[PATCH 5/9] drm/nouveau/pm: Annotate struct nvkm_perfdom with __counted_by

[Kees Cook]

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct nvkm_perfdom.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: nouveau@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h b/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h
index 6ae25d3e7f45..c011227f7052 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h
@@ -82,7 +82,7 @@ struct nvkm_perfdom {
 	u8  mode;
 	u32 clk;
 	u16 signal_nr;
-	struct nvkm_perfsig signal[];
+	struct nvkm_perfsig signal[] __counted_by(signal_nr);
 };
 
 struct nvkm_funcdom {
-- 
2.34.1