Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+19
-6
+2
-1
kernel/locking/lockdep.c
+2
-1
kernel/locking/lockdep.c
···
3900
3900
list_del_rcu(&class->hash_entry);
3901
3901
list_del_rcu(&class->lock_entry);
3902
3902
3903
-
class->key = NULL;
3903
+
RCU_INIT_POINTER(class->key, NULL);
3904
+
RCU_INIT_POINTER(class->name, NULL);
3904
3905
}
3905
3906
3906
3907
static inline int within(const void *addr, void *start, unsigned long size)
+17
-5
kernel/locking/lockdep_proc.c
+17
-5
kernel/locking/lockdep_proc.c
···
426
426
427
427
static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
428
428
{
429
-
char name[39];
430
-
struct lock_class *class;
429
+
struct lockdep_subclass_key *ckey;
431
430
struct lock_class_stats *stats;
431
+
struct lock_class *class;
432
+
const char *cname;
432
433
int i, namelen;
434
+
char name[39];
433
435
434
436
class = data->class;
435
437
stats = &data->stats;
···
442
440
if (class->subclass)
443
441
namelen -= 2;
444
442
445
-
if (!class->name) {
443
+
rcu_read_lock_sched();
444
+
cname = rcu_dereference_sched(class->name);
445
+
ckey = rcu_dereference_sched(class->key);
446
+
447
+
if (!cname && !ckey) {
448
+
rcu_read_unlock_sched();
449
+
return;
450
+
451
+
} else if (!cname) {
446
452
char str[KSYM_NAME_LEN];
447
453
const char *key_name;
448
454
449
-
key_name = __get_key_name(class->key, str);
455
+
key_name = __get_key_name(ckey, str);
450
456
snprintf(name, namelen, "%s", key_name);
451
457
} else {
452
-
snprintf(name, namelen, "%s", class->name);
458
+
snprintf(name, namelen, "%s", cname);
453
459
}
460
+
rcu_read_unlock_sched();
461
+
454
462
namelen = strlen(name);
455
463
if (class->name_version > 1) {
456
464
snprintf(name+namelen, 3, "#%d", class->name_version);