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 4-byte
ACPI identifier arrays with __nonstring (and the new __nonstring_array)
to correctly identify the char arrays as "not C strings" and thereby
eliminate the many warnings like this:
In file included from include/acpi/actbl.h:371,
from include/acpi/acpi.h:26,
from include/linux/acpi.h:26,
from drivers/acpi/tables.c:19:
include/acpi/actbl1.h:30:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (5 chars into 4 available) [-Wunterminated-string-initialization]
30 | #define ACPI_SIG_BERT "BERT" /* Boot Error Record Table */
| ^~~~~~
drivers/acpi/tables.c:400:9: note: in expansion of macro 'ACPI_SIG_BERT'
400 | ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
| ^~~~~~~~~~~~~
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1]
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>
---
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Robert Moore <robert.moore@xxxxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: acpica-devel@xxxxxxxxxxxxxxx
---
drivers/acpi/tables.c | 2 +-
include/acpi/actbl.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 2295abbecd14..0a9ade7117bd 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -396,7 +396,7 @@ static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
}
/* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
-static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
+static const char table_sigs[][ACPI_NAMESEG_SIZE] __nonstring_array __initconst = {
ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
diff --git a/include/acpi/actbl.h b/include/acpi/actbl.h
index 451f6276da49..2fc89704be17 100644
--- a/include/acpi/actbl.h
+++ b/include/acpi/actbl.h
@@ -66,7 +66,7 @@
******************************************************************************/
struct acpi_table_header {
- char signature[ACPI_NAMESEG_SIZE]; /* ASCII table signature */
+ char signature[ACPI_NAMESEG_SIZE] __nonstring; /* ASCII table signature */
u32 length; /* Length of table in bytes, including this header */
u8 revision; /* ACPI Specification minor version number */
u8 checksum; /* To make sum of entire table == 0 */
--
2.34.1
