Messages in this thread Patch in this message | | | From | Vladimir Oltean <> | Subject | [PATCH v2 net-next 1/7] net/sched: taprio: taprio_offload_config_changed() is protected by rtnl_mutex | Date | Thu, 15 Sep 2022 13:50:40 +0300 |
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The locking in taprio_offload_config_changed() is wrong (but also inconsequentially so). The current_entry_lock does not serialize changes to the admin and oper schedules, only to the current entry. In fact, the rtnl_mutex does that, and that is taken at the time when taprio_change() is called.
Replace the rcu_dereference_protected() method with the proper RCU annotation, and drop the unnecessary spin lock.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- v1->v2: patch is new
net/sched/sch_taprio.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 5bffc37022e0..550afbbae8bc 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1194,16 +1194,10 @@ static void taprio_offload_config_changed(struct taprio_sched *q) { struct sched_gate_list *oper, *admin; - spin_lock(&q->current_entry_lock); - - oper = rcu_dereference_protected(q->oper_sched, - lockdep_is_held(&q->current_entry_lock)); - admin = rcu_dereference_protected(q->admin_sched, - lockdep_is_held(&q->current_entry_lock)); + oper = rtnl_dereference(q->oper_sched); + admin = rtnl_dereference(q->admin_sched); switch_schedules(q, &admin, &oper); - - spin_unlock(&q->current_entry_lock); } static u32 tc_map_to_queue_mask(struct net_device *dev, u32 tc_mask) -- 2.34.1
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