net/sched: taprio: use rtnl_dereference for oper and admin sched in taprio_destroy()

Sparse complains that taprio_destroy() dereferences q->oper_sched and
q->admin_sched without rcu_dereference(), since they are marked as __rcu
in the taprio private structure.

1671:28: warning: incorrect type in argument 1 (different address spaces)
1671:28:    expected struct callback_head *head
1671:28:    got struct callback_head [noderef] __rcu *
1674:28: warning: incorrect type in argument 1 (different address spaces)
1674:28:    expected struct callback_head *head
1674:28:    got struct callback_head [noderef] __rcu *

To silence that build warning, do actually use rtnl_dereference(), since
we know the rtnl_mutex is held at the time of q->destroy().

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Vladimir Oltean 2022-09-15 13:50:42 +03:00 committed by Jakub Kicinski
parent 18cdd2f099
commit 9af23657b3

View file

@ -1634,6 +1634,7 @@ static void taprio_destroy(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct sched_gate_list *oper, *admin;
unsigned int i;
spin_lock(&taprio_list_lock);
@ -1657,11 +1658,14 @@ static void taprio_destroy(struct Qdisc *sch)
netdev_reset_tc(dev);
if (q->oper_sched)
call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb);
oper = rtnl_dereference(q->oper_sched);
admin = rtnl_dereference(q->admin_sched);
if (q->admin_sched)
call_rcu(&q->admin_sched->rcu, taprio_free_sched_cb);
if (oper)
call_rcu(&oper->rcu, taprio_free_sched_cb);
if (admin)
call_rcu(&admin->rcu, taprio_free_sched_cb);
}
static int taprio_init(struct Qdisc *sch, struct nlattr *opt,