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=-10.1 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_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 48E79C4CEC6 for ; Thu, 12 Sep 2019 17:57:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F8162075C for ; Thu, 12 Sep 2019 17:57:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="Ws37Eh+4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726618AbfILR5F (ORCPT ); Thu, 12 Sep 2019 13:57:05 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:35880 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbfILR5F (ORCPT ); Thu, 12 Sep 2019 13:57:05 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id x8CHsQM0025853 for ; Thu, 12 Sep 2019 10:57:03 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=JHcGIr6DfeeZGfRlp0Bw8MSSseCy7tNcl4Zfer3yjas=; b=Ws37Eh+4it10LaEbzqprrRYoR6i8fyBwmbB70feddo3KvOnHh2Ev0c0EM7XHb9TEqslA /MJbRaOrckgrmUOtNmfr62EObwVA3ajdVceCbAEhzZVlTzOReprBcrp8ne7bIRs/zxm0 Ks4NZE4CCTU0VenxfprPN4jzLDkXeNDah6Y= Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2uytd6g4ug-8 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Thu, 12 Sep 2019 10:57:03 -0700 Received: from mx-out.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Thu, 12 Sep 2019 10:56:47 -0700 Received: by devvm2643.prn2.facebook.com (Postfix, from userid 111017) id DA16717690C09; Thu, 12 Sep 2019 10:56:46 -0700 (PDT) Smtp-Origin-Hostprefix: devvm From: Roman Gushchin Smtp-Origin-Hostname: devvm2643.prn2.facebook.com To: Tejun Heo , CC: , , Mark Crossen , Roman Gushchin , Smtp-Origin-Cluster: prn2c23 Subject: [PATCH 2/2] cgroup: freezer: fix frozen state inheritance Date: Thu, 12 Sep 2019 10:56:45 -0700 Message-ID: <20190912175645.2841713-2-guro@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190912175645.2841713-1-guro@fb.com> References: <20190912175645.2841713-1-guro@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.70,1.0.8 definitions=2019-09-12_09:2019-09-11,2019-09-12 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=7 suspectscore=0 clxscore=1015 mlxscore=7 mlxlogscore=110 spamscore=7 impostorscore=0 phishscore=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1908290000 definitions=main-1909120188 X-FB-Internal: deliver Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org If a new child cgroup is created in the frozen cgroup hierarchy (one or more of ancestor cgroups is frozen), the CGRP_FREEZE cgroup flag should be set. Otherwise if a process will be attached to the child cgroup, it won't become frozen. The problem can be reproduced with the test_cgfreezer_mkdir test. This is the output before this patch: ~/test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb Cgroup /sys/fs/cgroup/cg_test_mkdir_A/cg_test_mkdir_B isn't frozen not ok 4 test_cgfreezer_mkdir ok 5 test_cgfreezer_rmdir ok 6 test_cgfreezer_migrate ok 7 test_cgfreezer_ptrace ok 8 test_cgfreezer_stopped ok 9 test_cgfreezer_ptraced ok 10 test_cgfreezer_vfork And with this patch: ~/test_freezer ok 1 test_cgfreezer_simple ok 2 test_cgfreezer_tree ok 3 test_cgfreezer_forkbomb ok 4 test_cgfreezer_mkdir ok 5 test_cgfreezer_rmdir ok 6 test_cgfreezer_migrate ok 7 test_cgfreezer_ptrace ok 8 test_cgfreezer_stopped ok 9 test_cgfreezer_ptraced ok 10 test_cgfreezer_vfork Reported-by: Mark Crossen Signed-off-by: Roman Gushchin Cc: Tejun Heo Cc: stable@vger.kernel.org --- kernel/cgroup/cgroup.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 753afbca549f..8be1da1ebd9a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5255,8 +5255,16 @@ static struct cgroup *cgroup_create(struct cgroup *parent) * if the parent has to be frozen, the child has too. */ cgrp->freezer.e_freeze = parent->freezer.e_freeze; - if (cgrp->freezer.e_freeze) + if (cgrp->freezer.e_freeze) { + /* + * Set the CGRP_FREEZE flag, so when a process will be + * attached to the child cgroup, it will become frozen. + * At this point the new cgroup is unpopulated, so we can + * consider it frozen immediately. + */ + set_bit(CGRP_FREEZE, &cgrp->flags); set_bit(CGRP_FROZEN, &cgrp->flags); + } spin_lock_irq(&css_set_lock); for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) { -- 2.21.0