Re: [PATCH v2 1/2] rtc: wilco-ec: Remove yday and wday calculations

From: Pavel Machek
Date: Sun Sep 22 2019 - 12:14:41 EST


On Mon 2019-09-16 12:12:15, Nick Crews wrote:
> The tm_yday and tm_wday fields are not used by userspace,
> so since they aren't needed within the driver, don't
> bother calculating them. This is especially needed since
> the rtc_year_days() call was crashing if the HW returned
> an invalid time.
>
> Signed-off-by: Nick Crews <ncrews@xxxxxxxxxxxx>
> ---
> drivers/rtc/rtc-wilco-ec.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c
> index 8ad4c4e6d557..e84faa268caf 100644
> --- a/drivers/rtc/rtc-wilco-ec.c
> +++ b/drivers/rtc/rtc-wilco-ec.c
> @@ -110,10 +110,6 @@ static int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm)
> tm->tm_mday = rtc.day;
> tm->tm_mon = rtc.month - 1;
> tm->tm_year = rtc.year + (rtc.century * 100) - 1900;
> - tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
> -
> - /* Don't compute day of week, we don't need it. */
> - tm->tm_wday = -1;
>
> return 0;

Are you sure? It would be bad to pass unititialized memory to userspace...

If userspace does not need those fields, why are they there?

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html