OK, figured out how that code is supposed to work. The KAuth::Action constructor orders an EnumerateActions ASYNC signal to polkit. It expects a callback when polkit responds. The callback is updateCache which populates m_knownActions.

KAuth does not receive the callback, even though I can see polkit returning all actions on the dbus system bus.

I took a look at polkit and I see it uses g_dbus_proxy_call (from glib) to send the dbus message and supplying a callback method. That callback is never called.

So I'm thinking the fault lies in glib and/or dbus.

Where is the best place to get support on glib and dbus? Any forums or mailing lists?

Unfortunately i'm not sure exactly where you would need to go to get that, although as a first part I would ensure that polkit, Qt, kdelibs and System Settings had all been compiled with GLib integration enabled.

I had trouble changing the system time. I got authentication working in a 2-step process.
(1) I enabled root login by editing /etc/kde4/kdm/kdmrc and changing the line AllowRootLogin=false to AllowRootLogin=true. Then I rebooted.

I then had trouble contacting the time server. I solved this by
(2) installing ntpdate from a Debian archive.

I hope this helps.

Update (or rather lack thereof): I'm now on KDE 4.8 and the problem is still the same.

I tried the suggestion to allow root login but when I attempt it I'm just kicked back to the KDM login screen. Not sure what, if anything, that signifies.

Edit: Found this in /var/log/messages when I try logging in as root:

Feb 5 21:31:20 markuspc kdm: :0[27659]: pam_unix(kde:session): session opened for user root by (uid=0)
Feb 5 21:31:20 markuspc kernel: kdm[27678]: segfault at 0 ip 000000000040d58f sp 00007fff1ca9b230 error 4 in kdm[400000+2b000]
Feb 5 21:31:20 markuspc kdm: :0[27659]: pam_unix(kde:session): session closed for user root

The problem you seem to have here is that for otherwise unknown reasons KDM is crashing. I have not seen KDM crash before, so this is extremely unusual. Are you able to log in as a normal user?

Yes, I can login as a regular user. It is only root that cannot login.

At this point, you likely need to enable Core Dumps, and use GDB to generate a suitable backtrace from the Core Dump to have any insight into why this crash occurs.

Hmmm. not really getting much from gdb. Do I need to recompile kdm with debug enabled?

Code: Select all

markuspc / # gdb /usr/bin/kdm --core core                                                                                             
GNU gdb (Gentoo 7.4 p1) 7.4
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-pc-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.gentoo.org/>...
Reading symbols from /usr/bin/kdm...(no debugging symbols found)...done.
[New LWP 2603]

warning: Can't read pathname for load map: Input/output error.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `-:0'        '.
Program terminated with signal 11, Segmentation fault.
#0  0x000000000040d58f in startClient ()
(gdb) bt
#0  0x000000000040d58f in startClient ()
#1  0x000000000041a257 in manageSession ()
#2  0x0000000000412ea1 in startDisplayP2 ()
#3  0x00000000004123f1 in main ()
(gdb)

It may help, yes - as lines of code in the source are not being mentioned.

Sorry for the delay, had to read up on compiler flags.

Code: Select all

markuspc / # gdb /usr/bin/kdm --core core
gdb /usr/bin/kdm --core core
GNU gdb (Gentoo 7.4 p1) 7.4
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-pc-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.gentoo.org/>...
Reading symbols from /usr/bin/kdm...Reading symbols from /usr/lib64/debug/usr/bin/kdm.debug...done.
done.
[New LWP 26527]
Core was generated by `-:0'        '.
Program terminated with signal 11, Segmentation fault.
#0  0x000000000040d80c in startClient (pid=0x0) at /var/tmp/portage/kde-base/kdm-4.8.0-r1/work/kdm-4.8.0/kdm/backend/client.c:1496
1496            mergeSessionArgs(True);
(gdb) bt
#0  0x000000000040d80c in startClient (pid=0x0) at /var/tmp/portage/kde-base/kdm-4.8.0-r1/work/kdm-4.8.0/kdm/backend/client.c:1496
#1  0x0000000000413131 in anyReserveDisplays () at /var/tmp/portage/kde-base/kdm-4.8.0-r1/work/kdm-4.8.0/kdm/backend/dpylist.c:72
#2  0x00000000014674b8 in ?? ()
#3  0x0000000000000010 in ?? ()
#4  0x0000000001467460 in ?? ()
#5  0x0000000001467460 in ?? ()
#6  0x0000000001468c20 in ?? ()
#7  0x0000000001468bb0 in ?? ()
#8  0x00007fff311ead70 in ?? ()
#9  0x00000000004127af in storePid () at /var/tmp/portage/kde-base/kdm-4.8.0-r1/work/kdm-4.8.0/kdm/backend/dm.c:1640
#10 main (argc=<optimized out>, argv=<optimized out>) at /var/tmp/portage/kde-base/kdm-4.8.0-r1/work/kdm-4.8.0/kdm/backend/dm.c:270
(gdb)


Can you please post a bug report at bugs.kde.org regarding that?
Please be aware however that KDE in general usually does not support you logging in as root - as it should not be needed.

Done:

https://bugs.kde.org/show_bug.cgi?id=293902