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Date: Thu, 31 Jan 2008 09:42:07 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Arjan van de Ven <arjan@infradead.org>
CC: Jan Engelhardt <jengelh@computergmbh.de>, linux-kernel@vger.kernel.org,
       davej@redhat.com, mingo@elte.hu, tglx@tglx.de
Subject: Re: [PATCH] x86: introduce /dev/mem restrictions with a config option
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Arjan van de Ven wrote:
> On Thu, 31 Jan 2008 17:53:04 +0100 (CET)
> Jan Engelhardt <jengelh@computergmbh.de> wrote:
> 
>> On Jan 30 2008 12:48, Arjan van de Ven wrote:
>>> Subject: [PATCH] x86: introduce /dev/mem restrictions with a config
>>> option
>>>
>>> This patch introduces a restriction on /dev/mem: Only non-memory can
>>> be read or written unless the newly introduced config option is set.
>> Would not it be nicer to add a /dev/pcimem that implements the given 
>> restrictive semantics?
>>
>> Maybe it's just wishful thinking, but I am dreaming of an
>> unprivileged X, and /dev/pcimem (owned by an 'x11' user or so) would
>> be a step in that direction.
> 
> /dev/pcimem is wrong; X can use the exact bar in sysfs already.
> This is more for compatibility with legacy X
> 

Legacy X, and non-BAR X memory (originally ISA, of course; now probably 
more often "stolen system memory").

	-hpa