linux-kernel - Re: [PATCH 2/2] Add dev.mem.restricted sysctl

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Message-ID: <20081115194914.6791b96c@infradead.org>
Date:	Sat, 15 Nov 2008 19:49:14 -0800
From:	Arjan van de Ven <arjan@...radead.org>
To:	Bernhard Walle <bwalle@...e.de>
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org, Bernhard Walle <bwalle@...e.de>
Subject: Re: [PATCH 2/2] Add dev.mem.restricted sysctl

On Sun, 16 Nov 2008 01:03:43 +0100
Bernhard Walle <bwalle@...e.de> wrote:

> When CONFIG_STRICT_DEVMEM is set, live debugging is not possible with
> the crash utility (see http://people.redhat.com/~anderson). For
> distributors who ship a generic kernel it's difficult: Disabling
> CONFIG_STRICT_DEVMEM is possible, but in general the protection
> provided by CONFIG_STRICT_DEVMEM is useful. However, live debugging
> should be still neceessary.
> 
> This patch now adds a dev.mem.restricted sysctl that defaults to 0
> (off). When set to 1 (on), /dev/mem access is unrestricted and crash
> can be used.
> 


sounds like a really bad idea to me.
If you want to use /dev/mem like this, don't enable the config option
to restrict it. Really.


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org
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