From: Vladimir Oltean olteanv@gmail.com
taprio_init may fail earlier than this line:
list_add(&q->taprio_list, &taprio_list);
i.e. due to the net device not being multi queue.
Attempting to remove q from the global taprio_list when it is not part of it will result in a kernel panic.
Fix it by matching list_add and list_del better to one another in the order of operations. This way we can keep the deletion unconditional and with lower complexity - O(1).
Cc: Leandro Dorileo leandro.maciel.dorileo@intel.com Fixes: 7b9eba7ba0c1 ("net/sched: taprio: fix picos_per_byte miscalculation") Signed-off-by: Vladimir Oltean olteanv@gmail.com Acked-by: Vinicius Costa Gomes vinicius.gomes@intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_taprio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -903,6 +903,10 @@ static int taprio_init(struct Qdisc *sch */ q->clockid = -1;
+ spin_lock(&taprio_list_lock); + list_add(&q->taprio_list, &taprio_list); + spin_unlock(&taprio_list_lock); + if (sch->parent != TC_H_ROOT) return -EOPNOTSUPP;
@@ -920,10 +924,6 @@ static int taprio_init(struct Qdisc *sch if (!opt) return -EINVAL;
- spin_lock(&taprio_list_lock); - list_add(&q->taprio_list, &taprio_list); - spin_unlock(&taprio_list_lock); - for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *dev_queue; struct Qdisc *qdisc;