Re: [PATCH] ioctl entries for joystick in compat_ioctl.h

[Pavel Machek]

Hi!

> > > I wanted to use a joystick on my sparc64 workstation, and discovered that the
> > > joystick driver uses simple ioclt that are safe to pass from 32bit user space
> > > to 64bit kernel space. My patch adds the necessary entries in compat_ioctl.h.
> > > 
> > > There is only one missing ioctl in the patch. The ioctl is defined like this:
> > > #define JSIOCGNAME(len)         _IOC(_IOC_READ, 'j', 0x13, len)
> > > so the command does not have a fixed value. I dont know how to handle this one,
> > > but it is only used to get the joystick name, all the applications I tried work
> > > well even if this ioctl fails.
> > 
> > Well, whoever invented that JSIOCGNAME should be shot. That is not
> > single ioctl, its 2^14 of them!
> 
> Well, who could ever have known that this will be a problem in 1998?
> It's not the only ioctl done this way.

So it was you? :-)

I believe ultrasparcs were around in '98. Anyway, what are other
ioctls doing this? They look pretty problematic from compat_ioctl
perspective.

We could do better by pushing compat handler down to the drivers for
ugly cases like this...
									Pavel
-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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