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=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 18FF2C3A5A1 for ; Thu, 22 Aug 2019 13:09:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9D5021726 for ; Thu, 22 Aug 2019 13:09:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388927AbfHVNJF (ORCPT ); Thu, 22 Aug 2019 09:09:05 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:53241 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732441AbfHVNJD (ORCPT ); Thu, 22 Aug 2019 09:09:03 -0400 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 Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org 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) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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