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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Thu, 4 Jul 2019 14:10:22 +0200
Message-ID: <CAMuHMdXDN60WWFerok1h05COdNNPZTMDCgKXejmQZMj9B6y5Cw@mail.gmail.com>
Subject: Re: [PATCH] iio: adc: gyroadc: fix uninitialized return code
To:     Wolfram Sang <wsa@the-dreams.de>
Cc:     Arnd Bergmann <arnd@arndb.de>, Marek Vasut <marek.vasut@gmail.com>,
        Jonathan Cameron <jic23@kernel.org>,
        stable <stable@vger.kernel.org>,
        Marek Vasut <marek.vasut+renesas@gmail.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Simon Horman <horms+renesas@verge.net.au>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Hartmut Knaack <knaack.h@gmx.de>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        Rob Herring <robh@kernel.org>,
        Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
        linux-iio@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Wolfram,

On Thu, Jul 4, 2019 at 2:08 PM Wolfram Sang <wsa@the-dreams.de> wrote:
> On Thu, Jul 04, 2019 at 01:37:47PM +0200, Arnd Bergmann wrote:
> > gcc-9 complains about a blatant uninitialized variable use that
> > all earlier compiler versions missed:
> >
> > drivers/iio/adc/rcar-gyroadc.c:510:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
> >
> > Return -EINVAL instead here.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: 059c53b32329 ("iio: adc: Add Renesas GyroADC driver")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> This is correct but missing that the above 'return ret' is broken, too.
> ret is initialized but 0 in that case.

Nice catch! Oh well, given enough eyeballs, ...

> And maybe we can use something else than -EINVAL for this case? I am on
> the go right now, I will look for a suggestion later.

-EINVAL is correct here (and in the above case, too), IMHO.

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