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-rw-r--r--security/keys/key.c34
1 files changed, 18 insertions, 16 deletions
diff --git a/security/keys/key.c b/security/keys/key.c
index 01bbc6d9d19b..fdd5ca6d89fc 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -1,6 +1,6 @@
-/* key.c: basic authentication token and access key management
+/* Basic authentication token and access key management
*
- * Copyright (C) 2004-6 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
@@ -34,7 +34,7 @@ static void key_cleanup(struct work_struct *work);
static DECLARE_WORK(key_cleanup_task, key_cleanup);
/* we serialise key instantiation and link */
-DECLARE_RWSEM(key_construction_sem);
+DEFINE_MUTEX(key_construction_mutex);
/* any key who's type gets unegistered will be re-typed to this */
static struct key_type key_type_dead = {
@@ -104,7 +104,7 @@ struct key_user *key_user_lookup(uid_t uid)
candidate->qnkeys = 0;
candidate->qnbytes = 0;
spin_lock_init(&candidate->lock);
- INIT_LIST_HEAD(&candidate->consq);
+ mutex_init(&candidate->cons_lock);
rb_link_node(&candidate->node, parent, p);
rb_insert_color(&candidate->node, &key_user_tree);
@@ -418,7 +418,7 @@ static int __key_instantiate_and_link(struct key *key,
awaken = 0;
ret = -EBUSY;
- down_write(&key_construction_sem);
+ mutex_lock(&key_construction_mutex);
/* can't instantiate twice */
if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
@@ -443,11 +443,11 @@ static int __key_instantiate_and_link(struct key *key,
}
}
- up_write(&key_construction_sem);
+ mutex_unlock(&key_construction_mutex);
/* wake up anyone waiting for a key to be constructed */
if (awaken)
- wake_up_all(&request_key_conswq);
+ wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
return ret;
@@ -500,7 +500,7 @@ int key_negate_and_link(struct key *key,
if (keyring)
down_write(&keyring->sem);
- down_write(&key_construction_sem);
+ mutex_lock(&key_construction_mutex);
/* can't instantiate twice */
if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
@@ -525,14 +525,14 @@ int key_negate_and_link(struct key *key,
key_revoke(instkey);
}
- up_write(&key_construction_sem);
+ mutex_unlock(&key_construction_mutex);
if (keyring)
up_write(&keyring->sem);
/* wake up anyone waiting for a key to be constructed */
if (awaken)
- wake_up_all(&request_key_conswq);
+ wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
return ret;
@@ -899,12 +899,14 @@ void key_revoke(struct key *key)
{
key_check(key);
- /* make sure no one's trying to change or use the key when we mark
- * it */
- down_write(&key->sem);
- set_bit(KEY_FLAG_REVOKED, &key->flags);
-
- if (key->type->revoke)
+ /* make sure no one's trying to change or use the key when we mark it
+ * - we tell lockdep that we might nest because we might be revoking an
+ * authorisation key whilst holding the sem on a key we've just
+ * instantiated
+ */
+ down_write_nested(&key->sem, 1);
+ if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&
+ key->type->revoke)
key->type->revoke(key);
up_write(&key->sem);

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