clps711xfb: convert to proc_fops

[safe/jmp/linux-2.6] / security / keys / keyring.c

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 3dba81c..8ec0274 100644 (file)
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1000,3 +1000,102 @@ static void keyring_revoke(struct key *keyring)
        }
 
 } /* end keyring_revoke() */
+
+/*
+ * Determine whether a key is dead
+ */
+static bool key_is_dead(struct key *key, time_t limit)
+{
+       return test_bit(KEY_FLAG_DEAD, &key->flags) ||
+               (key->expiry > 0 && key->expiry <= limit);
+}
+
+/*
+ * Collect garbage from the contents of a keyring
+ */
+void keyring_gc(struct key *keyring, time_t limit)
+{
+       struct keyring_list *klist, *new;
+       struct key *key;
+       int loop, keep, max;
+
+       kenter("{%x,%s}", key_serial(keyring), keyring->description);
+
+       down_write(&keyring->sem);
+
+       klist = keyring->payload.subscriptions;
+       if (!klist)
+               goto no_klist;
+
+       /* work out how many subscriptions we're keeping */
+       keep = 0;
+       for (loop = klist->nkeys - 1; loop >= 0; loop--)
+               if (!key_is_dead(klist->keys[loop], limit))
+                       keep++;
+
+       if (keep == klist->nkeys)
+               goto just_return;
+
+       /* allocate a new keyring payload */
+       max = roundup(keep, 4);
+       new = kmalloc(sizeof(struct keyring_list) + max * sizeof(struct key *),
+                     GFP_KERNEL);
+       if (!new)
+               goto nomem;
+       new->maxkeys = max;
+       new->nkeys = 0;
+       new->delkey = 0;
+
+       /* install the live keys
+        * - must take care as expired keys may be updated back to life
+        */
+       keep = 0;
+       for (loop = klist->nkeys - 1; loop >= 0; loop--) {
+               key = klist->keys[loop];
+               if (!key_is_dead(key, limit)) {
+                       if (keep >= max)
+                               goto discard_new;
+                       new->keys[keep++] = key_get(key);
+               }
+       }
+       new->nkeys = keep;
+
+       /* adjust the quota */
+       key_payload_reserve(keyring,
+                           sizeof(struct keyring_list) +
+                           KEYQUOTA_LINK_BYTES * keep);
+
+       if (keep == 0) {
+               rcu_assign_pointer(keyring->payload.subscriptions, NULL);
+               kfree(new);
+       } else {
+               rcu_assign_pointer(keyring->payload.subscriptions, new);
+       }
+
+       up_write(&keyring->sem);
+
+       call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
+       kleave(" [yes]");
+       return;
+
+discard_new:
+       new->nkeys = keep;
+       keyring_clear_rcu_disposal(&new->rcu);
+       up_write(&keyring->sem);
+       kleave(" [discard]");
+       return;
+
+just_return:
+       up_write(&keyring->sem);
+       kleave(" [no dead]");
+       return;
+
+no_klist:
+       up_write(&keyring->sem);
+       kleave(" [no_klist]");
+       return;
+
+nomem:
+       up_write(&keyring->sem);
+       kleave(" [oom]");
+}