[SOLVED] Lightdm autologin and Xorg signal 6

thefiercerabbit · 2021-03-23 16:49:12

When autologin is setup with Lightdm, my session opens (automatically) for a brief instant and then closes again. I noticed that it works fine when the Intel drivers are not installed. If I type in my password, then I can login my session without issue.
At the moment, I have both the Intel and nouveau drivers installed.

The issue seems similar to the one reported here: https://bbs.archlinux.org/viewtopic.php?id=259863
However, in my case, I do not use nvidia drivers.

Below is a part of the log file /var/log/Xorg.0.log.old.

[     4.421] (II) No input driver specified, ignoring this device.
[     4.421] (II) This device may have been added with another device file.
[     4.659] (II) config/udev: removing GPU device /sys/devices/pci0000:00/0000:00:1c.0/0000:01:00.0/drm/card1 /dev/dri/card1
[     4.659] (II) config/udev: Adding drm device (/dev/dri/card1)
[     4.659] (II) xfree86: Adding drm device (/dev/dri/card1)
[     4.660] (II) LoadModule: "modesetting"
[     4.660] (II) Loading /usr/lib/xorg/modules/drivers/modesetting_drv.so
[     4.665] (II) Module modesetting: vendor="X.Org Foundation"
[     4.665] 	compiled for 1.20.10, module version = 1.20.10
[     4.665] 	Module class: X.Org Video Driver
[     4.665] 	ABI class: X.Org Video Driver, version 24.1
[     4.665] (II) modeset(G0): using drv /dev/dri/card1
[     4.666] (==) modeset(G0): Depth 24, (==) framebuffer bpp 32
[     4.666] (==) modeset(G0): RGB weight 888
[     4.666] (==) modeset(G0): Default visual is TrueColor
[     4.666] (II) Loading sub module "glamoregl"
[     4.666] (II) LoadModule: "glamoregl"
[     4.666] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[     4.676] (II) Module glamoregl: vendor="X.Org Foundation"
[     4.676] 	compiled for 1.20.10, module version = 1.0.1
[     4.676] 	ABI class: X.Org ANSI C Emulation, version 0.4
[     5.050] (II) modeset(G0): glamor X acceleration enabled on NV117
[     5.050] (II) modeset(G0): glamor initialized
[     5.050] (==) modeset(G0): Using gamma correction (1.0, 1.0, 1.0)
[     5.050] (==) modeset(G0): DPI set to (96, 96)
[     5.050] (II) Loading sub module "fb"
[     5.050] (II) LoadModule: "fb"
[     5.051] (II) Loading /usr/lib/xorg/modules/libfb.so
[     5.052] (II) Module fb: vendor="X.Org Foundation"
[     5.052] 	compiled for 1.20.10, module version = 1.0.0
[     5.052] 	ABI class: X.Org ANSI C Emulation, version 0.4
[     5.053] (EE) 
[     5.053] (EE) Backtrace:
[     5.053] (EE) 0: /usr/lib/Xorg (xorg_backtrace+0x53) [0x5654e9c39f63]
[     5.053] (EE) 1: /usr/lib/Xorg (0x5654e9af3000+0x151da5) [0x5654e9c44da5]
[     5.053] (EE) 2: /usr/lib/libc.so.6 (0x7fd2eb859000+0x3cf80) [0x7fd2eb895f80]
[     5.053] (EE) 3: /usr/lib/libc.so.6 (gsignal+0x145) [0x7fd2eb895ef5]
[     5.054] (EE) 4: /usr/lib/libc.so.6 (abort+0x116) [0x7fd2eb87f862]
[     5.054] (EE) 5: /usr/lib/libc.so.6 (0x7fd2eb859000+0x26747) [0x7fd2eb87f747]
[     5.054] (EE) 6: /usr/lib/libc.so.6 (0x7fd2eb859000+0x35646) [0x7fd2eb88e646]
[     5.054] (EE) 7: /usr/lib/Xorg (dixRegisterPrivateKey+0x0) [0x5654e9b88870]
[     5.054] (EE) 8: /usr/lib/xorg/modules/libglamoregl.so (glamor_init+0xc9) [0x7fd2e8557fb9]
[     5.054] (EE) 9: /usr/lib/xorg/modules/drivers/modesetting_drv.so (0x7fd2e85c4000+0x140fd) [0x7fd2e85d80fd]
[     5.054] (EE) 10: /usr/lib/Xorg (AddGPUScreen+0x10e) [0x5654e9b6c40e]
[     5.054] (EE) 11: /usr/lib/Xorg (0x5654e9af3000+0x185eb9) [0x5654e9c78eb9]
[     5.054] (EE) 12: /usr/lib/Xorg (0x5654e9af3000+0x1bb288) [0x5654e9cae288]
[     5.054] (EE) 13: /usr/lib/Xorg (0x5654e9af3000+0x1bbb12) [0x5654e9caeb12]
[     5.054] (EE) 14: /usr/lib/Xorg (0x5654e9af3000+0x14a331) [0x5654e9c3d331]
[     5.054] (EE) 15: /usr/lib/Xorg (WaitForSomething+0x250) [0x5654e9c38c00]
[     5.054] (EE) 16: /usr/lib/Xorg (0x5654e9af3000+0x39914) [0x5654e9b2c914]
[     5.054] (EE) 17: /usr/lib/libc.so.6 (__libc_start_main+0xd5) [0x7fd2eb880b25]
[     5.054] (EE) 18: /usr/lib/Xorg (_start+0x2e) [0x5654e9b2d5de]
[     5.054] (EE) 
[     5.054] (EE) 
Fatal server error:
[     5.054] (EE) Caught signal 6 (Aborted). Server aborting
[     5.054] (EE) 
[     5.054] (EE)

Here is a part of the log file /var/log/lightdm/lightdm.log

[+0.17s] DEBUG: Launching process 429: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.17s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.17s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.17s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.87s] DEBUG: Got signal 10 from process 429
[+0.87s] DEBUG: XServer 0: Got signal from X server :0
[+0.87s] DEBUG: XServer 0: Connecting to XServer :0
[+0.87s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+0.87s] DEBUG: Session pid=442: Started with service 'lightdm-autologin', username 'myusername'
[+0.90s] DEBUG: Session pid=442: Authentication complete with return value 0: Success
[+0.90s] DEBUG: Seat seat0: Session authenticated, running command
[+0.90s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+0.90s] DEBUG: Session pid=442: Running command /etc/lightdm/Xsession i3
[+0.90s] DEBUG: Creating shared data directory /var/lib/lightdm-data/myusername
[+0.90s] DEBUG: Session pid=442: Logging to .xsession-errors
[+1.04s] DEBUG: Activating VT 7
[+1.04s] DEBUG: Activating login1 session 1
[+1.04s] DEBUG: Seat seat0 changes active session to 1
[+1.04s] DEBUG: Session 1 is already active
[+1.50s] DEBUG: Session pid=442: Exited with return value 1
[+1.50s] DEBUG: Seat seat0: Session stopped
[+1.50s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+1.50s] DEBUG: Sending signal 15 to process 429
[+1.51s] DEBUG: Seat seat0 changes active session to 
[+2.43s] DEBUG: Process 429 terminated with signal 6
[+2.43s] DEBUG: XServer 0: X server stopped
[+2.43s] DEBUG: Releasing VT 7

Full Xorg log: https://pastebin.com/h1iFBWru
Full lightdm log: https://pastebin.com/JGfHt0TR

Last edited by thefiercerabbit (2021-03-24 14:26:08)

seth · 2021-03-24 08:10:09

You're running that server on the xf86-video-intel gpu and it crashes when the modesetting driver tries to add the nvidia chip, which is operated by nouveau.

However, in my case, I do not use nvidia drivers.

I'd try that first, because the problem is likely the nouveau kernel module.

Also please post your lightdm config and a "good" session xorg log

thefiercerabbit · 2021-03-24 10:52:20

I installed nvidia's driver, activated DRM in the kernel parameters, and don't have a xorg configuration file. Altough the system was booting (and the autologin working as expected), I had to add the modules nvidia, nvidia_modeset, nvidia_uvm and nvidia_drm to the initramfs, as explained here: https://wiki.archlinux.org/index.php/NV … de_setting

I don't have the issue anymore (autologin works as expected), so I'll mark this thread as solved. Thanks for your help!

------------------

FYI:

Content of /etc/lightdm/lightdm.conf:

[LightDM]
run-directory=/run/lightdm

[Seat:*]
session-wrapper=/etc/lightdm/Xsession
autologin-user=myusername

A "good" Xorg log before installing nvidia driver: https://pastebin.com/harAZz6s
Note that this "good" log corresponds to the log when I had to type my session password to log in (lightdm would open my session and then close it almost immediately; I would then type my password and log in successfully).
I wonder how nouveau can create this issue; as far as I know, it's a zero-configuration driver. If we can identify the bug, I could report it.

Last edited by thefiercerabbit (2021-03-24 11:44:35)

seth · 2021-03-24 14:25:12

In case of the "good" xorg log, the nouveau ddx driver is operating the nvidia chip.
I assume it's a matter of https://wiki.archlinux.org/index.php/Ke … _KMS_start ie. "autologin" likely means to boot straight into the session and the nvidia chip isn't fully initialized by the nouveau kernel module at that time, causing it to be operated by the modesetting driver and that may fail either (and likely) because the chip isn't ready or some deficiency in its interaction w/ the nouveau kms.

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

Arch Linux

#1 2021-03-23 16:49:12

[SOLVED] Lightdm autologin and Xorg signal 6

#2 2021-03-24 08:10:09

Re: [SOLVED] Lightdm autologin and Xorg signal 6

#3 2021-03-24 10:52:20

Re: [SOLVED] Lightdm autologin and Xorg signal 6

#4 2021-03-24 14:25:12

Re: [SOLVED] Lightdm autologin and Xorg signal 6

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