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Date: Sat, 23 Jul 2011 09:17:01 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Andrew Morton <akpm@linux-foundation.org>
cc: LKML <linux-kernel@vger.kernel.org>, John Stultz <john.stultz@linaro.org>,
        Ingo Molnar <mingo@elte.hu>, Ben Greear <greearb@candelatech.com>,
        stable@kernel.org
Subject: Re: [patch 3/3] rtc: Limit frequency
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On Fri, 22 Jul 2011, Andrew Morton wrote:

> On Fri, 22 Jul 2011 09:12:51 -0000
> Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> > The RTC hrtimer is self rearming. We really need to limit the
> > frequency to something sensible.
> 
> > Cc: stable@kernel.org
> 
> Why?  What failures does the current code cause?  What effect do these
> failures have upon users?

Due to the hrtimer self rearming mode a user can DoS the machine
simply because it's starved by hrtimer events.