From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH 06/14] Pramfs: Include files
Date: Wed, 24 Jun 2009 17:30:36 +0200
Message-ID: <200906241730.37151.arnd@arndb.de>
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To: Marco Stornelli <marco.stornelli@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>, =?iso-8859-1?q?J=F6rn_Engel?= <joern@lazybastard.org>, Sam Ravnborg <sam@ravnborg.org>, Tim Bird <tim.bird@am.sony.com>, Chris Simmonds <chris@2net.co.uk>, Linux FS Devel <linux-fsdevel@vger.kernel.org>, Linux Embedded <linux-embedded@vger.kernel.org>, Linux Kernel <linux-kernel@vger.kernel.org>

On Wednesday 24 June 2009, Marco Stornelli wrote:
> > Actually, reading from /dev/mem is only valid on real RAM. If the nvram
> > is part of an IO memory mapping, you have to do mmap()+memcpy() rather
> > than read(). So dd won't do it, but it's still easy to read from user
> > space.
> 
> For "security" reasons pram reserve the region of memory with
> reserve_mem_region_exclusive().....

That will only prevent other device drivers from stepping on it,
/dev/mem does not care about mem_region reservations.

	Arnd <><