Re: [PATCH v2] drivers/tty/serial: check the return value of uart_port_check()

From: Ilpo Järvinen
Date: Mon Aug 29 2022 - 03:09:37 EST


On Sun, 28 Aug 2022, Li Zhong wrote:

> On Fri, Aug 26, 2022 at 9:01 AM Andy Shevchenko
> <andy.shevchenko@xxxxxxxxx> wrote:
> >
> > On Fri, Aug 26, 2022 at 11:38 AM Li Zhong <floridsleeves@xxxxxxxxx> wrote:
> > >
> > > uart_port_check() will return NULL pointer when state->uart_port is
> > > NULL. Check the return value before dereference it to avoid
> > > null-pointer-dereference error.
> >
> > Have you taken the locking into consideration?
> > If no, please do, if yes, expand your commit message to explain why
> > the current locking scheme doesn't prevent an error from happening.
> >
>
> The locking is taken into consideration but these three checks do not need to
> unlock in error-handling because unlock() will be called in the callers. Will
> add the comment in v2 patch.

I think he meant you should indicate why the current locking doesn't cover
the case you're fixing, not whether this function should call unlock() or
not.

--
i.