Commit 2af7e566 authored by Saeed Mahameed's avatar Saeed Mahameed Committed by Jakub Kicinski
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net/mlx5e: Fix build warning, detected write beyond size of field 



When merged with Linus tree, the cited patch below will cause the
following build warning:

In function 'fortify_memset_chk',
    inlined from 'mlx5e_xmit_xdp_frame' at drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c:438:3:
include/linux/fortify-string.h:242:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
  242 |                         __write_overflow_field(p_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix that by grouping the fields to memeset in struct_group() to avoid
the false alarm.

Fixes: 9ded70fa ("net/mlx5e: Don't prefill WQEs in XDP SQ in the multi buffer mode")
Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarSaeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20220322172224.31849-1-saeed@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b20bdd9c

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c

+1 −2
Original line number Diff line number Diff line
@@ -435,8 +435,7 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct mlx5e_xmit_data *xdptxd, 
		u8 num_pkts = 1 + num_frags;

		int i;



		memset(&cseg->signature, 0, sizeof(*cseg) -

		       sizeof(cseg->opmod_idx_opcode) - sizeof(cseg->qpn_ds));

		memset(&cseg->trailer, 0, sizeof(cseg->trailer));

		memset(eseg, 0, sizeof(*eseg) - sizeof(eseg->trailer));



		eseg->inline_hdr.sz = cpu_to_be16(inline_hdr_sz);

include/linux/mlx5/qp.h

+5 −0
Original line number Diff line number Diff line
@@ -202,6 +202,9 @@ struct mlx5_wqe_fmr_seg { 
struct mlx5_wqe_ctrl_seg {

	__be32			opmod_idx_opcode;

	__be32			qpn_ds;



	struct_group(trailer,



	u8			signature;

	u8			rsvd[2];

	u8			fm_ce_se;
@@ -211,6 +214,8 @@ struct mlx5_wqe_ctrl_seg { 
		__be32		umr_mkey;

		__be32		tis_tir_num;

	};



	); /* end of trailer group */

};



#define MLX5_WQE_CTRL_DS_MASK 0x3f