On Mon, Jan 18, 2021 at 7:21 AM root jason <jason.root.w@xxxxxxxxx> wrote:
> From: jason.wang <jason.root.w@xxxxxxxxx>
>
> add compat_ioctl define for dmx_dvr to handle ioctl when CONFIG_COMPAT is enable.
>
> Signed-off-by: .jason.wang <jason.root.w@xxxxxxxxx>
> ---
> drivers/media/dvb-core/dmxdev.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
> index f14a872d1268..4a9e027de827 100644
> --- a/drivers/media/dvb-core/dmxdev.c
> +++ b/drivers/media/dvb-core/dmxdev.c
> @@ -1393,6 +1393,7 @@ static const struct file_operations dvb_dvr_fops = {
> .read = dvb_dvr_read,
> .write = dvb_dvr_write,
> .unlocked_ioctl = dvb_dvr_ioctl,
> + .compat_ioctl = dvb_dvr_ioctl,
> .open = dvb_dvr_open,
> .release = dvb_dvr_release,
> .poll = dvb_dvr_poll,
This is correct for DMX_SET_BUFFER_SIZE, which takes an integer
argument, but not strictly correct for the other ones that take a pointer
argument and need a compat_ptr() conversion.
You could do it by either passing both the 'unsigned long arg'
and the 'void __user *argp' pointer to dvb_usercopy(), with the
pointer coming from compat_ptr() in case of compat, or you
add something like
if (in_compat_syscall())
arg = compat_ptr(unsigned long arg);
in the function itself. I checked the DVB ioctls to make sure that
no other ioctl commands need any special handling, and found
that DMX_SET_BUFFER_SIZE is the only one.
Arnd
