Arch Linux

Profjim

Member

From: NYC

Registered: 2008-03-24

Posts: 658

Note: xscreensaver no longer blocks VT-switching

I may be remembering wrong, but I'm pretty sure that xscreensaver used to block VT-switching keys. I think X-killing keys, too, but I may be wrong about that too.

So if you left your laptop switched into X, and xscreensaver locked the screen, your machine was locked, even if you had VT sessions logged in.

Now however---probably as a result of my switching over to KMS on Intel---I notice that xscreensaver no longer blocks you from doing VT switches, even when it's locking the X screen. I'm not sure whether it still (or ever) blocked against X-killing.

I'm headed out the door for a bit, so I can't follow this up upstream. But others should know not to trust xscreensaver for the time being, if they've also got VTs running.

Of course, if I'm misremembering and this hole has always been there, well in that case it's also worth calling your attention to it.

JohannesSM64

Member

From: Norway

Registered: 2009-10-11

Posts: 623

Website

Re: Note: xscreensaver no longer blocks VT-switching

alias bgx='startx &! exit' will start X independently of the shell and exit back to agetty. (edit: zsh only)

Last edited by JohannesSM64 (2010-01-14 20:11:28)

azleifel

Member

Registered: 2007-10-28

Posts: 486

Re: Note: xscreensaver no longer blocks VT-switching

man xscreensaver

XFree86's Magic Keystrokes
               The XFree86 X server traps certain  magic  keystrokes  before
               client  programs  ever  see  them.   Two that are of note are
               Ctrl+Alt+Backspace, which causes the X server  to  exit;  and
               Ctrl+Alt+Fn,  which  switches virtual consoles.  The X server
               will respond to these keystrokes even if xscreensaver has the
               screen  locked.   Depending on your setup, you might consider
               this a problem.

               Unfortunately, there is no way  for  xscreensaver  itself  to
               override  the  interpretation  of these keys.  If you want to
               disable Ctrl+Alt+Backspace globally,  you  need  to  set  the
               DontZap  flag  in your /etc/X11/XF86Config file.  To globally
               disable VT switching, you can set the DontVTSwitch flag.  See
               the XF86Config(5) manual for details.

Profjim

Member

From: NYC

Registered: 2008-03-24

Posts: 658

Re: Note: xscreensaver no longer blocks VT-switching

Thanks, my bad. This hole has always been there.