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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 45273C3A5A3 for ; Thu, 22 Aug 2019 13:41:53 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 027FE233A2 for ; Thu, 22 Aug 2019 13:41:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 027FE233A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46Dm0Z2zq2zDqss for ; Thu, 22 Aug 2019 23:41:50 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46DlGk64BszDrQ2 for ; Thu, 22 Aug 2019 23:09:02 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix, from userid 1034) id 46DlGj1KgTz9sPQ; Thu, 22 Aug 2019 23:09:00 +1000 (AEST) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 38a0d0cdb46d3f91534e5b9839ec2d67be14c59d In-Reply-To: <86b72f0c134367b214910b27b9a6dd3321af93bb.1565774657.git.christophe.leroy@c-s.fr> To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras From: Michael Ellerman Subject: Re: [PATCH] powerpc/futex: fix warning: 'oldval' may be used uninitialized in this function Message-Id: <46DlGj1KgTz9sPQ@ozlabs.org> Date: Thu, 22 Aug 2019 23:09:00 +1000 (AEST) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 2019-08-14 at 09:25:52 UTC, Christophe Leroy wrote: > CC kernel/futex.o > kernel/futex.c: In function 'do_futex': > kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized] > return oldval == cmparg; > ^ > kernel/futex.c:1651:6: note: 'oldval' was declared here > int oldval, ret; > ^ > > This is because arch_futex_atomic_op_inuser() only sets *oval > if ret is NUL and GCC doesn't see that it will use it only when > ret is NUL. > > Anyway, the non-NUL ret path is an error path that won't suffer from > setting *oval, and as *oval is a local var in futex_atomic_op_inuser() > it will have no impact. > > Signed-off-by: Christophe Leroy Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/38a0d0cdb46d3f91534e5b9839ec2d67be14c59d cheers