[PATCH] iio: magnetometer: ak8974: Add __nonstring annotations for unterminated strings

From: Kees Cook
Date: Mon Mar 10 2025 - 18:24:55 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: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
Cc: linux-iio@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>
---
drivers/iio/magnetometer/ak8974.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c
index 08975c60e325..44d8428a69b0 100644
--- a/drivers/iio/magnetometer/ak8974.c
+++ b/drivers/iio/magnetometer/ak8974.c
@@ -535,8 +535,8 @@ static int ak8974_detect(struct ak8974 *ak8974)
fab_data2, sizeof(fab_data2));

for (i = 0; i < 3; ++i) {
- static const char axis[3] = "XYZ";
- static const char pgaxis[6] = "ZYZXYX";
+ static const char axis[3] __nonstring = "XYZ";
+ static const char pgaxis[6] __nonstring = "ZYZXYX";
unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
unsigned fine = le16_to_cpu(fab_data1[i]);
unsigned sens = le16_to_cpu(fab_data1[i + 3]);
--
2.34.1