diff options
| author | Ying Xue <ying.xue@windriver.com> | 2015-03-26 18:10:24 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-29 12:40:28 -0700 |
| commit | 8a0f6ebe8494c5c6ccfe12264385b64c280e3241 (patch) | |
| tree | 2f106a95ffda73b8e8f1596cc95152398cd5379b /net/tipc/name_distr.c | |
| parent | b952b2befb6f6b009e91f087285b9a0a6beb1cc8 (diff) | |
tipc: involve reference counter for node structure
TIPC node hash node table is protected with rcu lock on read side.
tipc_node_find() is used to look for a node object with node address
through iterating the hash node table. As the entire process of what
tipc_node_find() traverses the table is guarded with rcu read lock,
it's safe for us. However, when callers use the node object returned
by tipc_node_find(), there is no rcu read lock applied. Therefore,
this is absolutely unsafe for callers of tipc_node_find().
Now we introduce a reference counter for node structure. Before
tipc_node_find() returns node object to its caller, it first increases
the reference counter. Accordingly, after its caller used it up,
it decreases the counter again. This can prevent a node being used by
one thread from being freed by another thread.
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/name_distr.c')
| -rw-r--r-- | net/tipc/name_distr.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c index 506aaa565da7..41e7b7e4dda0 100644 --- a/net/tipc/name_distr.c +++ b/net/tipc/name_distr.c @@ -244,6 +244,7 @@ static void tipc_publ_subscribe(struct net *net, struct publication *publ, tipc_node_lock(node); list_add_tail(&publ->nodesub_list, &node->publ_list); tipc_node_unlock(node); + tipc_node_put(node); } static void tipc_publ_unsubscribe(struct net *net, struct publication *publ, @@ -258,6 +259,7 @@ static void tipc_publ_unsubscribe(struct net *net, struct publication *publ, tipc_node_lock(node); list_del_init(&publ->nodesub_list); tipc_node_unlock(node); + tipc_node_put(node); } /** |