debug cgroup: use task_css_set instead of rcu_dereference

This macro `task_css_set` verifies that the caller is
inside proper critical section if the kernel set CONFIG_PROVE_RCU=y.

Signed-off-by: Wang Long <wanglong19@meituan.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c
index 5f780d8f6a9d..9caeda610249 100644
--- a/kernel/cgroup/debug.c
+++ b/kernel/cgroup/debug.c
@@ -50,7 +50,7 @@ static int current_css_set_read(struct seq_file *seq, void *v)
 
         spin_lock_irq(&css_set_lock);
         rcu_read_lock();
-        cset = rcu_dereference(current->cgroups);
+        cset = task_css_set(current);
         refcnt = refcount_read(&cset->refcount);
         seq_printf(seq, "css_set %pK %d", cset, refcnt);
         if (refcnt > cset->nr_tasks)
@@ -96,7 +96,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
 
         spin_lock_irq(&css_set_lock);
         rcu_read_lock();
-        cset = rcu_dereference(current->cgroups);
+        cset = task_css_set(current);
         list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
                 struct cgroup *c = link->cgrp;