Re: [bug report] net: pcs: xpcs: convert to phylink_pcs_ops

[Dan Carpenter <dan.carpenter@oracle.com>]

On Tue, Jun 08, 2021 at 12:37:08PM +0000, Vladimir Oltean wrote:
> Hello Dan Carpenter,
> 
> On Tue, Jun 08, 2021 at 03:23:42PM +0300, Dan Carpenter wrote:
> > Hello Vladimir Oltean,
> > 
> > The patch 11059740e616: "net: pcs: xpcs: convert to phylink_pcs_ops"
> > from Jun 2, 2021, leads to the following static checker warning:
> > 
> > 	drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:1237 stmmac_phy_setup()
> > 	error: we previously assumed 'mdio_bus_data' could be null (see line 1225)
> > 
> > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> >   1215  static int stmmac_phy_setup(struct stmmac_priv *priv)
> >   1216  {
> >   1217          struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data;
> >                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >   1218          struct fwnode_handle *fwnode = of_fwnode_handle(priv->plat->phylink_node);
> >   1219          int mode = priv->plat->phy_interface;
> >   1220          struct phylink *phylink;
> >   1221  
> >   1222          priv->phylink_config.dev = &priv->dev->dev;
> >   1223          priv->phylink_config.type = PHYLINK_NETDEV;
> >   1224          priv->phylink_config.pcs_poll = true;
> >   1225          if (priv->plat->mdio_bus_data)
> >                     ^^^^^^^^^^^^^^^^^^^^^^^^^
> > This old code assumes mdio_bus_data can be NULL.
> > 
> >   1226                  priv->phylink_config.ovr_an_inband =
> >   1227                          mdio_bus_data->xpcs_an_inband;
> >   1228  
> >   1229          if (!fwnode)
> >   1230                  fwnode = dev_fwnode(priv->device);
> >   1231  
> >   1232          phylink = phylink_create(&priv->phylink_config, fwnode,
> >   1233                                   mode, &stmmac_phylink_mac_ops);
> >   1234          if (IS_ERR(phylink))
> >   1235                  return PTR_ERR(phylink);
> >   1236  
> >   1237          if (mdio_bus_data->has_xpcs) {
> >                     ^^^^^^^^^^^^^^^^^^^^^^^
> > Unchecked dereference.
> > 
> >   1238                  struct mdio_xpcs_args *xpcs = priv->hw->xpcs;
> >   1239  
> >   1240                  phylink_set_pcs(phylink, &xpcs->pcs);
> >   1241          }
> >   1242  
> >   1243          priv->phylink = phylink;
> >   1244          return 0;
> >   1245  }
> > 
> > regards,
> > dan carpenter
> 
> This should be solved here:
> https://lore.kernel.org/netdev/20210604112825.011148a3@canb.auug.org.au/ 

Nope.  That is a fix for merge conflict and it has been removed from
today's linux-next.  It's unrelated.

regards,
dan carpenter