leds: mt6360: Annotate struct mt6360_priv with __counted_by

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 mt6360_priv.

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

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230915201020.never.433-kees@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/leds/flash/leds-mt6360.c b/drivers/leds/flash/leds-mt6360.c
index 81401c481e2b9cfe507441c13946e60c788b8d1d..a90de82f4568371fa0d88164778b2a12968648c3 100644 (file)
--- a/drivers/leds/flash/leds-mt6360.c
+++ b/drivers/leds/flash/leds-mt6360.c
@@ -91,7 +91,7 @@ struct mt6360_priv {
        unsigned int fled_torch_used;
        unsigned int leds_active;
        unsigned int leds_count;
-       struct mt6360_led leds[];
+       struct mt6360_led leds[] __counted_by(leds_count);
 };
 
 static int mt6360_mc_brightness_set(struct led_classdev *lcdev,