From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753155AbcGMQNH (ORCPT ); Wed, 13 Jul 2016 12:13:07 -0400 Received: from mout.kundenserver.de ([212.227.126.130]:58184 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753096AbcGMQMf (ORCPT ); Wed, 13 Jul 2016 12:12:35 -0400 From: Arnd Bergmann To: Jason Baron , kernel-build-reports@lists.linaro.org Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH v2 4/4] dynamic_debug: add jump label support Date: Wed, 13 Jul 2016 18:03:24 +0200 Message-ID: <4481273.afaatbzpKs@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-28-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <5786613E.6010509@akamai.com> References: <10022037.rzjeY1zYxh@wuerfel> <5786613E.6010509@akamai.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:unhNSSICoidAIrwZZwhpAaYVX+2/+UCVAVQT/kFjZwgk8EHoh7c B3zvArFLmuh9J+WOVTt05tFDvvfzSjiQ1RHe8INmeFK/9l3MJAm+rmQHWHELkdp99a9oZrO pFfWh8kFgK2ZYFJptMuUOoTn2jKEXnrVaAGz6uciPcvIOBAkHEVCJt1xbuXlyJGSnlT/6qy vkgVf7syVLC3MzMXqiugw== X-UI-Out-Filterresults: notjunk:1;V01:K0:7ZQwLb3LZkE=:dZbTmyetdH3ngZzSd7JLWR OAkOncgxdISajwIw9AwkknlzH5ynJtlP6fO+7ghdy2PRPFhzizamJjCeI2cpp499goZ1CWQ5m ArImDzVHvgKkmqdtiAAgbMrZ469LScRUrEpiYJDoq680zDo3lrkSQpzNAlXFjwpJ5XNB8ONB9 3c7euPXwuegEkm5XI7s+uSW7Fax+o8473VqaRYZq9kNCiiS75tIRH/YFa334FOeZn73438FsS XSnt9GidUfPiNjsc1pdwTIWjyg8by7pC2zzzbaMYuipDYgUweyrH76zVrFo3M9j0VwtsDckjj Z0fRoafOcapwedQ9Up5/uVOiKaPqEcwNaIPoiIwO1LC83WbNXnE8nHL+5mF1t6/woIgPAw6rX SyQ+bJgWtlsLmkPj97cedUaOftau8UmxqWy4yzeotCS1MvDwU17z4SEftsYFw7260MjFlYjEJ zNRtmxmCTt4QMRvDBpHI3JwSW/VsKM/j26/8daWDh+HmDSjKyj4s9pgYOEu6k4N1/W3NzHsah gNrUgH6LFdSsw6asJyfPCp0oFgg2IkLG4QPeSvQzB3AZokKi42fUxEFlmP2jgXxLELeVHJdvR 7CYFx75n/zEAecc5xhoRLnuR6ZWfX63BnL7GySH4X6zZvReyPYqaw4WXDpYM8vO67k4sgrWfv v3dv9di2RL0nBEKWlVaNRHHXl1QEgFWFbyoB377DJsG+ffQ+H3BMyuHQdZ3ZWHlpKXtIbwPzR 6/AFTSmgU3+zbzri Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, July 13, 2016 11:41:50 AM CEST Jason Baron wrote: > > Hi Arnd, > > Ok, this is back in linux-next now (with hopefully a fix for arm). I > was never able to quite reproduce the arm failure you saw. So if > you get the chance to test this it would be great. > I've had a day's worth of randconfig tests without running into the problem so far. However, I did get one new compiler warning that I have just bisected down to 21413cd0e4ed ("dynamic_debug: add jump label support"): /git/arm-soc/drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_tune_tc': /git/arm-soc/drivers/media/dvb-frontends/cxd2841er.c:3253:40: error: 'carrier_offset' may be used uninitialized in this function [-Werror=maybe-uninitialized] if (ret) ^ return ret; ~~~~~~~~~ /git/arm-soc/drivers/media/dvb-frontends/cxd2841er.c:3209:11: note: 'carrier_offset' was declared here int ret, carrier_offset; ^~~~~~~~~~~~~~ It's clearly a false positive warning, the code is correct, but if this is the only one that the dynamic_debug jump labels introduce, we may as well just work around it in the driver. I think this is caused by the "unlikely" annotation in dynamic_dev_dbg(), which confuses the compiler trying to figure out whether the variable is initialized or not. Arnd