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Commit 5bd2c286 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 lockdep fix from Ingo Molnar:
 "A lockdep/modules unload race fix that can oops"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix a race between /proc/lock_stat and module unload
parents d37479aa cee34d88

kernel/locking/lockdep.c

+2 −1
Original line number Diff line number Diff line
@@ -3900,7 +3900,8 @@ static void zap_class(struct lock_class *class) 
	list_del_rcu(&class->hash_entry);

	list_del_rcu(&class->lock_entry);



	class->key = NULL;

	RCU_INIT_POINTER(class->key, NULL);

	RCU_INIT_POINTER(class->name, NULL);

}



static inline int within(const void *addr, void *start, unsigned long size)

kernel/locking/lockdep_proc.c

+17 −5
Original line number Diff line number Diff line
@@ -426,10 +426,12 @@ static void seq_lock_time(struct seq_file *m, struct lock_time *lt) 


static void seq_stats(struct seq_file *m, struct lock_stat_data *data)

{

	char name[39];

	struct lock_class *class;

	struct lockdep_subclass_key *ckey;

	struct lock_class_stats *stats;

	struct lock_class *class;

	const char *cname;

	int i, namelen;

	char name[39];



	class = data->class;

	stats = &data->stats;
@@ -440,15 +442,25 @@ static void seq_stats(struct seq_file *m, struct lock_stat_data *data) 
	if (class->subclass)

		namelen -= 2;



	if (!class->name) {

	rcu_read_lock_sched();

	cname = rcu_dereference_sched(class->name);

	ckey  = rcu_dereference_sched(class->key);



	if (!cname && !ckey) {

		rcu_read_unlock_sched();

		return;



	} else if (!cname) {

		char str[KSYM_NAME_LEN];

		const char *key_name;



		key_name = __get_key_name(class->key, str);

		key_name = __get_key_name(ckey, str);

		snprintf(name, namelen, "%s", key_name);

	} else {

		snprintf(name, namelen, "%s", class->name);

		snprintf(name, namelen, "%s", cname);

	}

	rcu_read_unlock_sched();



	namelen = strlen(name);

	if (class->name_version > 1) {

		snprintf(name+namelen, 3, "#%d", class->name_version);