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Bug 1185893 - KDE root apps fail to render using X w/o root rights
Summary: KDE root apps fail to render using X w/o root rights
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: xorg-x11-server
Version: 21
Hardware: x86_64
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Hans de Goede
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On: qt4-no-root
Blocks: F22FinalBlocker
TreeView+ depends on / blocked
 
Reported: 2015-01-26 15:01 UTC by Andrew Travneff
Modified: 2015-06-29 12:40 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-04-20 14:49:13 UTC
Type: Bug
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Bugzilla 1078902 0 unspecified CLOSED Xorg without root rights 2022-05-16 11:32:56 UTC
Red Hat Bugzilla 1196237 0 unspecified CLOSED hp-plugin does not work in Fedora 22 2022-05-16 11:32:56 UTC

Internal Links: 1196237

Description Andrew Travneff 2015-01-26 15:01:13 UTC 
Related to RHBZ #1078902

When X server runs without root rights, (some?) KDE apps launched from root don't work. They just don't paint their UI.
Besides that, there are errors in console which might be related.
Screenshot attached here: https://bugzilla.redhat.com/show_bug.cgi?id=1078902#c18

X apps (xclock e.g.) and GTK apps (GIMP) seem fine.

Giving root privileges back to X fixes this.

xorg-x11-server-Xorg-1.16.2.901-1.fc21.x86_64
xorg-x11-xinit-1.3.4-3.fc21.x86_64
kernel 3.17.8-300.fc21.x86_64
Comment 1 Hans de Goede 2015-01-29 09:22:34 UTC 
I've send a mail about this to the xorg-devel list to discuss this further, as said already I believe this ultimately is a Qt/KDe bug, but lets see where the discussion goes first.
Comment 2 Martin Gräßlin 2015-01-29 09:51:12 UTC 
Please try to run the kde application with
--graphicssystem native

e.g: kcalc --graphicssystem native

The native graphicssystem might bypass the shm extension.
Comment 3 Andrew Travneff 2015-01-29 09:55:47 UTC 
It works, thanks!
Comment 4 Adam Williamson 2015-04-20 14:26:29 UTC 
This is affecting some non-KDE apps that are fairly significant, I think (thanks Andrew):

https://bugzilla.redhat.com/show_bug.cgi?id=1212180 - liveusb-creator
https://bugzilla.redhat.com/show_bug.cgi?id=1196237 - hplip (HP printer utilities)
Comment 5 Adam Williamson 2015-04-20 14:26:58 UTC 
*** Bug 1212180 has been marked as a duplicate of this bug. ***
Comment 6 Hans de Goede 2015-04-20 14:49:13 UTC 
Hi Adam,

(In reply to awilliam from comment #4)
> This is affecting some non-KDE apps that are fairly significant, I think
> (thanks Andrew):
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1212180 - liveusb-creator
> https://bugzilla.redhat.com/show_bug.cgi?id=1196237 - hplip (HP printer
> utilities)

I'm afraid that there is nothing which we can do about this from the Xorg side, this is really an apllication side bug, specifically the application / toolkit is not doing proper error checking of the MIT SHM extension related X calls. And more in general people should really not be running gui apps as root (I realize this is sometimes easiest, but at least we should not ship anything setup this way ootb).

Since this really is an application bug I'll add a comment to the bugs in question and re-open them where necessary.

Note I've also discussed this with the some qt people and it is fixed in qt5, and currently there are no plans to fix this for qt4, there answer to this problem is: Do not run gui apps as root.

Regards,

Hans
Comment 7 Adam Williamson 2015-05-06 23:26:48 UTC 
As this affects multiple Qt apps - at least, liveusb-creator and hp-plugin - should we figure it's a Qt bug?
Comment 8 Adam Williamson 2015-05-06 23:27:25 UTC 
oh, never mind, just saw the end of c6.
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