sfc: fix NULL dereferences in ef100_process_design_param()

Since cited commit, ef100_probe_main() and hence also
 ef100_check_design_params() run before efx->net_dev is created;
 consequently, we cannot netif_set_tso_max_size() or _segs() at this
 point.
Move those netif calls to ef100_probe_netdev(), and also replace
 netif_err within the design params code with pci_err.

Reported-by: Kyungwook Boo <[email protected]>
Fixes: 98ff4c7 ("sfc: Separate netdev probe/remove from PCI probe/remove")
Signed-off-by: Edward Cree <[email protected]>
Reviewed-by: Michal Swiatkowski <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Edward Cree

drivers/net/ethernet/sfc/ef100_netdev.c

@@ -450,8 +450,9 @@ int ef100_probe_netdev(struct efx_probe_data *probe_data)
 	net_dev->hw_enc_features |= efx->type->offload_features;
 	net_dev->vlan_features |= NETIF_F_HW_CSUM | NETIF_F_SG |
 				  NETIF_F_HIGHDMA | NETIF_F_ALL_TSO;
-	netif_set_tso_max_segs(net_dev,
-			       ESE_EF100_DP_GZ_TSO_MAX_HDR_NUM_SEGS_DEFAULT);
+	nic_data = efx->nic_data;
+	netif_set_tso_max_size(efx->net_dev, nic_data->tso_max_payload_len);
+	netif_set_tso_max_segs(efx->net_dev, nic_data->tso_max_payload_num_segs);
 
 	rc = efx_ef100_init_datapath_caps(efx);
 	if (rc < 0)
@@ -477,7 +478,6 @@ int ef100_probe_netdev(struct efx_probe_data *probe_data)
 	/* Don't fail init if RSS setup doesn't work. */
 	efx_mcdi_push_default_indir_table(efx, efx->n_rx_channels);
 
-	nic_data = efx->nic_data;
 	rc = ef100_get_mac_address(efx, net_dev->perm_addr, CLIENT_HANDLE_SELF,
 				   efx->type->is_vf);
 	if (rc)

drivers/net/ethernet/sfc/ef100_nic.c

@@ -887,8 +887,7 @@ static int ef100_process_design_param(struct efx_nic *efx,
 	case ESE_EF100_DP_GZ_TSO_MAX_HDR_NUM_SEGS:
 		/* We always put HDR_NUM_SEGS=1 in our TSO descriptors */
 		if (!reader->value) {
-			netif_err(efx, probe, efx->net_dev,
-				  "TSO_MAX_HDR_NUM_SEGS < 1\n");
+			pci_err(efx->pci_dev, "TSO_MAX_HDR_NUM_SEGS < 1\n");
 			return -EOPNOTSUPP;
 		}
 		return 0;
@@ -901,32 +900,28 @@ static int ef100_process_design_param(struct efx_nic *efx,
 		 */
 		if (!reader->value || reader->value > EFX_MIN_DMAQ_SIZE ||
 		    EFX_MIN_DMAQ_SIZE % (u32)reader->value) {
-			netif_err(efx, probe, efx->net_dev,
-				  "%s size granularity is %llu, can't guarantee safety\n",
-				  reader->type == ESE_EF100_DP_GZ_RXQ_SIZE_GRANULARITY ? "RXQ" : "TXQ",
-				  reader->value);
+			pci_err(efx->pci_dev,
+				"%s size granularity is %llu, can't guarantee safety\n",
+				reader->type == ESE_EF100_DP_GZ_RXQ_SIZE_GRANULARITY ? "RXQ" : "TXQ",
+				reader->value);
 			return -EOPNOTSUPP;
 		}
 		return 0;
 	case ESE_EF100_DP_GZ_TSO_MAX_PAYLOAD_LEN:
 		nic_data->tso_max_payload_len = min_t(u64, reader->value,
 						      GSO_LEGACY_MAX_SIZE);
-		netif_set_tso_max_size(efx->net_dev,
-				       nic_data->tso_max_payload_len);
 		return 0;
 	case ESE_EF100_DP_GZ_TSO_MAX_PAYLOAD_NUM_SEGS:
 		nic_data->tso_max_payload_num_segs = min_t(u64, reader->value, 0xffff);
-		netif_set_tso_max_segs(efx->net_dev,
-				       nic_data->tso_max_payload_num_segs);
 		return 0;
 	case ESE_EF100_DP_GZ_TSO_MAX_NUM_FRAMES:
 		nic_data->tso_max_frames = min_t(u64, reader->value, 0xffff);
 		return 0;
 	case ESE_EF100_DP_GZ_COMPAT:
 		if (reader->value) {
-			netif_err(efx, probe, efx->net_dev,
-				  "DP_COMPAT has unknown bits %#llx, driver not compatible with this hw\n",
-				  reader->value);
+			pci_err(efx->pci_dev,
+				"DP_COMPAT has unknown bits %#llx, driver not compatible with this hw\n",
+				reader->value);
 			return -EOPNOTSUPP;
 		}
 		return 0;
@@ -946,10 +941,10 @@ static int ef100_process_design_param(struct efx_nic *efx,
 		 * So the value of this shouldn't matter.
 		 */
 		if (reader->value != ESE_EF100_DP_GZ_VI_STRIDES_DEFAULT)
-			netif_dbg(efx, probe, efx->net_dev,
-				  "NIC has other than default VI_STRIDES (mask "
-				  "%#llx), early probing might use wrong one\n",
-				  reader->value);
+			pci_dbg(efx->pci_dev,
+				"NIC has other than default VI_STRIDES (mask "
+				"%#llx), early probing might use wrong one\n",
+				reader->value);
 		return 0;
 	case ESE_EF100_DP_GZ_RX_MAX_RUNT:
 		/* Driver doesn't look at L2_STATUS:LEN_ERR bit, so we don't
@@ -961,9 +956,9 @@ static int ef100_process_design_param(struct efx_nic *efx,
 		/* Host interface says "Drivers should ignore design parameters
 		 * that they do not recognise."
 		 */
-		netif_dbg(efx, probe, efx->net_dev,
-			  "Ignoring unrecognised design parameter %u\n",
-			  reader->type);
+		pci_dbg(efx->pci_dev,
+			"Ignoring unrecognised design parameter %u\n",
+			reader->type);
 		return 0;
 	}
 }
@@ -999,13 +994,13 @@ static int ef100_check_design_params(struct efx_nic *efx)
 	 */
 	if (reader.state != EF100_TLV_TYPE) {
 		if (reader.state == EF100_TLV_TYPE_CONT)
-			netif_err(efx, probe, efx->net_dev,
-				  "truncated design parameter (incomplete type %u)\n",
-				  reader.type);
+			pci_err(efx->pci_dev,
+				"truncated design parameter (incomplete type %u)\n",
+				reader.type);
 		else
-			netif_err(efx, probe, efx->net_dev,
-				  "truncated design parameter %u\n",
-				  reader.type);
+			pci_err(efx->pci_dev,
+				"truncated design parameter %u\n",
+				reader.type);
 		rc = -EIO;
 	}
 out: