[PATCH] cachefiles: Add __nonstring annotations for unterminated strings

From: Kees Cook
Date: Mon Mar 10 2025 - 18:25:17 EST


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]
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: netfs@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>
---
fs/cachefiles/key.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cachefiles/key.c b/fs/cachefiles/key.c
index bf935e25bdbe..b48525680e73 100644
--- a/fs/cachefiles/key.c
+++ b/fs/cachefiles/key.c
@@ -8,7 +8,7 @@
#include <linux/slab.h>
#include "internal.h"

-static const char cachefiles_charmap[64] =
+static const char cachefiles_charmap[64] __nonstring =
"0123456789" /* 0 - 9 */
"abcdefghijklmnopqrstuvwxyz" /* 10 - 35 */
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" /* 36 - 61 */
--
2.34.1