Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1704f47b authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Greg Kroah-Hartman
Browse files

lockdep: Add novalidate class for dev->mutex conversion 



The conversion of device->sem to device->mutex resulted in lockdep
warnings. Create a novalidate class for now until the driver folks
come up with separate classes. That way we have at least the basic
mutex debugging coverage.

Add a checkpatch error so the usage is reserved for device->mutex.

[ tglx: checkpatch and compile fix for LOCKDEP=n ]

Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3142788b

drivers/base/core.c

+1 −0
Original line number Diff line number Diff line
@@ -559,6 +559,7 @@ void device_initialize(struct device *dev) 
	kobject_init(&dev->kobj, &device_ktype);

	INIT_LIST_HEAD(&dev->dma_pools);

	mutex_init(&dev->mutex);

	lockdep_set_novalidate_class(&dev->mutex);

	spin_lock_init(&dev->devres_lock);

	INIT_LIST_HEAD(&dev->devres_head);

	device_pm_init(dev);

include/linux/lockdep.h

+8 −0
Original line number Diff line number Diff line
@@ -44,6 +44,8 @@ struct lock_class_key { 
	struct lockdep_subclass_key	subkeys[MAX_LOCKDEP_SUBCLASSES];

};



extern struct lock_class_key __lockdep_no_validate__;



#define LOCKSTAT_POINTS		4



/*
@@ -270,6 +272,9 @@ extern void lockdep_init_map(struct lockdep_map *lock, const char *name, 
#define lockdep_set_subclass(lock, sub)	\

		lockdep_init_map(&(lock)->dep_map, #lock, \

				 (lock)->dep_map.key, sub)



#define lockdep_set_novalidate_class(lock) \

	lockdep_set_class(lock, &__lockdep_no_validate__)

/*

 * Compare locking classes

 */
@@ -354,6 +359,9 @@ static inline void lockdep_on(void) 
#define lockdep_set_class_and_subclass(lock, key, sub) \

		do { (void)(key); } while (0)

#define lockdep_set_subclass(lock, sub)		do { } while (0)



#define lockdep_set_novalidate_class(lock) do { } while (0)



/*

 * We don't define lockdep_match_class() and lockdep_match_key() for !LOCKDEP

 * case since the result is not well defined and the caller should rather

kernel/lockdep.c

+5 −0
Original line number Diff line number Diff line
@@ -2711,6 +2711,8 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name, 
}

EXPORT_SYMBOL_GPL(lockdep_init_map);



struct lock_class_key __lockdep_no_validate__;



/*

 * This gets called for every mutex_lock*()/spin_lock*() operation.

 * We maintain the dependency maps and validate the locking attempt:
@@ -2745,6 +2747,9 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, 
		return 0;

	}



	if (lock->key == &__lockdep_no_validate__)

		check = 1;



	if (!subclass)

		class = lock->class_cache;

	/*

scripts/checkpatch.pl

+11 −0
Original line number Diff line number Diff line
@@ -2656,6 +2656,7 @@ sub process { 
# check for semaphores used as mutexes

		if ($line =~ /^.\s*init_MUTEX_LOCKED\s*\(/) {

			WARN("consider using a completion\n" . $herecurr);



		}

# recommend strict_strto* over simple_strto*

		if ($line =~ /\bsimple_(strto.*?)\s*\(/) {
@@ -2740,6 +2741,16 @@ sub process { 
				WARN("use of in_atomic() is incorrect outside core kernel code\n" . $herecurr);

			}

		}



# check for lockdep_set_novalidate_class

		if ($line =~ /^.\s*lockdep_set_novalidate_class\s*\(/ ||

		    $line =~ /__lockdep_no_validate__\s*\)/ ) {

			if ($realfile !~ m@^kernel/lockdep@ &&

			    $realfile !~ m@^include/linux/lockdep@ &&

			    $realfile !~ m@^drivers/base/core@) {

				ERROR("lockdep_no_validate class is reserved for device->mutex.\n" . $herecurr);

			}

		}

	}



	# If we have no input at all, then there is nothing to report on