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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Mon, 30 Jul 2018 13:29:49 +0200
Message-ID: <CAMuHMdWXfS9gFxOq5nvJWx2KMOae5_c8Lb0omeE3P9yjyYZ7gA@mail.gmail.com>
Subject: Re: [PATCH v2 1/2] clk: Add of_clk_get_by_name_optional() function
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Phil Edworthy <phil.edworthy@renesas.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Simon Horman <horms@verge.net.au>,
        linux-clk <linux-clk@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>
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Hi Andy,

On Mon, Jul 30, 2018 at 12:57 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> 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@renesas.com> 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@linux-m68k.org

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