Re: [PATCH] [media] dvb: avoid warning in dvb_net

From: Arnd Bergmann
Date: Thu Oct 27 2016 - 11:16:24 EST


On Thursday, October 27, 2016 10:13:27 AM CEST Jarod Wilson wrote:
> On Thu, Oct 27, 2016 at 03:57:41PM +0200, Arnd Bergmann wrote:
> > With gcc-5 or higher on x86, we can get a bogus warning in the
> > dvb-net code:
> >
> > drivers/media/dvb-core/dvb_net.c: In function âdvb_net_uleâ:
> > arch/x86/include/asm/string_32.h:77:14: error: âdest_addrâ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> > drivers/media/dvb-core/dvb_net.c:633:8: note: âdest_addrâ was declared here
> >
> > The problem here is that gcc doesn't track all of the conditions
> > to prove it can't end up copying uninitialized data.
> > This changes the logic around so we zero out the destination
> > address earlier when we determine that it is not set here.
> > This allows the compiler to figure it out.
> >
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > ---
> > drivers/media/dvb-core/dvb_net.c | 12 +++++-------
> > 1 file changed, 5 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c
> > index 088914c4623f..f1b416de9dab 100644
> > --- a/drivers/media/dvb-core/dvb_net.c
> > +++ b/drivers/media/dvb-core/dvb_net.c
> > @@ -688,6 +688,9 @@ static void dvb_net_ule( struct net_device *dev, const u8 *buf, size_t buf_len )
> > ETH_ALEN);
> > skb_pull(priv->ule_skb, ETH_ALEN);
> > }
> > + } else {
> > + /* othersie use zero destination address */
>
> I'm assuming you meant "otherwise" there instead of "othersie".
>

Yes, I sent a v2 now, thanks for taking a look. I assume this means
you have no other objections to the patch?

Arnd