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| author | Ying Xue <ying.xue@windriver.com> | 2014-10-20 14:44:25 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-21 15:28:15 -0400 |
| commit | 7b8613e0a1502b43b3b36c93c66f835c891f63b3 (patch) | |
| tree | a2152fd6e1094c6716855e1ae5a4299f1c95a203 /net/tipc/node.h | |
| parent | 73829bf6fec70703f10e360676d81d327f21ebf6 (diff) | |
| download | linux-7b8613e0a1502b43b3b36c93c66f835c891f63b3.tar.gz linux-7b8613e0a1502b43b3b36c93c66f835c891f63b3.tar.bz2 linux-7b8613e0a1502b43b3b36c93c66f835c891f63b3.zip | |
tipc: fix a potential deadlock
Locking dependency detected below possible unsafe locking scenario:
CPU0 CPU1
T0: tipc_named_rcv() tipc_rcv()
T1: [grab nametble write lock]* [grab node lock]*
T2: tipc_update_nametbl() tipc_node_link_up()
T3: tipc_nodesub_subscribe() tipc_nametbl_publish()
T4: [grab node lock]* [grab nametble write lock]*
The opposite order of holding nametbl write lock and node lock on
above two different paths may result in a deadlock. If we move the
the updating of the name table after link state named out of node
lock, the reverse order of holding locks will be eliminated, and
as a result, the deadlock risk.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/node.h')
| -rw-r--r-- | net/tipc/node.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/tipc/node.h b/net/tipc/node.h index 67513c3c852c..04e91458bb29 100644 --- a/net/tipc/node.h +++ b/net/tipc/node.h @@ -53,6 +53,7 @@ * TIPC_WAIT_OWN_LINKS_DOWN: wait until peer node is declared down * TIPC_NOTIFY_NODE_DOWN: notify node is down * TIPC_NOTIFY_NODE_UP: notify node is up + * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type */ enum { TIPC_WAIT_PEER_LINKS_DOWN = (1 << 1), @@ -60,7 +61,9 @@ enum { TIPC_NOTIFY_NODE_DOWN = (1 << 3), TIPC_NOTIFY_NODE_UP = (1 << 4), TIPC_WAKEUP_USERS = (1 << 5), - TIPC_WAKEUP_BCAST_USERS = (1 << 6) + TIPC_WAKEUP_BCAST_USERS = (1 << 6), + TIPC_NOTIFY_LINK_UP = (1 << 7), + TIPC_NOTIFY_LINK_DOWN = (1 << 8) }; /** @@ -100,6 +103,7 @@ struct tipc_node_bclink { * @working_links: number of working links to node (both active and standby) * @link_cnt: number of links to node * @signature: node instance identifier + * @link_id: local and remote bearer ids of changing link, if any * @nsub: list of "node down" subscriptions monitoring node * @rcu: rcu struct for tipc_node */ @@ -116,6 +120,7 @@ struct tipc_node { int link_cnt; int working_links; u32 signature; + u32 link_id; struct list_head nsub; struct sk_buff_head waiting_sks; struct list_head conn_sks; |