[PATCH v2] net: macb: Add __nonstring annotations for unterminated strings

[Kees Cook <kees@kernel.org>]

When a character array without a terminating NUL character has a static
initializer, GCC 15's -Wunterminated-string-initialization will only
warn if the array lacks the "nonstring" attribute[1]. Mark the arrays
with __nonstring to and correctly identify the char array as "not a C
string" and thereby eliminate the warning.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
---
 v1: https://lore.kernel.org/lkml/20250310222415.work.815-kees@kernel.org/
 v2: switch to __nonstring annotation
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
---
 drivers/net/ethernet/cadence/macb.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 2847278d9cd4..003483073223 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -1027,7 +1027,7 @@ struct gem_stats {
  * this register should contribute to.
  */
 struct gem_statistic {
-	char stat_string[ETH_GSTRING_LEN];
+	char stat_string[ETH_GSTRING_LEN] __nonstring;
 	int offset;
 	u32 stat_bits;
 };
@@ -1068,6 +1068,7 @@ static const struct gem_statistic gem_statistics[] = {
 	GEM_STAT_TITLE(TX512CNT, "tx_512_1023_byte_frames"),
 	GEM_STAT_TITLE(TX1024CNT, "tx_1024_1518_byte_frames"),
 	GEM_STAT_TITLE(TX1519CNT, "tx_greater_than_1518_byte_frames"),
+
 	GEM_STAT_TITLE_BITS(TXURUNCNT, "tx_underrun",
 			    GEM_BIT(NDS_TXERR)|GEM_BIT(NDS_TXFIFOERR)),
 	GEM_STAT_TITLE_BITS(SNGLCOLLCNT, "tx_single_collision_frames",
-- 
2.34.1