Warning: evdev changes - no auto-grabs anymore

Ville Syrjälä syrjala at sci.fi
Thu Aug 14 23:51:59 PDT 2008

On Fri, Aug 15, 2008 at 09:54:58AM +0930, Peter Hutterer wrote:
> On Thu, Aug 14, 2008 at 01:50:09PM -0400, Adam Jackson wrote:
> > > Sounds good, but unfortunately, this change seems to cause trouble of
> > > its own, namely that hitting ctrl-C terminates the X server - not very
> > > useful. :) It looks like all the input intended for the X server also
> > > goes to a VT (I can briefly see fragments of what I typed before hitting
> > > ctrl-C until the server restarts), and that's probably how the ctrl-C
> > > results in a SIGTERM to the X server.
> > 
> > This is, in fact, one of the main reasons I put SIOCGRAB there in the
> > first place; you need to keep the keyboard's event stream out of the tty
> > layer entirely, not just out of reach of the kbd driver.  At the time
> > the argument was also that you wanted to keep them out of reach of
> > normal users so you couldn't snoop passwords, but now that there's a
> > ConsoleKit I think that's less true.
> > 
> > Mac mouse emulation we could probably just blacklist away from the evdev
> > driver.  rfkill is... harder?  Does it get its own event device or not?
> > I'd think it would have to get one kill device per wireless device.
> The issue is not grabbing the mouse emulation device, it's grabbing the
> keyboard that generates those keys events that should result in a button click
> on a different device. So we'd need something in the kernel I guess.

I was pondering about the same issue wrt. DirectFB. I wonder if
KDSETMODE/KD_GRAPHICS could be extended to take care of this or
would it break some existing applications.

Ville Syrjälä
syrjala at sci.fi

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