linux-kernel - Re: [PATCH v7 01/16] pinctrl: check the return value of pinmux_ops::get_function

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Message-ID: <aLb2HH5zgxdbDiPo@smile.fi.intel.com>
Date: Tue, 2 Sep 2025 16:50:20 +0300
From: Andy Shevchenko <andriy.shevchenko@...el.com>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Linus Walleij <linus.walleij@...aro.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konradybcio@...nel.org>,
	Alexey Klimov <alexey.klimov@...aro.org>,
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	Paul Cercueil <paul@...pouillou.net>, Kees Cook <kees@...nel.org>,
	Andy Shevchenko <andy@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	David Hildenbrand <david@...hat.com>,
	Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
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	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
	stable@...r.kernel.org
Subject: Re: [PATCH v7 01/16] pinctrl: check the return value of
 pinmux_ops::get_function_name()

On Tue, Sep 02, 2025 at 03:29:31PM +0200, Bartosz Golaszewski wrote:
> On Tue, Sep 2, 2025 at 3:06 PM Andy Shevchenko
> <andriy.shevchenko@...el.com> wrote:
> > On Tue, Sep 02, 2025 at 01:59:10PM +0200, Bartosz Golaszewski wrote:
> > >
> > > While the API contract in docs doesn't specify it explicitly,
> >
> > So, why not to amend the doc at the same time?
> 
> Because this series is already big as is. That would be another commit
> that can be separate.

I meant _in the same_ patch.

> > > the generic implementation of the get_function_name() callback from struct
> > > pinmux_ops - pinmux_generic_get_function_name() - can fail and return
> > > NULL. This is already checked in pinmux_check_ops() so add a similar
> > > check in pinmux_func_name_to_selector() instead of passing the returned
> > > pointer right down to strcmp() where the NULL can get dereferenced. This
> > > is normal operation when adding new pinfunctions.

> > Fixes?
> 
> This has always been like that.
> 
> > Reported?
> 
> I mean, technically Mark Brown reported my previous patch failing but
> I don't think we do this if we're still within the same series just
> another iteration?
> 
> > Closes?
> 
> Ditto.

I meant that this fixes a potential issue disregard to your series, right?

...

> > >       while (selector < nfuncs) {
> > >               const char *fname = ops->get_function_name(pctldev, selector);
> > >
> > > -             if (!strcmp(function, fname))
> > > +             if (fname && !strcmp(function, fname))
> > >                       return selector;
> >
> > I would slightly refactor this:
> >
> >                 const char *fname;
> >
> >                 fname = ops->get_function_name(pctldev, selector);
> >                 if (fname && !strcmp(function, fname))
> >                         return selector;
> >
> > >               selector++;
> >
> 
> You can do this in a subsequent patch, I prefer a smaller diff personally.

Sure.

-- 
With Best Regards,
Andy Shevchenko