net: dsa: realtek: replace deprecated strncpy with ethtool_sprintf

`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

ethtool_sprintf() is designed specifically for get_strings() usage.
Let's replace strncpy in favor of this more robust and easier to
understand interface.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20231009-strncpy-drivers-net-dsa-realtek-rtl8366-core-c-v1-1-74e1b5190778@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/realtek/rtl8366-core.c b/drivers/net/dsa/realtek/rtl8366-core.c
index dc5f75be3017f18801704ba94ba00e79e87448ef..82e267b8fddb1fc315cc83af0aae4d165bf70f7e 100644 (file)
--- a/drivers/net/dsa/realtek/rtl8366-core.c
+++ b/drivers/net/dsa/realtek/rtl8366-core.c
@@ -395,17 +395,13 @@ void rtl8366_get_strings(struct dsa_switch *ds, int port, u32 stringset,
                         uint8_t *data)
 {
        struct realtek_priv *priv = ds->priv;
-       struct rtl8366_mib_counter *mib;
        int i;
 
        if (port >= priv->num_ports)
                return;
 
-       for (i = 0; i < priv->num_mib_counters; i++) {
-               mib = &priv->mib_counters[i];
-               strncpy(data + i * ETH_GSTRING_LEN,
-                       mib->name, ETH_GSTRING_LEN);
-       }
+       for (i = 0; i < priv->num_mib_counters; i++)
+               ethtool_sprintf(&data, "%s", priv->mib_counters[i].name);
 }
 EXPORT_SYMBOL_GPL(rtl8366_get_strings);