Re: [PATCH] watchdog: mena21_wdt: Fix a possible data race in a21_wdt_set_timeout

[Jia-Ju Bai]

On 2018/5/8 11:42, Guenter Roeck wrote:
> On 05/07/2018 08:32 PM, Jia-Ju Bai wrote:
> > On 2018/5/8 11:28, Guenter Roeck wrote:
> > > On 05/07/2018 08:18 PM, Jia-Ju Bai wrote:
> > > > The write operation to "wdt->timeout" is protected by
> > > > the lock on line 118, but the read operation to
> > > > this data on line 105 is not protected by the lock.
> > > > Thus, there may exist a data race for "wdt->timeout".
> > > >
> > > > To fix this data race, the read operation to "wdt->timeout"
> > > > should be also protected by the lock.
> > >
> > > There is no race. There is already a mutex in the watchdog core 
> > > which serializes
> > > calls to the various API functions. It would make more sense to drop 
> > > drv->lock
> > > from the driver.
> >
> > Thanks for your reply :)
> > Need I submit a patch of dropping all calls to "drv->lock"?
>
> You don't _need_ to, but I would happily give it my Reviewed-by: tag 
> if you do.

Okay, I will write a patch today :)


Best wishes,
Jia-Ju Bai