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authorVladimir Oltean <olteanv@gmail.com>2019-08-30 04:07:21 +0300
committerDavid S. Miller <davem@davemloft.net>2019-08-31 18:45:34 -0700
commitefb55222d31c8c2af8b4ba42bb56b0b0beedf98e (patch)
tree86883eb68e11e1c388b8f418b2f1dc3d30894103
parent5f81d5455589df2f580e634c2e9da55b80e63c30 (diff)
taprio: Fix kernel panic in taprio_destroy
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>
-rw-r--r--net/sched/sch_taprio.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index e25d414ae12f..8c85f61e98dd 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1249,6 +1249,10 @@ static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
*/
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;
@@ -1266,10 +1270,6 @@ static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
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;