Session window disappears when connecting to KDE

[doertel]

I have also the problem that after update from 22.04 to 24.04 with KDE the nxplayer crashes. The machine on which this problem appears has a nvidia NVIDIA GeForce GT 710/PCIe/SSE2. The problem appears not with the X.org nouveau driver but with the nvidia-driver-470 package “Enable hardware accelerated decoding” false or disabled do not change anything. The connection starts, password is accepted and than the session window disappears without any message. The syslog says nxplayer.bin has crashed. Any idea ?

NoMachine 8.14.2 (and before) freeversion, connecting to a physical Linux or macOS machine

uname -a
Linux sepia 6.8.0-45-generic #45-Ubuntu SMP PREEMPT_DYNAMIC Fri Aug 30 12:02:04 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

Attachments:

1. nxclient.zip
2. nxsyslog.log_.gz

[doertel]

After

sudo /usr/NX/bin/nxserver –eglcapture yes
[sudo] Passwort für detlef:
NX> 900 EnableEGLCapture key set to: 1.
NX> 900 Enabled EGL screen capture in ‘/usr/lib/x86_64-linux-gnu/libexec/plasma-dbus-run-session-if-needed’.

I still have the same behavior.
syslog:
2024-10-04T12:35:41.285050+02:00 sepia kernel: nxplayer.bin[200815]: segfault at 0 ip 0000000000000000 sp 000071d0fcdff5f8 error 14 in nxplayer.bin[400000+63d000] likely on CPU 8 (core 2, s
ocket 0)
2024-10-04T12:35:41.285062+02:00 sepia kernel: Code: Unable to access opcode bytes at 0xffffffffffffffd6.
2024-10-04T12:37:03.178268+02:00 sepia systemd[7080]: app-NoMachine\x2dbase-c4e1f44c4565493bb1a9405231314ceb.scope: Consumed 4.224s CPU time.

any further idea ?

[Britgirl]

I have split your issue to create a new topic as it looks to be a totally different problem. (old topic is https://forum.nomachine.com/topic/after-upgrade-to-ubuntu-24-04-1-lts-players-immediately-disconnects/page/2).

Can you look for core files of the nxplayer and submit the backtrace?

[doertel]

Hi,

I hope this is what you mean with backtrace :

root@sepia:/var/log# gdb /usr/NX/bin/nxplayer.bin /var/lib/apport/coredump/core._usr_NX_bin_nxplayer_bin.1000.d8a09b5a-40cf-43fe-9a56-7b5e1c51c2d0.461137.2941256
GNU gdb (Ubuntu 15.0.50.20240403-0ubuntu1) 15.0.50.20240403-git
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Reading symbols from /usr/NX/bin/nxplayer.bin…
(No debugging symbols found in /usr/NX/bin/nxplayer.bin)

warning: Can’t open file /memfd:/.glXXXXXX (deleted) during file-backed mapping note processing

warning: Can’t open file /memfd:/.nvidia_drv.XXXXXX (deleted) during file-backed mapping note processing
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–Type for more, q to quit, c to continue without paging–
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warning: could not find ‘.gnu_debugaltlink’ file for /lib/x86_64-linux-gnu/libpulse.so.0

warning: could not find ‘.gnu_debugaltlink’ file for /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-16.1.so

warning: could not find ‘.gnu_debugaltlink’ file for /lib/x86_64-linux-gnu/libcap.so.2
[Thread debugging using libthread_db enabled]
Using host libthread_db library “/lib/x86_64-linux-gnu/libthread_db.so.1”.
Core was generated by `/usr/NX/bin/nxplayer.bin –session /home/detlef/.nx/cache/d8f21156-8652-4186-a6′.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x0000000000000000 in ?? ()
[Current thread is 1 (Thread 0x78f22be006c0 (LWP 461301))]
(gdb)

By the way:
The problem occurs not only when I connect to a KDE machine. It is the same while connecting to macOS box or a Windows. I
So I think it is completely a client side problem which is related to the nvidia graphic driver

Can I do anything else ?
Thanks

detlef

[fra81]

Hi Detlef,

Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x0000000000000000 in ?? ()
[Current thread is 1 (Thread 0x78f22be006c0 (LWP 461301))]
(gdb)

When you get to that point in gdb, please type the ‘bt’ command and show us the output.

“Enable hardware accelerated decoding” false or disabled do not change anything.

Did you change the key to ‘disabled’ after quitting the NoMachine player? Here are more details on how to set it: https://kb.nomachine.com/AR07U01202. Please make sure it is set to ‘disabled’ rather than ‘false’.

[doertel]

Hi,
here is the gdb output:

Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x0000000000000000 in ?? ()
[Current thread is 1 (Thread 0x7785554006c0 (LWP 185065))]
(gdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x0000778529c02357 in vaDisplayIsValid () from /lib/x86_64-linux-gnu/libva.so.1
#2 0x0000778529c03839 in vaInitialize () from /lib/x86_64-linux-gnu/libva.so.1
#3 0x000077857244a0b9 in VADecoder::openDisplayDRM() () from /usr/NX/lib/libnxcim.so
#4 0x000077857244a289 in VADecoder::openDisplay() () from /usr/NX/lib/libnxcim.so
#5 0x000077857244a8b3 in VADecoder::initialize() () from /usr/NX/lib/libnxcim.so
#6 0x000077857244a9ad in VADecoder::preinitialize(_NXVideoContext*, VALibrary*) () from /usr/NX/lib/libnxcim.so
#7 0x000077857244f1f7 in VAUnpackInit(_NXVideoContext*) () from /usr/NX/lib/libnxcim.so
#8 0x000077857244f559 in VATestDecode() () from /usr/NX/lib/libnxcim.so
#9 0x000077857244f5fd in VALoadLibrary() () from /usr/NX/lib/libnxcim.so
#10 0x0000778572452083 in AVCCodecFunctions::AVCLoadVA() () from /usr/NX/lib/libnxcim.so
#11 0x00007785724584aa in AVCCodecFunctions::AVCSupportedMethods(int, int) () from /usr/NX/lib/libnxcim.so
#12 0x0000778571ee2ab1 in ServerChannel::handleEncode(ChannelEncoder*, unsigned char const*, unsigned int) () from /usr/NX/lib/libnxc.so
#13 0x0000778571e9af19 in ChannelBase::dataMessage(char*, int) () from /usr/NX/lib/libnxc.so
#14 0x00007785718c2708 in Reader::consumeMessage(int&) () from /usr/NX/lib/libnx.so
#15 0x00007785718c2f46 in Reader::readMessage() () from /usr/NX/lib/libnx.so
#16 0x00007785718888fe in DispatchFdList::callRunnables(IoRecord const*) () from /usr/NX/lib/libnx.so
#17 0x000077857189ff51 in Dispatcher::innerDispatch() () from /usr/NX/lib/libnx.so
#18 0x00007785718a0e88 in Dispatcher::innerLoop() () from /usr/NX/lib/libnx.so
#19 0x00007785718a10d0 in Dispatcher::dispatch(int) () from /usr/NX/lib/libnx.so
#20 0x00007785718f1a5c in Threadable::loop(void*) () from /usr/NX/lib/libnx.so
#21 0x000077856c49ca94 in start_thread (arg=) at ./nptl/pthread_create.c:447
#22 0x000077856c529c3c in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
(gdb)

Yes – I missed to close the player completely.
With:

"Enable hardware accelerated decoding" value="disabled"

there is no more crash. So the core dump above was made with:

"Enable hardware accelerated decoding" value="true"

Thanks.
Can I do any thing else for you ?
detlef

[Britgirl]

Can you also send us the output of this command on the player side?

for DEVNAME in /dev/dri/* ; do LIBVA_DRIVER_NAME=nvidia vainfo --display drm --device $DEVNAME ; done

[doertel]

Hi,
here is the output:


root@sepia:/home/detlef# for DEVNAME in /dev/dri/* ; do LIBVA_DRIVER_NAME=nvidia vainfo --display drm --device $DEVNAME ; done
Failed to open the given device!
libva info: VA-API version 1.20.0
libva info: User environment variable requested driver 'nvidia'
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so
libva info: Found init function __vaDriverInit_1_0
Speicherzugriffsfehler (Speicherabzug geschrieben)
libva info: VA-API version 1.20.0
libva info: User environment variable requested driver 'nvidia'
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/nvidia_drv_video.so
libva info: Found init function __vaDriverInit_1_0
Speicherzugriffsfehler (Speicherabzug geschrieben)


“Speicherzugriffsfehler (Speicherabzug geschrieben)” means: “Access Violation – crash dump written”

Can I do any thing else for you ?
detlef

[Britgirl]

Thanks for the additional info. Your output shows that it is not a NoMachine issue but that your vainfo command segfaults. Keep hardware decoding disabled and you should be ok.

[Author]

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