Re: [PATCH v8 0/2] gpiolib: don't allow user-space to crash the kernel with hot-unplugs

From: Andy Shevchenko
Date: Mon Dec 05 2022 - 08:01:22 EST


On Mon, Dec 05, 2022 at 02:59:42PM +0200, Andy Shevchenko wrote:
> On Mon, Dec 05, 2022 at 01:39:01PM +0100, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > Linus Torvalds pointed out that using trylock here is wrong. This iteration
> > drops it in favor of unconditional locks but keeps all the fixes that came
> > later.
> >
> > I will also not send it for this release but make it part of the updates PR
> > for v6.2 to give it some time in next.
> >
> > v7 -> v8:
> > - don't use down_read_trylock(), just go straight for a full lock
>
> Yep, it was a good wrap-up explanation.

But he also suggested to fold NULL check into call_*_locked(). Any points why
you decided not to go that way?

--
With Best Regards,
Andy Shevchenko