Commit 7a113ff6 authored by Andrzej Hajda's avatar Andrzej Hajda Committed by Jakub Kicinski
Browse files

lib/ref_tracker: add unlocked leak print helper 



To have reliable detection of leaks, caller must be able to check under
the same lock both: tracked counter and the leaks. dir.lock is natural
candidate for such lock and unlocked print helper can be called with this
lock taken.
As a bonus we can reuse this helper in ref_tracker_dir_exit.

Signed-off-by: default avatarAndrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7877cb91

include/linux/ref_tracker.h

+8 −0
Original line number Diff line number Diff line
@@ -36,6 +36,9 @@ static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir, 


void ref_tracker_dir_exit(struct ref_tracker_dir *dir);



void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,

				  unsigned int display_limit);



void ref_tracker_dir_print(struct ref_tracker_dir *dir,

			   unsigned int display_limit);
@@ -56,6 +59,11 @@ static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir) 
{

}



static inline void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,

						unsigned int display_limit)

{

}



static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir,

					 unsigned int display_limit)

{

lib/ref_tracker.c

+38 −28
Original line number Diff line number Diff line
@@ -14,6 +14,38 @@ struct ref_tracker { 
	depot_stack_handle_t	free_stack_handle;

};



void ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,

				  unsigned int display_limit)

{

	struct ref_tracker *tracker;

	unsigned int i = 0;



	lockdep_assert_held(&dir->lock);



	list_for_each_entry(tracker, &dir->list, head) {

		if (i < display_limit) {

			pr_err("leaked reference.\n");

			if (tracker->alloc_stack_handle)

				stack_depot_print(tracker->alloc_stack_handle);

			i++;

		} else {

			break;

		}

	}

}

EXPORT_SYMBOL(ref_tracker_dir_print_locked);



void ref_tracker_dir_print(struct ref_tracker_dir *dir,

			   unsigned int display_limit)

{

	unsigned long flags;



	spin_lock_irqsave(&dir->lock, flags);

	ref_tracker_dir_print_locked(dir, display_limit);

	spin_unlock_irqrestore(&dir->lock, flags);

}

EXPORT_SYMBOL(ref_tracker_dir_print);



void ref_tracker_dir_exit(struct ref_tracker_dir *dir)

{

	struct ref_tracker *tracker, *n;
@@ -27,14 +59,14 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) 
		kfree(tracker);

		dir->quarantine_avail++;

	}

	list_for_each_entry_safe(tracker, n, &dir->list, head) {

		pr_err("leaked reference.\n");

		if (tracker->alloc_stack_handle)

			stack_depot_print(tracker->alloc_stack_handle);

	if (!list_empty(&dir->list)) {

		ref_tracker_dir_print_locked(dir, 16);

		leak = true;

		list_for_each_entry_safe(tracker, n, &dir->list, head) {

			list_del(&tracker->head);

			kfree(tracker);

		}

	}

	spin_unlock_irqrestore(&dir->lock, flags);

	WARN_ON_ONCE(leak);

	WARN_ON_ONCE(refcount_read(&dir->untracked) != 1);
@@ -42,28 +74,6 @@ void ref_tracker_dir_exit(struct ref_tracker_dir *dir) 
}

EXPORT_SYMBOL(ref_tracker_dir_exit);



void ref_tracker_dir_print(struct ref_tracker_dir *dir,

			   unsigned int display_limit)

{

	struct ref_tracker *tracker;

	unsigned long flags;

	unsigned int i = 0;



	spin_lock_irqsave(&dir->lock, flags);

	list_for_each_entry(tracker, &dir->list, head) {

		if (i < display_limit) {

			pr_err("leaked reference.\n");

			if (tracker->alloc_stack_handle)

				stack_depot_print(tracker->alloc_stack_handle);

			i++;

		} else {

			break;

		}

	}

	spin_unlock_irqrestore(&dir->lock, flags);

}

EXPORT_SYMBOL(ref_tracker_dir_print);



int ref_tracker_alloc(struct ref_tracker_dir *dir,

		      struct ref_tracker **trackerp,

		      gfp_t gfp)