Re: A question about PROT_NONE on Sparc and Sparc64

From: Jamie Lokier
Date: Wed Jun 30 2004 - 17:53:30 EST


David S. Miller wrote:
> On Wed, 30 Jun 2004 04:28:05 -0400
> Jakub Jelinek <jakub@xxxxxxxxxx> wrote:
>
> > I believe R!X and X!R pages ought to be possible on sparc64 too,
> > just use a different bit as "read" in the fast ITLB miss handler
> > from the one fast DTLB miss uses.
>
> That's correct. But I have no plans to implement this
> any time soon :-)

The PaX security patch already implements R!X pages on Sparc64, so you
could just cut out that part of the patch. Just pick out the changes
to arch/sparc64/* and include/asm-sparc64/*:

http://pax.grsecurity.net/pax-linux-2.6.7-200406252135.patch

It appears to use exactly the technique Jakub describes, and has been tested.

-- Jamie
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