From: Saeed Mahameed <saeedm@nvidia.com>
Date: Tue, 22 Mar 2022 10:22:24 -0700
Subject: net/mlx5e: Fix build warning, detected write beyond size of field
Patch-mainline: v5.18-rc1
Git-commit: 2af7e566a8616c278e1d7287ce86cd3900bed943
References: jsc#PED-1549
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: 9ded70fa1d81 ("net/mlx5e: Don't prefill WQEs in XDP SQ in the multi buffer mode")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20220322172224.31849-1-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c | 3 +--
include/linux/mlx5/qp.h | 5 +++++
2 files changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -435,8 +435,7 @@ mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq
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);
--- a/include/linux/mlx5/qp.h
+++ b/include/linux/mlx5/qp.h
@@ -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