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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44BB6C77B61 for ; Thu, 27 Apr 2023 10:53:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243651AbjD0Kx2 (ORCPT ); Thu, 27 Apr 2023 06:53:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243614AbjD0KxU (ORCPT ); Thu, 27 Apr 2023 06:53:20 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA8985597; Thu, 27 Apr 2023 03:53:15 -0700 (PDT) Received: from pps.filterd (m0353726.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33RAiS5D004717; Thu, 27 Apr 2023 10:53:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=pp1; bh=waMiVDV3D2LxsboyukziMcKMg/Mz3ihGHrTSUGS3JT0=; b=eIXwiIYy9PX2TJzuwedp+7IN9Y6ctLslNweC1oVQ00WVJAYKek1C+TfHYzoMHZKJVUv+ e73nXgp/4/1GosYMZGfSk2Cm7jFdaGq4b5oeLnPnqJ7i/iW/zShRwC0OtKhHb/KGG/QJ VWQT9jAMfXKoZ73gT3erMBfesLm7OCJzpS/g6pxAyI6fCsA6alQMeAMVa8BkZva0l5jo zN3Py+i9gamifkNluisY8pWclpFVFD2RYnMwPkiRQEdktMPYn4G7oD73ZfWx4GE3Rshx i1x8H7MW8VNlo2l2llWSEQw7AYWC28FIIYZyty9PH82q5RqcJWoRSviGghM8LP7EJi5k rg== Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3q7mp5e28f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 27 Apr 2023 10:53:13 +0000 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 33R4QXBJ008911; Thu, 27 Apr 2023 10:53:11 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma04ams.nl.ibm.com (PPS) with ESMTPS id 3q47772wvp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 27 Apr 2023 10:53:11 +0000 Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 33RAr5Xp41091362 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 27 Apr 2023 10:53:05 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2F8742004F; Thu, 27 Apr 2023 10:53:05 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D6CC320040; Thu, 27 Apr 2023 10:53:04 +0000 (GMT) Received: from osiris (unknown [9.152.212.90]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTPS; Thu, 27 Apr 2023 10:53:04 +0000 (GMT) Date: Thu, 27 Apr 2023 12:53:04 +0200 From: Heiko Carstens To: Claudio Imbrenda Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, borntraeger@de.ibm.com, nrb@linux.ibm.com, nsg@linux.ibm.com, seiden@linux.ibm.com, jgg@nvidia.com Subject: Re: [PATCH v2 1/1] KVM: s390: fix race in gmap_make_secure Message-ID: References: <20230426134834.35199-1-imbrenda@linux.ibm.com> <20230426134834.35199-2-imbrenda@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230426134834.35199-2-imbrenda@linux.ibm.com> X-TM-AS-GCONF: 00 X-Proofpoint-GUID: uuGKR60KHL88HP5te0lWx2XwiRQhINMB X-Proofpoint-ORIG-GUID: uuGKR60KHL88HP5te0lWx2XwiRQhINMB X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-27_07,2023-04-27_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 impostorscore=0 mlxlogscore=526 lowpriorityscore=0 suspectscore=0 priorityscore=1501 clxscore=1011 spamscore=0 adultscore=0 phishscore=0 mlxscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304270092 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Apr 26, 2023 at 03:48:34PM +0200, Claudio Imbrenda wrote: > This patch fixes a potential race in gmap_make_secure and removes the > last user of follow_page without FOLL_GET. > > Signed-off-by: Claudio Imbrenda > Suggested-by: Jason Gunthorpe > Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests") > --- > arch/s390/kernel/uv.c | 32 +++++++++++--------------------- > 1 file changed, 11 insertions(+), 21 deletions(-) It would be helpful if this would be a bit more descriptive. "Fix race" is not very helpful :) What race does this fix? When can this happen? What are the consequences if the race window is being hit?