Re: [PATCH v2 1/2] clk: Add of_clk_get_by_name_optional() function

From: Geert Uytterhoeven
Date: Mon Jul 30 2018 - 07:30:04 EST


Hi Andy,

On Mon, Jul 30, 2018 at 12:57 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> On Mon, 2018-07-30 at 10:55 +0200, Geert Uytterhoeven wrote:
> > On Mon, Jul 30, 2018 at 10:36 AM Phil Edworthy
> > <phil.edworthy@xxxxxxxxxxx> wrote:
>
> > > +struct clk *of_clk_get_by_name_optional(struct device_node *np,
> > > + const char *name)
> > > +{
> > > + if (!np)
> > > + return ERR_PTR(-ENOENT);
> >
> > Shouldn't this return NULL?
> > Or let __of_clk_get_by_name() handle that (cfr. above)?
> >
> > Hmm, of_clk_get_by_name() has a similar check, while the current
> > __of_clk_get_by_name() already handle np == NULL, too.
>
> This check is needed to prevent NULL pointer dereference below.

Thank, I had missed that unexpected detail.

> > > +
> > > + return __of_clk_get_by_name(np, np->full_name, name, true);
> > > +}

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