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=-13.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,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 CE164C43612 for ; Thu, 10 Jan 2019 21:11:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AF59208E3 for ; Thu, 10 Jan 2019 21:11:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="chPszpAi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731149AbfAJVLY (ORCPT ); Thu, 10 Jan 2019 16:11:24 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:52110 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729343AbfAJVLT (ORCPT ); Thu, 10 Jan 2019 16:11:19 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id x0AL8qFJ192900; Thu, 10 Jan 2019 21:10:44 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : in-reply-to : references; s=corp-2018-07-02; bh=un0wieK7yWFodUoPf/TbQJCMffDoPehxHgZRzLFUW2o=; b=chPszpAiJAbkg+zkadcOBGkMBvHUigW7P3J5U9kXh/4WR4WaTdIqSIJKmzOC/NYFDsyM MrFViq/HYuHukuzNxvfAtgv5S+929Mdu9AdazByjvd+OPJMDXYmo8iFtHbKf7joRxxl/ QVImhgrAo9iB2tmKxcqYcyE2n9GTsgn+pHOsq5kbq0i5OjnVPX2uEIwCk/3vgDm7ck2L gdt2Jf6KBycEqmPAG9bKtRrQvpN6O6xgeHZxhQyKMbbVoWzO9mVK92OnrDy3zK7hhBVl 4ErVypdkvqQImbKrKUjb7pLwtF16Ii9FhyFfMXHHcbV30+4FHsmkdvwuL+W2nUMEn+cL gQ== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2120.oracle.com with ESMTP id 2ptn7r9f50-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Jan 2019 21:10:44 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id x0ALAh5k029012 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Jan 2019 21:10:43 GMT Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x0ALAhqP023547; Thu, 10 Jan 2019 21:10:43 GMT Received: from concerto.internal (/24.9.64.241) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 10 Jan 2019 13:10:42 -0800 From: Khalid Aziz To: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de, ak@linux.intel.com, torvalds@linux-foundation.org, liran.alon@oracle.com, keescook@google.com, konrad.wilk@oracle.com Cc: Khalid Aziz , deepa.srinivasan@oracle.com, chris.hyser@oracle.com, tyhicks@canonical.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.com, jcm@redhat.com, boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com, joao.m.martins@oracle.com, jmattson@google.com, pradeep.vincent@oracle.com, john.haxby@oracle.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de, steven.sistare@oracle.com, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v7 15/16] xpfo, mm: Fix hang when booting with "xpfotlbflush" Date: Thu, 10 Jan 2019 14:09:47 -0700 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9132 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901100164 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Kernel hangs when booted up with "xpfotlbflush" option. This is caused by xpfo_kunmap() fliushing TLB while holding xpfo lock starving other tasks waiting for the lock. This patch moves tlb flush outside of the code holding xpfo lock. Signed-off-by: Khalid Aziz --- mm/xpfo.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/mm/xpfo.c b/mm/xpfo.c index 85079377c91d..79ffdba6af69 100644 --- a/mm/xpfo.c +++ b/mm/xpfo.c @@ -148,6 +148,8 @@ EXPORT_SYMBOL(xpfo_kmap); void xpfo_kunmap(void *kaddr, struct page *page) { + bool flush_tlb = false; + if (!static_branch_unlikely(&xpfo_inited)) return; @@ -168,10 +170,13 @@ void xpfo_kunmap(void *kaddr, struct page *page) if (atomic_read(&page->xpfo_mapcount) == 0) { SetPageXpfoUnmapped(page); set_kpte(kaddr, page, __pgprot(0)); - xpfo_cond_flush_kernel_tlb(page, 0); + flush_tlb = true; } spin_unlock(&page->xpfo_lock); } + + if (flush_tlb) + xpfo_cond_flush_kernel_tlb(page, 0); } EXPORT_SYMBOL(xpfo_kunmap); -- 2.17.1