From patchwork Mon Mar 1 16:14:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 389576 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 CA2EDC433DB for ; Mon, 1 Mar 2021 18:51:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BB3F6023B for ; Mon, 1 Mar 2021 18:51:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240297AbhCASvG (ORCPT ); Mon, 1 Mar 2021 13:51:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:53934 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240022AbhCASo3 (ORCPT ); Mon, 1 Mar 2021 13:44:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AE456650FB; Mon, 1 Mar 2021 17:02:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614618122; bh=Qfn0aUat3ceZQ1ghd+EeB4wkAMI8sShpeAtkKyiVw5E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ySd2DovywqtmS3HVgEDTxO2ybnvgHivPYikvt0lxMUtcCmtESdAl5BLerhvy+I7eB D0BviHFPwuounLDJcJ8vnkdKKW2veb/NJ5m26DmJ4Xc7XV1as0VvLIMpMfI5FJOZZc psui4vsbTix5dQqF1tPT0arj+3z8LbPCA4qWVw34= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christian Borntraeger , Heiko Carstens , Vasily Gorbik Subject: [PATCH 5.4 314/340] s390/vtime: fix inline assembly clobber list Date: Mon, 1 Mar 2021 17:14:18 +0100 Message-Id: <20210301161103.742017602@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161048.294656001@linuxfoundation.org> References: <20210301161048.294656001@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Heiko Carstens commit b29c5093820d333eef22f58cd04ec0d089059c39 upstream. The stck/stckf instruction used within the inline assembly within do_account_vtime() changes the condition code. This is not reflected with the clobber list, and therefore might result in incorrect code generation. It seems unlikely that the compiler could generate incorrect code considering the surrounding C code, but it must still be fixed. Cc: Reviewed-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/vtime.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -136,7 +136,8 @@ static int do_account_vtime(struct task_ " stck %1" /* Store current tod clock value */ #endif : "=Q" (S390_lowcore.last_update_timer), - "=Q" (S390_lowcore.last_update_clock)); + "=Q" (S390_lowcore.last_update_clock) + : : "cc"); clock = S390_lowcore.last_update_clock - clock; timer -= S390_lowcore.last_update_timer;