Re: [Y2038] [PATCH v6 31/43] compat_ioctl: move WDIOC handling into wdt drivers

From: Arnd Bergmann
Date: Fri Oct 18 2019 - 09:31:36 EST


On Fri, Oct 18, 2019 at 2:49 PM Ben Hutchings
<ben.hutchings@xxxxxxxxxxxxxxx> wrote:
>
> On Wed, 2019-10-09 at 21:10 +0200, Arnd Bergmann wrote:
> > All watchdog drivers implement the same set of ioctl commands, and
> > fortunately all of them are compatible between 32-bit and 64-bit
> > architectures.
> >
> > Modern drivers always go through drivers/watchdog/wdt.c as an abstraction
> > layer, but older ones implement their own file_operations on a character
> > device for this.
> >
> > Move the handling from fs/compat_ioctl.c into the individual drivers.
> >
> > Note that most of the legacy drivers will never be used on 64-bit
> > hardware, because they are for an old 32-bit SoC implementation, but
> > doing them all at once is safer than trying to guess which ones do
> > or do not need the compat_ioctl handling.
> >
> > Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> > arch/powerpc/platforms/52xx/mpc52xx_gpt.c | 1 +
> > arch/um/drivers/harddog_kern.c | 1 +
> > drivers/char/ipmi/ipmi_watchdog.c | 1 +
> > drivers/hwmon/fschmd.c | 1 +
> > drivers/rtc/rtc-ds1374.c | 1 +
> [...]
>
> It Looks like you missed a couple:
>
> drivers/rtc/rtc-m41t80.c

No idea how I missed this. Adding it now.

> drivers/watchdog/kempld_wdt.c

This one is covered: the watchdog_ops->ioctl is called by
the wdt_dev_ioctl() function as a fallback.

After checking once more, I did find another instance I missed
though: drivers/hwmon/w83793.c, I'm adding that as welll now.

m41t80 does not seem to have any 64-bit machines using it,
but w83793 does, and they clearly both should have been
changed.

Thanks for the review!

Arnd