Re: New packet list - out of memory?

["Anders Broman" <a.broman () telia com>]

-----Ursprungligt meddelande-----
Från: wireshark-dev-bounces () wireshark org
[mailto:wireshark-dev-bounces () wireshark org] För Jeff Morriss
Skickat: den 9 oktober 2009 22:06
Till: Developer support list for Wireshark
Ämne: Re: [Wireshark-dev] New packet list - out of memory?

Anders Broman wrote:
> > > I don't think we can/should turn off canaries in se_ allocations. 
> > > Instead we should create a new canary-less allocator.  (Not sure what
> > such a thing should 
> > > be named, of course...)
> >
> > Well as I see it EP memory is not a problem we only use one chunk (10M)
> > During the life time of a packet so memory efficency isn't a big issue.
> >
> > But when dealing with large files waisting +30% of the memory is not an
> > option I think.
>
> True, especially at the rate we're using memory :-)
>
> > A way to still test se_alloc() could be to let the buildbot doing fuzz
> > test use canaries forinstance.
> >
> > I don't see that a new allocator would solve the problem, when to use
> > it?
>
> Well, you know, we could only use the canary allocator when we think we 
> might stomp on the memory.  Hmmm, I guess that logic doesn't work too 
> well, huh? ;-)
>
> My initial thought had been something like: only use the canary-less 
> allocator for stuff that we allocate a LOT of or core-stuff (and make 
> dissectors use the canaries on the assumption we trust them less).  I'm 
> not sure that makes a lot of sense either, though...
>
> I just keep thinking of a time a while ago where we saw quite a lot of 
> dissector bugs due to memory (canary) corruption.  Apparently most of 
> those were ep_ allocations.  Maybe you're right that just doing it on 
> the buildbot would work; keeping it on during development work would be 
> a good practice too.

I thought about a define/switch DEVELOPMENT/PRODUCTION
But I'm not sure it's a good idea. You might want good performance from the
development build and it's easy to forget about these kind of things.
Regards
Anders
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