Commit 9e55f87c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull locking fixes from Thomas Gleixner:
 "A few fixes for lockdep:

   - initialize lockdep internal RCU head after initializing RCU

   - prevent use after free in a alloc_workqueue() error handling path

   - plug a memory leak in the workqueue core which fails to free a
     dynamically allocated lock name.

   - make Clang happy"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  workqueue, lockdep: Fix a memory leak in wq->lock_name
  workqueue, lockdep: Fix an alloc_workqueue() error path
  locking/lockdep: Only call init_rcu_head() after RCU has been initialized
  locking/lockdep: Avoid a Clang warning
parents 077d3daf 69a106c0

kernel/locking/lockdep.c

+14 −5
Original line number Diff line number Diff line
@@ -842,7 +842,9 @@ static bool class_lock_list_valid(struct lock_class *c, struct list_head *h) 
	return true;

}



static u16 chain_hlocks[];

#ifdef CONFIG_PROVE_LOCKING

static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];

#endif



static bool check_lock_chain_key(struct lock_chain *chain)

{
@@ -980,15 +982,22 @@ static inline void check_data_structures(void) { } 
 */

static void init_data_structures_once(void)

{

	static bool initialization_happened;

	static bool ds_initialized, rcu_head_initialized;

	int i;



	if (likely(initialization_happened))

	if (likely(rcu_head_initialized))

		return;



	initialization_happened = true;



	if (system_state >= SYSTEM_SCHEDULING) {

		init_rcu_head(&delayed_free.rcu_head);

		rcu_head_initialized = true;

	}



	if (ds_initialized)

		return;



	ds_initialized = true;



	INIT_LIST_HEAD(&delayed_free.pf[0].zapped);

	INIT_LIST_HEAD(&delayed_free.pf[1].zapped);

kernel/workqueue.c

+4 −0
Original line number Diff line number Diff line
@@ -3445,6 +3445,8 @@ static void wq_init_lockdep(struct workqueue_struct *wq) 
	lock_name = kasprintf(GFP_KERNEL, "%s%s", "(wq_completion)", wq->name);

	if (!lock_name)

		lock_name = wq->name;



	wq->lock_name = lock_name;

	lockdep_init_map(&wq->lockdep_map, lock_name, &wq->key, 0);

}
@@ -4291,6 +4293,8 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, 
	return wq;



err_free_wq:

	wq_unregister_lockdep(wq);

	wq_free_lockdep(wq);

	free_workqueue_attrs(wq->unbound_attrs);

	kfree(wq);

	return NULL;

CRA Git | Maintained and supported by SUSTech CRA and CCSE