Re: [PATCH net] bnxt_en: Fix potential race condition in bnxt_tx_enable()

From: David Miller
Date: Sat Jul 16 2016 - 02:20:52 EST


From: Florian Fainelli <f.fainelli@xxxxxxxxx>
Date: Fri, 15 Jul 2016 16:42:01 -0700

> @@ -4599,7 +4599,9 @@ static void bnxt_tx_enable(struct bnxt *bp)
> for (i = 0; i < bp->tx_nr_rings; i++) {
> txr = &bp->tx_ring[i];
> txq = netdev_get_tx_queue(bp->dev, i);
> + __netif_tx_lock(txq, smp_processor_id());
> txr->dev_state = 0;
> + __netif_tx_unlock(txq);

You're going to have to explain how this could possibly cause a
problem, because I'm pretty sure it can't.

Either the reader sees 0, or non-zero, in this value.

And adding locking around this assignment does not change that at all.