Re: [example PATCH - not for applying] exclude certain commands

[Oliver Neukum <oliver@neukum.org>]

> Do you mean it makes user space drivers inferior to kernel drivers?  I
> don't see how.  The LLDD would treat them both the same, doing a minimum
> of modifications.

You got to make up your mind :-)
So the LLDD should filter in both cases?

> If you mean that it would make user space drivers inferior to the way they
> work now, then I agree.  At least, they might be inferior in terms of
> performance, since they would no longer have commands altered
> automatically for their benefit.  On the other hand, they would be
> superior in terms of receiving a more transparent channel directly to the
> device.  For some people this is very important.

For the larger part it's vastly important that exactly that doesn't happen.
Eg. I want the user to have access to a device, but I don't want him to
be able to crash the device. It's a multiuser system and others might
want to use the device afterwards.
We usually require root level to get a transparent channel to hardware.

If filtering is marginal you need to use yet another demon to be checked for
buffer overflows, etc. ... .

> I think it won't really be a problem.  A user-space driver _ought_ to be
> prepared to cope with the quirks and special requirements of a particular
> device.

But can you depend on it? From an administration viewpoint you create a
hole for a DoS attack.

	Regards
		Oliver