[PATCH] i3c: svc: Annotate struct svc_i3c_xfer 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 svc_i3c_xfer.

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

Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Conor Culhane <conor.culhane@xxxxxxxxxxx>
Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Cc: linux-i3c@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/i3c/master/svc-i3c-master.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 8f8295acdadb..32eca2d6caf0 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -143,7 +143,7 @@ struct svc_i3c_xfer {
 	int ret;
 	unsigned int type;
 	unsigned int ncmds;
-	struct svc_i3c_cmd cmds[];
+	struct svc_i3c_cmd cmds[] __counted_by(ncmds);
 };
 
 struct svc_i3c_regs_save {
-- 
2.34.1