mtd: rawnand: cadence: Annotate struct cdns_nand_chip 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 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 cdns_nand_chip.

Cc: Miquel Raynal <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Vignesh Raghavendra <[email protected]>
Cc: "Gustavo A. R. Silva" <[email protected]>
Cc: Martin Blumenstingl <[email protected]>
Cc: Nicolas Ferre <[email protected]>
Cc: Roger Quadros <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Yang Yingliang <[email protected]>
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Valentin Korenblit <[email protected]>
Cc: ye xingchen <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Miquel Raynal <[email protected]>
Link: https://lore.kernel.org/linux-mtd/[email protected]

Author: kees

drivers/mtd/nand/raw/cadence-nand-controller.c

@@ -526,7 +526,7 @@ struct cdns_nand_chip {
 	/* ECC strength index. */
 	u8 corr_str_idx;
 
-	u8 cs[];
+	u8 cs[] __counted_by(nsels);
 };
 
 struct ecc_info {