net: dsa: lan9303: use ethtool_puts() for lan9303_get_strings()

This pattern of strncpy with some pointer arithmetic setting fixed-sized
intervals with string literal data is a bit weird so let's use
ethtool_puts() as this has more obvious behavior and is less-error
prone.

Nicely, we also get to drop a usage of the now deprecated strncpy() [1].

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Link: https://github.com/KSPP/linux/issues/90
Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20240425-strncpy-drivers-net-dsa-lan9303-core-c-v4-1-9fafd419d7bb@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
index 666b4d7..02f07b8 100644 (file)
--- a/drivers/net/dsa/lan9303-core.c
+++ b/drivers/net/dsa/lan9303-core.c
@@ -1007,15 +1007,14 @@ static const struct lan9303_mib_desc lan9303_mib[] = {
 static void lan9303_get_strings(struct dsa_switch *ds, int port,
                                u32 stringset, uint8_t *data)
 {
+       u8 *buf = data;
        unsigned int u;
 
        if (stringset != ETH_SS_STATS)
                return;
 
-       for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++) {
-               strncpy(data + u * ETH_GSTRING_LEN, lan9303_mib[u].name,
-                       ETH_GSTRING_LEN);
-       }
+       for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++)
+               ethtool_puts(&buf, lan9303_mib[u].name);
 }
 
 static void lan9303_get_ethtool_stats(struct dsa_switch *ds, int port,