security: Apply lockdep-based checking to rcu_dereference() uses

Apply lockdep-ified RCU primitives to key_gc_keyring() and
keyring_destroy().

Cc: David Howells <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
LKML-Reference: <1266887105[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/security/keys/gc.c b/security/keys/gc.c
index 4770be375ffece3d506ea86b769aee3bf8607595..19902319d097acc75ef6246d6981e33b43a8c69f 100644 (file)
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -77,7 +77,8 @@ static bool key_gc_keyring(struct key *keyring, time_t limit)
                goto dont_gc;
 
        /* scan the keyring looking for dead keys */
-       klist = rcu_dereference(keyring->payload.subscriptions);
+       klist = rcu_dereference_check(keyring->payload.subscriptions,
+                                     lockdep_is_held(&key_serial_lock));
        if (!klist)
                goto dont_gc;
 

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 8ec02746ca993fa697da600757fbcd21b319e2f7..e814d2109f8ef170ea60043fa83b1f37c3e35de1 100644 (file)
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -151,7 +151,9 @@ static void keyring_destroy(struct key *keyring)
                write_unlock(&keyring_name_lock);
        }
 
-       klist = rcu_dereference(keyring->payload.subscriptions);
+       klist = rcu_dereference_check(keyring->payload.subscriptions,
+                                     rcu_read_lock_held() ||
+                                     atomic_read(&keyring->usage) == 0);
        if (klist) {
                for (loop = klist->nkeys - 1; loop >= 0; loop--)
                        key_put(klist->keys[loop]);