Re: [patch 07/28] posix-timers: Convert clock_nanosleep_restart toclockid_to_kclock()

From: Thomas Gleixner
Date: Tue Feb 01 2011 - 15:47:13 EST


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@xxxxxxxxxxxxx>
> > Cc: John Stultz <john.stultz@xxxxxxxxxx>
> > Cc: Richard Cochran <richard.cochran@xxxxxxxxxx>
>
> 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
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