[PATCH 16/27] locking/lockdep: Stop using RCU primitives to access all_lock_classes

[Bart Van Assche]

Due to the previous patch all code that accesses the 'all_lock_classes'
list holds the graph lock. Hence use regular list primitives instead of
their RCU variants to access this list.

Signed-off-by: Bart Van Assche <bvanass...@acm.org>
---
 kernel/locking/lockdep.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index ab6abe52e974..96fc8e92c2a6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -626,7 +626,8 @@ static int static_obj(void *obj)
 
 /*
  * To make lock name printouts unique, we calculate a unique
- * class->name_version generation counter:
+ * class->name_version generation counter. The caller must hold the graph
+ * lock.
  */
 static int count_matching_names(struct lock_class *new_class)
 {
@@ -636,7 +637,7 @@ static int count_matching_names(struct lock_class 
*new_class)
        if (!new_class->name)
                return 0;
 
-       list_for_each_entry_rcu(class, &all_lock_classes, lock_entry) {
+       list_for_each_entry(class, &all_lock_classes, lock_entry) {
                if (new_class->key - new_class->subclass == class->key)
                        return class->name_version;
                if (class->name && !strcmp(class->name, new_class->name))
@@ -801,7 +802,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int 
subclass, int force)
        /*
         * Add it to the global list of classes:
         */
-       list_add_tail_rcu(&class->lock_entry, &all_lock_classes);
+       list_add_tail(&class->lock_entry, &all_lock_classes);
 
        if (verbose(class)) {
                graph_unlock();
@@ -4120,6 +4121,9 @@ void lockdep_reset(void)
        raw_local_irq_restore(flags);
 }
 
+/*
+ * Remove all references to a lock class. The caller must hold the graph lock.
+ */
 static void zap_class(struct lock_class *class)
 {
        int i;
@@ -4136,7 +4140,7 @@ static void zap_class(struct lock_class *class)
         * Unhash the class and remove it from the all_lock_classes list:
         */
        hlist_del_rcu(&class->hash_entry);
-       list_del_rcu(&class->lock_entry);
+       list_del(&class->lock_entry);
 
        RCU_INIT_POINTER(class->key, NULL);
        RCU_INIT_POINTER(class->name, NULL);
-- 
2.20.0.rc0.387.gc7a69e6b6c-goog