cgroup: unexport locking interface and cgroup_attach_task()
Now that all external cgroup_lock() users are gone, we can finally
unexport the locking interface and prevent future abuse of
cgroup_mutex.
Make cgroup_[un]lock() and cgroup_lock_live_group() static. Also,
cgroup_attach_task() doesn't have any user left and can't be used
without locking interface anyway. Make it static too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index ae76170..32ca030 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -336,7 +336,7 @@
* On success, returns true; the lock should be later released with
* cgroup_unlock(). On failure returns false with no lock held.
*/
-bool cgroup_lock_live_group(struct cgroup *cgrp)
+static bool cgroup_lock_live_group(struct cgroup *cgrp)
{
mutex_lock(&cgroup_mutex);
if (cgroup_is_removed(cgrp)) {
@@ -345,7 +345,6 @@
}
return true;
}
-EXPORT_SYMBOL_GPL(cgroup_lock_live_group);
/* the list of cgroups eligible for automatic release. Protected by
* release_list_lock */
@@ -824,22 +823,20 @@
* cgroup_lock - lock out any changes to cgroup structures
*
*/
-void cgroup_lock(void)
+static void cgroup_lock(void)
{
mutex_lock(&cgroup_mutex);
}
-EXPORT_SYMBOL_GPL(cgroup_lock);
/**
* cgroup_unlock - release lock on cgroup changes
*
* Undo the lock taken in a previous cgroup_lock() call.
*/
-void cgroup_unlock(void)
+static void cgroup_unlock(void)
{
mutex_unlock(&cgroup_mutex);
}
-EXPORT_SYMBOL_GPL(cgroup_unlock);
/*
* A couple of forward declarations required, due to cyclic reference loop: