[PATCH] video: fbdev: mmp: Annotate struct mmphw_ctrl with __counted_by

From: Kees Cook
Date: Fri Sep 22 2023 - 13:52:55 EST


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 mmphw_ctrl.

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

Cc: Helge Deller <deller@xxxxxx>
Cc: linux-fbdev@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/video/fbdev/mmp/hw/mmp_ctrl.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/mmp/hw/mmp_ctrl.h b/drivers/video/fbdev/mmp/hw/mmp_ctrl.h
index 167585a889d3..719b99a9bc77 100644
--- a/drivers/video/fbdev/mmp/hw/mmp_ctrl.h
+++ b/drivers/video/fbdev/mmp/hw/mmp_ctrl.h
@@ -1406,7 +1406,7 @@ struct mmphw_ctrl {

/*pathes*/
int path_num;
- struct mmphw_path_plat path_plats[];
+ struct mmphw_path_plat path_plats[] __counted_by(path_num);
};

static inline int overlay_is_vid(struct mmp_overlay *overlay)
--
2.34.1