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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 4567AC4360C for ; Sun, 6 Oct 2019 17:56:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11DDD2087E for ; Sun, 6 Oct 2019 17:56:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570384585; bh=I8B5kB4woAS8zeIX3RW9KSgJ4z9Xq/XpjsL8Ffdl0vQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VXAtab0v7xwZKD/hUWXE7iWjrv5hJi7AYwq3EhGcqrG7Io4bgPXuIGJw3wv+QSETM vNLFynB+c0VupjWGi9EmFaROlsk/wjQ8q6XGteL2bvHwvLfnLLz95JBpZeaaAGHGDs Q/IlUMRpJ8qaWNMkymePEGX7HNbH7eA2z1Z4yk3w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730012AbfJFRfS (ORCPT ); Sun, 6 Oct 2019 13:35:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:33796 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730015AbfJFRfJ (ORCPT ); Sun, 6 Oct 2019 13:35:09 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 0115B2133F; Sun, 6 Oct 2019 17:35:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570383308; bh=I8B5kB4woAS8zeIX3RW9KSgJ4z9Xq/XpjsL8Ffdl0vQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MTV1Z4CRDXfcVxye3l+4iIXR5b3ngWsixS2/3oCz/dUuI8+lF+51BazCNYSpn/tm6 OmpIkQm+gaoxMMIafauwgsu5qH2yyELF87Gjd3KwCRA3krg8rtD/jrUcZJzXI3VBxi F/31lHYf7pXa5OT20yk2XY+Uf8R90ITnTw8gNESU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Michael Ellerman , Sasha Levin Subject: [PATCH 5.2 056/137] powerpc/futex: Fix warning: oldval may be used uninitialized in this function Date: Sun, 6 Oct 2019 19:20:40 +0200 Message-Id: <20191006171213.340011100@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171209.403038733@linuxfoundation.org> References: <20191006171209.403038733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christophe Leroy [ Upstream commit 38a0d0cdb46d3f91534e5b9839ec2d67be14c59d ] We see warnings such as: 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 0 and GCC doesn't see that it will only use it when ret is 0. Anyway, the non-zero 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 [mpe: reword change log slightly] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/86b72f0c134367b214910b27b9a6dd3321af93bb.1565774657.git.christophe.leroy@c-s.fr Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/futex.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/futex.h b/arch/powerpc/include/asm/futex.h index 3a6aa57b9d901..eea28ca679dbb 100644 --- a/arch/powerpc/include/asm/futex.h +++ b/arch/powerpc/include/asm/futex.h @@ -60,8 +60,7 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, pagefault_enable(); - if (!ret) - *oval = oldval; + *oval = oldval; prevent_write_to_user(uaddr, sizeof(*uaddr)); return ret; -- 2.20.1