Bug 476412 - Display freezes when disconnecting to Lenovo Thunderbolt 4 dock
Summary: Display freezes when disconnecting to Lenovo Thunderbolt 4 dock
Status: RESOLVED UPSTREAM
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (show other bugs)
Version: 5.27.9
Platform: Neon Linux
: NOR major
Target Milestone: ---
Assignee: KWin default assignee
URL: https://gitlab.freedesktop.org/xorg/x...
Keywords: multiscreen, wayland
Depends on:
Blocks:
 
Reported: 2023-11-01 12:41 UTC by Lassi Väätämöinen
Modified: 2023-11-15 22:46 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In: xwayland-22.1.2


Attachments
Log from the dock connect - disconnect - reconnect - REISUB-boot (482.76 KB, text/plain)
2023-11-01 12:41 UTC, Lassi Väätämöinen
Details
HDMI cable disconnected, XWayland crashed (169.85 KB, text/plain)
2023-11-07 10:16 UTC, Lassi Väätämöinen
Details
XWayland GDB trace of the crash (61.43 KB, text/plain)
2023-11-14 16:15 UTC, Lassi Väätämöinen
Details
XWayland GDB trace of the crash (83.53 KB, text/plain)
2023-11-14 16:24 UTC, Lassi Väätämöinen
Details

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Description Lassi Väätämöinen 2023-11-01 12:41:34 UTC
Created attachment 162792 [details]
Log from the dock connect - disconnect - reconnect - REISUB-boot

SUMMARY
When disconnecting Lenovo P15 Gen2 laptop from the dock and reconnecting, the internal display freezes and the only way to rememdy is either a Alt + SysReq + "REISUB", or a hard reset.  


STEPS TO REPRODUCE
1. Setup Lenovo TB4 Dock with two displays (DP + USB-C as the only working combination..) 
2. Connect Lenovo P15 laptop, observe two external displays working properly
3. Disconnect from dock
4. Reconnect to dock

OBSERVED RESULT
Nothing displayed on external displays, laptop internal display frozen
Sometimes this  happens already when disconnecting from the dock (step 3.)

EXPECTED RESULT
External displays should work properly, as they did in the first dock connection. Disconnecting once more and the  internal display should work.

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.27
KDE Plasma Version: 5.27.9
KDE Frameworks Version: 5.111.0
Qt Version: 5.15.11
Kernel Version: 6.2.0-33-generic (64-bit)
Graphics Platform: Wayland
Processors: 16 × 11th Gen Intel® Core™ i7-11850H @ 2.50GHz
Memory: 46,7 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics
Manufacturer: LENOVO
Product Name: 20YRS21300
System Version: ThinkPad P15 Gen 2i

ADDITIONAL INFORMATION
NVIDIA Driver Version: 535.113.01
Comment 1 Lassi Väätämöinen 2023-11-01 13:04:21 UTC
Particularly annoying, when I need to daily disconnect the laptop from the dock for meetings etc., and all work apps need to be reopened and setup.


Upon disconnect, there is a Wayland segfault, but I think at this point the laptop internal display still works:

marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE)
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) Backtrace:
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 0: /usr/bin/Xwayland (0x555e01857000+0x1651c9) [0x555e019bc1c9]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 1: /usr/bin/Xwayland (0x555e01857000+0x1652d2) [0x555e019bc2d2]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7fd1f2800000+0x42520) [0x7fd1f2842520]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 3: /usr/bin/Xwayland (0x555e01857000+0x39389) [0x555e01890389]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 4: /lib/x86_64-linux-gnu/libffi.so.8 (0x7fd1f2ae6000+0x7e2e) [0x7fd1f2aede2e]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 5: /lib/x86_64-linux-gnu/libffi.so.8 (0x7fd1f2ae6000+0x4493) [0x7fd1f2aea493]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 6: /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x7fd1f3059000+0x6b20) [0x7fd1f305fb20]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 7: /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x7fd1f3059000+0x72c3) [0x7fd1f30602c3]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 8: /lib/x86_64-linux-gnu/libwayland-client.so.0 (wl_display_dispatch_queue_pending+0x7c) [0x7fd1f30604bc]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 9: /usr/bin/Xwayland (0x555e01857000+0x3e4bb) [0x555e018954bb]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 10: /usr/bin/Xwayland (0x555e01857000+0x166901) [0x555e019bd901]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 11: /usr/bin/Xwayland (0x555e01857000+0xa6cb0) [0x555e018fdcb0]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 12: /usr/bin/Xwayland (0x555e01857000+0x34c63) [0x555e0188bc63]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 13: /lib/x86_64-linux-gnu/libc.so.6 (0x7fd1f2800000+0x29d90) [0x7fd1f2829d90]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 14: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0x80) [0x7fd1f2829e40]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) 15: /usr/bin/Xwayland (0x555e01857000+0x36495) [0x555e0188d495]
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE)
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) Segmentation fault at address 0x41
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE)
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: Fatal server error:
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE) Caught signal 11 (Segmentation fault). Server aborting
marras 01 14:02:50 mopo kwin_wayland_wrapper[2439]: (EE)
marras 01 14:02:50 mopo kded5[3065]: X connection to :1 broken (explicit kill or server shutdown).
marras 01 14:02:50 mopo chrome[3422]: The X11 connection broke: I/O error (code 1) 

Around the time of the disconnec there is also a kernel oops, but not sure if this is related:

marras 01 14:03:15 mopo kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
marras 01 14:03:15 mopo kernel: #PF: supervisor read access in kernel mode
marras 01 14:03:15 mopo kernel: #PF: error_code(0x0000) - not-present page
marras 01 14:03:15 mopo kernel: PGD 0 P4D 0 
marras 01 14:03:15 mopo kernel: Oops: 0000 [#1] PREEMPT SMP NOPTI
marras 01 14:03:15 mopo kernel: CPU: 11 PID: 1589 Comm: kworker/u32:11 Tainted: P           O       6.2.0-33-generic #33~22.04.1-Ubuntu
marras 01 14:03:15 mopo kernel: Hardware name: LENOVO 20YRS21300/20YRS21300, BIOS N37ET46W (1.27 ) 07/12/2023
marras 01 14:03:15 mopo kernel: Workqueue: USBC000:00-con1 ucsi_poll_worker [typec_ucsi]
marras 01 14:03:15 mopo kernel: RIP: 0010:ucsi_acpi_async_write+0x31/0x60 [ucsi_acpi]
marras 01 14:03:15 mopo kernel: Code: 89 e5 41 56 49 89 ce 41 55 49 89 d5 41 54 53 89 f3 e8 73 8b 2a 00 4c 89 f2 4c 89 ee 89 df 48 03 78 10 49 89 c4 e8 7f 3c cc d8 <49> 8b 45 00 4c 89 e7 be 01 00 00 00 49 89 44 24 50 e8 b9 fc ff ff
marras 01 14:03:15 mopo kernel: RSP: 0018:ffffb685c2a37d10 EFLAGS: 00010282
marras 01 14:03:15 mopo kernel: RAX: ffffb685c00f5002 RBX: 0000000000000002 RCX: 0000000000000000
marras 01 14:03:15 mopo kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffb685c00f5002
marras 01 14:03:15 mopo kernel: RBP: ffffb685c2a37d30 R08: 0000000000000000 R09: 0000000000000000
marras 01 14:03:15 mopo kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffffa096c33074a8
marras 01 14:03:15 mopo kernel: R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000000c
marras 01 14:03:15 mopo kernel: FS:  0000000000000000(0000) GS:ffffa0a1ef6c0000(0000) knlGS:0000000000000000
marras 01 14:03:15 mopo kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
marras 01 14:03:15 mopo kernel: CR2: 0000000000000000 CR3: 0000000a80410005 CR4: 0000000000770ee0
marras 01 14:03:15 mopo kernel: PKRU: 55555554
marras 01 14:03:15 mopo kernel: Call Trace:
marras 01 14:03:15 mopo kernel:  <TASK>
marras 01 14:03:15 mopo kernel:  ? show_regs+0x72/0x90
marras 01 14:03:15 mopo kernel:  ? __die+0x25/0x80
marras 01 14:03:15 mopo kernel:  ? page_fault_oops+0x79/0x190
marras 01 14:03:15 mopo kernel:  ? do_user_addr_fault+0x30c/0x640
marras 01 14:03:15 mopo kernel:  ? exc_page_fault+0x81/0x1b0
marras 01 14:03:15 mopo kernel:  ? asm_exc_page_fault+0x27/0x30
marras 01 14:03:15 mopo kernel:  ? ucsi_acpi_async_write+0x31/0x60 [ucsi_acpi]
marras 01 14:03:15 mopo kernel:  ucsi_exec_command+0xd9/0xf0 [typec_ucsi]
marras 01 14:03:15 mopo kernel:  ucsi_send_command+0x4b/0xf0 [typec_ucsi]
marras 01 14:03:15 mopo kernel:  ucsi_register_altmodes+0xd7/0x210 [typec_ucsi]
marras 01 14:03:15 mopo kernel:  ucsi_check_altmodes+0x1c/0xb0 [typec_ucsi]
marras 01 14:03:15 mopo kernel:  ? mutex_lock+0x13/0x50
marras 01 14:03:15 mopo kernel:  ucsi_poll_worker+0x3c/0x100 [typec_ucsi]
marras 01 14:03:15 mopo kernel:  process_one_work+0x21c/0x440
marras 01 14:03:15 mopo kernel:  worker_thread+0x50/0x3f0
marras 01 14:03:15 mopo kernel:  ? __pfx_worker_thread+0x10/0x10
marras 01 14:03:15 mopo kernel:  kthread+0xeb/0x120
marras 01 14:03:15 mopo kernel:  ? __pfx_kthread+0x10/0x10
marras 01 14:03:15 mopo kernel:  ret_from_fork+0x29/0x50
marras 01 14:03:15 mopo kernel:  </TASK>
marras 01 14:03:15 mopo kernel: Modules linked in: ccm rfcomm xt_conntrack nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack_netlink nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xfrm_user xfrm_algo xt_addrtype br_netfilter bridge stp llc vboxnetadp(O) vboxnetflt(O) vboxdrv(O) xt_comment nft_compat nf_tables nfnetlink cmac algif_hash overlay algif_skcipher af_alg 
bnep binfmt_misc dm_crypt nvidia_uvm(PO) snd_ctl_led snd_soc_skl_hda_dsp snd_soc_intel_hda_dsp_common snd_soc_hdac_hdmi snd_sof_probes nvidia_drm(PO) intel_tcc_cooling nvidia_modeset(PO) snd_hda_codec_realtek x86_pkg_temp_thermal snd_hda_codec_generic intel_powerclamp coretemp snd_soc_dmic snd_sof_pci_intel_tgl kvm_intel snd_sof_intel_hda_common soundwire_int
el kvm soundwire_generic_allocation nvidia(PO) soundwire_cadence snd_sof_intel_hda snd_sof_pci snd_sof_xtensa_dsp irqbypass snd_sof snd_sof_utils snd_soc_hdac_hda snd_hda_ext_core snd_soc_acpi_intel_match snd_soc_acpi soundwire_bus snd_soc_core snd_compress snd_hda_codec_hdmi ac97_bus
marras 01 14:03:15 mopo kernel:  snd_pcm_dmaengine snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi iwlmvm snd_usb_audio snd_hda_codec btusb btrtl uvcvideo snd_hda_core snd_usbmidi_lib btbcm mac80211 videobuf2_vmalloc snd_hwdep btintel videobuf2_memops snd_seq_midi processor_thermal_device_pci_legacy libarc4 btmtk intel_rapl_msr videobuf2_v4l2 mei_hdcp mei_p
xp snd_seq_midi_event processor_thermal_device cmdlinepart videodev bluetooth snd_seq snd_rawmidi iwlwifi processor_thermal_rfim spi_nor videobuf2_common rapl joydev snd_seq_device thinkpad_acpi think_lmi snd_pcm ecdh_generic processor_thermal_mbox nls_iso8859_1 intel_cstate serio_raw input_leds mc firmware_attributes_class wmi_bmof snd_timer mtd ee1004 nvram
 ecc cfg80211 processor_thermal_rapl snd mei_me intel_rapl_common mei soundcore intel_soc_dts_iosf ledtrig_audio int3403_thermal int3400_thermal platform_profile intel_hid int340x_thermal_zone mac_hid acpi_thermal_rel acpi_tad sparse_keymap acpi_pad sch_fq_codel msr parport_pc ppdev lp parport
marras 01 14:03:15 mopo kernel:  efi_pstore ip_tables x_tables autofs4 btrfs blake2b_generic xor raid6_pq libcrc32c hid_logitech_hidpp hid_logitech_dj hid_jabra hid_generic usbhid hid i915 drm_buddy i2c_algo_bit ttm drm_display_helper cec rc_core crct10dif_pclmul drm_kms_helper crc32_pclmul polyval_clmulni polyval_generic ghash_clmulni_intel sha512_ssse3 sysc
opyarea nvme aesni_intel sysfillrect ucsi_acpi crypto_simd sysimgblt rtsx_pci_sdmmc spi_intel_pci i2c_i801 xhci_pci nvme_core cryptd typec_ucsi psmouse drm thunderbolt igc spi_intel rtsx_pci i2c_smbus xhci_pci_renesas nvme_common typec video wmi pinctrl_tigerlake
marras 01 14:03:15 mopo kernel: CR2: 0000000000000000
marras 01 14:03:15 mopo kernel: ---[ end trace 0000000000000000 ]---
Comment 2 Nate Graham 2023-11-01 21:10:10 UTC
There are similarities to Bug 476342 and Bug 476340, which I experience on Plasma 6
Comment 3 Bug Janitor Service 2023-11-07 09:07:38 UTC
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/4605
Comment 4 Lassi Väätämöinen 2023-11-07 10:16:59 UTC
Created attachment 162920 [details]
HDMI cable disconnected, XWayland crashed
Comment 5 Lassi Väätämöinen 2023-11-07 10:18:13 UTC
(In reply to Lassi Väätämöinen from comment #4)
> Created attachment 162920 [details]
> HDMI cable disconnected, XWayland crashed

Similar XWayland crash, but *not* connected to the dock. Just disconnecting the HDMI cable.

Could not provide detailed stack trace, as I could not find out which package holds the XWayland debug syms.
Comment 6 Lassi Väätämöinen 2023-11-14 14:38:15 UTC
Any advice where I could find Xwayland debug symbols?


Today reproduced this. It's actually happening at the USB dock *dis*connect, not reconnect. And there is no kernel crash/oops happening, based on syslog. But switching between VTs does not work, only Alt + SysRq + REISUB. 

Stacktrace:

marras 14 16:25:35 mopo xdg-desktop-portal-kde[2712]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo polkit-kde-authentication-agent-1[2710]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo kdeconnectd[2806]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo kactivitymanagerd[2708]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo DiscoverNotifier[2828]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo kwalletd5[2428]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo konsole[5823]: qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
marras 14 16:25:35 mopo plasmashell[3568]: [3563:3563:1114/162535.833152:ERROR:browser_main_loop.cc(276)] Gdk: gdk_monitor_get_scale_factor: assertion 'GDK_IS_MONITOR (monitor)' failed
marras 14 16:25:35 mopo plasmashell[3568]: [3563:3563:1114/162535.834401:ERROR:browser_main_loop.cc(276)] Gdk: gdk_monitor_get_scale_factor: assertion 'GDK_IS_MONITOR (monitor)' failed
marras 14 16:25:35 mopo plasmashell[3568]: [3563:3563:1114/162535.834965:ERROR:browser_main_loop.cc(276)] Gdk: gdk_monitor_get_scale_factor: assertion 'GDK_IS_MONITOR (monitor)' failed
marras 14 16:25:35 mopo kwin_wayland[2467]: kwin_core: Could not find window with uuid "{5835e9bf-659a-4c7e-8029-b4abd44bf5d3}"
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE)
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) Backtrace:
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 0: /usr/bin/Xwayland (0x559dc7e16000+0x1651c9) [0x559dc7f7b1c9]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 1: /usr/bin/Xwayland (0x559dc7e16000+0x1652d2) [0x559dc7f7b2d2]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7f96ea600000+0x42520) [0x7f96ea642520]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 3: /usr/bin/Xwayland (0x559dc7e16000+0x39389) [0x559dc7e4f389]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 4: /lib/x86_64-linux-gnu/libffi.so.8 (0x7f96ea89c000+0x7e2e) [0x7f96ea8a3e2e]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 5: /lib/x86_64-linux-gnu/libffi.so.8 (0x7f96ea89c000+0x4493) [0x7f96ea8a0493]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 6: /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x7f96eae0f000+0x6b20) [0x7f96eae15b20]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 7: /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x7f96eae0f000+0x72c3) [0x7f96eae162c3]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 8: /lib/x86_64-linux-gnu/libwayland-client.so.0 (wl_display_dispatch_queue_pending+0x7c) [0x7f96eae164bc]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 9: /usr/bin/Xwayland (0x559dc7e16000+0x3e4bb) [0x559dc7e544bb]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 10: /usr/bin/Xwayland (0x559dc7e16000+0x166901) [0x559dc7f7c901]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 11: /usr/bin/Xwayland (0x559dc7e16000+0xa6cb0) [0x559dc7ebccb0]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 12: /usr/bin/Xwayland (0x559dc7e16000+0x34c63) [0x559dc7e4ac63]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 13: /lib/x86_64-linux-gnu/libc.so.6 (0x7f96ea600000+0x29d90) [0x7f96ea629d90]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 14: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0x80) [0x7f96ea629e40]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) 15: /usr/bin/Xwayland (0x559dc7e16000+0x36495) [0x559dc7e4c495]
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE)
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) Segmentation fault at address 0x10
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE)
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: Fatal server error:
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE) Caught signal 11 (Segmentation fault). Server aborting
marras 14 16:25:35 mopo kwin_wayland_wrapper[2533]: (EE)
marras 14 16:25:35 mopo kded5[3200]: X connection to :1 broken (explicit kill or server shutdown).
marras 14 16:25:35 mopo chrome[3563]: The X11 connection broke: I/O error (code 1)
marras 14 16:25:35 mopo plasmashell[3568]: XIO:  fatal IO error 25 (Inappropriate ioctl for device) on X server ":1"
marras 14 16:25:35 mopo plasmashell[3568]:       after 375 requests (375 known processed) with 10 events remaining.
marras 14 16:25:35 mopo plasmashell[3568]: [3636:3636:1114/162535.852529:ERROR:connection.cc(46)] X connection error received.
marras 14 16:25:35 mopo gmenudbusmenuproxy[2709]: failed to get the primary output of the screen
marras 14 16:25:35 mopo gmenudbusmenuproxy[2709]: failed to get the primary output of the screen
marras 14 16:25:35 mopo gmenudbusmenuproxy[2709]: The X11 connection broke (error 1). Did the X11 server die?
Comment 7 Lassi Väätämöinen 2023-11-14 15:12:37 UTC
(In reply to Lassi Väätämöinen from comment #6)
> Any advice where I could find Xwayland debug symbols?

OK, figured it out:

sudo apt install neon-repositories-ubuntu-ddebs
sudo apt install xwayland-dbgsym


With symbols installed, I got the stacktrace:

ras 14 17:08:25 mopo plasmashell[3818]: [3813:3813:1114/170825.636074:ERROR:browser_main_loop.cc(276)] Gdk: gdk_monitor_get_scale_factor: assertion 'GDK_IS_MONITOR (monitor)' failed
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE)
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) Backtrace:
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 0: /usr/bin/Xwayland (0x5560c6a6a000+0x1651c9) [0x5560c6bcf1c9]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 1: /usr/bin/Xwayland (0x5560c6a6a000+0x1652d2) [0x5560c6bcf2d2]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7ffa16a00000+0x42520) [0x7ffa16a42520]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 3: /usr/bin/Xwayland (0x5560c6a6a000+0x39389) [0x5560c6aa3389]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 4: /lib/x86_64-linux-gnu/libffi.so.8 (0x7ffa16913000+0x7e2e) [0x7ffa1691ae2e]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 5: /lib/x86_64-linux-gnu/libffi.so.8 (0x7ffa16913000+0x4493) [0x7ffa16917493]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 6: /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x7ffa170af000+0x6b20) [0x7ffa170b5b20]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 7: /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x7ffa170af000+0x72c3) [0x7ffa170b62c3]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 8: /lib/x86_64-linux-gnu/libwayland-client.so.0 (wl_display_dispatch_queue_pending+0x7c) [0x7ffa170b64bc]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 9: /usr/bin/Xwayland (0x5560c6a6a000+0x3e4bb) [0x5560c6aa84bb]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 10: /usr/bin/Xwayland (0x5560c6a6a000+0x166901) [0x5560c6bd0901]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 11: /usr/bin/Xwayland (0x5560c6a6a000+0xa6cb0) [0x5560c6b10cb0]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 12: /usr/bin/Xwayland (0x5560c6a6a000+0x34c63) [0x5560c6a9ec63]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 13: /lib/x86_64-linux-gnu/libc.so.6 (0x7ffa16a00000+0x29d90) [0x7ffa16a29d90]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 14: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0x80) [0x7ffa16a29e40]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) 15: /usr/bin/Xwayland (0x5560c6a6a000+0x36495) [0x5560c6aa0495]
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE)
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) Segmentation fault at address 0x10
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE)
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: Fatal server error:
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE) Caught signal 11 (Segmentation fault). Server aborting
marras 14 17:08:25 mopo kwin_wayland_wrapper[2753]: (EE)
Comment 8 Lassi Väätämöinen 2023-11-14 15:24:39 UTC
Hm, even though debug syms are installed, the stack trace remains the same...
Comment 9 Lassi Väätämöinen 2023-11-14 16:15:28 UTC
Created attachment 163154 [details]
XWayland GDB trace of the crash

Taken with:

echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
sudo gdb -pid $(pidof Xwayland) -batch -ex "set logging file Xwayland.gdb" -ex "set logging enabled" -ex "continue" -ex "thread apply all backtrace" -ex "quit"
Comment 10 Lassi Väätämöinen 2023-11-14 16:24:40 UTC
Created attachment 163155 [details]
XWayland GDB trace of the crash
Comment 11 Zamundaaa 2023-11-14 16:59:01 UTC
What version of Xwayland is that backtrace for?
Comment 12 Lassi Väätämöinen 2023-11-14 17:36:53 UTC
(In reply to Zamundaaa from comment #11)
> What version of Xwayland is that backtrace for?

XWayland 22.1
Comment 13 Lassi Väätämöinen 2023-11-14 17:42:52 UTC
(In reply to Lassi Väätämöinen from comment #12)
> (In reply to Zamundaaa from comment #11)
> > What version of Xwayland is that backtrace for?
> 
> XWayland 22.1

Ah, to be exact: in KDE Neon User edition: 
2:22.1.1-1ubuntu0.7
Comment 14 Zamundaaa 2023-11-14 17:47:36 UTC
hmm, I don't see what could be wrong there. Please report that crash to https://gitlab.freedesktop.org/xorg/xserver/-/issues, hopefully someone knows what's going on there