xinit problems after latest XORG update & workaround

[gkreidl]

If you have been using xinit to start a small X-environment for embedded applications (kiosks, digital signage) or alternate desktops you may have noticed that this doesn't work any more after the latest XORG updates. My kweb and omxplayerGUI manuals describe such scenarios and these descriptions are now obsolete without modifications.

The upstream (testing) XORG seems to have bugs, which they cannot solve at the moment and in order to keep the system secure they have decided to modify some security settings, which in turn keeps xinit from working as it did before and especially for using it from rc.local to boot into such applications.

For the following I assume you have a script named "kiosk" in the root of your home directory (could be anything else), which is executed by xinit; usually it starts a window manager, a task bar, any start-up application etc. From the command line it could be called like this

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xinit ./kiosk

but this doesn't work any more.

A solution for command line use is simple. You just have to add something:

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xinit ./kiosk -- vt$(fgconsole) 

Unfortunately this doesn't work from rc.local (for starting your X application at boot time). The only solution I have found so far is to modify the access rights of all (or some) tty devices, which introduces new security risks.

1) Add user pi to group tty:

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sudo usermod -a -G tty pi

2) Modify Xwrapper (that has always been required on a new Jessie installation):

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sudo nano /etc/X11/Xwrapper.config

and set:

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allowed_users=anybody

3) Add the following to /etc/rc.local (before the "exit 0" line).

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chmod a+rw /dev/tty0
chmod g+rw /dev/tty*
su -l pi -c "xinit ./kiosk" &

This is not a perfect solution, but at least booting into your application is possible again.

[owntheweb]

Thanks for posting this! Life is good now thanks to you.

...The only solution I have found so far is to modify the access rights of all (or some) tty devices, which introduces new security risks.

Just checking on this. I'm guessing you have to be logged in as someone first before causing security mayhem of some kind? I'm just trying to keep things somewhat secure as I proceed to make my internet-connected kiosk.

I appreciate the feedback.

[gkreidl]

There is one other method I have found:
Set you RPi to boot to the desktop with auto-login,
On the desktop run
lxsession-default-apps
Click on "Autostart" on the left. In the upper right part you will see the applications which are started automatically (pcmanfm --desktop ... for example). Add the programs you need. Disable everything which you don't need (taskbar and desktop, for example).
Close the desktop and start it again.

[owntheweb]

Thanks for the feedback!