RE: [PATCH][next] i40e: Replace one-element array with flexible-array member

[Saleem, Shiraz]

> Subject: [PATCH][next] i40e: Replace one-element array with flexible-array member
> 
> 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
> i40e_qvlist_info instead of one-element array, and use the struct_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@xxxxxxxxxx>

This looks ok to me.
Acked-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>

It seems we should add this to the new irdma driver submission as well which replaces i40iw.
I will fold it into v7 of the rdma portion of the series
https://lore.kernel.org/linux-rdma/20210520200326.GX1096940@xxxxxxxx/

Additionally we will add this patch when we resend this PR on iwl-next.
https://lore.kernel.org/linux-rdma/62555c6de641e10cb4169653731389a51d086345.camel@xxxxxxxxx/


> ---
>  drivers/infiniband/hw/i40iw/i40iw_main.c      | 5 ++---
>  drivers/net/ethernet/intel/i40e/i40e_client.c | 2 +-
>  include/linux/net/intel/i40e_client.h         | 2 +-
>  3 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c
> b/drivers/infiniband/hw/i40iw/i40iw_main.c
> index b496f30ce066..364f69cd620f 100644
> --- a/drivers/infiniband/hw/i40iw/i40iw_main.c
> +++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
> @@ -1423,7 +1423,7 @@ static enum i40iw_status_code
> i40iw_save_msix_info(struct i40iw_device *iwdev,
>  	struct i40e_qv_info *iw_qvinfo;
>  	u32 ceq_idx;
>  	u32 i;
> -	u32 size;
> +	size_t size;
> 
>  	if (!ldev->msix_count) {
>  		i40iw_pr_err("No MSI-X vectors\n");
> @@ -1433,8 +1433,7 @@ static enum i40iw_status_code
> i40iw_save_msix_info(struct i40iw_device *iwdev,
>  	iwdev->msix_count = ldev->msix_count;
> 
>  	size = sizeof(struct i40iw_msix_vector) * iwdev->msix_count;
> -	size += sizeof(struct i40e_qvlist_info);
> -	size +=  sizeof(struct i40e_qv_info) * iwdev->msix_count - 1;
> +	size += struct_size(iw_qvlist, qv_info, iwdev->msix_count);
>  	iwdev->iw_msixtbl = kzalloc(size, GFP_KERNEL);
> 
>  	if (!iwdev->iw_msixtbl)
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_client.c
> b/drivers/net/ethernet/intel/i40e/i40e_client.c
> index 32f3facbed1a..63eab14a26df 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_client.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_client.c
> @@ -579,7 +579,7 @@ static int i40e_client_setup_qvlist(struct i40e_info *ldev,
>  	u32 v_idx, i, reg_idx, reg;
> 
>  	ldev->qvlist_info = kzalloc(struct_size(ldev->qvlist_info, qv_info,
> -				    qvlist_info->num_vectors - 1), GFP_KERNEL);
> +				    qvlist_info->num_vectors), GFP_KERNEL);
>  	if (!ldev->qvlist_info)
>  		return -ENOMEM;
>  	ldev->qvlist_info->num_vectors = qvlist_info->num_vectors; diff --git
> a/include/linux/net/intel/i40e_client.h b/include/linux/net/intel/i40e_client.h
> index f41387a8969f..fd7bc860a241 100644
> --- a/include/linux/net/intel/i40e_client.h
> +++ b/include/linux/net/intel/i40e_client.h
> @@ -48,7 +48,7 @@ struct i40e_qv_info {
> 
>  struct i40e_qvlist_info {
>  	u32 num_vectors;
> -	struct i40e_qv_info qv_info[1];
> +	struct i40e_qv_info qv_info[];
>  };
> 
> 
> --
> 2.27.0