RE: [PATCH 0/5] add initial io_uring_cmd support for sockets

[David Laight <David.Laight@ACULAB.COM>]

From: Willem de Bruijn
> Sent: 13 April 2023 15:25
...
> > For instance the raw_ioctl()/rawv6_ioctl() case. The "arg" argument is
> > used in different ways (one for input and one for output):
> >
> >   1) If cmd == SIOCOUTQ or SIOCINQ, then the return value will be
> >   returned to userspace:
> >   	put_user(amount, (int __user *)arg)

There is always the option of defining alternate ioctl
'cmd' codes that user IOR() and IOW() and requiring that
io_uring applications use the alternate forms.

Then have two 'ioctl' functions with a new one for IOR()
type commands and the existing one for compatibility
that might just do a translation (or return a translated
command to avoid extra stack use).

You may still want to pass through both the kernel and
user (if a user request) buffer addresses to allow for
those broken requests where the buffer direction bits
are wrong.

	David

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