Wireshark-dev: Re: [Wireshark-dev] New packet list - out of memory?
From: Jeff Morriss <[email protected]>
Date: Fri, 09 Oct 2009 16:05:33 -0400
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.