[PATCH] leds: aw200xx: Annotate struct aw200xx 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 aw200xx.

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

Cc: Pavel Machek <pavel@xxxxxx>
Cc: Lee Jones <lee@xxxxxxxxxx>
Cc: linux-leds@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/leds/leds-aw200xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/leds/leds-aw200xx.c b/drivers/leds/leds-aw200xx.c
index 691a743cc9b0..4d517cace3e7 100644
--- a/drivers/leds/leds-aw200xx.c
+++ b/drivers/leds/leds-aw200xx.c
@@ -112,7 +112,7 @@ struct aw200xx {
 	struct mutex mutex;
 	u32 num_leds;
 	u32 display_rows;
-	struct aw200xx_led leds[];
+	struct aw200xx_led leds[] __counted_by(num_leds);
 };
 
 static ssize_t dim_show(struct device *dev, struct device_attribute *devattr,
-- 
2.34.1