kmemleak: Scan objects allocated during a scanning episode (2587362e) · Commits · 戴 / test

mm/kmemleak.c

+40 −3

Original line number	Diff line number	Diff line
		@@ -106,6 +106,7 @@
		#define MSECS_MIN_AGE 5000 /* minimum object age for reporting */
		#define SECS_FIRST_SCAN 60 /* delay before the first scan */
		#define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */
		#define GRAY_LIST_PASSES 25 /* maximum number of gray list scans */

		#define BYTES_PER_POINTER sizeof(void *)

		@@ -157,6 +158,8 @@ struct kmemleak_object {
		#define OBJECT_REPORTED (1 << 1)
		/* flag set to not scan the object */
		#define OBJECT_NO_SCAN (1 << 2)
		/* flag set on newly allocated objects */
		#define OBJECT_NEW (1 << 3)

		/* the list of all allocated objects */
		static LIST_HEAD(object_list);
		@@ -270,6 +273,11 @@ static int color_gray(const struct kmemleak_object *object)
		return object->min_count != -1 && object->count >= object->min_count;
		}

		static int color_black(const struct kmemleak_object *object)
		{
		return object->min_count == -1;
		}

		/*
		* Objects are considered unreferenced only if their color is white, they have
		* not be deleted and have a minimum age to avoid false positives caused by
		@@ -447,7 +455,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count,
		INIT_HLIST_HEAD(&object->area_list);
		spin_lock_init(&object->lock);
		atomic_set(&object->use_count, 1);
		object->flags = OBJECT_ALLOCATED;
		object->flags = OBJECT_ALLOCATED \| OBJECT_NEW;
		object->pointer = ptr;
		object->size = size;
		object->min_count = min_count;
		@@ -901,6 +909,7 @@ static void kmemleak_scan(void)
		struct task_struct *task;
		int i;
		int new_leaks = 0;
		int gray_list_pass = 0;

		jiffies_last_scan = jiffies;

		@@ -921,6 +930,7 @@ static void kmemleak_scan(void)
		#endif
		/* reset the reference count (whiten the object) */
		object->count = 0;
		object->flags &= ~OBJECT_NEW;
		if (color_gray(object) && get_object(object))
		list_add_tail(&object->gray_list, &gray_list);

		@@ -983,6 +993,7 @@ static void kmemleak_scan(void)
		* kmemleak objects cannot be freed from outside the loop because their
		* use_count was increased.
		*/
		repeat:
		object = list_entry(gray_list.next, typeof(*object), gray_list);
		while (&object->gray_list != &gray_list) {
		cond_resched();
		@@ -1000,12 +1011,38 @@ static void kmemleak_scan(void)

		object = tmp;
		}

		if (scan_should_stop() \|\| ++gray_list_pass >= GRAY_LIST_PASSES)
		goto scan_end;

		/*
		* Check for new objects allocated during this scanning and add them
		* to the gray list.
		*/
		rcu_read_lock();
		list_for_each_entry_rcu(object, &object_list, object_list) {
		spin_lock_irqsave(&object->lock, flags);
		if ((object->flags & OBJECT_NEW) && !color_black(object) &&
		get_object(object)) {
		object->flags &= ~OBJECT_NEW;
		list_add_tail(&object->gray_list, &gray_list);
		}
		spin_unlock_irqrestore(&object->lock, flags);
		}
		rcu_read_unlock();

		if (!list_empty(&gray_list))
		goto repeat;

		scan_end:
		WARN_ON(!list_empty(&gray_list));

		/*
		* If scanning was stopped do not report any new unreferenced objects.
		* If scanning was stopped or new objects were being allocated at a
		* higher rate than gray list scanning, do not report any new
		* unreferenced objects.
		*/
		if (scan_should_stop())
		if (scan_should_stop() \|\| gray_list_pass >= GRAY_LIST_PASSES)
		return;

		/*

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