Re: [PATCH net 4/9] net: stmmac: selftests: Must remove UC/MC addresses to prevent false positives
From: David Miller <davem@davemloft.net>
Date: 2019-10-30 21:52:38
Also in:
linux-arm-kernel, lkml
From: Jose Abreu <Jose.Abreu@synopsys.com> Date: Tue, 29 Oct 2019 15:14:48 +0100
quoted hunk ↗ jump to hunk
@@ -499,9 +501,18 @@ static int stmmac_test_hfilt(struct stmmac_priv *priv) if (netdev_mc_count(priv->dev) >= priv->hw->multicast_filter_bins) return -EOPNOTSUPP;
This test above...
+ dummy_dev = alloc_etherdev(0); + if (!dummy_dev) + return -ENOMEM; + + /* Remove all MC addresses */ + netdev_for_each_mc_addr(ha, priv->dev) + dev_mc_add(dummy_dev, ha->addr); + dev_mc_flush(priv->dev);
No longer makes any sense now that you're removing all of the MC addresses. Also I know it seems that it should be guaranteed that re-adding all of the previously configured MC addresses should succeed. But I am always wary when I see error codes ignored like this. This test makes destructure changes to the device's configuration, perhaps in a non-restorable fashion if errors occur re-adding the MC list entries. Running a test should never even remotely introduce a change in the device state like that. I really don't like this, to be honest. I'd hate to be the user who had this somehow trigger on them and then have to diagnose it. :-/