Re: [PATCH][next] nfp: tls: Avoid -Wflex-array-member-not-at-end warnings

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 20 Nov 2025 11:39:39 +0900 Gustavo A. R. Silva wrote:
>  struct nfp_crypto_req_add_front {
> -	struct nfp_ccm_hdr hdr;
> -	__be32 ep_id;
> -	u8 resv[3];
> -	u8 opcode;
> -	u8 key_len;
> -	__be16 ipver_vlan __packed;
> -	u8 l4_proto;
> +	/* New members MUST be added within the struct_group() macro below. */
> +	struct_group_tagged(nfp_crypto_req_add_front_hdr, __hdr,
> +		struct nfp_ccm_hdr hdr;
> +		__be32 ep_id;
> +		u8 resv[3];
> +		u8 opcode;
> +		u8 key_len;
> +		__be16 ipver_vlan __packed;
> +		u8 l4_proto;
> +	);
>  #define NFP_NET_TLS_NON_ADDR_KEY_LEN	8
>  	u8 l3_addrs[];
>  };
> +static_assert(offsetof(struct nfp_crypto_req_add_front, l3_addrs) ==
> +	      sizeof(struct nfp_crypto_req_add_front_hdr),
> +	      "struct member likely outside of struct_group_tagged()");
>  
>  struct nfp_crypto_req_add_back {
>  	__be16 src_port;
> @@ -55,14 +61,14 @@ struct nfp_crypto_req_add_back {
>  };
>  
>  struct nfp_crypto_req_add_v4 {
> -	struct nfp_crypto_req_add_front front;
> +	struct nfp_crypto_req_add_front_hdr front;
>  	__be32 src_ip;
>  	__be32 dst_ip;
>  	struct nfp_crypto_req_add_back back;
>  };
>  
>  struct nfp_crypto_req_add_v6 {
> -	struct nfp_crypto_req_add_front front;
> +	struct nfp_crypto_req_add_front_hdr front;
>  	__be32 src_ip[4];
>  	__be32 dst_ip[4];
>  	struct nfp_crypto_req_add_back back;
> diff --git a/drivers/net/ethernet/netronome/nfp/crypto/tls.c b/drivers/net/ethernet/netronome/nfp/crypto/tls.c
> index f252ecdcd2cd..a6d6a334c84b 100644
> --- a/drivers/net/ethernet/netronome/nfp/crypto/tls.c
> +++ b/drivers/net/ethernet/netronome/nfp/crypto/tls.c
> @@ -180,7 +180,8 @@ nfp_net_tls_set_ipv4(struct nfp_net *nn, struct nfp_crypto_req_add_v4 *req,
>  	req->front.key_len += sizeof(__be32) * 2;
>  
>  	if (direction == TLS_OFFLOAD_CTX_DIR_TX) {
> -		nfp_net_tls_assign_conn_id(nn, &req->front);
> +		nfp_net_tls_assign_conn_id(nn,
> +			container_of(&req->front, struct nfp_crypto_req_add_front, __hdr));

Once again you're making the code unacceptably ugly.
-- 
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