From 7a3bb24f7c5ceebad19b12b66fd832a27a7e90df Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 16 May 2014 13:22:52 -0400 Subject: [PATCH] device_cgroup: use css_has_online_children() instead of has_children() 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 Acked-by: Aristeu Rozanski Acked-by: Serge Hallyn Acked-by: Li Zefan --- 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 084c8e417564..d9d69e6930ed 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -587,21 +587,6 @@ 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 @@ -634,7 +619,7 @@ 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)) @@ -650,7 +635,7 @@ 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);