On Thu, 11 Mar 2021 13:12:25 -0800 Xie He wrote: > On Thu, Mar 11, 2021 at 12:43 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > > > > Is this a theoretical issues or do you see a path where it triggers? > > > > Who are the callers sending frames to a device which went down? > > This is a theoretical issue. I didn't see this issue in practice. > > When "__dev_queue_xmit" and "sch_direct_xmit" call > "dev_hard_start_xmit", there appears to be no locking mechanism > preventing the netif from going down while "dev_hard_start_xmit" is > doing its work. Normally driver's ndo_stop() calls netif_tx_disable() which takes TX locks, so unless your driver is lockless (LLTX) there should be no xmit calls after that point.
