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Subject[PATCH v6 06/16] locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock()
Date
This patch does not change the behavior of these functions but makes the
patch that frees unused lock classes easier to read.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
kernel/locking/lockdep.c | 74 +++++++++++++++++++++-------------------
1 file changed, 38 insertions(+), 36 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 5ca5904ad489..52b280480a08 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4172,6 +4172,26 @@ static inline int within(const void *addr, void *start, unsigned long size)
return addr >= start && addr < start + size;
}

+static void __lockdep_free_key_range(void *start, unsigned long size)
+{
+ struct lock_class *class;
+ struct hlist_head *head;
+ int i;
+
+ /*
+ * Unhash all classes that were created by this module:
+ */
+ for (i = 0; i < CLASSHASH_SIZE; i++) {
+ head = classhash_table + i;
+ hlist_for_each_entry_rcu(class, head, hash_entry) {
+ if (!within(class->key, start, size) &&
+ !within(class->name, start, size))
+ continue;
+ zap_class(class);
+ }
+ }
+}
+
/*
* Used in module.c to remove lock classes from memory that is going to be
* freed; and possibly re-used by other modules.
@@ -4182,30 +4202,14 @@ static inline int within(const void *addr, void *start, unsigned long size)
*/
void lockdep_free_key_range(void *start, unsigned long size)
{
- struct lock_class *class;
- struct hlist_head *head;
unsigned long flags;
- int i;
int locked;

init_data_structures_once();

raw_local_irq_save(flags);
locked = graph_lock();
-
- /*
- * Unhash all classes that were created by this module:
- */
- for (i = 0; i < CLASSHASH_SIZE; i++) {
- head = classhash_table + i;
- hlist_for_each_entry_rcu(class, head, hash_entry) {
- if (within(class->key, start, size))
- zap_class(class);
- else if (within(class->name, start, size))
- zap_class(class);
- }
- }
-
+ __lockdep_free_key_range(start, size);
if (locked)
graph_unlock();
raw_local_irq_restore(flags);
@@ -4247,16 +4251,11 @@ static bool lock_class_cache_is_registered(struct lockdep_map *lock)
return false;
}

-void lockdep_reset_lock(struct lockdep_map *lock)
+/* The caller must hold the graph lock. Does not sleep. */
+static void __lockdep_reset_lock(struct lockdep_map *lock)
{
struct lock_class *class;
- unsigned long flags;
- int j, locked;
-
- init_data_structures_once();
-
- raw_local_irq_save(flags);
- locked = graph_lock();
+ int j;

/*
* Remove all classes this lock might have:
@@ -4273,19 +4272,22 @@ void lockdep_reset_lock(struct lockdep_map *lock)
* Debug check: in the end all mapped classes should
* be gone.
*/
- 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 (WARN_ON_ONCE(lock_class_cache_is_registered(lock)))
+ debug_locks_off();
+}
+
+void lockdep_reset_lock(struct lockdep_map *lock)
+{
+ unsigned long flags;
+ int locked;
+
+ init_data_structures_once();
+
+ raw_local_irq_save(flags);
+ locked = graph_lock();
+ __lockdep_reset_lock(lock);
if (locked)
graph_unlock();
-
-out_restore:
raw_local_irq_restore(flags);
}

--
2.20.1.97.g81188d93c3-goog
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