net: macb: use ethtool_sprintf to fill ethtool stats strings

The RISC-V toolchain triggers a stringop-truncation warning when using
snprintf() with a fixed ETH_GSTRING_LEN (32 bytes) buffer.

Convert the driver to use the modern ethtool_sprintf() API from
linux/ethtool.h. This removes the need for manual snprintf() and
memcpy() calls, handles the 32-byte padding automatically, and
simplifies the logic by removing manual pointer arithmetic.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Sean Chang <seanwascoding@gmail.com>
Link: https://patch.msgid.link/20260302142931.49108-1-seanwascoding@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 02eab26fd98b78a5ef60a07643b4adda7e013560..17f0ad3d7a0924a7dc2fc0a13505aff7d2499ffa 100644 (file)
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3161,7 +3161,6 @@ static int gem_get_sset_count(struct net_device *dev, int sset)
 
 static void gem_get_ethtool_strings(struct net_device *dev, u32 sset, u8 *p)
 {
-       char stat_string[ETH_GSTRING_LEN];
        struct macb *bp = netdev_priv(dev);
        struct macb_queue *queue;
        unsigned int i;
@@ -3174,11 +3173,8 @@ static void gem_get_ethtool_strings(struct net_device *dev, u32 sset, u8 *p)
                               ETH_GSTRING_LEN);
 
                for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
-                       for (i = 0; i < QUEUE_STATS_LEN; i++, p += ETH_GSTRING_LEN) {
-                               snprintf(stat_string, ETH_GSTRING_LEN, "q%d_%s",
-                                               q, queue_statistics[i].stat_string);
-                               memcpy(p, stat_string, ETH_GSTRING_LEN);
-                       }
+                       for (i = 0; i < QUEUE_STATS_LEN; i++)
+                               ethtool_sprintf(&p, "q%u_%s", q, queue_statistics[i].stat_string);
                }
                break;
        }