Re: [PATCH V2] Serial: core: Add compat ioctl support

[Greg KH]

On Wed, Jan 25, 2023 at 05:04:18PM +0530, Viken Dadhaniya wrote:
> Current serial core driver doesn't support compat_ioctl
> due to which 32-bit application is not able to send
> ioctls to driver on a 64-bit platform.
> 
> Added compat_ioctl support in serial core to handle
> ioctls from 32-bit applications on a 64-bit platform.
> 
> Signed-off-by: Viken Dadhaniya <quic_vdadhani@xxxxxxxxxxx>
> ---
>  drivers/tty/serial/serial_core.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index b9fbbee598b8..ad4c3a5a3d29 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -1601,6 +1601,12 @@ uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
>  	return ret;
>  }
>  
> +static long
> +uart_compat_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
> +{
> +	return (long)uart_ioctl(tty, cmd, arg);

How does this "fix" your out-of-tree driver at all?  What command is
being sent that has this incorrect that this simple "pass through" is
going to solve?

Can you point us at the out-of-tree code please?

thanks,

greg k-h