[PATCH v3 1/3] net: mana: Add flex array to struct mana_cfg_rx_steer_req_v2

[Erick Archer]

The "struct mana_cfg_rx_steer_req_v2" uses a dynamically sized set of
trailing elements. Specifically, it uses a "mana_handle_t" array. So,
use the preferred way in the kernel declaring a flexible array [1].

At the same time, 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).

This is a previous step to refactor the two consumers of this structure.

 drivers/infiniband/hw/mana/qp.c
 drivers/net/ethernet/microsoft/mana/mana_en.c

The ultimate goal is to avoid the open-coded arithmetic in the memory
allocator functions [2] using the "struct_size" macro.

Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-and-one-element-arrays [1]
Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2]
Signed-off-by: Erick Archer <erick.archer@xxxxxxxxxxx>
---
 include/net/mana/mana.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 4eeedf14711b..561f6719fb4e 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -670,6 +670,7 @@ struct mana_cfg_rx_steer_req_v2 {
 	u8 hashkey[MANA_HASH_KEY_SIZE];
 	u8 cqe_coalescing_enable;
 	u8 reserved2[7];
+	mana_handle_t indir_tab[] __counted_by(num_indir_entries);
 }; /* HW DATA */
 
 struct mana_cfg_rx_steer_resp {
-- 
2.25.1