Return-path: Received: from mx3.molgen.mpg.de ([141.14.17.11]:41724 "EHLO mx1.molgen.mpg.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755093AbdLTLAw (ORCPT ); Wed, 20 Dec 2017 06:00:52 -0500 Subject: Re: UBSAN: Undefined behaviour in drivers/net/wireless/intel/iwlwifi/mvm/utils.c:838:5 To: Luca Coelho , Johannes Berg , Emmanuel Grumbach , Intel Linux Wireless Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, it+linux-wireless@molgen.mpg.de References: <75bc638e-99a8-2f3f-6260-491f8a018af6@molgen.mpg.de> <1513175552.4827.365.camel@intel.com> <1513621815.4827.430.camel@coelho.fi> From: Paul Menzel Message-ID: (sfid-20171220_120130_394009_703881DC) Date: Wed, 20 Dec 2017 12:00:48 +0100 MIME-Version: 1.0 In-Reply-To: <1513621815.4827.430.camel@coelho.fi> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: Dear Luca, Am 18.12.2017 um 19:30 schrieb Luca Coelho: > On Wed, 2017-12-13 at 16:32 +0200, Luciano Coelho wrote: >> On Wed, 2017-12-13 at 14:25 +0100, Paul Menzel wrote: >>> I enabled the undefined behavior sanitizer, and built Linus’ >>> master branch under Ubuntu 17.10 with gcc (Ubuntu 7.2.0-8ubuntu3) >>> 7.2.0. >>> >>> ``` $ grep UBSAN /boot/config-4.15.0-rc3+ >>> CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y # >>> CONFIG_ARCH_WANTS_UBSAN_NO_NULL is not set CONFIG_UBSAN=y >>> CONFIG_UBSAN_SANITIZE_ALL=y # CONFIG_UBSAN_ALIGNMENT is not set >>> CONFIG_UBSAN_NULL=y ``` >>> >>> Starting the system the messages below are printed. >>> >>> Starting the system and using the wireless device shows the >>> messages below. >> >> Thanks for reporting! This shouldn't cause any problems, but I'll >> fix it by checking that the mac80211_queue is not INVALID_QUEUE >> (255) which seems to be the trigger for this warning. > > Can you try the following patch to see if the problem goes away? > > http://pastebin.coelho.fi/7b624f474846da52.txt Thank you. The warning is gone now. Thank you. For the next time, it’d be great to provide the output of `git format-patch -1`, which can be applied with `git am`. The output of `git show` is with my knowledge hard to apply. Kind regards, Paul