Valdis.Kletnieks@vt.edu wrote:
> On Mon, 05 Apr 2010 16:09:45 PDT, akpm@linux-foundation.org said:
>> The mm-of-the-moment snapshot 2010-04-05-16-09 has been uploaded to
>>
>>    http://userweb.kernel.org/~akpm/mmotm/
> 
> Seen in dmesg, 2.6.34-rc2-mmotm0323 didn't do this. Tossing it at all the
> likely suspects, hopefully somebody will recognize it and save me the
> bisecting. ;)
> 
> [   11.488535] ctnetlink v0.93: registering with nfnetlink.
> [   11.488579] 
> [   11.488579] ===================================================
> [   11.489529] [ INFO: suspicious rcu_dereference_check() usage. ]
> [   11.489988] ---------------------------------------------------
> [   11.490494] net/netfilter/nf_conntrack_ecache.c:88 invoked rcu_dereference_check() without protection!
> [   11.491024] 
> [   11.491024] other info that might help us debug this:
> [   11.491025] 
> [   11.492834] 
> [   11.492835] rcu_scheduler_active = 1, debug_locks = 0
> [   11.494124] 1 lock held by swapper/1:
> [   11.494776]  #0:  (nf_ct_ecache_mutex){+.+...}, at: [<ffffffff8148c606>] nf_conntrack_register_notifier+0x1a/0x76
> [   11.495505] 

There are some unnecessary rcu_dereference() calls in the conntrack
notifier registration and unregistration functions.

Does this fix it?