Re: [PATCH 7/7] [v2] drivers/misc: introduce Freescale hypervisor management driver

On Friday 03 June 2011, Timur Tabi wrote:

Arnd Bergmann wrote:

quoted

For an ioctl, please follow the normal pattern of defining a separate
structure for each case, no union.

You can use a void __user * in the common ioctl function, and pass that
to the typed argument list in the specific functions.

I have a GPL question.  This header file is currently licensed under the  GPL v2
only.  Does that mean that any application that includes this header file so
that it can talk to the driver/hypervisor also needs to be licensed under the GPL?

If you have a license question, ask your lawyer.

Common answers that you would hear are:

* User space interfaces of the kernel are excluded from the License by the
  "normal system call" exception in linux/COPYING.

* If the header files only contain interfaces but no code, they are not
  copyrighted.

* If you want to ship a copy of the file with a user space application source,
  but have to make it available under multiple licenses to do that, e.g. dual
  GPL/BSD.

	Arnd