On 11/21/22 10:29?AM, Stefan Roesch wrote:
> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> index 4f432694cbed..cf0e7cc8ad2e 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -4122,6 +4122,48 @@ static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
> return ret;
> }
>
> +static int io_register_napi(struct io_ring_ctx *ctx, void __user *arg)
> +{
> +#ifdef CONFIG_NET_RX_BUSY_POLL
> + const struct io_uring_napi curr = {
> + .busy_poll_to = ctx->napi_busy_poll_to,
> + };
> + struct io_uring_napi *napi;
> +
> + napi = memdup_user(arg, sizeof(*napi));
> + if (IS_ERR(napi))
> + return PTR_ERR(napi);
> +
> + WRITE_ONCE(ctx->napi_busy_poll_to, napi->busy_poll_to);
> +
> + kfree(napi);
> +
> + if (copy_to_user(arg, &curr, sizeof(curr)))
> + return -EFAULT;
> +
> + return 0;
> +#else
> + return -EINVAL;
> +#endif
> +}
This should return -EINVAL if any of the padding or reserved fields are
non-zero. If you don't do that, then it's not expendable in the future.
--
Jens Axboe
