Re: TCP-MD5 checksum failure on x86_64 SMP

Bhaskar Dutta
2010-05-04T14:28:35Z

On Tue, May 4, 2010 at 5:02 PM, Ben Hutchings <bhutchings@solarflare.com> wrote:
> On Tue, 2010-05-04 at 09:00 +0530, Bhaskar Dutta wrote:
>> Hi,
>>
>> I am observing intermittent TCP-MD5 checksum failures
>> (CONFIG_TCP_MD5SIG)  on kernel 2.6.31 while talking to a BGP router.
>>
>> The problem is only seen in multi-core 64 bit machines.
>> Is there any known bug in the per_cpu_ptr implementation (I am aware
>> that the percpu allocator has been re-implemented in 2.6.33) that
>> might cause a corruption in 64 bit SMP machines?
>>
>> Any pointers would be appreciated.
>
> There was another recent report of incorrect MD5 signatures in
> <http://thread.gmane.org/gmane.linux.network/159556>, but without any
> response.
>
> Ben.
>

I found another thread posted back in Jan 2007 with a similar bug
(x86_64 on 2.6.20) but no replies to that as well.
http://lkml.org/lkml/2007/1/20/56

Bhaskar