mtd: Annotate struct lpddr_private 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 lpddr_private.

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

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230915201159.never.112-kees@kernel.org

diff --git a/include/linux/mtd/qinfo.h b/include/linux/mtd/qinfo.h
index 2e3f43788d4839420ec565043802fb19b2d7398c..0421f12156b5c9cae86165cf20543e1b2ab0cf42 100644 (file)
--- a/include/linux/mtd/qinfo.h
+++ b/include/linux/mtd/qinfo.h
@@ -24,7 +24,7 @@ struct lpddr_private {
        struct qinfo_chip *qinfo;
        int numchips;
        unsigned long chipshift;
-       struct flchip chips[];
+       struct flchip chips[] __counted_by(numchips);
 };
 
 /* qinfo_query_info structure contains request information for