Hi,
>
> we need a min() here. Better version below:
No need. copy_to_iter will do it for us.
Best Regards,
Du, Changbin
>
> diff --git a/drivers/usb/gadget/function/f_fs.c
> b/drivers/usb/gadget/function/f_fs.c
> index 73515d54e1cc..6c49b152f46e 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -156,6 +156,8 @@ struct ffs_io_data {
> struct usb_request *req;
>
> struct ffs_data *ffs;
> +
> + ssize_t expected_len;
> };
>
> struct ffs_desc_helper {
> @@ -730,8 +732,10 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
> * Controller may require buffer size to be aligned to
> * maxpacketsize of an out endpoint.
> */
> - if (io_data->read)
> + if (io_data->read) {
> + io_data->expected_len = data_len;
> data_len = usb_ep_align_maybe(gadget, ep->ep,
> data_len);
> + }
> spin_unlock_irq(&epfile->ffs->eps_lock);
>
> data = kmalloc(data_len, GFP_KERNEL);
> @@ -811,7 +815,15 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
> */
> ret = interrupted ? -EINTR : ep->status;
> if (io_data->read && ret > 0) {
> - ret = copy_to_iter(data, ret, &io_data->data);
> + ssize_t bytes;
> +
> + if (ret > io_data->expected_len)
> + pr_debug("FFS: size mismatch: %zd for %zd",
> + ret, io_data->expected_len);
> +
> + bytes = min(ret, io_data->expected_len);
> +
> + ret = copy_to_iter(data, bytes, &io_data->data);
> if (!ret)
> ret = -EFAULT;
> }
>
>
> --
> balbi
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