From: Madhuparna Bhowmik Date: Sat, 18 Jan 2020 03:10:51 +0000 (+0530) Subject: cgroup.c: Use built-in RCU list checking X-Git-Tag: Ubuntu-5.10.0-12.13~3172^2~15 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=3010c5b9f5f476b35b24955f08a3a6c06ec8e878;p=mirror_ubuntu-hirsute-kernel.git cgroup.c: Use built-in RCU list checking list_for_each_entry_rcu has built-in RCU and lock checking. Pass cond argument to list_for_each_entry_rcu() to silence false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled by default. Even though the function css_next_child() already checks if cgroup_mutex or rcu_read_lock() is held using cgroup_assert_mutex_or_rcu_locked(), there is a need to pass cond to list_for_each_entry_rcu() to avoid false positive lockdep warning. Signed-off-by: Madhuparna Bhowmik Acked-by: Michal Koutný Signed-off-by: Tejun Heo --- diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index b4c4c4fbd6de..7a310db6c807 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4148,7 +4148,8 @@ struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, } else if (likely(!(pos->flags & CSS_RELEASED))) { next = list_entry_rcu(pos->sibling.next, struct cgroup_subsys_state, sibling); } else { - list_for_each_entry_rcu(next, &parent->children, sibling) + list_for_each_entry_rcu(next, &parent->children, sibling, + lockdep_is_held(&cgroup_mutex)) if (next->serial_nr > pos->serial_nr) break; }