Re: Suspicious RCU usage in bridge with Linux v4.0-9362-g1fc149933fd4

From: Josh Boyer <jwboyer@fedoraproject.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev <netdev@vger.kernel.org>, Dominick Grift <dac.override@gmail.com>
Subject: Re: Suspicious RCU usage in bridge with Linux v4.0-9362-g1fc149933fd4
Date: Thu, 21 May 2015 15:22:16 -0400	[thread overview]
Message-ID: <CA+5PVA70p=y_62fkEG6OU=+-QpLX-SFi_mZ3UNgA4nu7GmvwcQ@mail.gmail.com> (raw)
In-Reply-To: <20150512182741.GD9693@x131e>

On Tue, May 12, 2015 at 2:27 PM, Dominick Grift <dac.override@gmail.com> wrote:
> On Mon, May 11, 2015 at 07:53:06AM -0700, Eric Dumazet wrote:
>>
>> Hi Dominick
>>
>> Have you tried this patch I sent last monday ?
>>
>> I will submit formally when I get a test result.
>>
>> Thanks
>
> Eric,
>
> I have tested the below patch and everything is in order!
>
> Thank you!
>
>>
>> diff --git a/net/bridge/br_stp_timer.c b/net/bridge/br_stp_timer.c
>> index 4fcaa67750fda845ad0a180332c4cd96a9524086..7caf7fae2d5b8aa369b924e1c87a47c343fb8954 100644
>> --- a/net/bridge/br_stp_timer.c
>> +++ b/net/bridge/br_stp_timer.c
>> @@ -97,7 +97,9 @@ static void br_forward_delay_timer_expired(unsigned long arg)
>>               netif_carrier_on(br->dev);
>>       }
>>       br_log_state(p);
>> +     rcu_read_lock();
>>       br_ifinfo_notify(RTM_NEWLINK, p);
>> +     rcu_read_unlock();
>>       spin_unlock(&br->lock);
>>  }
>>
>>
>>

I'm still seeing this with Linus' tree as of yesterday.  Is this
queued anywhere for 4.1?

josh