[PATCH 2/6] Convert infiniband uverbs to struct_size

[Matthew Wilcox <willy@infradead.org>]

From: Matthew Wilcox <mawilcox@microsoft.com>

The flows were hidden from the C compiler; expose them as a zero-length
array to allow struct_size to work.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
 drivers/infiniband/core/uverbs_cmd.c | 4 ++--
 include/rdma/ib_verbs.h              | 5 +----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index e3662a8ee465..67cab6102f7a 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -3478,8 +3478,8 @@ int ib_uverbs_ex_create_flow(struct ib_uverbs_file *file,
 		goto err_uobj;
 	}
 
-	flow_attr = kzalloc(sizeof(*flow_attr) + cmd.flow_attr.num_of_specs *
-			    sizeof(union ib_flow_spec), GFP_KERNEL);
+	flow_attr = kzalloc(struct_size(flow_attr, flows,
+				cmd.flow_attr.num_of_specs), GFP_KERNEL);
 	if (!flow_attr) {
 		err = -ENOMEM;
 		goto err_put;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 9fc8a825aa28..bb6125ceb187 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2035,10 +2035,7 @@ struct ib_flow_attr {
 	u32	     flags;
 	u8	     num_of_specs;
 	u8	     port;
-	/* Following are the optional layers according to user request
-	 * struct ib_flow_spec_xxx
-	 * struct ib_flow_spec_yyy
-	 */
+	union ib_flow_spec flows[];
 };
 
 struct ib_flow {
-- 
2.17.0