From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21333C433E0 for ; Mon, 22 Jun 2020 12:27:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F24B820716 for ; Mon, 22 Jun 2020 12:27:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="UvymxQap" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728166AbgFVM1f (ORCPT ); Mon, 22 Jun 2020 08:27:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728044AbgFVM1e (ORCPT ); Mon, 22 Jun 2020 08:27:34 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CF5AC061794 for ; Mon, 22 Jun 2020 05:27:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=YfMOzPuDOeX4F8QITGOgeYF7rNWEDYNWfPQiK8lEsik=; b=UvymxQapcE7G9G3BNTsfVoWsAb fZmDam+SDYF0RgZ4jiOp+7/7gPZWzGAG/TUtctH4Eqic5aqhN7oVwjo+ioPIRs5ZeVBl8dnwywvF5 EA7lMmLB3RyR2Q74YVlBrN+h7Zk+/ZmIwiYGz81OJzz2UblNm8ADO/TlMuucDyIphFy5UQImZGUy/ WRtKPGf+RamqB45FMAPFdYZA+dtQ41ouB7b1BhTVmK3T5kEAS8WmHux8Fy0NNTmcnyQrIrYiucmml JBaZXZs6UiGyTqEelgstXdPFaORQ64QdAlB61NIx5TRPECKpr6pdRKPjJ3CdKfeYaWqmald2Tsy9m eKouWOCA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnLXa-0004J3-P2; Mon, 22 Jun 2020 12:27:10 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 4847A301631; Mon, 22 Jun 2020 14:27:08 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id CAED4236D2014; Mon, 22 Jun 2020 14:27:08 +0200 (CEST) Date: Mon, 22 Jun 2020 14:27:08 +0200 From: Peter Zijlstra To: Dan Carpenter Cc: kbuild@lists.01.org, lkp@intel.com, kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, "Paul E. McKenney" Subject: Re: [rcu:dev.2020.06.17a 35/38] kernel/sched/core.c:2650 try_to_wake_up() error: uninitialized symbol 'cpu'. Message-ID: <20200622122708.GB576871@hirez.programming.kicks-ass.net> References: <20200622121116.GD4151@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200622121116.GD4151@kadam> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 22, 2020 at 03:11:17PM +0300, Dan Carpenter wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2020.06.17a > head: d3779e78b9848a707448dbb4a0cb6c4bb651fe9c > commit: 59a5d883f2ccdce1700862b5983cfd3473630aea [35/38] EXP sched: Alleged fix for v5.8 merge-window scheduler issue > config: x86_64-randconfig-m001-20200621 (attached as .config) > compiler: gcc-9 (Debian 9.3.0-13) 9.3.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot > Reported-by: Dan Carpenter > > smatch warnings: > kernel/sched/core.c:2650 try_to_wake_up() error: uninitialized symbol 'cpu'. > > # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=59a5d883f2ccdce1700862b5983cfd3473630aea > git remote add rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > git remote update rcu > git checkout 59a5d883f2ccdce1700862b5983cfd3473630aea > vim +/cpu +2650 kernel/sched/core.c > > ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 2644 > b5179ac70de85e kernel/sched/core.c Peter Zijlstra 2016-05-11 2645 ttwu_queue(p, cpu, wake_flags); > aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 2646 unlock: > 013fdb8086acaa kernel/sched.c Peter Zijlstra 2011-04-05 2647 raw_spin_unlock_irqrestore(&p->pi_lock, flags); > aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 2648 out: > aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 2649 if (success) > aacedf26fb7601 kernel/sched/core.c Peter Zijlstra 2019-06-07 @2650 ttwu_stat(p, cpu, wake_flags); > ^^^ > This can be uninitialized on a couple "goto unlock;" paths. Lines > 2581 and 2622. The KASan tool will warn about this at run time as well. > I'm not sure why the build bot doesn't include the whole function for > this bug report... Indeed, lemme go fix.