Subject: Re: Patch 4/6  randomize the stack pointer
From: Arjan van de Ven <arjan@infradead.org>
To: John Richard Moser <nigelenki@comcast.net>
Cc: linux-kernel@vger.kernel.org, akpm@osdl.org, torvalds@osdl.org
In-Reply-To: <41F92721.1030903@comcast.net>
References: <20050127101117.GA9760@infradead.org>
	 <20050127101322.GE9760@infradead.org>  <41F92721.1030903@comcast.net>
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Date: Thu, 27 Jan 2005 18:47:30 +0100
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On Thu, 2005-01-27 at 12:38 -0500, John Richard Moser wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
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> 
> 
> Arjan van de Ven wrote:
> > 
> > The patch below replaces the existing 8Kb randomisation of the userspace
> > stack pointer (which is currently only done for Hyperthreaded P-IVs) with a 
> > more general randomisation over a 64Kb range.
> > 
> 
> 64k of stack randomization is trivial to evade. 

I think you're focussing on the 64k number WAY too much. Yes it's too
small. But it's an initial number to show the infrastructure and get it
tested. Yes it should and will be increased later on in the patch
series.

Same for the other heap randomisation.

This thing is about getting the infrastructure in place and used. The
actual numbers are mere finetuning that can be done near the end.


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