[PATCH] nfp: nsp: Annotate struct nfp_eth_table 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 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_eth_table.

Cc: Simon Horman <simon.horman@xxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: Yinjun Zhang <yinjun.zhang@xxxxxxxxxxxx>
Cc: Leon Romanovsky <leon@xxxxxxxxxx>
Cc: Yu Xiao <yu.xiao@xxxxxxxxxxxx>
Cc: Sixiang Chen <sixiang.chen@xxxxxxxxxxxx>
Cc: oss-drivers@xxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.h b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.h
index 6e044ac04917..00264af13b49 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.h
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.h
@@ -241,7 +241,7 @@ struct nfp_eth_table {
 
 		u64 link_modes_supp[2];
 		u64 link_modes_ad[2];
-	} ports[];
+	} ports[] __counted_by(count);
 };
 
 struct nfp_eth_table *nfp_eth_read_ports(struct nfp_cpp *cpp);
-- 
2.34.1