From: Andi Kleen <ak@suse.de>
To: Benjamin LaHaise <bcrl@kvack.org>
Subject: Re: [PATCH/RFC] Shared page tables
Date: Tue, 24 Jan 2006 02:38:29 +0100
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Cc: Ray Bryant <raybry@mpdtxmail.amd.com>, Dave McCracken <dmccr@us.ibm.com>,
       Robin Holt <holt@sgi.com>, Hugh Dickins <hugh@veritas.com>,
       Linux Kernel <linux-kernel@vger.kernel.org>,
       Linux Memory Management <linux-mm@kvack.org>
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On Tuesday 24 January 2006 02:23, Benjamin LaHaise wrote:
> On Tue, Jan 24, 2006 at 02:10:03AM +0100, Andi Kleen wrote:
> > The randomization is not for cache coloring, but for security purposes
> > (except for the old very small stack randomization that was used
> > to avoid conflicts on HyperThreaded CPUs). I would be surprised if the
> > mmap made much difference because it's page aligned and at least
> > on x86 the L2 and larger caches are usually PI.
> 
> Actually, does this even affect executable segments?  Iirc, prelinking 
> already results in executables being mapped at the same physical offset 
> across binaries in a given system.  An strace seems to confirm that.

Shared libraries should be affected. And prelink is not always used.

-Andi
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