[Libwebsockets] Valgrind

"Andy Green (林安廸)" andy at warmcat.com
Mon Feb 11 15:08:38 CET 2013


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




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