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Date: Tue, 14 Jun 2016 14:14:56 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Uwe =?UTF-8?B?S2xlaW5lLUvDtm5pZw==?= 
	<u.kleine-koenig@pengutronix.de>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] printk: Add kernel parameter to control writes to
 /dev/kmsg
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On Tue, 14 Jun 2016 12:21:35 +0200
Ingo Molnar <mingo@kernel.org> wrote:

> * Borislav Petkov <bp@alien8.de> wrote:
> 
> > From: Borislav Petkov <bp@suse.de>
> > 
> > Add a "printk.kmsg" kernel command line parameter which controls how
> > userspace writes into /dev/kmsg. It has two options:
> > 
> > * on  - unlimited logging from userspace
> > * off - logging from userspace gets ignored  
> 
> Please also add a sysctl!
> 
> I *so* want to enable this on distro kernels without having to reboot the 
> kernel...
> 

But can we make it a one way feature (or a kernel parameter to do so?)
that will prevent userspace from enabling it after it's been disabled.

-- Steve