[PATCH] drm/i915/gvt: Add __nonstring annotations for unterminated strings

From: Kees Cook
Date: Mon Mar 10 2025 - 18:25:06 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: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Cc: Zhi Wang <zhi.wang.linux@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Tvrtko Ursulin <tursulin@xxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Simona Vetter <simona@xxxxxxxx>
Cc: intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx
Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/opregion.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/opregion.c b/drivers/gpu/drm/i915/gvt/opregion.c
index 509f9ccae3a9..f701638d3145 100644
--- a/drivers/gpu/drm/i915/gvt/opregion.c
+++ b/drivers/gpu/drm/i915/gvt/opregion.c
@@ -43,7 +43,7 @@
#define DEVICE_TYPE_EFP4 0x10

struct opregion_header {
- u8 signature[16];
+ u8 signature[16] __nonstring;
u32 size;
u32 opregion_ver;
u8 bios_ver[32];
@@ -222,7 +222,7 @@ int intel_vgpu_init_opregion(struct intel_vgpu *vgpu)
u8 *buf;
struct opregion_header *header;
struct vbt v;
- const char opregion_signature[16] = OPREGION_SIGNATURE;
+ const char opregion_signature[16] __nonstring = OPREGION_SIGNATURE;

gvt_dbg_core("init vgpu%d opregion\n", vgpu->id);
vgpu_opregion(vgpu)->va = (void *)__get_free_pages(GFP_KERNEL |
--
2.34.1