Commit ff93bca7 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

ila: make lockdep happy again 



Previously, alloc_ila_locks() and bucket_table_alloc() call
spin_lock_init() separately, therefore they have two different
lock names and lock class keys. However, after commit b8932817
("ila: Call library function alloc_bucket_locks") they both call
helper alloc_bucket_spinlocks() which now only has one lock
name and lock class key. This causes a few bogus lockdep warnings
as reported by syzbot.

Fix this by making alloc_bucket_locks() a macro and pass declaration
name as lock name and a static lock class key inside the macro.

Fixes: b8932817 ("ila: Call library function alloc_bucket_locks")
Reported-by: default avatar <syzbot+b66a5a554991a8ed027c@syzkaller.appspotmail.com>
Cc: Tom Herbert <tom@quantonium.net>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 32039eac

include/linux/spinlock.h

+14 −3
Original line number Diff line number Diff line
@@ -451,9 +451,20 @@ extern int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock, 
#define atomic_dec_and_lock_irqsave(atomic, lock, flags) \

		__cond_lock(lock, _atomic_dec_and_lock_irqsave(atomic, lock, &(flags)))



int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,

int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,

			     size_t max_size, unsigned int cpu_mult,

			   gfp_t gfp);

			     gfp_t gfp, const char *name,

			     struct lock_class_key *key);



#define alloc_bucket_spinlocks(locks, lock_mask, max_size, cpu_mult, gfp)    \

	({								     \

		static struct lock_class_key key;			     \

		int ret;						     \

									     \

		ret = __alloc_bucket_spinlocks(locks, lock_mask, max_size,   \

					       cpu_mult, gfp, #locks, &key); \

		ret;							     \

	})



void free_bucket_spinlocks(spinlock_t *locks);

lib/bucket_locks.c

+7 −4
Original line number Diff line number Diff line
@@ -11,8 +11,9 @@ 
 * to a power of 2 to be suitable as a hash table.

 */



int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,

			   size_t max_size, unsigned int cpu_mult, gfp_t gfp)

int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,

			     size_t max_size, unsigned int cpu_mult, gfp_t gfp,

			     const char *name, struct lock_class_key *key)

{

	spinlock_t *tlocks = NULL;

	unsigned int i, size;
@@ -33,8 +34,10 @@ int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask, 
		tlocks = kvmalloc_array(size, sizeof(spinlock_t), gfp);

		if (!tlocks)

			return -ENOMEM;

		for (i = 0; i < size; i++)

		for (i = 0; i < size; i++) {

			spin_lock_init(&tlocks[i]);

			lockdep_init_map(&tlocks[i].dep_map, name, key, 0);

		}

	}



	*locks = tlocks;
@@ -42,7 +45,7 @@ int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask, 


	return 0;

}

EXPORT_SYMBOL(alloc_bucket_spinlocks);

EXPORT_SYMBOL(__alloc_bucket_spinlocks);



void free_bucket_spinlocks(spinlock_t *locks)

{

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