From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932429AbaEIVb7 (ORCPT ); Fri, 9 May 2014 17:31:59 -0400 Received: from mail-qa0-f45.google.com ([209.85.216.45]:58025 "EHLO mail-qa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932360AbaEIVb4 (ORCPT ); Fri, 9 May 2014 17:31:56 -0400 From: Tejun Heo To: lizefan@huawei.com Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, Tejun Heo , Aristeu Rozanski , Serge Hallyn Subject: [PATCH 13/14] device_cgroup: use css_has_online_children() instead of has_children() Date: Fri, 9 May 2014 17:31:30 -0400 Message-Id: <1399671091-23867-14-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1399671091-23867-1-git-send-email-tj@kernel.org> References: <1399671091-23867-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org devcgroup_update_access() wants to know whether there are child cgroups which are online and visible to userland and has_children() may return false positive. Replace it with css_has_online_children(). Signed-off-by: Tejun Heo Cc: Aristeu Rozanski Cc: Serge Hallyn --- security/device_cgroup.c | 19 ++----------------- 1 file changed, 2 insertions(+), 17 deletions(-) diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 75b4b18..22de334 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -475,21 +475,6 @@ static int propagate_exception(struct dev_cgroup *devcg_root, return rc; } -static inline bool has_children(struct dev_cgroup *devcgroup) -{ - bool ret; - - /* - * FIXME: There may be lingering offline csses and this function - * may return %true when there isn't any userland-visible child - * which is incorrect for our purposes. - */ - rcu_read_lock(); - ret = css_next_child(NULL, &devcgroup->css); - rcu_read_unlock(); - return ret; -} - /* * Modify the exception list using allow/deny rules. * CAP_SYS_ADMIN is needed for this. It's at least separate from CAP_MKNOD @@ -522,7 +507,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, case 'a': switch (filetype) { case DEVCG_ALLOW: - if (has_children(devcgroup)) + if (css_has_online_children(&devcgroup->css)) return -EINVAL; if (!may_allow_all(parent)) @@ -538,7 +523,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, return rc; break; case DEVCG_DENY: - if (has_children(devcgroup)) + if (css_has_online_children(&devcgroup->css)) return -EINVAL; dev_exception_clean(devcgroup); -- 1.9.0