[Libwebsockets] Valgrind

Jack Mitchell ml at communistcode.co.uk
Mon Feb 11 15:27:58 CET 2013

On 11/02/13 14:08, "Andy Green (林安廸)" wrote:
> On 11/02/13 18:23, the mail apparently from Jack Mitchell included:
>> On 11/02/13 07:04, "Andy Green (林安廸)" wrote:
>>> Hi -
>>> I pushed a bunch of bloat-reduction patches, the allocation for a
>>> websocket with the library built for openssl, client and server and
>>> the rest of the stuff defaults, on x86_64, is now only 240 bytes. An
>>> extra 1328 is needed during header processing but is freed as soon as
>>> that's done.
>>> I was curious about memory leaking, so I ran valgrind on both sides.
>>> It found a few problems which I also fixed and pushed.
>>> Without building for ssl, it's now valgrind-clean on both the test
>>> server and client.
>>> With SSL, just initializing the library leaks 88 bytes
>>> http://git.libwebsockets.org/cgi-bin/cgit/libwebsockets/commit/?id=ad68639a7bd74b8a4800168fc8963ab98bf7d716 
>>> and running it, it claims there's some unitnitialized accesses coming,
>>> which cascade into quite a few warnings. I'm unclear whether that's a
>>> real problem or some kind of valgrind-noise, sincee there's no symptom
>>> and it does not appear without ssl configured.
>>> Does anyone have any experience with OpenSSL valgrind complaints or
>>> suggestions?
>>> -Andy
>>> _______________________________________________
>>> Libwebsockets mailing list
>>> Libwebsockets at ml.libwebsockets.org
>>> http://ml.libwebsockets.org/mailman/listinfo/libwebsockets
>> I've just had a quick browse and some very nice work, well done!
> Thanks.
>> Unfortuantly, I have no experience with OpenSSl, so cannot be of
>> assistance.
> Interestingly when I use Joakim's CyaSSL in place of OpenSSL, there's 
> no problem, test server and client with a chrome session too are both 
> totally clean with valgrind.
> There's more info here
> http://git.libwebsockets.org/cgi-bin/cgit/libwebsockets/commit/?id=224149ab58fb0db7eff47c535e90b6c0f5cf2060 
> AFAIK there's nothing more to do for OpenSSL + valgrind from our side.
> I'll be very interested if anyone sees any funnies with valgrind under 
> different loads / conditions, bearing in mind OpenSSL is known to blow 
> 3 lost allocations and occasional uninitialized complaints.  There are 
> still 20 mallocs() in the main code + test server, and 2 realloc in 
> the deflate-frame extension despite a lot got thrown out today.
> -Andy

I'll give it a whirl on my arm platform this afternoon and see if I come 
up with anything.


   Jack Mitchell (jack at embed.me.uk)
   Embedded Systems Engineer


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