Subject: [PATCH] nfp: Annotate struct nfp_reprs with __counted_by

From: Kees Cook <[email-masked]>
Date: Tue, 3 Oct 2023 16:18:43 -0700

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 nfp_reprs.

Cc: Simon Horman <[email-masked]>
Cc: Jakub Kicinski <[email-masked]>
Cc: "David S. Miller" <[email-masked]>
Cc: Eric Dumazet <[email-masked]>
Cc: Paolo Abeni <[email-masked]>
Cc: [email-masked]
Cc: [email-masked]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email-masked]>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_repr.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
index 48a74accbbd3..77bf4198dbde 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.h
@@ -18,7 +18,7 @@ struct nfp_port;
  */
 struct nfp_reprs {
 	unsigned int num_reprs;
-	struct net_device __rcu *reprs[];
+	struct net_device __rcu *reprs[] __counted_by(num_reprs);
 };
 
 /**
-- 
2.34.1