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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 CD7A5ECE58B for ; Sat, 5 Oct 2019 16:16:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5E72222C8 for ; Sat, 5 Oct 2019 16:16:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570292171; bh=eqnryWtzabgZzM7uNXAO12dttpuheq0j+RkDpfvQTto=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=1Mpe0uPLFwXb5j0EvptA6/x803UVd18tU9hL1fqZewSi3A/31DbaCYxfVX/t8E7sX SICg0U04t98C8sfC4k7mdglwynojr+edq8/NpIHZHvvb8+sUKzjy7KAZLWYBjtqz+X BL1ZxTImDDoWhCi9IWxKXAoI98Jqle8+4Y0vbHYw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729142AbfJEQQL (ORCPT ); Sat, 5 Oct 2019 12:16:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:39004 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728101AbfJEQQK (ORCPT ); Sat, 5 Oct 2019 12:16:10 -0400 Received: from paulmck-ThinkPad-P72 (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A754120862; Sat, 5 Oct 2019 16:16:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570292169; bh=eqnryWtzabgZzM7uNXAO12dttpuheq0j+RkDpfvQTto=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=QjucN5lc/gzfxGIgPsljQW0GS6FHdu1CwpKXYK7mTFlpz/AfwWyzp6UklxFWg+5Vk Xc8Z5D9joQ9RinxnLFFi7Ka8Wx67MCKOXmgTZj51GWKXZoxCobrVSZJx++J2KOr3H2 FCMH2XaJaFOTg049hKtoBFuon7x665OQve2NGngc= Date: Sat, 5 Oct 2019 09:16:08 -0700 From: "Paul E. McKenney" To: Geert Uytterhoeven Cc: rcu@vger.kernel.org, Linux Kernel Mailing List , Ingo Molnar , Lai Jiangshan , dipankar@in.ibm.com, Andrew Morton , Mathieu Desnoyers , Josh Triplett , Thomas Gleixner , Peter Zijlstra , Steven Rostedt , David Howells , Eric Dumazet , Frederic Weisbecker , Oleg Nesterov , Joel Fernandes Subject: Re: [PATCH tip/core/rcu 9/9] rcu: Suppress levelspread uninitialized messages Message-ID: <20191005161608.GH2689@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20191003014710.GA13323@paulmck-ThinkPad-P72> <20191003014728.13496-9-paulmck@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 03, 2019 at 10:53:03AM +0200, Geert Uytterhoeven wrote: > Hi Paul, > > On Thu, Oct 3, 2019 at 3:49 AM wrote: > > From: "Paul E. McKenney" > > > > New tools bring new warnings, and with v5.3 comes: > > According to the kisskb build logs, it happens with gcc 4.6.3 only ;-) > > > kernel/rcu/srcutree.c: warning: 'levelspread[]' may be used uninitialized in this function [-Wuninitialized]: => 121:34 > > > > This commit suppresses this warning by initializing the full array > > to INT_MIN, which will result in failures should any out-of-bounds > > references appear. > > > > Reported-by: Michael Ellerman > > Reported-by: Geert Uytterhoeven > > Signed-off-by: Paul E. McKenney > > Thanks for your patch! > > Reviewed-by: Geert Uytterhoeven > (for the initialization loop, not for the actual INT_MIN value) Applied, thank you! > Unfortunately I don't have a gcc-4.6.3 Linux cross-compiler anymore. > I tried with msp430-gcc-4.6.3 and some hackery to get it to compile, > but that didn't let me reproduce the warning. OK, please let me know when gcc-4.6.3 is old enough that this patch should be reverted. Or just submit the revert at that point, as the case may be. ;-) Thanx, Paul