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Subject: Re: [patch] threading fix, tid-2.5.47-A3
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Ingo Molnar <mingo@elte.hu>
Cc: Luca Barbieri <ldb@ldb.ods.org>, Ulrich Drepper <drepper@redhat.com>,
       Linus Torvalds <torvalds@transmeta.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Mon, 2002-11-18 at 12:26, Ingo Molnar wrote:
> 
> and we have VM_DONTCOPY already, which is used by the DRM code. So it
> would only be a question of exporting this API to userspace. The attached
> patch adds MAP_DONTCOPY. I made it unpriviledged, i doubt it has any
> security impact.

What is the behaviour of someone setting VM_DONTCOPY on memory that was
copy on write between a large number of processes (say an executable
image) ?  Don't copy - but don't copy from what, from the original
mapping or from the COW mapping of the original mapping ?

Alan

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