Subject: Re: mmap'ing framebuffer memory in MI drivers...
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Jonathan Stone <jonathan@DSG.Stanford.EDU>
List: tech-kern
Date: 03/05/1999 19:28:33
In message <199903060314.TAA19521@lestat.nas.nasa.gov>Jason Thorpe writes
>On Fri, 5 Mar 1999 18:50:07 -0800 (PST) 
> "Eduardo E. Horvath" <eeh@one-o.com> wrote:

>...because, for one, the first N times it's called, you're not entering
>any mappings at all... You're just checking that the mapping request is
>valid.
>
>Take a look at udv_fault() for how the mappings are actually entered.


i.e., it just iterates over each page in the region, calling the
d_mmap() routine to verify that permission and bounds checks will
succeed.

But what do you think of GWR's idea of a separate once-per-mmap() call
to do that?  If we had that entrypoint, couldn't we do what Eduardo
suggests?