[PATCH v3 20/24] locking/lockdep: Introduce __lockdep_free_key_range()

[Bart Van Assche]

This patch does not change any functionality but makes the next patch
in this series easier to read.

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Waiman Long <longman@xxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 kernel/locking/lockdep.c | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 78f14c151407..8c69516b1283 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4478,27 +4478,17 @@ static void schedule_free_zapped_classes(void)
 }
 
 /*
- * Used in module.c to remove lock classes from memory that is going to be
- * freed; and possibly re-used by other modules.
- *
- * We will have had one sync_sched() before getting here, so we're guaranteed
- * nobody will look up these exact classes -- they're properly dead but still
- * allocated.
+ * Remove all lock classes from the class hash table and from the
+ * all_lock_classes list whose key or name is in the address range [start,
+ * start + size). Move these lock classes to the zapped_classes list. Must
+ * be called with the graph lock held.
  */
-void lockdep_free_key_range(void *start, unsigned long size)
+static 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;
-
-	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) {
@@ -4511,7 +4501,24 @@ void lockdep_free_key_range(void *start, unsigned long size)
 	}
 
 	schedule_free_zapped_classes();
+}
 
+/*
+ * Used in module.c to remove lock classes from memory that is going to be
+ * freed; and possibly re-used by other modules.
+ *
+ * We will have had one sync_sched() before getting here, so we're guaranteed
+ * nobody will look up these exact classes -- they're properly dead but still
+ * allocated.
+ */
+void lockdep_free_key_range(void *start, unsigned long size)
+{
+	unsigned long flags;
+	int locked;
+
+	raw_local_irq_save(flags);
+	locked = graph_lock();
+	__lockdep_free_key_range(start, size);
 	if (locked)
 		graph_unlock();
 	raw_local_irq_restore(flags);
-- 
2.20.0.rc2.403.gdbc3b29805-goog