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=-13.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 B8117C43219 for ; Tue, 30 Apr 2019 01:01:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EBD321707 for ; Tue, 30 Apr 2019 01:01:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="smVllj4R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729679AbfD3BBw (ORCPT ); Mon, 29 Apr 2019 21:01:52 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:38159 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728997AbfD3BBv (ORCPT ); Mon, 29 Apr 2019 21:01:51 -0400 Received: by mail-ed1-f66.google.com with SMTP id w11so4058231edl.5; Mon, 29 Apr 2019 18:01:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=B3gDh2REee/qywEIFiYNH8hrzOOKejsHhyYhN3OyguA=; b=smVllj4Rw+I/C7sGyIkHVFuoI00NANpFxPV6FTp5nIqjcwyT9zDLawbf0hdfgDIta1 xYGOAH80CAqJeTgm8+y/dYekKREARHma/e3XRgo+lMgLDhbSZmLg9tUs9Xq9OMi3wwco AOURn4tfEJhtHjww0HDwYayvQzLJrLulo5aEu/juGpefSYY4ooor0lnvmOcnAfVeSiXU HnFaj4n/50Vq8SCT8TatOY5R8w6dHfye5fEPPgwbmY9if2in+Mfi/OphQ7gztRDv4BvU jvfB58uzX5tc+0R+rP6XFzPN0n17GZZHyp9ulyL4/Kj1k24/DGDEEYfWmHTU/ibcUHxK sU3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=B3gDh2REee/qywEIFiYNH8hrzOOKejsHhyYhN3OyguA=; b=M3HY2do4KwQ5TbsM7GmzDIHSFBM6yyl6SLm8jaB39bG5+xOqQ8lPhEkcfKWn5ZXhGo xnhDXYopBoRspw4jZSWh8j9FJofbOofukF0WWS0Z2NKbT7yAU72j7wYs2ucNwkvqF/Ou bEsxQTcV6ASYR0HEnvVG0yoz/AEzd1jeQLBI2MUmef94fC0JR9H2ME0Euo3PQ7bJ1Gtt 2DDCagYmcYZeuB3BbDTliirKDO9pZKmZ80SGc5Hw06gNjiL/zPN63TOCatX0Libthgez on0Jh6GD7zScQdjqEKqbs0J/Z6Alizb+6iFsRsydObq4tfuSYyOTz5YJaFbr5bzg/p8o QI2w== X-Gm-Message-State: APjAAAXc4IKZfz3eQGkVQg8KzOvsTEdVxWNdyGBUQ/5NOUbu41p0ZZlt v5d7GtPf3yQu7a0SSVOetIQ= X-Google-Smtp-Source: APXvYqypsZ3rUaABQ4Dsp+Lif+n0v9xmZgTTEpdMmMakchOMnRLQiuva+5xVF8/MB5UfwRHy5E02AA== X-Received: by 2002:a17:906:1e4f:: with SMTP id i15mr2551656ejj.239.1556586109493; Mon, 29 Apr 2019 18:01:49 -0700 (PDT) Received: from localhost.localdomain ([2a01:4f9:2b:2b84::2]) by smtp.gmail.com with ESMTPSA id ay12sm6151507ejb.15.2019.04.29.18.01.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 29 Apr 2019 18:01:48 -0700 (PDT) From: Nathan Chancellor To: Masahiro Yamada , Michal Marek Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Nick Desaulniers , Arnd Bergmann , Nathan Chancellor Subject: [PATCH] kbuild: Enable -Wsometimes-uninitialized Date: Mon, 29 Apr 2019 18:00:38 -0700 Message-Id: <20190430010037.6216-1-natechancellor@gmail.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-Patchwork-Bot: notify Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is Clang's version of GCC's -Wmaybe-uninitialized. Up to this point, it has not been used because -Wuninitialized has been disabled, which also turns off -Wsometimes-uninitialized, meaning that we miss out on finding some bugs [1]. In my experience, it appears to be more accurate than GCC and catch some things that GCC can't. All of these warnings have now been fixed in -next across arm, arm64, and x86_64 defconfig/allyesconfig so this should be enabled for everyone to prevent more from easily creeping in. As of next-20190429: $ git log --oneline --grep="sometimes-uninitialized" | wc -l 45 [1]: https://lore.kernel.org/lkml/86649ee4-9794-77a3-502c-f4cd10019c36@lca.pw/ Link: https://github.com/ClangBuiltLinux/linux/issues/381 Signed-off-by: Nathan Chancellor --- Masahiro, I am not sure how you want to handle merging this with regards to all of the patches floating around in -next but I wanted to send this out to let everyone know this is ready to be turned on. Arnd, are there many remaning -Wsometimes-uninitialized warnings in randconfigs? scripts/Makefile.extrawarn | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 768306add591..f4332981ea85 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -72,5 +72,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format) KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare) KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length) KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized) +KBUILD_CFLAGS += $(call cc-option, -Wsometimes-uninitialized) endif endif -- 2.21.0