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Commit 72dcd505 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

locking/lockdep: Add module_param to enable consistency checks 



And move the whole lot under CONFIG_DEBUG_LOCKDEP.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent f214737b

kernel/locking/lockdep.c

+33 −13
Original line number Diff line number Diff line
@@ -74,8 +74,6 @@ module_param(lock_stat, int, 0644); 
#define lock_stat 0

#endif



static bool check_data_structure_consistency;



/*

 * lockdep_lock: protects the lockdep graph, the hashes and the

 *               class/list/hash allocators.
@@ -791,6 +789,8 @@ static bool assign_lock_key(struct lockdep_map *lock) 
	return true;

}



#ifdef CONFIG_DEBUG_LOCKDEP



/* Check whether element @e occurs in list @h */

static bool in_list(struct list_head *e, struct list_head *h)

{
@@ -855,15 +855,15 @@ static bool check_lock_chain_key(struct lock_chain *chain) 
	 * The 'unsigned long long' casts avoid that a compiler warning

	 * is reported when building tools/lib/lockdep.

	 */

	if (chain->chain_key != chain_key)

	if (chain->chain_key != chain_key) {

		printk(KERN_INFO "chain %lld: key %#llx <> %#llx\n",

		       (unsigned long long)(chain - lock_chains),

		       (unsigned long long)chain->chain_key,

		       (unsigned long long)chain_key);

	return chain->chain_key == chain_key;

#else

	return true;

		return false;

	}

#endif

	return true;

}



static bool in_any_zapped_class_list(struct lock_class *class)
@@ -871,15 +871,15 @@ static bool in_any_zapped_class_list(struct lock_class *class) 
	struct pending_free *pf;

	int i;



	for (i = 0, pf = delayed_free.pf; i < ARRAY_SIZE(delayed_free.pf);

	     i++, pf++)

	for (i = 0, pf = delayed_free.pf; i < ARRAY_SIZE(delayed_free.pf); i++, pf++) {

		if (in_list(&class->lock_entry, &pf->zapped))

			return true;

	}



	return false;

}



static bool check_data_structures(void)

static bool __check_data_structures(void)

{

	struct lock_class *class;

	struct lock_chain *chain;
@@ -896,7 +896,6 @@ static bool check_data_structures(void) 
			printk(KERN_INFO "class %px/%s is not in any class list\n",

			       class, class->name ? : "(?)");

			return false;

			return false;

		}

	}
@@ -953,6 +952,27 @@ static bool check_data_structures(void) 
	return true;

}



int check_consistency = 0;

module_param(check_consistency, int, 0644);



static void check_data_structures(void)

{

	static bool once = false;



	if (check_consistency && !once) {

		if (!__check_data_structures()) {

			once = true;

			WARN_ON(once);

		}

	}

}



#else /* CONFIG_DEBUG_LOCKDEP */



static inline void check_data_structures(void) { }



#endif /* CONFIG_DEBUG_LOCKDEP */



/*

 * Initialize the lock_classes[] array elements, the free_lock_classes list

 * and also the delayed_free structure.
@@ -4474,10 +4494,11 @@ static void remove_class_from_lock_chain(struct pending_free *pf, 
		if (chain_hlocks[i] != class - lock_classes)

			continue;

		/* The code below leaks one chain_hlock[] entry. */

		if (--chain->depth > 0)

		if (--chain->depth > 0) {

			memmove(&chain_hlocks[i], &chain_hlocks[i + 1],

				(chain->base + chain->depth - i) *

				sizeof(chain_hlocks[0]));

		}

		/*

		 * Each lock class occurs at most once in a lock chain so once

		 * we found a match we can break out of this loop.
@@ -4631,8 +4652,7 @@ static void __free_zapped_classes(struct pending_free *pf) 
{

	struct lock_class *class;



	if (check_data_structure_consistency)

		WARN_ON_ONCE(!check_data_structures());

	check_data_structures();



	list_for_each_entry(class, &pf->zapped, lock_entry)

		reinit_class(class);