Recent changes have caused Xorg to fail to start. Possibly nvidia driver related.

[Lucy Llewellyn]

I am unsure where the problem stems, but changes since the 25th have caused my system to fail to initialise the Xorg display. The console remains operational for debugging. I am currently using ZFS snapshots to use the system as it was on the 25th of March 2020 because that is the last snapshot before this issue.

This bug was captured using ubuntu-bug when booted into the broken (i.e. not working) latest snapshot of my filesystem.

The versions of packages from the not broken (i.e. correctly working) earlier snapshot of my filesystem are:

libnvidia-cfg1-440:amd64 440.64-0ubuntu2
libnvidia-common-440 440.64-0ubuntu2
libnvidia-compute-440:amd64 440.64-0ubuntu2
libnvidia-compute-440:i386 440.64-0ubuntu2
libnvidia-decode-440:amd64 440.64-0ubuntu2
libnvidia-decode-440:i386 440.64-0ubuntu2
libnvidia-encode-440:amd64 440.64-0ubuntu2
libnvidia-encode-440:i386 440.64-0ubuntu2
libnvidia-fbc1-440:amd64 440.64-0ubuntu2
libnvidia-fbc1-440:i386 440.64-0ubuntu2
libnvidia-gl-440:amd64 440.64-0ubuntu2
libnvidia-gl-440:i386 440.64-0ubuntu2
libnvidia-ifr1-440:amd64 440.64-0ubuntu2
libnvidia-ifr1-440:i386 440.64-0ubuntu2
nvidia-compute-utils-440 440.64-0ubuntu2
nvidia-dkms-440 440.64-0ubuntu2
nvidia-driver-440 440.64-0ubuntu2
nvidia-kernel-common-440 440.64-0ubuntu2
nvidia-kernel-source-440 440.64-0ubuntu2
nvidia-prime 0.8.14
nvidia-settings 440.64-0ubuntu1
nvidia-utils-440 440.64-0ubuntu2
xserver-xorg-video-nvidia-440 440.64-0ubuntu2

$ lsb_release -rd
Description: Ubuntu Focal Fossa (development branch)
Release: 20.04

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-18.22-generic 5.4.24
Uname: Linux 5.4.0-18-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
.proc.driver.nvidia.gpus.0000.01.00.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0000:01:00.0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.suspend: suspend hibernate resume
.proc.driver.nvidia.suspend_depth: default modeset uvm
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 440.64 Fri Feb 21 01:17:26 UTC 2020
 GCC version: gcc version 9.3.0 (Ubuntu 9.3.0-3ubuntu1)
ApportVersion: 2.20.11-0ubuntu21
Architecture: amd64
Date: Mon Mar 30 15:49:12 2020
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus: nvidia, 440.64, 5.4.0-18-generic, x86_64: installed
ExtraDebuggingInterest: Yes
InstallationDate: Installed on 2020-03-03 (26 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Alpha amd64 (20200303)
MachineType: Gigabyte Technology Co., Ltd. Z170X-UD5 TH
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=linux
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/BOOT/ubuntu_7176ku@/vmlinuz-5.4.0-18-generic root=ZFS=rpool/ROOT/ubuntu_7176ku ro quiet splash intel_iommu=on vt.handoff=1
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/09/2018
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F22g
dmi.board.asset.tag: Default string
dmi.board.name: Z170X-UD5 TH-CF
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: Default string
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF22g:bd03/09/2018:svnGigabyteTechnologyCo.,Ltd.:pnZ170X-UD5TH:pvrDefaultstring:rvnGigabyteTechnologyCo.,Ltd.:rnZ170X-UD5TH-CF:rvrDefaultstring:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: Default string
dmi.product.name: Z170X-UD5 TH
dmi.product.sku: Default string
dmi.product.version: Default string
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.100-4
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.2-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 20.0.2-1ubuntu1
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.7-2ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20190815-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Daniel van Vugt (vanvugt)]

Yes it's a crash but the stack trace in the log is confused:

[ 411.772] (EE) Backtrace:
[ 411.772] (EE) 0: /usr/lib/xorg/Xorg (OsLookupColor+0x13c) [0x55cd86b5fd2c]
[ 411.772] (EE) 1: /lib/x86_64-linux-gnu/libpthread.so.0 (funlockfile+0x60) [0x7f3b483c341f]
[ 411.773] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (gsignal+0xcb) [0x7f3b4820018b]
[ 411.773] (EE) 3: /lib/x86_64-linux-gnu/libc.so.6 (abort+0x12b) [0x7f3b481df859]
[ 411.773] (EE) unw_get_proc_name failed: no unwind info found [-10]
[ 411.773] (EE) 4: /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so (?+0x0) [0x7f3b42d54375]
[ 411.774] (EE) 5: /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so (nouveau_drm_screen_create+0x203457) [0x7f3b439462f7]
[ 411.774] (EE) 6: /usr/lib/x86_64-linux-gnu/dri/radeonsi_dri.so (__driDriverGetExtensions_zink+0x24ee8) [0x7f3b42da45c8]

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It sounds like some part of the system has crashed. To help us find the cause of the crash please follow these steps:

1. Look in /var/crash for crash files and if found run:
    ubuntu-bug YOURFILE.crash
Then tell us the ID of the newly-created bug.

2. If step 1 failed then look at https://errors.ubuntu.com/user/ID where ID is the content of file /var/lib/whoopsie/whoopsie-id on the machine. Do you find any links to recent problems on that page? If so then please send the links to us.

3. If step 2 also failed then apply the workaround from bug 994921, reboot, reproduce the crash, and retry step 1.

Please take care to avoid attaching .crash files to bugs as we are unable to process them as file attachments. It would also be a security risk for yourself.

[Lucy Llewellyn (lucyllewy)]

I've submitted it as bug #1869882

[Lucy Llewellyn (lucyllewy)]

It looks like the stacktrace mentions AMDGPU related functions. For the record, I have three graphics devices in this box currently, one from each vendor to allow easily testing apps on each: nVidia, AMD, and Intel. The displays are currently only connected to the nVidia card's outputs.

[Lucy Llewellyn (lucyllewy)]

Possible smoking gun: removing `intel_iommu=on` from the grub commandline successfully brings up gui desktop on boot.

[Sebastien Bacher (seb128)]

could you make bug #1869882 public if it has no private information? (either it's private or a wrong reference?)

[Lucy Llewellyn (lucyllewy)]

it's the correct reference, but I don't know whether it contains sensitive info or not.

[Lucy Llewellyn (lucyllewy)]

There are two whoopsies that my system has submitted, too:

https://errors.ubuntu.com/oops/51e0231a-7138-11ea-98c4-fa163e102db1
https://errors.ubuntu.com/oops/5f9c714a-7352-11ea-aaf5-fa163e983629

[Lucy Llewellyn (lucyllewy)]

OK, I've flipped it public. I had a browse through the attachments and my untrained eye can't see anything glaringly secret, so have at it :-)

[Sebastien Bacher (seb128)]

@diddledan, one of those errors are in the radeon driver and the other one in the iris one

[Martin Wimpress  (flexiondotorg)]

Marked at "Won't Fix". If anyone can provide a reproducer and evidence this is still an issue we can re-open it.