Re: [PATCH 1/6] mm: use mm_struct to resolve gate vma's in__get_user_pages

From: Al Viro
Date: Wed Mar 09 2011 - 01:06:47 EST


On Wed, Mar 09, 2011 at 02:19:30PM +0900, KOSAKI Motohiro wrote:

> Hmm..
> Is this works? In exec() case task has two mm, old and new-borned. tsk has
> no enough information to detect gate area if 64bit process exec 32bit process
> or oppsite case. On Linux, 32bit and 64bit processes have perfectly different
> process vma layout.
>
> Am I missing something?

Patch series refered to in [0/6] ;-) FWIW, that would probably be better
off as one mail thread - would be easier to find.

What happens is that mm_struct gets marked as 32bit/64bit at execve time
(on x86, everything else doesn't care), so this stuff becomes possible
to calculate by mm_struct alone.
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