On Thu, Aug 18, 2022 at 08:26:38AM +0200, Greg KH wrote:
> On Wed, Aug 17, 2022 at 02:47:25PM -0700, Axel Rasmussen wrote:
> > +static int userfaultfd_dev_open(struct inode *inode, struct file *file)
> > +{
> > + return 0;
>
> If your open does nothing, no need to list it here at all, right?
>
> > +}
> > +
> > +static long userfaultfd_dev_ioctl(struct file *file, unsigned int cmd, unsigned long flags)
> > +{
> > + if (cmd != USERFAULTFD_IOC_NEW)
> > + return -EINVAL;
> > +
> > + return new_userfaultfd(flags);
> > +}
> > +
> > +static const struct file_operations userfaultfd_dev_fops = {
> > + .open = userfaultfd_dev_open,
> > + .unlocked_ioctl = userfaultfd_dev_ioctl,
> > + .compat_ioctl = userfaultfd_dev_ioctl,
>
> Why do you need to set compat_ioctl? Shouldn't it just default to the
> existing one?
>
> And why is this a device node at all? Shouldn't the syscall handle all
> of this (to be honest, I didn't read anything but the misc code, sorry.)
Ah, read the documentation now. Seems you want to make it easier for
people to get permissions on a system. Doesn't seem wise, but hey, it's
not my feature...
thanks,
greg k-h
