On Sat, Jul 26, 2014 at 08:54:21AM +0200, Laurent Carlier wrote:

Le samedi 26 juillet 2014, 03:11:45 Karol Blazewicz a écrit :

...

I can start only one rootless X session at a time. If I want to start a second one while the first one is running, I have to use 'sudo startx'. I'm logging into tty and starting X as a user.

Did I mis-configure something or is it a "feature'? Can you start multiple X sessions simultaneously with xorg 1.16?

I have not yet found how to do this with xorg 1.16 in rootless mode. Multiple X sessions should work flawlessly with root rights.

Not really, in general. For me, Xserver 1.16 with root rights works only on KMS-less systems. In other setups I have tested, X simply segfaults if running as root. This happens on real hw as well as in vmware player (which provides KMS). In the latter case I had to downgrade to xorg-server 1.15 to get my desktop back (also, I do not use proprietary vmware tools).

Here are the errors on a real machine with hybrid AMD/Intel graphics: ------ $ lspci | grep VGA 00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06) 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Venus XT [Radeon HD 8870M / R9 M270X] (rev ff)

$ grep "(EE)" /var/log/Xorg.0.log (WW) warning, (EE) error, (NI) not implemented, (??) unknown. [ 2484.378] (EE) systemd-logind: failed to take device /dev/dri/card0: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. [ 2485.302] (EE) /dev/dri/card0: failed to set DRM interface version 1.4: Permission denied [ 2485.305] (EE) Failed to load module "modesetting" (module does not exist, 0) [ 2485.305] (EE) Failed to load module "fbdev" (module does not exist, 0) [ 2485.305] (EE) Failed to load module "vesa" (module does not exist, 0) [ 2485.376] (EE) systemd-logind: failed to take device /dev/dri/card0: Device already taken [ 2485.376] (EE) /dev/dri/card0: failed to set DRM interface version 1.4: Permission denied [ 2491.936] (EE) [ 2491.936] (EE) Backtrace: [ 2491.937] (EE) 0: /usr/bin/Xorg.bin (xorg_backtrace+0x56) [0x5938f6] [ 2491.937] (EE) 1: /usr/bin/Xorg.bin (0x400000+0x197af9) [0x597af9] [ 2491.937] (EE) 2: /usr/lib/libc.so.6 (0x7f88e4e55000+0x33df0) [0x7f88e4e88df0] [ 2491.937] (EE) 3: /usr/lib/libc.so.6 (0x7f88e4e55000+0x128696) [0x7f88e4f7d696] [ 2491.937] (EE) 4: /usr/bin/Xorg.bin (0x400000+0xa14e8) [0x4a14e8] [ 2491.937] (EE) 5: /usr/lib/libdbus-1.so.3 (dbus_connection_dispatch+0x3f1) [0x7f88e69055b1] [ 2491.937] (EE) 6: /usr/lib/libdbus-1.so.3 (0x7f88e68f5000+0x10805) [0x7f88e6905805] [ 2491.937] (EE) 7: /usr/bin/Xorg.bin (0x400000+0x9ae09) [0x49ae09] [ 2491.937] (EE) 8: /usr/bin/Xorg.bin (WakeupHandler+0x6b) [0x43c3ab] [ 2491.937] (EE) 9: /usr/bin/Xorg.bin (WaitForSomething+0x1c7) [0x590d27] [ 2491.937] (EE) 10: /usr/bin/Xorg.bin (0x400000+0x374f1) [0x4374f1] [ 2491.937] (EE) 11: /usr/bin/Xorg.bin (0x400000+0x3b866) [0x43b866] [ 2491.937] (EE) 12: /usr/lib/libc.so.6 (__libc_start_main+0xf0) [0x7f88e4e75000] [ 2491.937] (EE) 13: /usr/bin/Xorg.bin (0x400000+0x25d0e) [0x425d0e] [ 2491.937] (EE) [ 2491.937] (EE) Segmentation fault at address 0x0 [ 2491.937] (EE) [ 2491.937] (EE) Caught signal 11 (Segmentation fault). Server aborting [ 2491.937] (EE) [ 2491.937] (EE) [ 2491.937] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information. [ 2491.937] (EE) [ 2493.888] (EE) systemd-logind: ReleaseControl failed: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. [ 2493.888] (EE) Server terminated with error (1). Closing log file. ------

Somehow, I can not make sense of the above error (X runs as root, so it can write to /var/log/ but lacks permissions for a device?). Any ideas?

Thanks,

On Sat, Jul 26, 2014 at 11:09:32PM +0200, Laurent Carlier wrote:

[...] Probably a bug related to PRIME, you should probably open an upstream bug report.

Yes. I'll wait for linux 3.16 and then do if the problem is still there. Although, this looks more like a kernel/systemd issue. Here is a log from a rootless X: ------ [ 143.639] (II) xfree86: Adding drm device (/dev/dri/card0) [ 143.639] (II) systemd-logind: got fd for /dev/dri/card0 226:0 fd 8 paused 0 [ 143.639] (II) xfree86: Adding drm device (/dev/dri/card1) [ 143.640] (II) systemd-logind: got fd for /dev/dri/card1 226:1 fd 9 paused 0 [ 143.640] (--) PCI:*(0:0:2:0) 8086:0416:1028:05cc rev 6, Mem @ 0xf6400000/4194304, 0xd0000000/268435456, I/O @ 0x0000f000/64 [ 143.640] (--) PCI: (0:1:0:0) 1002:6821:1028:05cc rev 0, Mem @ 0xe0000000/268435456, 0xf7d00000/262144, I/O @ 0x0000e000/256, BIOS @ 0x????????/131072 ------

Card0 = radeon; card1 = intel: ------ $ cat /sys/class/drm/card0/device/power/runtime_status suspended $ cat /sys/class/drm/card1/device/power/runtime_status active $ xrandr --listproviders Providers: number : 2 Provider 0: id: 0x82 cap: 0xb, Source Output, Sink Output, Sink Offload crtcs: 4 outputs: 5 associated providers: 0 name:Intel Provider 1: id: 0x59 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 6 outputs: 4 associated providers: 0 name:radeon ------

Cheers,

On Sat, Jul 26, 2014 at 11:40:18PM +0200, Laurent Carlier wrote:

[...]

Can you try to boot with the kernel parameter drm.rnodes=1 ?

Yes, but this doesn't make a difference. X still crashes when tries to run as root. However, after a closer look, I found this in auth.log (sorry, forgot to mention before): ------ 2014-07-26T23:09:56.000-04:00 borei polkitd[823]: Loading rules from directory /etc/polkit-1/rules.d 2014-07-26T23:09:56.000-04:00 borei polkitd[823]: Loading rules from directory /usr/share/polkit-1/rules.d 2014-07-26T23:09:56.000-04:00 borei polkitd[823]: Finished loading, compiling and executing 1 rules 2014-07-26T23:09:56.000-04:00 borei polkitd[823]: Acquired the name org.freedesktop.PolicyKit1 on the system bus 2014-07-26T23:09:59.000-04:00 borei systemd-logind[415]: kernel does not support evdev-revocation ------

What's the need for polkit when needs_root_rights = yes?

Thanks,