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=-11.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 1D513C31E46 for ; Wed, 12 Jun 2019 12:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8C3B20874 for ; Wed, 12 Jun 2019 12:27:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="qxoaAlGV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438902AbfFLM1d (ORCPT ); Wed, 12 Jun 2019 08:27:33 -0400 Received: from terminus.zytor.com ([198.137.202.136]:40333 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438842AbfFLM1c (ORCPT ); Wed, 12 Jun 2019 08:27:32 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x5CCQsjc684780 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 12 Jun 2019 05:26:54 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x5CCQsjc684780 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019051801; t=1560342415; bh=Alv9MRLP1mGRljy7+QwagBIBcl0cQij3a3UMVqGNvdk=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=qxoaAlGV6+kE9AQnm6WE8abQbghQLcCfbXhb8DkR8bTNigy7F7lNTx+UPkV7Eqe4h cqEK8o8ielQpHC7SDsSUpnFS/JEM6p20lj8W7PtPNRi1BFZ/kxv/bQgPg2FHiysRI9 snLC5JGXPeLXr9vM6IXB6E9eFvJPC0gZooUCP/GfEeeID8dEtx3JKjZAbq3G09omxo dYSvqeqJKDSoTAAn9BtkF65MsYaAB0GD4MJ+HhCVy2FeNKNo0phmC1T0+8xPwaZouN dWnIosOudmDPnljm1Vauw42vi44H3DWm8gm7ch9roYg9/nirmyWoq9mVwFOY0NOZqG GJ9ctKKtlxfjQ== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x5CCQrP3684777; Wed, 12 Jun 2019 05:26:53 -0700 Date: Wed, 12 Jun 2019 05:26:53 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Prarit Bhargava Message-ID: Cc: mingo@kernel.org, prarit@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, reinette.chatre@intel.com, fenghua.yu@intel.com, bp@alien8.de Reply-To: prarit@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, reinette.chatre@intel.com, tglx@linutronix.de, fenghua.yu@intel.com, bp@alien8.de In-Reply-To: <20190610171544.13474-1-prarit@redhat.com> References: <20190610171544.13474-1-prarit@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled Git-Commit-ID: c7563e62a6d720aa3b068e26ddffab5f0df29263 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c7563e62a6d720aa3b068e26ddffab5f0df29263 Gitweb: https://git.kernel.org/tip/c7563e62a6d720aa3b068e26ddffab5f0df29263 Author: Prarit Bhargava AuthorDate: Mon, 10 Jun 2019 13:15:44 -0400 Committer: Thomas Gleixner CommitDate: Wed, 12 Jun 2019 10:31:50 +0200 x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled Booting with kernel parameter "rdt=cmt,mbmtotal,memlocal,l3cat,mba" and executing "mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl" results in a NULL pointer dereference on systems which do not have local MBM support enabled.. BUG: kernel NULL pointer dereference, address: 0000000000000020 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 722 Comm: kworker/0:3 Not tainted 5.2.0-0.rc3.git0.1.el7_UNSUPPORTED.x86_64 #2 Workqueue: events mbm_handle_overflow RIP: 0010:mbm_handle_overflow+0x150/0x2b0 Only enter the bandwith update loop if the system has local MBM enabled. Fixes: de73f38f7680 ("x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth") Signed-off-by: Prarit Bhargava Signed-off-by: Thomas Gleixner Cc: Fenghua Yu Cc: Reinette Chatre Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190610171544.13474-1-prarit@redhat.com --- arch/x86/kernel/cpu/resctrl/monitor.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 1573a0a6b525..ff6e8e561405 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -368,6 +368,9 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm) struct list_head *head; struct rdtgroup *entry; + if (!is_mbm_local_enabled()) + return; + r_mba = &rdt_resources_all[RDT_RESOURCE_MBA]; closid = rgrp->closid; rmid = rgrp->mon.rmid;