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locking/lockdep: Introduce lock_class_cache_is_registered()

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This patch does not change any functionality but makes the
lockdep_reset_lock() function easier to read.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20181207011148.251812-11-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Bart Van Assche 2018-12-06 17:11:34 -08:00 committed by Ingo Molnar
parent d35568bdb6
commit 2904d9fa45
1 changed files with 30 additions and 20 deletions
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50
kernel/locking/lockdep.c
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@ -4201,13 +4201,33 @@ void lockdep_free_key_range(void *start, unsigned long size)
*/
}
void lockdep_reset_lock(struct lockdep_map *lock)
/*
* Check whether any element of the @lock->class_cache[] array refers to a
* registered lock class. The caller must hold either the graph lock or the
* RCU read lock.
*/
static bool lock_class_cache_is_registered(struct lockdep_map *lock)
{
struct lock_class *class;
struct hlist_head *head;
unsigned long flags;
int i, j;
int locked;
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
hlist_for_each_entry_rcu(class, head, hash_entry) {
for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
if (lock->class_cache[j] == class)
return true;
}
}
return false;
}
void lockdep_reset_lock(struct lockdep_map *lock)
{
struct lock_class *class;
unsigned long flags;
int j, locked;
raw_local_irq_save(flags);
@ -4227,24 +4247,14 @@ void lockdep_reset_lock(struct lockdep_map *lock)
* be gone.
*/
locked = graph_lock();
for (i = 0; i < CLASSHASH_SIZE; i++) {
head = classhash_table + i;
hlist_for_each_entry_rcu(class, head, hash_entry) {
int match = 0;
for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
match |= class == lock->class_cache[j];
if (unlikely(match)) {
if (debug_locks_off_graph_unlock()) {
/*
* We all just reset everything, how did it match?
*/
WARN_ON(1);
}
goto out_restore;
}
if (unlikely(lock_class_cache_is_registered(lock))) {
if (debug_locks_off_graph_unlock()) {
/*
* We all just reset everything, how did it match?
*/
WARN_ON(1);
}
goto out_restore;
}
if (locked)
graph_unlock();