Hi Jerry,
On Wed, Aug 29, 2018 at 10:55 PM Jerry Hoemann <jerry.hoemann@xxxxxxx> wrote:
> On Wed, Aug 29, 2018 at 09:42:38AM +0200, Wolfram Sang wrote:
> > To prevent removing if NOWAYOUT, we invalidate the .remove function and
> > suppress the bind/unbind attributes in sysfs. These are driver
> > capabilities, so we need to set it up at runtime during init. To avoid
> > boilerplate, introduce module_watchdog_driver() similar to
> > module_driver(). On top of that, we then build
> > module_watchdog_platform_driver(). Others may follow, if needed.
> >
> > Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> > ---
> > include/linux/watchdog.h | 17 +++++++++++++++++
> > 1 file changed, 17 insertions(+)
> >
> > diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
> > index 44985c4a1e86..c8ecbc53c807 100644
> > --- a/include/linux/watchdog.h
> > +++ b/include/linux/watchdog.h
> > @@ -216,4 +216,21 @@ extern void watchdog_unregister_device(struct watchdog_device *);
> > /* devres register variant */
> > int devm_watchdog_register_device(struct device *dev, struct watchdog_device *);
> >
> > +#define module_watchdog_driver(__driver, __register, __unregister, __nowayout, ...) \
> > +static int __init __driver##_init(void) \
> > +{ \
> > + __driver.driver.suppress_bind_attrs = !!(__nowayout); \
> > + return __register(&(__driver) ##__VA_ARGS__); \
> > +} \
>
> Sorry, I'm not familiar w/ this level of detail of the driver interface.
>
> Is the intent of the proposed changes to prevent the unload of
> a module if it was loaded with the "nowayout" parameter?
>
> If so, I thought the WD "nowayout" semantic was only supposed to be in effect
> after /dev/watchdog was opened. The proposed change looks like it makes the
> "nowayout" semantic take effect before /dev/watchdog is opened.
Thanks, that's IMHO a very valid point.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
