From patchwork Tue Dec 1 08:54:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 336765 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 95FF6C83011 for ; Tue, 1 Dec 2020 09:23:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5440B20674 for ; Tue, 1 Dec 2020 09:23:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GZ5RFX1q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729540AbgLAJXl (ORCPT ); Tue, 1 Dec 2020 04:23:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:42546 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388615AbgLAJGe (ORCPT ); Tue, 1 Dec 2020 04:06:34 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 10AAF20671; Tue, 1 Dec 2020 09:06:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606813578; bh=Z0sBvT0EL6CU55gckHLrogO86kVHb6i9O8ryaExbsL0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GZ5RFX1qv1ow0kQ/SCZxPk/2tHZFyQKEXO6usgekd2R2/mrPfGoM3EabRTraKUHua KxwPHj1QGBNlgk+72pXfdiWQGLR8J3rdhpJ7Pk5PxFlO5ycrwrClkMeD9uPX3V2T03 DWxlYiBDH9EtHehI3MWxgE5+z0VxB2iWO3slOX0s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gabriele Paoloni , Borislav Petkov , Tony Luck Subject: [PATCH 5.4 86/98] x86/mce: Do not overwrite no_way_out if mce_end() fails Date: Tue, 1 Dec 2020 09:54:03 +0100 Message-Id: <20201201084659.257135691@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084652.827177826@linuxfoundation.org> References: <20201201084652.827177826@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Gabriele Paoloni commit 25bc65d8ddfc17cc1d7a45bd48e9bdc0e729ced3 upstream. Currently, if mce_end() fails, no_way_out - the variable denoting whether the machine can recover from this MCE - is determined by whether the worst severity that was found across the MCA banks associated with the current CPU, is of panic severity. However, at this point no_way_out could have been already set by mca_start() after looking at all severities of all CPUs that entered the MCE handler. If mce_end() fails, check first if no_way_out is already set and, if so, stick to it, otherwise use the local worst value. [ bp: Massage. ] Signed-off-by: Gabriele Paoloni Signed-off-by: Borislav Petkov Reviewed-by: Tony Luck Cc: Link: https://lkml.kernel.org/r/20201127161819.3106432-2-gabriele.paoloni@intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/mce/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1361,8 +1361,10 @@ void do_machine_check(struct pt_regs *re * When there's any problem use only local no_way_out state. */ if (!lmce) { - if (mce_end(order) < 0) - no_way_out = worst >= MCE_PANIC_SEVERITY; + if (mce_end(order) < 0) { + if (!no_way_out) + no_way_out = worst >= MCE_PANIC_SEVERITY; + } } else { /* * If there was a fatal machine check we should have