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From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
	Andi Kleen <andi@firstfloor.org>,
	Robert Hancock <hancockrwd@gmail.com>,
	"Anton D. Kachalov" <mouse@mayc.ru>,
	linux-kernel@vger.kernel.org
Subject: Re: Reading /dev/mem by dd
Date: Fri, 13 Nov 2009 00:29:35 +0300	[thread overview]
Message-ID: <20091112212935.GE5728@lenovo> (raw)
In-Reply-To: <m3639flaet.fsf@intrepid.localdomain>

On Thu, Nov 12, 2009 at 10:07:22PM +0100, Krzysztof Halasa wrote:
> "Henrique de Moraes Holschuh" <hmh@hmh.eng.br> writes:
> 
> > In this case, the problem seems to be access over /dev/mem to stuff the
> > kernel is already taking care of.
> 
> Not sure if local APIC counts as "PCI space and the BIOS code and data
> regions" but:
> 
> $ grep STRICT_DEVMEM -A 15 arch/x86/Kconfig.debug
> config STRICT_DEVMEM
>         bool "Filter access to /dev/mem"
>         ---help---
> 

Yes, having this option turned on an access to LAPIC/IO_APIC
space will be forbidden.

	-- Cyrill

  reply	other threads:[~2009-11-12 21:29 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-11 14:36 Reading /dev/mem by dd Anton D. Kachalov
2009-11-11 16:20 ` Américo Wang
2009-11-12 15:46   ` Anton D. Kachalov
2009-11-11 21:09 ` Robert Hancock
2009-11-12  2:12   ` Henrique de Moraes Holschuh
2009-11-12 11:09     ` Alan Cox
2009-11-12 16:06       ` Henrique de Moraes Holschuh
2009-11-12 17:52         ` Alan Cox
2009-11-12 16:44     ` Andi Kleen
2009-11-12 17:37       ` Henrique de Moraes Holschuh
2009-11-12 17:49         ` Alan Cox
2009-11-12 17:57           ` Henrique de Moraes Holschuh
2009-11-12 18:13             ` Alan Cox
2009-11-12 20:02               ` Henrique de Moraes Holschuh
2009-11-12 20:06                 ` Alan Cox
2009-11-12 21:07         ` Krzysztof Halasa
2009-11-12 21:29           ` Cyrill Gorcunov [this message]
  -- strict thread matches above, loose matches on Subject: below --
2010-02-16  8:35 Nameer Yarkon
2010-02-16  8:41 ` Andi Kleen
2010-02-16  9:03   ` Nameer Yarkon
2010-02-16 12:31 ` Alan Cox

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