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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 62ECBC2BA19 for ; Tue, 21 Apr 2020 04:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BAFE20781 for ; Tue, 21 Apr 2020 04:03:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587441815; bh=RgxAeo6o21slOdeo/oi5CMpvkiC62LoMPO2UXH4ytCg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=QxTQ5ZJK58q5Skob9yCEl6GVP0kIVUnFIB2WQuF925UZgkmIcesvi5whFAnjyYdoI KSGxeaWaLzB4UNDISvP6bxqApqXvW9SuK65gkjTqcKsNCX9ViQ6f6AgZHMoa9bG7W9 NnbXcg4AwfN/RTVyG7TreFnJvX6MoJ5D9vILO5K4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726448AbgDUEDe (ORCPT ); Tue, 21 Apr 2020 00:03:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:49646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725283AbgDUEDe (ORCPT ); Tue, 21 Apr 2020 00:03:34 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 346EA206CD; Tue, 21 Apr 2020 04:03:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587441813; bh=RgxAeo6o21slOdeo/oi5CMpvkiC62LoMPO2UXH4ytCg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=FGLJJlZ/+pwYtllfiyvbICis0kR+XtiFWxk8jd4DCCrB0AVKN6G0EEvo0s3IyG5hJ OoLitET1styvnih6JBJnLm+5ftxRowAsgfZvhK8SXw2ENrQaH21ENEYQD76wP6mpJ6 QBWhmiL/3DUF0iZsaw1bADGS4Kt+owXLiEWtycFA= Date: Mon, 20 Apr 2020 21:03:32 -0700 From: Andrew Morton To: Nathan Chancellor Cc: Masahiro Yamada , Michal Marek , Arnd Bergmann , Steven Rostedt , Ingo Molnar , Jason Baron , Catalin Marinas , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH 0/6] Silence some instances of -Wtautological-compare and enable globally Message-Id: <20200420210332.7ff9652c8bdca7fb91ccfb0c@linux-foundation.org> In-Reply-To: <20200219045423.54190-1-natechancellor@gmail.com> References: <20200219045423.54190-1-natechancellor@gmail.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 Feb 2020 21:54:17 -0700 Nathan Chancellor wrote: > Hi everyone, > > This patch series aims to silence some instances of clang's > -Wtautological-compare that are not problematic and enable it globally > for the kernel because it has a bunch of subwarnings that can find real > bugs in the kernel such as > https://lore.kernel.org/lkml/20200116222658.5285-1-natechancellor@gmail.com/ > and https://bugs.llvm.org/show_bug.cgi?id=42666, which was specifically > requested by Dmitry. > > The first patch adds a macro that casts the section variables to > unsigned long (uintptr_t), which silences the warning and adds > documentation. > > Patches two through four silence the warning in the places I have > noticed it across all of my builds with -Werror, including arm, arm64, > and x86_64 defconfig/allmodconfig/allyesconfig. There might still be > more lurking but those will have to be teased out over time. > > Patch six finally enables the warning, while leaving one of the > subwarnings disabled because it is rather noisy and somewhat pointless > for the kernel, where core kernel code is expected to build and run with > many different configurations where variable types can be different > sizes. > For some reason none of these patches apply. Not sure why - prehaps something in the diff headers. Anyway, the kmemleak.c code has recently changed in ways which impact these patches. Please take a look at that, redo, retest and resend?