From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943353AbcJ0PQV convert rfc822-to-8bit (ORCPT ); Thu, 27 Oct 2016 11:16:21 -0400 Received: from mout.kundenserver.de ([212.227.126.135]:52689 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935350AbcJ0PQT (ORCPT ); Thu, 27 Oct 2016 11:16:19 -0400 From: Arnd Bergmann To: Jarod Wilson Cc: Mauro Carvalho Chehab , Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [media] dvb: avoid warning in dvb_net Date: Thu, 27 Oct 2016 17:09:28 +0200 Message-ID: <20018611.sQONvMWYdP@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-34-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <20161027141327.GE42084@redhat.com> References: <20161027140835.2345937-1-arnd@arndb.de> <20161027141327.GE42084@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K0:RxnO23TU6NyImks4sgFtJrgYhlcFTUVt7Jy4b5VU2HCJxlppDIw tlFkck+Qk/b8/vdDebmdvv3nhJB4O5TMumGhZbBovn98jjiEE7rNpVV/qYIwqPEkUf/uoyr Tg/drBKji/ogk5/9CN9j977CCDwpCssmWMVli/frHSkmi6A27uqW9ioF4FlsySZdwB/Yude 1oWKyOcPre7T8l63poFRQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:bganZuVPx6Y=:ORotTW8T14X+s83bqYYnSS 6DyWJo2ZvNCEFLj6b4GjAMhP+x4S2RlNJeVp0cVJsZE+H9Yai6yS29YF4+UyQC068gMooirwU Y0H9psB/60adz1lHMoKbUOfDXqZhPw/qK0Imszjqr2oNsQFj80nYfJFr1jgGXLt6z64Pzk7RB T9qI/EsJ19eYyYQrwXGRuKAqa4FRv1tQw07U1KRsNk/s2C3VRcGLYVzladVvV/SBOVs77qRcY PVeusRNORFLTtZzQktQywmbRxOQSI1JLGyQibU68aJ4GfHImsGMunfHlkAC9dpuRSByDQufLm D4o2DGUNpB3nR2h/owOnyoDScLhGdk1QimjgS74K5p0J36OOxq1mCADuulEKz3qB0P7QGZ/0D GGFBnW6GqJxzHmYvDVI3o8AhIwaNMF/V15OIMe80wWbfOa7GnhbWqvHq7DrgEG/xtWOGiyBLs UAPftFUBT6ENNnvqMnw4i1b9xKd6CVLiuXU54eclQiw686No0ew3SIc1cIW1tha4P7tOY93Sz 6A7R6t48dNVqQJuyoQVv4W8l8UZnUST5ra3GQFZBl7DAleW1lK41ULHk70U3hZSaNo5EddA/0 K1OjYettDEWUStuy+1wCPrzuJZT5gi3/i1mw4FNAnYV6ez0mXM5i7WHGGN2gWxFEcmyDP1qFX Uj43a0D4G0uTDpbqdR5+AFRZLzXGR2SsZ460Ks7otNNTDulCm1uHqYjvtpsogNKm58teOe3q2 NHwXMnIiEjLjcP4/ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 ‘dvb_net_ule’: > > arch/x86/include/asm/string_32.h:77:14: error: ‘dest_addr’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > drivers/media/dvb-core/dvb_net.c:633:8: note: ‘dest_addr’ 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 > > --- > > 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