Subject: Re: RFC: Network privilege separation.

From: Andi Kleen <[email-masked]>
Date: Mon, 12 Jan 2009 21:14:35 +0100

> Expanding the heap,

That's a problem agreed  Ok you can just always use very
bss arrays sized for the worst case.

> Getting timestamps. 

At least on 64bit that's done in ring 3 only with a vsyscall.

> Waiting on futexes, 
> catching signals, polling file descriptors. Seeking, doing vectorized I/O. 
> Cloning.

That all can be done by the frontend reading/feeding
data into the pipe. But it shouldn't directly access the user data
to be immune against attacks.

> Codecs don't like to read/write raw video through a pipe...

I don't think that's given. It would need some restructuring,
but I think the end result would be likely worth it.

-Andi

-- 
[email-masked] -- Speaking for myself only.