intel: fix string truncation warnings

Fix -Wformat-truncated warnings to complete the intel directories' W=1
clean efforts. The W=1 recently got enhanced with a few new flags and
this brought up some new warnings.

Switch to using kasprintf() when possible so we always allocate the
right length strings.

summary of warnings:
drivers/net/ethernet/intel/iavf/iavf_virtchnl.c:1425:60: warning: ‘%s’ directive output may be truncated writing 4 bytes into a region of size between 1 and 11 [-Wformat-truncation=]
drivers/net/ethernet/intel/iavf/iavf_virtchnl.c:1425:17: note: ‘snprintf’ output between 7 and 17 bytes into a destination of size 13
drivers/net/ethernet/intel/ice/ice_ptp.c:43:27: warning: ‘%s’ directive output may be truncated writing up to 479 bytes into a region of size 64 [-Wformat-truncation=]
drivers/net/ethernet/intel/ice/ice_ptp.c:42:17: note: ‘snprintf’ output between 1 and 480 bytes into a destination of size 64
drivers/net/ethernet/intel/igb/igb_main.c:3092:53: warning: ‘%d’ directive output may be truncated writing between 1 and 5 bytes into a region of size between 1 and 13 [-Wformat-truncation=]
drivers/net/ethernet/intel/igb/igb_main.c:3092:34: note: directive argument in the range [0, 65535]
drivers/net/ethernet/intel/igb/igb_main.c:3092:34: note: directive argument in the range [0, 65535]
drivers/net/ethernet/intel/igb/igb_main.c:3090:25: note: ‘snprintf’ output between 23 and 43 bytes into a destination of size 32
Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20231017190411.2199743-2-jacob.e.keller@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/intel/iavf/iavf_ethtool.c

@@ -396,8 +396,8 @@ static void iavf_get_priv_flag_strings(struct net_device *netdev, u8 *data)
 	unsigned int i;
 
 	for (i = 0; i < IAVF_PRIV_FLAGS_STR_LEN; i++) {
-		snprintf(data, ETH_GSTRING_LEN, "%s",
-			 iavf_gstrings_priv_flags[i].flag_string);
+		strscpy(data, iavf_gstrings_priv_flags[i].flag_string,
+			ETH_GSTRING_LEN);
 		data += ETH_GSTRING_LEN;
 	}
 }

drivers/net/ethernet/intel/iavf/iavf_virtchnl.c

@@ -1378,8 +1378,6 @@ void iavf_disable_vlan_insertion_v2(struct iavf_adapter *adapter, u16 tpid)
 				  VIRTCHNL_OP_DISABLE_VLAN_INSERTION_V2);
 }
 
-#define IAVF_MAX_SPEED_STRLEN	13
-
 /**
  * iavf_print_link_message - print link up or down
  * @adapter: adapter structure
@@ -1397,10 +1395,6 @@ static void iavf_print_link_message(struct iavf_adapter *adapter)
 		return;
 	}
 
-	speed = kzalloc(IAVF_MAX_SPEED_STRLEN, GFP_KERNEL);
-	if (!speed)
-		return;
-
 	if (ADV_LINK_SUPPORT(adapter)) {
 		link_speed_mbps = adapter->link_speed_mbps;
 		goto print_link_msg;
@@ -1438,17 +1432,17 @@ static void iavf_print_link_message(struct iavf_adapter *adapter)
 
 print_link_msg:
 	if (link_speed_mbps > SPEED_1000) {
-		if (link_speed_mbps == SPEED_2500)
-			snprintf(speed, IAVF_MAX_SPEED_STRLEN, "2.5 Gbps");
-		else
+		if (link_speed_mbps == SPEED_2500) {
+			speed = kasprintf(GFP_KERNEL, "%s", "2.5 Gbps");
+		} else {
 			/* convert to Gbps inline */
-			snprintf(speed, IAVF_MAX_SPEED_STRLEN, "%d %s",
-				 link_speed_mbps / 1000, "Gbps");
+			speed = kasprintf(GFP_KERNEL, "%d Gbps",
+					  link_speed_mbps / 1000);
+		}
 	} else if (link_speed_mbps == SPEED_UNKNOWN) {
-		snprintf(speed, IAVF_MAX_SPEED_STRLEN, "%s", "Unknown Mbps");
+		speed = kasprintf(GFP_KERNEL, "%s", "Unknown Mbps");
 	} else {
-		snprintf(speed, IAVF_MAX_SPEED_STRLEN, "%d %s",
-			 link_speed_mbps, "Mbps");
+		speed = kasprintf(GFP_KERNEL, "%d Mbps", link_speed_mbps);
 	}
 
 	netdev_info(netdev, "NIC Link is Up Speed is %s Full Duplex\n", speed);

drivers/net/ethernet/intel/ice/ice_ptp.c

@@ -39,8 +39,8 @@ ice_get_sma_config_e810t(struct ice_hw *hw, struct ptp_pin_desc *ptp_pins)
 
 	/* initialize with defaults */
 	for (i = 0; i < NUM_PTP_PINS_E810T; i++) {
-		snprintf(ptp_pins[i].name, sizeof(ptp_pins[i].name),
-			 "%s", ice_pin_desc_e810t[i].name);
+		strscpy(ptp_pins[i].name, ice_pin_desc_e810t[i].name,
+			sizeof(ptp_pins[i].name));
 		ptp_pins[i].index = ice_pin_desc_e810t[i].index;
 		ptp_pins[i].func = ice_pin_desc_e810t[i].func;
 		ptp_pins[i].chan = ice_pin_desc_e810t[i].chan;

drivers/net/ethernet/intel/igb/igb_main.c

@@ -3069,6 +3069,7 @@ void igb_set_fw_version(struct igb_adapter *adapter)
 {
 	struct e1000_hw *hw = &adapter->hw;
 	struct e1000_fw_version fw;
+	char *lbuf;
 
 	igb_get_fw_version(hw, &fw);
 
@@ -3076,36 +3077,34 @@ void igb_set_fw_version(struct igb_adapter *adapter)
 	case e1000_i210:
 	case e1000_i211:
 		if (!(igb_get_flash_presence_i210(hw))) {
-			snprintf(adapter->fw_version,
-				 sizeof(adapter->fw_version),
-				 "%2d.%2d-%d",
+			lbuf = kasprintf(GFP_KERNEL, "%2d.%2d-%d",
 					 fw.invm_major, fw.invm_minor,
 					 fw.invm_img_type);
 			break;
 		}
 		fallthrough;
 	default:
-		/* if option is rom valid, display its version too */
+		/* if option rom is valid, display its version too */
 		if (fw.or_valid) {
-			snprintf(adapter->fw_version,
-				 sizeof(adapter->fw_version),
-				 "%d.%d, 0x%08x, %d.%d.%d",
-				 fw.eep_major, fw.eep_minor, fw.etrack_id,
-				 fw.or_major, fw.or_build, fw.or_patch);
+			lbuf = kasprintf(GFP_KERNEL, "%d.%d, 0x%08x, %d.%d.%d",
+					 fw.eep_major, fw.eep_minor,
+					 fw.etrack_id, fw.or_major, fw.or_build,
+					 fw.or_patch);
 		/* no option rom */
 		} else if (fw.etrack_id != 0X0000) {
-			snprintf(adapter->fw_version,
-			    sizeof(adapter->fw_version),
-			    "%d.%d, 0x%08x",
-			    fw.eep_major, fw.eep_minor, fw.etrack_id);
+			lbuf = kasprintf(GFP_KERNEL, "%d.%d, 0x%08x",
+					 fw.eep_major, fw.eep_minor,
+					 fw.etrack_id);
 		} else {
-		snprintf(adapter->fw_version,
-		    sizeof(adapter->fw_version),
-		    "%d.%d.%d",
-		    fw.eep_major, fw.eep_minor, fw.eep_build);
+			lbuf = kasprintf(GFP_KERNEL, "%d.%d.%d", fw.eep_major,
+					 fw.eep_minor, fw.eep_build);
 		}
 		break;
 	}
+
+	/* the truncate happens here if it doesn't fit */
+	strscpy(adapter->fw_version, lbuf, sizeof(adapter->fw_version));
+	kfree(lbuf);
 }
 
 /**