On Fri, 10 Mar 2023 15:31:13 +0300
Dan Carpenter <error27@xxxxxxxxx> wrote:
> The copy_to/from_user() functions return the number of bytes remaining
> to be copied, but we want to return -EFAULT to the user.
I didn't realise that, thanks for fixing it!
Reviewed-by: Orlando Chamberlain <orlandlch.dev@xxxxxxxxx>
>
> Fixes: ce3fef2eb235 ("platform/x86: apple-gmux: add debugfs
> interface") Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> ---
> drivers/platform/x86/apple-gmux.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/platform/x86/apple-gmux.c
> b/drivers/platform/x86/apple-gmux.c index 787cf2a7e268..77e63d2da7b6
> 100644 --- a/drivers/platform/x86/apple-gmux.c
> +++ b/drivers/platform/x86/apple-gmux.c
> @@ -694,7 +694,6 @@ static ssize_t
> gmux_selected_port_data_write(struct file *file, const char __user
> *userbuf, size_t count, loff_t *ppos) {
> struct apple_gmux_data *gmux_data = file->private_data;
> - int ret;
>
> if (*ppos)
> return -EINVAL;
> @@ -702,16 +701,16 @@ static ssize_t
> gmux_selected_port_data_write(struct file *file, if (count == 1) {
> u8 data;
>
> - ret = copy_from_user(&data, userbuf, 1);
> - if (ret)
> - return ret;
> + if (copy_from_user(&data, userbuf, 1))
> + return -EFAULT;
> +
> gmux_write8(gmux_data, gmux_data->selected_port,
> data); } else if (count == 4) {
> u32 data;
>
> - ret = copy_from_user(&data, userbuf, 4);
> - if (ret)
> - return ret;
> + if (copy_from_user(&data, userbuf, 4))
> + return -EFAULT;
> +
> gmux_write32(gmux_data, gmux_data->selected_port,
> data); } else
> return -EINVAL;
