From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f180.google.com (mail-lb0-f180.google.com [209.85.217.180]) by kanga.kvack.org (Postfix) with ESMTP id 39310828DF for ; Fri, 15 Jan 2016 11:16:34 -0500 (EST) Received: by mail-lb0-f180.google.com with SMTP id x4so61019841lbm.0 for ; Fri, 15 Jan 2016 08:16:34 -0800 (PST) Received: from relay.parallels.com (relay.parallels.com. [195.214.232.42]) by mx.google.com with ESMTPS id ot1si6046814lbb.79.2016.01.15.08.16.31 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Jan 2016 08:16:32 -0800 (PST) Subject: Re: [linux-next:master 11446/11650] drivers/pwm/pwm-atmel-hlcdc.c:75:55: warning: 'clk_period_ns' may be used uninitialized in this function References: <201601151603.wGuE709l%fengguang.wu@intel.com> From: Andrey Ryabinin Message-ID: <56991B91.1050105@virtuozzo.com> Date: Fri, 15 Jan 2016 19:17:21 +0300 MIME-Version: 1.0 In-Reply-To: <201601151603.wGuE709l%fengguang.wu@intel.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: kbuild test robot Cc: kbuild-all@01.org, Andrew Morton , Linux Memory Management List On 01/15/2016 11:56 AM, kbuild test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > head: 39750fe2d360d6f1ccdc6b33d0a5cb624c97a5fd > commit: df423af30988b62df3905601742b8948bbbce329 [11446/11650] UBSAN: run-time undefined behavior sanity checker > config: x86_64-randconfig-s5-01151613 (attached as .config) > reproduce: > git checkout df423af30988b62df3905601742b8948bbbce329 > # save the attached .config to linux build tree > make ARCH=x86_64 > > Note: it may well be a FALSE warning. FWIW you are at least aware of it now. > http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings > Hmm.. UBSAN (and KASAN too) causes some maybe-uninitialized false positives. I'm not in favor of mucking different subsystems and initializing these variables as it brings some runtime overhead. So, perhaps we need turn off UBSAN/KASAN in all[yes|mod]config builds plus build with -Wno-maybe-uninitilized if any of those options enabled. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org