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Message-ID: <ee2c8631-6e3f-c113-cc8e-29834bcc348e@embeddedor.com>
Date:   Fri, 17 Jun 2022 18:00:55 +0200
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Subject: Re: [Intel-wired-lan] [PATCH][next] iavf: Replace one-element array
 in struct virtchnl_iwarp_qvlist_info and iavf_qvlist_info
Content-Language: en-US
To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>
Cc:     intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <20210525230429.GA175658@embeddedor>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20210525230429.GA175658@embeddedor>
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Hi all,

Friendly ping (after more than a year after I sent this patch :O):

Who can review and/or take this patch, please?

Thanks
--
Gustavo

On 5/26/21 01:04, Gustavo A. R. Silva wrote:
> There is a regular need in the kernel to provide a way to declare having a
> dynamically sized set of trailing elements in a structure. Kernel code
> should always use “flexible array members”[1] for these cases. The older
> style of one-element or zero-length arrays should no longer be used[2].
> 
> Refactor the code according to the use of a flexible-array member in struct
> virtchnl_iwarp_qvlist_info and iavf_qvlist_info instead of one-element array,
> and use the flex_array_size() helper.
> 
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Link: https://github.com/KSPP/linux/issues/79
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>   drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 2 +-
>   drivers/net/ethernet/intel/iavf/iavf_client.c      | 2 +-
>   drivers/net/ethernet/intel/iavf/iavf_client.h      | 2 +-
>   include/linux/avf/virtchnl.h                       | 8 ++++----
>   4 files changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> index c0afac8cf33b..6c55fe9cc132 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
> @@ -515,7 +515,7 @@ static int i40e_config_iwarp_qvlist(struct i40e_vf *vf,
>   
>   	kfree(vf->qvlist_info);
>   	vf->qvlist_info = kzalloc(struct_size(vf->qvlist_info, qv_info,
> -					      qvlist_info->num_vectors - 1),
> +					      qvlist_info->num_vectors),
>   				  GFP_KERNEL);
>   	if (!vf->qvlist_info) {
>   		ret = -ENOMEM;
> diff --git a/drivers/net/ethernet/intel/iavf/iavf_client.c b/drivers/net/ethernet/intel/iavf/iavf_client.c
> index 0c77e4171808..e70da05ef322 100644
> --- a/drivers/net/ethernet/intel/iavf/iavf_client.c
> +++ b/drivers/net/ethernet/intel/iavf/iavf_client.c
> @@ -470,7 +470,7 @@ static int iavf_client_setup_qvlist(struct iavf_info *ldev,
>   
>   	v_qvlist_info = (struct virtchnl_iwarp_qvlist_info *)qvlist_info;
>   	msg_size = struct_size(v_qvlist_info, qv_info,
> -			       v_qvlist_info->num_vectors - 1);
> +			       v_qvlist_info->num_vectors);
>   
>   	adapter->client_pending |= BIT(VIRTCHNL_OP_CONFIG_IWARP_IRQ_MAP);
>   	err = iavf_aq_send_msg_to_pf(&adapter->hw,
> diff --git a/drivers/net/ethernet/intel/iavf/iavf_client.h b/drivers/net/ethernet/intel/iavf/iavf_client.h
> index 9a7cf39ea75a..b14a82b65626 100644
> --- a/drivers/net/ethernet/intel/iavf/iavf_client.h
> +++ b/drivers/net/ethernet/intel/iavf/iavf_client.h
> @@ -53,7 +53,7 @@ struct iavf_qv_info {
>   
>   struct iavf_qvlist_info {
>   	u32 num_vectors;
> -	struct iavf_qv_info qv_info[1];
> +	struct iavf_qv_info qv_info[];
>   };
>   
>   #define IAVF_CLIENT_MSIX_ALL 0xFFFFFFFF
> diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h
> index 85a687bc6096..15b982911321 100644
> --- a/include/linux/avf/virtchnl.h
> +++ b/include/linux/avf/virtchnl.h
> @@ -658,10 +658,10 @@ VIRTCHNL_CHECK_STRUCT_LEN(12, virtchnl_iwarp_qv_info);
>   
>   struct virtchnl_iwarp_qvlist_info {
>   	u32 num_vectors;
> -	struct virtchnl_iwarp_qv_info qv_info[1];
> +	struct virtchnl_iwarp_qv_info qv_info[];
>   };
>   
> -VIRTCHNL_CHECK_STRUCT_LEN(16, virtchnl_iwarp_qvlist_info);
> +VIRTCHNL_CHECK_STRUCT_LEN(4, virtchnl_iwarp_qvlist_info);
>   
>   /* VF reset states - these are written into the RSTAT register:
>    * VFGEN_RSTAT on the VF
> @@ -1069,8 +1069,8 @@ virtchnl_vc_validate_vf_msg(struct virtchnl_version_info *ver, u32 v_opcode,
>   				err_msg_format = true;
>   				break;
>   			}
> -			valid_len += ((qv->num_vectors - 1) *
> -				sizeof(struct virtchnl_iwarp_qv_info));
> +			valid_len += flex_array_size(qv, qv_info,
> +						     qv->num_vectors);
>   		}
>   		break;
>   	case VIRTCHNL_OP_CONFIG_RSS_KEY: