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Date: Mon, 25 Apr 2016 12:18:15 -0700
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@kernel.org>,
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        Andrew Morton <akpm@linux-foundation.org>,
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	<u.kleine-koenig@pengutronix.de>
Subject: Re: [PATCH v2] printk: Add kernel parameter to disable writes to
 /dev/kmsg
Message-ID: <20160425191815.GA24761@kroah.com>
References: <20160425145606.598329f2@gandalf.local.home>
 <20160425190651.GL3448@twins.programming.kicks-ass.net>
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On Mon, Apr 25, 2016 at 09:06:51PM +0200, Peter Zijlstra wrote:
> On Mon, Apr 25, 2016 at 02:56:06PM -0400, Steven Rostedt wrote:
> > +static bool __read_mostly devkmsg_disabled;
> > +static int __init disable_devkmsg(char *str)
> > +{
> > +	devkmsg_disabled = true;
> > +	return 0;
> > +}
> > +__setup("printk.disable_kmsg_write", disable_devkmsg);
> 
> Again, please default enable and use an easier name to toggle this.
> Userspace flooding this with junk is really insane.

If you default enable, you break working systems today that want to log
stuff through this interface, sorry.

thanks,

greg k-h