @descr:      pointer to an object type specific debug description structure
  */
 struct debug_obj {
         struct hlist_node       node;
         enum debug_obj_state    state;
+        unsigned int            astate;
         void                    *object;
         struct debug_obj_descr  *descr;
 };
@@ -60,6 +62,15 @@ extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr);
 extern void debug_object_destroy   (void *addr, struct debug_obj_descr *descr);
 extern void debug_object_free      (void *addr, struct debug_obj_descr *descr);
 
+/*
+ * Active state:
+ * - Set at 0 upon initialization.
+ * - Must return to 0 before deactivation.
+ */
+extern void
+debug_object_active_state(void *addr, struct debug_obj_descr *descr,
+                          unsigned int expect, unsigned int next);
+
 extern void debug_objects_early_init(void);
 extern void debug_objects_mem_init(void);
 #else
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index b862b30369ff..076464fd2072 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -141,6 +141,7 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
                 obj->object = addr;
                 obj->descr  = descr;
                 obj->state  = ODEBUG_STATE_NONE;
+                obj->astate = 0;
                 hlist_del(&obj->node);
 
                 hlist_add_head(&obj->node, &b->list);
@@ -252,8 +253,10 @@ static void debug_print_object(struct debug_obj *obj, char *msg)
 
         if (limit < 5 && obj->descr != descr_test) {
                 limit++;
-                WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
-                       obj_states[obj->state], obj->descr->name);
+                WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
+                                 "object type: %s\n",
+                        msg, obj_states[obj->state], obj->astate,
+                        obj->descr->name);
         }
         debug_objects_warnings++;
 }
@@ -447,7 +450,10 @@ void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
                 case ODEBUG_STATE_INIT:
                 case ODEBUG_STATE_INACTIVE:
                 case ODEBUG_STATE_ACTIVE:
-                        obj->state = ODEBUG_STATE_INACTIVE;
+                        if (!obj->astate)
+                                obj->state = ODEBUG_STATE_INACTIVE;
+                        else
+                                debug_print_object(obj, "deactivate");
                         break;
 
                 case ODEBUG_STATE_DESTROYED:
@@ -553,6 +559,53 @@ out_unlock:
         raw_spin_unlock_irqrestore(&db->lock, flags);
 }
 
+/**
+ * debug_object_active_state - debug checks object usage state machine
+ * @addr:       address of the object
+ * @descr:      pointer to an object specific debug description structure
+ * @expect:     expected state
+ * @next:       state to move to if expected state is found
+ */
+void
+debug_object_active_state(void *addr, struct debug_obj_descr *descr,
+                          unsigned int expect, unsigned int next)
+{
+        struct debug_bucket *db;
+        struct debug_obj *obj;
+        unsigned long flags;
+
+        if (!debug_objects_enabled)
+                return;
+
+        db = get_bucket((unsigned long) addr);
+
+        raw_spin_lock_irqsave(&db->lock, flags);
+
+        obj = lookup_object(addr, db);
+        if (obj) {
+                switch (obj->state) {
+                case ODEBUG_STATE_ACTIVE:
+                        if (obj->astate == expect)
+                                obj->astate = next;
+                        else
+                                debug_print_object(obj, "active_state");
+                        break;
+
+                default:
+                        debug_print_object(obj, "active_state");
+                        break;
+                }
+        } else {
+                struct debug_obj o = { .object = addr,
+                                       .state = ODEBUG_STATE_NOTAVAILABLE,
+                                       .descr = descr };
+
+                debug_print_object(&o, "active_state");
+        }
+
+        raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+
 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 {