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 correctly identify the char array as "not a C string"
and thereby eliminate the warning:
../drivers/net/wireguard/cookie.c:29:56: warning: initializer-string for array of 'unsigned char' truncates NUL terminator but destination lacks 'nonstring' attribute (9 chars into 8 available) [-Wunterminated-string-initialization]
29 | static const u8 mac1_key_label[COOKIE_KEY_LABEL_LEN] = "mac1----";
| ^~~~~~~~~~
../drivers/net/wireguard/cookie.c:30:58: warning: initializer-string for array of 'unsigned char' truncates NUL terminator but destination lacks 'nonstring' attribute (9 chars into 8 available) [-Wunterminated-string-initialization]
30 | static const u8 cookie_key_label[COOKIE_KEY_LABEL_LEN] = "cookie--";
| ^~~~~~~~~~
../drivers/net/wireguard/noise.c:28:38: warning: initializer-string for array of 'unsigned char' truncates NUL terminator but destination lacks 'nonstring' attribute (38 chars into 37 available) [-Wunterminated-string-initialization]
28 | static const u8 handshake_name[37] = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s";
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/net/wireguard/noise.c:29:39: warning: initializer-string for array of 'unsigned char' truncates NUL terminator but destination lacks 'nonstring' attribute (35 chars into 34 available) [-Wunterminated-string-initialization]
29 | static const u8 identifier_name[34] = "WireGuard v1 zx2c4 Jason@zx2c4.com";
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The arrays are always used with their fixed size, so use __nonstring.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://patch.msgid.link/20250521212707.1767879-3-Jason@zx2c4.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
dc14addf6d
