Disable the ctrl-alt-backspace combination by default in xorg

Registered by François Terrier

In my opinion, the ctrl-alt-backspace command that kills the X server should not be activated on an end-user desktop system such as Ubuntu.
My arguments are the following:
- There is no need for such a feature for an end user desktop system (you cannot kill the X server in MacOSX...)
- The typical end user does not know about this feature (it is undocumented and hidden) and it is relatively easy to trigger it by mistake. It can have disastrous consequences.
- If one really needs to kill the X server, he can go to a tty term and do it by hand.

Blueprint information

Martin Pitt
Bryce Harrington
Bryce Harrington
Series goal:
Accepted for jaunty
Milestone target:
Started by
Bryce Harrington
Completed by
Bryce Harrington


[Prior commentary on whiteboard moved to the wiki page to refocus the whiteboard to status]

I'm going to postpone implementation of this for Gutsy. There is not a clear consensus in the community, as can be seen in the discussion - some favor it, some favor staying with the traditional approach. Canonical also does not have a definite preference; there seems to be strong pros and cons on both sides, and no solution has emerged which will satisfy the majority of use cases.

The code to simply disable the shortcut is simple, and is included in the spec. However, what we need is a definite consensus favoring either this or an alternate solution. Because of this, I'm setting the status back to discussion.

2007-10-15 bryce: Discussion on wiki has still not reached a consensus on proposal for addressing this, so I'm not planning for discussion of this at the Hardy UDS in Boston. (If anyone disagrees, there's less than 2 weeks before UDS, which might be sufficient time to draft a proposal worth discussion.)

2007-11-17 bryce: Deferring. We would need a strong consensus for how to do this.

2008-05-27 bryce: Discussed some of the proposed ideas at UDS Intrepid in Prague with Timo. Holding the key for 1-2 sec or hitting it twice in a row sounds like an acceptable compromise that looks like it could get a sufficient consensus. This is low priority for Intrepid, but if there's time I'll try to get it in.

2008-08-26 bryce: Postponing. There remains a lack of consensus among commenters about the change.

2008-11-18 bryce: Discussed this with upstream. They've decided to disable ctrl-alt-backspace as their default. We will be pulling their change for Jaunty when we next merge xserver. We can use 'xorg-options-editor' as a GUI tool for allowing users to re-enable this should they wish it.

2008-12-12 bryce: Discussed at UDS and reached consensus to take the upstream change as the default for Jaunty, with GUI tools to allow users to easily enable it as desired.

2008-12-15 Rick Spencer: The "GUI Tool" Bryce refers to is the xorg.conf editor under development.

2008-12-15 Martin Pitt: spec talks about 2 second delay and has BoF discussions; discussion results need to be worked into the actual spec, it should not have open questions or contradictory decisions. Please set back to pending review once spec is updated. Thanks!

2008-12-17 Claudio Moretti: There will be a way to re-enable it? I don't really like the idea of going to tty and restart X every time I need (even because running a development release means that X needs restarting lots of times, in some cases)

2008-12-17 Alberto Milone: as Bryce already pointed out, users will be able to switch back to the old behaviour through a GUI (for both GNOME and KDE). Nothing to worry about.

2008-12-17 bryce: Specification is cleaned up to reflect the decisions made at UDS and Martin Pitt's comments. Note that the GUI xorg.conf options editor tool design/implementation work will be done separately under the xorg.conf options editor specification.

2008-12-17 bryce: The change to disable ctrl-alt-backspace by default has now been deployed in Jaunty. Documentation review remains to be done before this spec can be marked Implemented.

2008-12-18 pitti: approved

2009-02-18 pitti: set to "beta available"; the code changes are in, but documentation is still missing, according to above status

2009-03-06 bryce: I've fixed up well over a hundred pages on help.ubuntu.com that including "ctrl-alt-backspace" in their directions (in many cases unnecessarily), and that weren't specifically targeted to an older ubuntu release. I found these both from the in-site search as well as google, and fixed all the pages returned. I think this should be sufficient for considering this blueprint closed now.


Work Items