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RE: [PATCH v4] MIPS: Make CP0 config registers readable via sysfs.

To: David Daney <ddaney.cavm@gmail.com>, "Maciej W. Rozycki" <macro@linux-mips.org>
Subject: RE: [PATCH v4] MIPS: Make CP0 config registers readable via sysfs.
From: "Hill, Steven" <sjhill@mips.com>
Date: Fri, 4 Jan 2013 18:38:32 +0000
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Thread-topic: [PATCH v4] MIPS: Make CP0 config registers readable via sysfs.
> You're exporting privileged context outside the kernel -- have all the
> security implications been considered?
>
Maciej,

I have gone through the config registers bit-by-bit and I do not see where 
there are any security implications. There are maybe 7 bits total in config 
registers 0 through 5 that are R/W and this patch, of course, is providing RO 
access. A motivated person could download the PRA documents from our website 
even without this patch to discover what was implemented in the system. I could 
certainly see security implications if we were exporting the STATUS, CAUSE, and 
other critical registers. Unless you can provide a counterexample, this patch 
does not compromise the system in anyway.  

-Steve

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