Bug 428748

Summary:	If there is no sound device, plasma_session crashes in Phonon::Factory::backend() on login
Product:	[Unmaintained] phonon-backend-gstreamer	Reporter:	tildearrow <tildearrow>
Component:	general	Assignee:	Unassigned bugs mailing-list <unassigned-bugs>
Status:	RESOLVED WORKSFORME
Severity:	crash	CC:	dvratil, myriam, nate, plasma-bugs, romain.perier, sitter, tdfischer
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description tildearrow 2020-11-06 02:14:10 UTC

SUMMARY
If there is no sound device, plasma_session crashes on login. It has more chance of happening if you have set a login sound in Plasma.

BACKTRACE
Application: plasma_session (plasma_session), signal: Segmentation fault

[New LWP 245567]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
0x00007f6be1bc6db0 in __lll_lock_wait () from /usr/lib/libpthread.so.0
[Current thread is 1 (Thread 0x7f6bde88f840 (LWP 245398))]

Thread 2 (Thread 0x7f6bddb2e640 (LWP 245567)):
[KCrash Handler]
#4  0x00007f6be340b090 in QObject::thread() const () at /usr/lib/libQt5Core.so.5
#5  0x00007f6bdd3171d1 in  () at /usr/lib/qt/plugins/phonon4qt5_backend/phonon_gstreamer.so
#6  0x00007f6be33e42ad in qAddPreRoutine(void (*)()) () at /usr/lib/libQt5Core.so.5
#7  0x00007f6be3b172de in call_init.part () at /lib64/ld-linux-x86-64.so.2
#8  0x00007f6be3b173c8 in _dl_init () at /lib64/ld-linux-x86-64.so.2
#9  0x00007f6be2eb60e5 in _dl_catch_exception () at /usr/lib/libc.so.6
#10 0x00007f6be3b1b705 in dl_open_worker () at /lib64/ld-linux-x86-64.so.2
#11 0x00007f6be2eb6088 in _dl_catch_exception () at /usr/lib/libc.so.6
#12 0x00007f6be3b1af3e in _dl_open () at /lib64/ld-linux-x86-64.so.2
#13 0x00007f6be13d034c in  () at /usr/lib/libdl.so.2
#14 0x00007f6be2eb6088 in _dl_catch_exception () at /usr/lib/libc.so.6
#15 0x00007f6be2eb6153 in _dl_catch_error () at /usr/lib/libc.so.6
#16 0x00007f6be13d0b89 in  () at /usr/lib/libdl.so.2
#17 0x00007f6be13d03d8 in dlopen () at /usr/lib/libdl.so.2
#18 0x00007f6be33dc9a9 in  () at /usr/lib/libQt5Core.so.5
#19 0x00007f6be33d6326 in  () at /usr/lib/libQt5Core.so.5
#20 0x00007f6be33d6913 in  () at /usr/lib/libQt5Core.so.5
#21 0x00007f6be33c7878 in QPluginLoader::load() () at /usr/lib/libQt5Core.so.5
#22 0x00007f6be36ac446 in  () at /usr/lib/libphonon4qt5.so.4
#23 0x00007f6be36add08 in  () at /usr/lib/libphonon4qt5.so.4
#24 0x00007f6be36ae1ae in Phonon::Factory::backend(bool) () at /usr/lib/libphonon4qt5.so.4
#25 0x00007f6be36ae7f7 in  () at /usr/lib/libphonon4qt5.so.4
#26 0x00007f6be36a3a5d in  () at /usr/lib/libphonon4qt5.so.4
#27 0x00007f6be36a1b48 in  () at /usr/lib/libphonon4qt5.so.4
#28 0x0000560dc4118ac5 in  ()
#29 0x00007f6be31fae8f in  () at /usr/lib/libQt5Core.so.5
#30 0x00007f6be1bbd3e9 in start_thread () at /usr/lib/libpthread.so.0
#31 0x00007f6be2e7b293 in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f6bde88f840 (LWP 245398)):
#0  0x00007f6be1bc6db0 in __lll_lock_wait () at /usr/lib/libpthread.so.0
#1  0x00007f6be1bbf7d1 in pthread_mutex_lock () at /usr/lib/libpthread.so.0
#2  0x00007f6be3b17537 in _dl_fini () at /lib64/ld-linux-x86-64.so.2
#3  0x00007f6be2dbadb7 in __run_exit_handlers () at /usr/lib/libc.so.6
#4  0x00007f6be2dbaf5e in  () at /usr/lib/libc.so.6
#5  0x00007f6be2da3159 in __libc_start_main () at /usr/lib/libc.so.6
#6  0x0000560dc41110ce in  ()
[Inferior 1 (process 245398) detached]

Ugh, how I wish Arch Linux had a debug symbols option....

STEPS TO REPRODUCE
1. Log in. It's random, and happens 1/1000 times. Hard to reproduce.

OBSERVED RESULT
Crash handler as soon as the login logo goes away.

EXPECTED RESULT
Nothing.

SOFTWARE/OS VERSIONS
Windows: None
macOS: None
Linux/KDE Plasma: 5.4.61-rt37-1-rt-lts #1 SMP PREEMPT_RT Sat, 12 Sep 2020 21:01:23 +0000 x86_64 GNU/Linux
(available in About System)
KDE Plasma Version: 5.20.1
KDE Frameworks Version: 5.75.0
Qt Version: 5.15.1

ADDITIONAL INFORMATION
You need to disable PulseAudio autospawn and use JACK configured to auto-start on login using Cadence.
Trying to reproduce on 5.20.2 would take years, honestly. It's a very very rare bug.
I totally forgot how did I set JACK up to run on startup...

Comment 1 Nate Graham 2021-02-23 23:39:35 UTC

crashing somewhere in phonon, gross.

Comment 2 Harald Sitter 2021-02-24 09:19:39 UTC

Unfortunately that backtrace is fairly useless -> https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Backtraces

Comment 3 Bug Janitor Service 2021-03-11 04:33:36 UTC

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

Comment 4 Bug Janitor Service 2021-03-26 04:33:42 UTC

This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!

Comment 5 tildearrow 2021-03-26 05:13:11 UTC

(In reply to Harald Sitter from comment #2)
> Unfortunately that backtrace is fairly useless ->
> https://community.kde.org/Guidelines_and_HOWTOs/Debugging/
> How_to_create_useful_crash_reports#Backtraces

Unfortunately, I do not have any time to recompile the entirety of KDE and Qt in order to reproduce a bug that happens once every 3 months.
I am very sorry.