KEYS: Give key types their own lockdep class for key->sem

Give keys their own lockdep class to differentiate them from each other in case
a key of one type has to refer to a key of another type.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

2 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/key-type.h b/include/linux/key-type.h
index 9efd081bb31e..39e3c082c49d 100644
--- a/include/linux/key-type.h
+++ b/include/linux/key-type.h
@@ -92,6 +92,7 @@ struct key_type {
 
         /* internal fields */
         struct list_head        link;           /* link in types list */
+        struct lock_class_key   lock_class;     /* key->sem lock class */
 };
 
 extern struct key_type key_type_keyring;
diff --git a/security/keys/key.c b/security/keys/key.c
index 4414abddcb5b..4f64c7267afb 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -291,6 +291,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 
         atomic_set(&key->usage, 1);
         init_rwsem(&key->sem);
+        lockdep_set_class(&key->sem, &type->lock_class);
         key->type = type;
         key->user = user;
         key->quotalen = quotalen;
@@ -946,6 +947,8 @@ int register_key_type(struct key_type *ktype)
         struct key_type *p;
         int ret;
 
+        memset(&ktype->lock_class, 0, sizeof(ktype->lock_class));
+
         ret = -EEXIST;
         down_write(&key_types_sem);