> On Fri, Apr 11, 2025 at 05:57:42PM +0800, Wei Fang wrote:
> > static const struct enetc_pf_ops enetc4_pf_ops = {
> > .set_si_primary_mac = enetc4_pf_set_si_primary_mac,
> > .get_si_primary_mac = enetc4_pf_get_si_primary_mac,
> > @@ -303,12 +489,55 @@ static void enetc4_pf_free(struct enetc_pf *pf)
> > enetc4_free_ntmp_user(pf->si);
> > }
> >
> > +static void enetc4_psi_do_set_rx_mode(struct work_struct *work)
> > +{
> > + struct enetc_si *si = container_of(work, struct enetc_si, rx_mode_task);
> > + struct enetc_pf *pf = enetc_si_priv(si);
> > + struct net_device *ndev = si->ndev;
> > + struct enetc_hw *hw = &si->hw;
> > + bool uc_promisc = false;
> > + bool mc_promisc = false;
> > + int type = 0;
> > +
> > + if (ndev->flags & IFF_PROMISC) {
> > + uc_promisc = true;
> > + mc_promisc = true;
> > + } else if (ndev->flags & IFF_ALLMULTI) {
>
> enetc4_psi_do_set_rx_mode() runs unlocked relative to changes made
> to ndev->flags, so could you at least read it just once to avoid
> inconsistencies?
>
> Speaking of running unlocked: if I'm not mistaken, this code design
> might lose consecutive updates to ndev->flags, as well as to the address
> lists, if queue_work() is executed while si->rx_mode_task is still
> running. There is a difference between statically allocating and
> continuously queuing the same work item, vs allocating one work item
> per each ndo_set_rx_mode() call.
>
> In practice it might be hard to trigger an actual issue, because the
> call sites serialize under rtnl_lock() which is so bulky that
> si->rx_mode_task should have time to finish by the time ndo_set_rx_mode()
> has a chance to be called again.
>
> I can't tell you exactly how, but my gut feeling is that the combination
> of these 2 things is going to be problematic.
I think we can add rtnl_lock() to enetc4_psi_do_set_rx_mode() to keep
consistency, as shown below.
--- a/drivers/net/ethernet/freescale/enetc/enetc4_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c
@@ -497,6 +497,8 @@ static void enetc4_psi_do_set_rx_mode(struct work_struct
*work)
bool mc_promisc = false;
int type = 0;
+ rtnl_lock();
+
if (ndev->flags & IFF_PROMISC) {
uc_promisc = true;
mc_promisc = true;
@@ -519,6 +521,8 @@ static void enetc4_psi_do_set_rx_mode(struct work_struct
*work)
/* Set new MAC filter */
enetc4_pf_set_mac_filter(pf, type);
+
+ rtnl_unlock();
}
