Re: Fw: memory corruption in tcp bind hash buckets on SMP?

[Raghu Angadi <raghuangadi@yahoo.com>]

--- kuznet@ms2.inr.ac.ru wrote:
> So, its absence in bind hash must be guaranteed to the time of destruction.
> Look at this from another aspect: imagine you increment refcnt when
> adding to binding table. 

> OK. So, what does guarantee that bucket
> will not remain in bind hash forever? 
ease of finding the bug :). 'cause this would leave tw in the list withought
deleting it.. that would blow tw_bind_bucket_cache pool and that is so much
easier to find. would've been fixed in very early days.. probably in 2.3.0.1
:->. Still not argueing for double refcount. Reversing the removal order
would work too.. now we will have "if (!tw->tb) return;" instead.

> And "it will not" is equivalent
> to "refcnt is not useful".
> 
> Anyway, I will think on this at night, I am not ready to tell how to
> do this right.
> 
> 
> > If you want to avoid timewait_kill() getting called twice altogether.
> 
> Sorry, I did not understand what do you mean here. It can be called
> twice or three times or more. This is impossible to avoid without adding
> spinlock to timewait bucket.

I didn't think you would want to avoid multiple calls to tw_kill() either. 

Raghu.
> Alexey


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