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 array
with __nonstring to correctly identify the char array as "not a C string"
and thereby eliminate the warning:
../fs/cachefiles/key.c:12:9: warning: initializer-string for array of 'char'
truncates NUL terminator but destination lacks 'nonstring' attribute (65 chars
into 64 available) [-Wunterminated-string-initialization]
12 | "0123456789" /* 0 - 9 */
| ^~~~~~~~~~~~
Since the array is used only for single character look-ups, use
__nonstring:
fs/cachefiles/key.c:123: name[len++] = cachefiles_charmap[acc &
63];
fs/cachefiles/key.c:125: name[len++] = cachefiles_charmap[acc &
63];
fs/cachefiles/key.c:127: name[len++] = cachefiles_charmap[acc &
63];
fs/cachefiles/key.c:129: name[len++] = cachefiles_charmap[acc &
63];
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Signed-off-by: Kees Cook <[email protected]>
---
v2: improve commit log
v1: https://lore.kernel.org/lkml/[email protected]/
Cc: David Howells <[email protected]>
Cc: [email protected]
---
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
