[PATCH v2 net-next 4/5] net: ena: Changes around strscpy calls

[<darinzon@amazon.com>]

From: David Arinzon <darinzon@amazon.com>

strscpy copies as much of the string as possible,
meaning that the destination string will be truncated
in case of no space. As this is a non-critical error in
our case, adding a debug level print for indication.

This patch also removes a -1 which was added to ensure
enough space for NUL, but strscpy destination string is
guaranteed to be NUL-terminted, therefore, the -1 is
not needed.

Signed-off-by: David Arinzon <darinzon@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_ethtool.c | 16 ++++++++++++----
 drivers/net/ethernet/amazon/ena/ena_netdev.c  | 17 +++++++++++++----
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_ethtool.c b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
index 28583db8..b24cc3f0 100644
--- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c
+++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
@@ -460,10 +460,18 @@ static void ena_get_drvinfo(struct net_device *dev,
 			    struct ethtool_drvinfo *info)
 {
 	struct ena_adapter *adapter = netdev_priv(dev);
-
-	strscpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
-	strscpy(info->bus_info, pci_name(adapter->pdev),
-		sizeof(info->bus_info));
+	ssize_t ret = 0;
+
+	ret = strscpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
+	if (ret < 0)
+		netif_dbg(adapter, drv, dev,
+			  "module name will be truncated, status = %zd\n", ret);
+
+	ret = strscpy(info->bus_info, pci_name(adapter->pdev),
+		      sizeof(info->bus_info));
+	if (ret < 0)
+		netif_dbg(adapter, drv, dev,
+			  "bus info will be truncated, status = %zd\n", ret);
 }
 
 static void ena_get_ringparam(struct net_device *netdev,
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 7398bc61..184b6e6c 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -2703,6 +2703,7 @@ static void ena_config_host_info(struct ena_com_dev *ena_dev, struct pci_dev *pd
 {
 	struct device *dev = &pdev->dev;
 	struct ena_admin_host_info *host_info;
+	ssize_t ret;
 	int rc;
 
 	/* Allocate only the host info */
@@ -2717,11 +2718,19 @@ static void ena_config_host_info(struct ena_com_dev *ena_dev, struct pci_dev *pd
 	host_info->bdf = pci_dev_id(pdev);
 	host_info->os_type = ENA_ADMIN_OS_LINUX;
 	host_info->kernel_ver = LINUX_VERSION_CODE;
-	strscpy(host_info->kernel_ver_str, utsname()->version,
-		sizeof(host_info->kernel_ver_str) - 1);
+	ret = strscpy(host_info->kernel_ver_str, utsname()->version,
+		      sizeof(host_info->kernel_ver_str));
+	if (ret < 0)
+		dev_dbg(dev,
+			"kernel version string will be truncated, status = %zd\n", ret);
+
 	host_info->os_dist = 0;
-	strscpy(host_info->os_dist_str, utsname()->release,
-		sizeof(host_info->os_dist_str));
+	ret = strscpy(host_info->os_dist_str, utsname()->release,
+		      sizeof(host_info->os_dist_str));
+	if (ret < 0)
+		dev_dbg(dev,
+			"OS distribution string will be truncated, status = %zd\n", ret);
+
 	host_info->driver_version =
 		(DRV_MODULE_GEN_MAJOR) |
 		(DRV_MODULE_GEN_MINOR << ENA_ADMIN_HOST_INFO_MINOR_SHIFT) |
-- 
2.40.1