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From: David Miller <davem@davemloft.net>
To: ying.xue@windriver.com
Cc: jon.maloy@ericsson.com, erik.hugne@ericsson.com,
	netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net
Subject: Re: [PATCH net] tipc: fix a potential deadlock
Date: Tue, 21 Oct 2014 15:30:13 -0400 (EDT)	[thread overview]
Message-ID: <20141021.153013.950822619392700910.davem@davemloft.net> (raw)
In-Reply-To: <1413787465-14600-1-git-send-email-ying.xue@windriver.com>

From: Ying Xue <ying.xue@windriver.com>
Date: Mon, 20 Oct 2014 14:44:25 +0800

> 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>

Applied.

      reply	other threads:[~2014-10-21 19:30 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-20  6:44 [PATCH net] tipc: fix a potential deadlock Ying Xue
2014-10-21 19:30 ` David Miller [this message]

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