diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 4855892798fdfd6aeee695a4fc1d2a70b96662eb..1e236640df2259145b08efe68bb21106fa724fc3 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
struct cgroup *cgrp = link->cgrp;
list_del(&link->cg_link_list);
list_del(&link->cgrp_link_list);
+
+ /*
+ * We may not be holding cgroup_mutex, and if cgrp->count is
+ * dropped to 0 the cgroup can be destroyed at any time, hence
+ * rcu_read_lock is used to keep it alive.
+ */
+ rcu_read_lock();
if (atomic_dec_and_test(&cgrp->count) &&
notify_on_release(cgrp)) {
if (taskexit)
set_bit(CGRP_RELEASABLE, &cgrp->flags);
check_for_release(cgrp);
}
+ rcu_read_unlock();
kfree(link);
}