[lucid] cherry-pick BUG->WARN change in tun

[Tim Gardner]

On 01/14/2011 01:30 PM, Stefan Bader wrote:
> On 01/13/2011 04:38 PM, dann frazier wrote:
>> Please consider pulling the following change into lucid. This resolves
>> LP #698883.
>>
>> SRU Justification:
>>   Avoids crash
>> Impact:
>>   BUG() causes system to crash
>> Fix:
>>   Upstream reduced BUG() to a WARN_ON_ONCE w/ additional diagnostic info.
>>   Upstream commit ef3db4a5954281bc1ea49a4739c88eaea091dc71.
>> Testcase:
>>   A tractable case would presumably require packet injection. Otherwise, a long
>>   stable run on a configuration that has hit this problem before.
>>
>> This was originally reported by a customer in restricted LP #680356. A
>> custom kernel w/ this fix was applied and neither the issue nor a
>> regression has been observed in the following month.
>>
>> Upstream change follows - it cherry-picks cleanly into the lucid git tree.
>>
>> commit ef3db4a5954281bc1ea49a4739c88eaea091dc71
>> Author: Michael S. Tsirkin<mst at redhat.com>
>> Date: Wed Jul 21 04:32:45 2010 +0000
>>
>>      tun: avoid BUG, dump packet on GSO errors
>>
>>      There are still some LRO cards that cause GSO errors in tun,
>>      and BUG on this is an unfriendly way to tell the admin
>>      to disable LRO.
>>
>>      Further, experience shows we might have more GSO bugs lurking.
>>      See https://bugzilla.kernel.org/show_bug.cgi?id=16413
>>      as a recent example.
>>      dumping a packet will make it easier to figure it out.
>>
>>      Replace BUG with warning+dump+drop the packet to make
>>      GSO errors in tun less critical and easier to debug.
>>
>>      Signed-off-by: Michael S. Tsirkin<mst at redhat.com>
>>      Tested-by: Alex Unigovsky<unik at compot.ru>
>>      Acked-by: Herbert Xu<herbert at gondor.apana.org.au>
>>      Signed-off-by: David S. Miller<davem at davemloft.net>
>>
>
> Sounds reasonable to me. May be also a candidate for hinting towards upstream
> longterm before .35
>
> Acked-by: Stefan Bader<stefan.bader at canonical.com>
>

acked and applied

-- 
Tim Gardner tim.gardner at canonical.com