> On Jan 30, 2019, at 7:46 PM, Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> wrote:
>
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> struct boo entry[];
> };
>
> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> net/sunrpc/xprtrdma/verbs.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
> index 4994e75945b8..9e8cf7456840 100644
> --- a/net/sunrpc/xprtrdma/verbs.c
> +++ b/net/sunrpc/xprtrdma/verbs.c
> @@ -811,8 +811,7 @@ static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
> {
> struct rpcrdma_sendctx *sc;
>
> - sc = kzalloc(sizeof(*sc) +
> - ia->ri_max_send_sges * sizeof(struct ib_sge),
> + sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
> GFP_KERNEL);
> if (!sc)
> return NULL;
> --
> 2.20.1
>
--
Chuck Lever
