Re: [PATCH][next] IB/qib: Use struct_size() helper

[Dennis Dalessandro]

On 5/29/2019 11:13 AM, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes, in particular in the
> context in which this code is being used.
>
> So, replace the following form:
>
> sizeof(*pkt) + sizeof(pkt->addr[0])*n
>
> with:
>
> struct_size(pkt, addr, n)
>
> Also, notice that variable size is unnecessary, hence it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
> ---
>   drivers/infiniband/hw/qib/qib_user_sdma.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/hw/qib/qib_user_sdma.c b/drivers/infiniband/hw/qib/qib_user_sdma.c
> index 0c204776263f..97649f64e09e 100644
> --- a/drivers/infiniband/hw/qib/qib_user_sdma.c
> +++ b/drivers/infiniband/hw/qib/qib_user_sdma.c
> @@ -904,10 +904,11 @@ static int qib_user_sdma_queue_pkts(const struct qib_devdata *dd,
>   		}
>   
>   		if (frag_size) {
> -			int pktsize, tidsmsize, n;
> +			int tidsmsize, n;
> +			size_t pktsize;
>   
>   			n = npages*((2*PAGE_SIZE/frag_size)+1);
> -			pktsize = sizeof(*pkt) + sizeof(pkt->addr[0])*n;
> +			pktsize = struct_size(pkt, addr, n);
>   
>   			/*
>   			 * Determine if this is tid-sdma or just sdma.

Again, same minor objection but correct patch none the less.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>