Re: [RFC PATCH 2/9] ntsync: Reserve a minor device number and ioctl range.

[Greg Kroah-Hartman]

On Tue, Jan 23, 2024 at 06:40:21PM -0600, Elizabeth Figura wrote:
> Signed-off-by: Elizabeth Figura <zfigura@xxxxxxxxxxxxxxx>
> ---

Note, we can't take patches without any changelog text, and you don't
want us to :)

>  Documentation/admin-guide/devices.txt              | 3 ++-
>  Documentation/userspace-api/ioctl/ioctl-number.rst | 2 ++
>  drivers/misc/ntsync.c                              | 3 ++-
>  include/linux/miscdevice.h                         | 1 +
>  4 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt
> index 94c98be1329a..041404397ee5 100644
> --- a/Documentation/admin-guide/devices.txt
> +++ b/Documentation/admin-guide/devices.txt
> @@ -376,8 +376,9 @@
>  		240 = /dev/userio	Serio driver testing device
>  		241 = /dev/vhost-vsock	Host kernel driver for virtio vsock
>  		242 = /dev/rfkill	Turning off radio transmissions (rfkill)
> +		243 = /dev/ntsync	NT synchronization primitive device
>  
> -		243-254			Reserved for local use
> +		244-254			Reserved for local use

Why do you need a fixed minor number?  Can't your userspace handle
dynamic numbers?  What systems require a static value?

thanks,

greg k-h