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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 A82D1C432C1 for ; Tue, 24 Sep 2019 16:43:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 748E5217F4 for ; Tue, 24 Sep 2019 16:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569343434; bh=I8B5kB4woAS8zeIX3RW9KSgJ4z9Xq/XpjsL8Ffdl0vQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BduCdnwtF4SLir1Ujbio4JgiCTFewVnSis9Ik7Tt7mgD2fy1Bg2fZi+tcJB3WH9uF nIjPDMg9/70MUeZCrZyIAmGXoT9UIpiazZae5fD5TwxQIdOuj4yy7M1dFuR895HkC2 oDklckBlDWDCXd3FEvA7vcZ/FAgIyKF+ZY3pu170= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389224AbfIXQnp (ORCPT ); Tue, 24 Sep 2019 12:43:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:60738 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387852AbfIXQnp (ORCPT ); Tue, 24 Sep 2019 12:43:45 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DDC57217F4; Tue, 24 Sep 2019 16:43:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569343424; bh=I8B5kB4woAS8zeIX3RW9KSgJ4z9Xq/XpjsL8Ffdl0vQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qo+BKvv2v6nLPWisOUaoKg3NukZBU0nImtxcS6pffrl0jdBYstxjSXJJil3ZA+QnT 9AaS8KhZWpt8NcpHkbKvIgrNcCdxYJSnZsyuYZOmVVHuRIaLcI0HlSqbCaji55erca /IpDI6PlJLJH2p4JJowMwulTuk0MzSUKsFy7gOdA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christophe Leroy , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.3 45/87] powerpc/futex: Fix warning: 'oldval' may be used uninitialized in this function Date: Tue, 24 Sep 2019 12:41:01 -0400 Message-Id: <20190924164144.25591-45-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190924164144.25591-1-sashal@kernel.org> References: <20190924164144.25591-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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