| Message ID | 20200907141516.16817-1-luobin9@huawei.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Driver Reviewers |
| Headers | show |
| Series | [net] hinic: fix rewaking txq after netif_tx_disable | expand |
On Mon, 7 Sep 2020 22:15:16 +0800 Luo bin wrote: > When calling hinic_close in hinic_set_channels, all queues are > stopped after netif_tx_disable, but some queue may be rewaken in > free_tx_poll by mistake while drv is handling tx irq. If one queue > is rewaken core may call hinic_xmit_frame to send pkt after > netif_tx_disable within a short time which may results in accessing > memory that has been already freed in hinic_close. So we judge > whether the netdev is in down state before waking txq in free_tx_poll > to fix this bug. The right fix is to call napi_disable() _before_ you call netif_tx_disable(), not after, like hinic_close() does.
On 2020/9/8 5:28, Jakub Kicinski wrote: > On Mon, 7 Sep 2020 22:15:16 +0800 Luo bin wrote: >> When calling hinic_close in hinic_set_channels, all queues are >> stopped after netif_tx_disable, but some queue may be rewaken in >> free_tx_poll by mistake while drv is handling tx irq. If one queue >> is rewaken core may call hinic_xmit_frame to send pkt after >> netif_tx_disable within a short time which may results in accessing >> memory that has been already freed in hinic_close. So we judge >> whether the netdev is in down state before waking txq in free_tx_poll >> to fix this bug. > > The right fix is to call napi_disable() _before_ you call > netif_tx_disable(), not after, like hinic_close() does. > . > Will fix. Thanks for your review.
diff --git a/drivers/net/ethernet/huawei/hinic/hinic_tx.c b/drivers/net/ethernet/huawei/hinic/hinic_tx.c index a97498ee6914..6eac6bdf164e 100644 --- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c +++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c @@ -718,7 +718,8 @@ static int free_tx_poll(struct napi_struct *napi, int budget) __netif_tx_lock(netdev_txq, smp_processor_id()); - netif_wake_subqueue(nic_dev->netdev, qp->q_id); + if (nic_dev->flags & HINIC_INTF_UP) + netif_wake_subqueue(nic_dev->netdev, qp->q_id); __netif_tx_unlock(netdev_txq);
When calling hinic_close in hinic_set_channels, all queues are stopped after netif_tx_disable, but some queue may be rewaken in free_tx_poll by mistake while drv is handling tx irq. If one queue is rewaken core may call hinic_xmit_frame to send pkt after netif_tx_disable within a short time which may results in accessing memory that has been already freed in hinic_close. So we judge whether the netdev is in down state before waking txq in free_tx_poll to fix this bug. Signed-off-by: Luo bin <luobin9@huawei.com> --- drivers/net/ethernet/huawei/hinic/hinic_tx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)