[PATCH 3/7] RDMA/usnic: Annotate struct usnic_uiom_chunk 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 usnic_uiom_chunk.

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

Cc: Christian Benvenuti <benve@xxxxxxxxx>
Cc: Nelson Escobar <neescoba@xxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Leon Romanovsky <leon@xxxxxxxxxx>
Cc: linux-rdma@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/infiniband/hw/usnic/usnic_uiom.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.h b/drivers/infiniband/hw/usnic/usnic_uiom.h
index 5a9acf941510..70d51d919d12 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.h
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.h
@@ -77,7 +77,7 @@ struct usnic_uiom_reg {
 struct usnic_uiom_chunk {
 	struct list_head		list;
 	int				nents;
-	struct scatterlist		page_list[];
+	struct scatterlist		page_list[] __counted_by(nents);
 };
 
 struct usnic_uiom_pd *usnic_uiom_alloc_pd(struct device *dev);
-- 
2.34.1