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Date: Tue, 1 Feb 2011 21:46:36 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: John Stultz <john.stultz@linaro.org>
cc: LKML <linux-kernel@vger.kernel.org>,
        Richard Cochran <richard.cochran@omicron.at>,
        Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <peterz@infradead.org>
Subject: Re: [patch 07/28] posix-timers: Convert clock_nanosleep_restart to
 clockid_to_kclock()
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On Tue, 1 Feb 2011, John Stultz wrote:

> On Tue, 2011-02-01 at 13:51 +0000, Thomas Gleixner wrote:
> > plain text document attachment
> > (posix-timers-convert-nanosleep-restart.patch)
> > Use the new kclock decoding function in clock_nanosleep_restart. No
> > need to check kclock here as the restart block always contains a valid
> > clockid. If not, we are in serious trouble anyway.
> > 
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > Cc: John Stultz <john.stultz@linaro.org>
> > Cc: Richard Cochran <richard.cochran@omicron.at>
> 
> One nit.
> 
> > -long
> > -clock_nanosleep_restart(struct restart_block *restart_block)
> > +long clock_nanosleep_restart(struct restart_block *restart_block)
> >  {
> >  	clockid_t which_clock = restart_block->arg0;
> > +	struct k_clock *kc = clockid_to_kclock(which_clock);
> > 
> > -	return CLOCK_DISPATCH(which_clock, nsleep_restart,
> > -			      (restart_block));
> > +	return kc->nsleep_restart(restart_block);
> >  }
> 
> 
> Should you be checking if kc is null before dereferencing? Or am I being
> overly paranoid?

See changelog. If we get a corrupted restart_block then checking kc is
probably the least of our worries.

Thanks,

	tglx