From patchwork Tue Jul 6 19:06:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Luck X-Patchwork-Id: 12361121 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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 09330C07E9C for ; Tue, 6 Jul 2021 19:06:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEA7C61C23 for ; Tue, 6 Jul 2021 19:06:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231702AbhGFTJI (ORCPT ); Tue, 6 Jul 2021 15:09:08 -0400 Received: from mga11.intel.com ([192.55.52.93]:6713 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231438AbhGFTJH (ORCPT ); Tue, 6 Jul 2021 15:09:07 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="206166874" X-IronPort-AV: E=Sophos;i="5.83,329,1616482800"; d="scan'208";a="206166874" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2021 12:06:27 -0700 X-IronPort-AV: E=Sophos;i="5.83,329,1616482800"; d="scan'208";a="427687568" Received: from agluck-desk2.sc.intel.com ([10.3.52.146]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jul 2021 12:06:26 -0700 From: Tony Luck To: Borislav Petkov Cc: Tony Luck , Ding Hui , naoya.horiguchi@nec.com, osalvador@suse.de, Youquan Song , huangcun@sangfor.com.cn, x86@kernel.org, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/3] More machine check recovery fixes Date: Tue, 6 Jul 2021 12:06:17 -0700 Message-Id: <20210706190620.1290391-1-tony.luck@intel.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org Fix a couple of issues in machine check handling 1) A repeated machine check inside the kernel without calling the task work function between machine checks it will go into an infinite loop 2) Machine checks in kernel functions copying data from user addresses send SIGBUS to the user as if the application had consumed the poison. But this is wrong. The user should see either an -EFAULT error return or a reduced byte count (in the case of write(2)). Tony Luck (3): x86/mce: Change to not send SIGBUS error during copy from user x86/mce: Avoid infinite loop for copy from user recovery x86/mce: Drop copyin special case for #MC arch/x86/kernel/cpu/mce/core.c | 62 ++++++++++++++++++++++++---------- arch/x86/lib/copy_user_64.S | 13 ------- include/linux/sched.h | 1 + 3 files changed, 45 insertions(+), 31 deletions(-)