Bug#979343: sddm: general protection fault in libQt5Qml.so.5.15.2

[Helge Kreutzmann]

Package: sddm
Version: 0.19.0-2
Severity: minor

Since a few days I see a generla protection fault of sddm in the logs.
Visually I haven't experienced any problems.

Lokal2020:Dec 27 22:29:53 samd kernel: [60297.066744] traps: sddm-greeter[878993] general protection fault ip:7f24d859c117 sp:7ffd57370af0 error:0 in libQt5Qml.so.5.15.2[7f24d8368000+2cd000]
Lokal2020:Dec 28 16:50:43 samd kernel: [ 25.089195] traps: sddm-greeter[1973] general protection fault ip:7fced8f24117 sp:7ffdb789f6b0 error:0 in libQt5Qml.so.5.15.2[7fced8cf0000+2cd000]
Lokal2020:Dec 29 07:53:19 samd kernel: [ 27.111068] traps: sddm-greeter[2007] general protection fault ip:7f98a68f4117 sp:7ffd06c48910 error:0 in libQt5Qml.so.5.15.2[7f98a66c0000+2cd000]
Lokal2020:Dec 31 06:47:22 samd kernel: [ 22.424780] traps: sddm-greeter[2007] general protection fault ip:7fb9e35cc117 sp:7ffec91b68d0 error:0 in libQt5Qml.so.5.15.2[7fb9e3398000+2cd000]
Lokal2020:Dec 31 10:37:32 samd kernel: [ 21.637736] traps: sddm-greeter[1940] general protection fault ip:7f2f470fc117 sp:7ffcd3102140 error:0 in libQt5Qml.so.5.15.2[7f2f46ec8000+2cd000]
Lokal2021:Jan 2 06:52:23 samd kernel: [ 24.511501] traps: sddm-greeter[2010] general protection fault ip:7f8865d54117 sp:7ffd10a64db0 error:0 in libQt5Qml.so.5.15.2[7f8865b20000+2cd000]
Lokal2021:Jan 3 06:35:52 samd kernel: [ 26.690626] traps: sddm-greeter[2013] general protection fault ip:7fcb47dbc117 sp:7ffc5c156f40 error:0 in libQt5Qml.so.5.15.2[7fcb47b88000+2cd000]
Lokal2021:Jan 4 11:19:49 samd kernel: [ 18.897536] traps: sddm-greeter[1979] general protection fault ip:7f1f25f4c117 sp:7ffdefa30b80 error:0 in libQt5Qml.so.5.15.2[7f1f25d18000+2cd000]

If this is harmelss, could you add an appropriate logcheck rule, so
that this no longer appears in the logs?


-- System Information:
Debian Release: bullseye/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel taint flags: TAINT_UNSIGNED_MODULE
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to de_DE.UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages sddm depends on:
ii adduser 3.118
ii debconf [debconf-2.0] 1.5.74
ii libc6 2.31-6
ii libgcc-s1 10.2.1-3
ii libpam0g 1.3.1-5
ii libqt5core5a 5.15.2+dfsg-2
ii libqt5dbus5 5.15.2+dfsg-2
ii libqt5gui5 5.15.2+dfsg-2
ii libqt5network5 5.15.2+dfsg-2
ii libqt5qml5 5.15.2+dfsg-2
ii libqt5quick5 5.15.2+dfsg-2
ii libstdc++6 10.2.1-3
ii libsystemd0 247.1-3+deb11u1
ii libxcb-xkb1 1.14-2.1
ii libxcb1 1.14-2.1
ii qml-module-qtquick2 5.15.2+dfsg-2
ii x11-common 1:7.7+21
ii xauth 1:1.0.10-1
ii xserver-xorg [xserver] 1:7.7+21

Versions of packages sddm recommends:
pn haveged <none>
ii libpam-systemd 247.1-3+deb11u1
ii sddm-theme-breeze [sddm-theme] 4:5.20.4-6

Versions of packages sddm suggests:
ii libpam-kwallet5 5.20.4-2
pn qtvirtualkeyboard-plugin <none>

-- debconf information:
* shared/default-x-display-manager: sddm
sddm/daemon_name: /usr/bin/sddm

[Bernhard Übelacker]

Hello Helge,
do you still see these messages in your logging?
If yes could you maybe add the surrounding logging
of one such fault? E.g. by something like this:
   journalctl | grep "traps:" -C20

Kind regards,
Bernhard

[Helge Kreutzmann]

Hello Bernhard,

Post by Bernhard Übelacker
do you still see these messages in your logging?

Yes.

Post by Bernhard Übelacker
If yes could you maybe add the surrounding logging
   journalctl | grep "traps:" -C20

As soon as it appears (last time was yesterday).

Greetings

Helge

[Lisandro Damián Nicanor Pérez Meyer]

Control: tag -1 unreproducible moreinfo

Hi!

Post by Helge Kreutzmann
Hello Bernhard,

Post by Bernhard Übelacker
do you still see these messages in your logging?

Yes.

Post by Bernhard Übelacker
If yes could you maybe add the surrounding logging
journalctl | grep "traps:" -C20

As soon as it appears (last time was yesterday).

The weird things here are that it does not always happens and so far
we have only seen your bug report. May I suggest you to check the
binary with debsums?

debsums libqt5qml5

If that is ok then I would run memtest to check the RAM.

[Helge Kreutzmann]

Hello Lisandro,

Post by Lisandro Damián Nicanor Pérez Meyer
Control: tag -1 unreproducible moreinfo

Post by Helge Kreutzmann

Post by Bernhard Übelacker
do you still see these messages in your logging?

Yes.

Post by Bernhard Übelacker
If yes could you maybe add the surrounding logging
journalctl | grep "traps:" -C20

As soon as it appears (last time was yesterday).

The weird things here are that it does not always happens and so far
we have only seen your bug report. May I suggest you to check the

Well, since it is not causing any visible problems, other users
probably don't even notice it, least they report it. I monitor my logs
with logcheck, so I notice unusual log messages and report them.

Post by Lisandro Damián Nicanor Pérez Meyer
binary with debsums?
debsums libqt5qml5

***@samd:~# debsums libqt5qml5
/usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.15.2 OK
/usr/lib/x86_64-linux-gnu/qt5/qml/builtins.qmltypes OK
/usr/share/doc/libqt5qml5/changelog.Debian.gz OK
/usr/share/doc/libqt5qml5/copyright OK

Post by Lisandro Damián Nicanor Pérez Meyer
If that is ok then I would run memtest to check the RAM.

I can probably do this some time, but this looks like search in the
dark. Since December 4th, when this started, this was the only
programm crashing on my machine, and in 2020 I only had one additional
crash in vlc.

Also (several years back) I had a faulty RAM module, and the
experience was quite different - under heavy load memory corruption,
including disc corruption. Nothing I've seen since (and definitely not
in 2020/2021).

Again, if there is some debug version helpful and if I could get the
core (currently I don't know how to create it in this case), I could
provide it to you.

Best greetings

Helge

[Helge Kreutzmann]

Hello Bernhard,

Post by Bernhard Übelacker
do you still see these messages in your logging?

For example today.

Post by Bernhard Übelacker
If yes could you maybe add the surrounding logging
   journalctl | grep "traps:" -C20

Here you are:
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:103: TypeError: Cannot read property 'largeSpacing' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:44: TypeError: Cannot read property 'gridUnit' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:78: TypeError: Cannot read property 'largeSpacing' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:69: TypeError: Cannot read property 'largeSpacing' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:95: TypeError: Cannot read property 'gridUnit' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/components.3/TextField.qml:152: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/components.3/private/TextFieldFocus.qml:80: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:50: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:75: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:50: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:75: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:50: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:75: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:50: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:75: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:50: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:75: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/components.3/TextField.qml:128: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd sddm-greeter[2001]: file:///usr/lib/x86_64-linux-gnu/qt5/qml/org/kde/plasma/components.3/TextField.qml:128: TypeError: Cannot read property 'longDuration' of null
MÀr 20 16:13:35 samd systemd[2378]: gpgconf: Fehler bei AusfÌhrung von `/usr/lib/gnupg/scdaemon': wahrscheinlich nicht installiert
MÀr 20 16:13:35 samd kernel: traps: sddm-greeter[2001] general protection fault ip:7fd51dfe3ec7 sp:7ffccf696ee0 error:0 in libQt5Qml.so.5.15.2[7fd51ddb0000+2cd000]
MÀr 20 16:13:35 samd sddm-helper[1975]: [PAM] Closing session
MÀr 20 16:13:35 samd sddm-helper[1975]: pam_unix(sddm-greeter:session): session closed for user sddm
MÀr 20 16:13:35 samd sddm-helper[1975]: [PAM] Ended.
MÀr 20 16:13:35 samd sddm[1923]: Auth: sddm-helper exited with 11
MÀr 20 16:13:35 samd sddm[1923]: Greeter stopped.
MÀr 20 16:13:35 samd systemd[1]: session-2.scope: Succeeded.
MÀr 20 16:13:35 samd systemd[1]: session-2.scope: Consumed 1.357s CPU time.
MÀr 20 16:13:35 samd systemd-logind[669]: Session 2 logged out. Waiting for processes to exit.
MÀr 20 16:13:35 samd systemd-logind[669]: Removed session 2.
MÀr 20 16:13:35 samd systemd[1977]: pulseaudio.service: Succeeded.
MÀr 20 16:13:35 samd systemd[2373]: Queued start job for default target Main User Target.
MÀr 20 16:13:35 samd systemd[2373]: Created slice User Application Slice.
MÀr 20 16:13:35 samd systemd[2373]: Reached target Paths.
MÀr 20 16:13:35 samd systemd[2373]: Reached target Timers.
MÀr 20 16:13:35 samd systemd[2373]: Starting D-Bus User Message Bus Socket.
MÀr 20 16:13:35 samd systemd[2373]: Listening on GnuPG network certificate management daemon.
MÀr 20 16:13:35 samd systemd[2373]: Listening on GnuPG cryptographic agent and passphrase cache (access for web browsers).
MÀr 20 16:13:35 samd systemd[2373]: Listening on GnuPG cryptographic agent and passphrase cache (restricted).
MÀr 20 16:13:35 samd systemd[2373]: Listening on GnuPG cryptographic agent (ssh-agent emulation).
MÀr 20 16:13:35 samd systemd[2373]: Listening on GnuPG cryptographic agent and passphrase cache.

If I should install a -dbg version or something else please
inform me.

Greetings

Helge

[Bernhard Übelacker]

Post by Helge Kreutzmann
If I should install a -dbg version or something else please
inform me.

Thank you for the additional information.
There might really be something more. If you have not, is it possible
to install the package "systemd-coredump".

If then a crash happens again and it gets recorded it should
be mentioned in journalctl and this command should list them:
coredumpctl list
And a core should be stored. (But maybe just for the current boot)

There should be already a slight backtrace in journalctl
that might be helpful, but with 'coredumpctl gdb' and at the gdb
prompt with 'bt' it might reveal some more information.
Even better when sddm-dbgsym is installed, and if sufficiently RAM is
available, libqt5qml5-dbgsym. (and some more not yet known in between ...)

There might be more pointer in:
https://wiki.debian.org/HowToGetABacktrace

Kind regards,
Bernhard

[Helge Kreutzmann]

Hello Bernhard,

Post by Bernhard Übelacker

Post by Helge Kreutzmann
If I should install a -dbg version or something else please
inform me.

Thank you for the additional information.
There might really be something more. If you have not, is it possible
to install the package "systemd-coredump".
If then a crash happens again and it gets recorded it should
coredumpctl list
And a core should be stored. (But maybe just for the current boot)
There should be already a slight backtrace in journalctl
that might be helpful, but with 'coredumpctl gdb' and at the gdb
prompt with 'bt' it might reveal some more information.
Even better when sddm-dbgsym is installed, and if sufficiently RAM is
available, libqt5qml5-dbgsym. (and some more not yet known in between ...)

I installed those three packages and report the core dump back.

Post by Bernhard Übelacker
https://wiki.debian.org/HowToGetABacktrace

Greetings

Helge

[Lisandro Damián Nicanor Pérez Meyer]

Hi!

Post by Helge Kreutzmann
Hello Bernhard,

Post by Bernhard Übelacker

Post by Helge Kreutzmann
If I should install a -dbg version or something else please
inform me.

Thank you for the additional information.
There might really be something more. If you have not, is it possible
to install the package "systemd-coredump".
If then a crash happens again and it gets recorded it should
coredumpctl list
And a core should be stored. (But maybe just for the current boot)
There should be already a slight backtrace in journalctl
that might be helpful, but with 'coredumpctl gdb' and at the gdb
prompt with 'bt' it might reveal some more information.
Even better when sddm-dbgsym is installed, and if sufficiently RAM is
available, libqt5qml5-dbgsym. (and some more not yet known in between ...)

Add libqt5core5a-dbgsym, as it's the basic package every Qt app relies on.

[Helge Kreutzmann]

Hello all,

Post by Lisandro Damián Nicanor Pérez Meyer

Post by Helge Kreutzmann
Hello Bernhard,

Post by Bernhard Übelacker

Post by Helge Kreutzmann
If I should install a -dbg version or something else please
inform me.

Thank you for the additional information.
There might really be something more. If you have not, is it possible
to install the package "systemd-coredump".
If then a crash happens again and it gets recorded it should
coredumpctl list
And a core should be stored. (But maybe just for the current boot)
There should be already a slight backtrace in journalctl
that might be helpful, but with 'coredumpctl gdb' and at the gdb
prompt with 'bt' it might reveal some more information.
Even better when sddm-dbgsym is installed, and if sufficiently RAM is
available, libqt5qml5-dbgsym. (and some more not yet known in between ...)

Add libqt5core5a-dbgsym, as it's the basic package every Qt app relies on.

I added it, and now I got one:
Tue 2021-03-23 20:20:40 CET 2000 109 115 11 present /usr/bin/sddm-greeter

If I extract it, I get:
Executable: /usr/bin/sddm-greeter
Control Group: /user.slice/user-109.slice/session-2.scope
Unit: session-2.scope
Slice: user-109.slice
Session: 2
Owner UID: 109 (sddm)
Boot ID: 55dcd237fc794d05a6946fe117d23b60
Machine ID: b25779ab94cf4c318e85f954d3dd3acc
Hostname: samd
Storage: /var/lib/systemd/coredump/core.sddm-greeter.109.55dcd237fc794d05a6946fe117d23b60.2000.1616527238000000.zst
Message: Process 2000 (sddm-greeter) of user 109 dumped core.

Stack trace of thread 2000:
#0 0x00007fe7b5523ec7 _ZNK9QMetaType8destructEPv (libQt5Qml.so.5 + 0x2d3ec7)
#1 0x00007fe7b52fa55f _ZN3QV45Chunk5sweepEPNS_15ExecutionEngineE (libQt5Qml.so.5 + 0xaa55f)
#2 0x00007fe7b52fa7f3 operator() (libQt5Qml.so.5 + 0xaa7f3)
#3 0x00007fe7b52fb415 _ZN3QV413MemoryManager5sweepEbPFvPKcE (libQt5Qml.so.5 + 0xab415)
#4 0x00007fe7b52fbf2d _ZN3QV413MemoryManager5runGCEv (libQt5Qml.so.5 + 0xabf2d)
#5 0x00007fe7b52fddb5 _ZN3QV413MemoryManager8allocateEPNS_14BlockAllocatorEm (libQt5Qml.so.5 + 0xaddb5)
#6 0x00007fe7b536418e _ZN3QV413MemoryManager19allocWithStringDataINS_6StringE7QStringEEPNT_4DataEmT0_ (libQt5Qml.so.5 + 0x11418e)
#7 0x00007fe7b539f688 _ZN3QV414ErrorPrototype15method_toStringEPKNS_14FunctionObjectEPKNS_5ValueES6_i (libQt5Qml.so.5 + 0x14f688)
#8 0x00007fe7b541706f _ZNK3QV414FunctionObject4callEPKNS_5ValueES3_i (libQt5Qml.so.5 + 0x1c706f)
#9 0x00007fe7b5417394 _ZN3QV414RuntimeHelpers18objectDefaultValueEPKNS_6ObjectEi (libQt5Qml.so.5 + 0x1c7394)
#10 0x00007fe7b541bd75 _ZN3QV414RuntimeHelpers11toPrimitiveERKNS_5ValueENS_8TypeHintE (libQt5Qml.so.5 + 0x1cbd75)
#11 0x00007fe7b536d5de _ZN3QV415ExecutionEngine24catchExceptionAsQmlErrorEv (libQt5Qml.so.5 + 0x11d5de)
#12 0x00007fe7b5518412 _ZN16QQmlDelayedError24catchJavaScriptExceptionEPN3QV415ExecutionEngineE (libQt5Qml.so.5 + 0x2c8412)
#13 0x00007fe7b551d4c4 _ZN11QQmlBinding8evaluateEPb (libQt5Qml.so.5 + 0x2cd4c4)
#14 0x00007fe7b5521367 _ZN21QQmlNonbindingBinding8doUpdateERKN24QQmlJavaScriptExpression13DeleteWatcherE6QFlagsIN16QQmlPropertyData9WriteFlagEERN3QV45ScopeE (libQt5Qml.so.5 + 0x2d1367)
#15 0x00007fe7b551f144 _ZN11QQmlBinding6updateE6QFlagsIN16QQmlPropertyData9WriteFlagEE (libQt5Qml.so.5 + 0x2cf144)
#16 0x00007fe7b54fc1ad _ZN12QQmlNotifier10emitNotifyEP20QQmlNotifierEndpointPPv (libQt5Qml.so.5 + 0x2ac1ad)
#17 0x00007fe7b47940d5 _Z10doActivateILb0EEvP7QObjectiPPv (libQt5Core.so.5 + 0x2e40d5)
#18 0x00007fe7b4794546 _ZN9QtPrivate15QSlotObjectBase4callEP7QObjectPPv (libQt5Core.so.5 + 0x2e4546)
#19 0x00007fe7b478d94f _ZN7QObject9destroyedEPS_ (libQt5Core.so.5 + 0x2dd94f)
#20 0x00007fe7b47928cd _ZN7QObjectD2Ev (libQt5Core.so.5 + 0x2e28cd)
#21 0x00007fe7b41364d7 n/a (libc.so.6 + 0x3e4d7)
#22 0x00007fe7b413667a exit (libc.so.6 + 0x3e67a)
#23 0x00007fe7b411ed11 __libc_start_main (libc.so.6 + 0x26d11)
#24 0x000056346320e04a _start (sddm-greeter + 0x1b04a)

Stack trace of thread 2359:
#0 0x00007fe7b41eb3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007fe7b31ca0ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007fe7b31ca1cf g_main_context_iteration (libglib-2.0.so.0 + 0x521cf)
#3 0x00007fe7b47b54bf _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5 + 0x3054bf)
#4 0x00007fe7b475c92b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 + 0x2ac92b)
#5 0x00007fe7b457ba3e _ZN7QThread4execEv (libQt5Core.so.5 + 0xcba3e)
#6 0x00007fe7b5908926 n/a (libQt5Quick.so.5 + 0x150926)
#7 0x00007fe7b457cb81 _ZN14QThreadPrivate5startEPv (libQt5Core.so.5 + 0xccb81)
#8 0x00007fe7b3a98ea7 start_thread (libpthread.so.0 + 0x8ea7)
#9 0x00007fe7b41f5def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 2005:
#0 0x00007fe7b41eb3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007fe7b31ca0ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007fe7b31ca1cf g_main_context_iteration (libglib-2.0.so.0 + 0x521cf)
#3 0x00007fe7b47b54bf _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5 + 0x3054bf)
#4 0x00007fe7b475c92b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 + 0x2ac92b)
#5 0x00007fe7b457ba3e _ZN7QThread4execEv (libQt5Core.so.5 + 0xcba3e)
#6 0x00007fe7b0758a27 n/a (libQt5DBus.so.5 + 0x18a27)
#7 0x00007fe7b457cb81 _ZN14QThreadPrivate5startEPv (libQt5Core.so.5 + 0xccb81)
#8 0x00007fe7b3a98ea7 start_thread (libpthread.so.0 + 0x8ea7)
#9 0x00007fe7b41f5def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 2018:
#0 0x00007fe7b41eb3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007fe7b31ca0ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007fe7b31ca1cf g_main_context_iteration (libglib-2.0.so.0 + 0x521cf)
#3 0x00007fe7b47b54bf _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5 + 0x3054bf)
#4 0x00007fe7b475c92b _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 + 0x2ac92b)
#5 0x00007fe7b457ba3e _ZN7QThread4execEv (libQt5Core.so.5 + 0xcba3e)
#6 0x00007fe7b5557f85 _ZN17QQmlThreadPrivate3runEv (libQt5Qml.so.5 + 0x307f85)
#7 0x00007fe7b457cb81 _ZN14QThreadPrivate5startEPv (libQt5Core.so.5 + 0xccb81)
#8 0x00007fe7b3a98ea7 start_thread (libpthread.so.0 + 0x8ea7)
#9 0x00007fe7b41f5def __clone (libc.so.6 + 0xfddef)

You can get the core file, if you like, at
https://www.helgefjell.de/data/sddm.core

If there is anything else you want me to do, please let me know.

Greetings

Helge

[Bernhard Übelacker]

Hello everyone,

Post by Helge Kreutzmann
Tue 2021-03-23 20:20:40 CET 2000 109 115 11 present /usr/bin/sddm-greeter
Executable: /usr/bin/sddm-greeter

...

Post by Helge Kreutzmann
#9 0x00007fe7b41f5def __clone (libc.so.6 + 0xfddef)

With this "coredumpctl gdb 2000", and when you have gdb installed,
you should get a prompt "(gdb) ".
There a command "bt" should get a better backtrace than the automatic one.

Post by Helge Kreutzmann
You can get the core file, if you like, at
https://www.helgefjell.de/data/sddm.core

I tried to have a look at this one in the hope I have the same
package versions installed as you, and have received a backtrace
showing we are inside the __run_exit_handlers.
This might explain why you get no issue with it except the logging,
because this process has already done its main work
and is about to end itself.

What I further see is some object destruction going on
with mentioning QV4 - which I believe is tightly related to
Qts javascript engine.

And finally it is in a method QMetaType::destruct, which is
unfortunately about to call a function pointer m_destructor
that consists of some string data.

Getting a traps instead of a segfault might be because of
the function pointer using more than the lower 48 bits, to
which address space is currently limited?
At least a short test with the value 0x0070006d006f0063
leads to such a traps message, using 0x0000006d006f0063
shows a "segfault at" message in dmesg.

But having this string at this position might just be coincidence,
a few debugging details might be found in attached file.

Kind regards,
Bernhard


Core was generated by `/usr/bin/sddm-greeter --socket /tmp/sddm-:0-aSeIQL --theme /usr/share/sddm/them'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 QMetaType::destruct (data=0x563464af9d00, this=0x5634649ea3b8) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qmetatype.h:2375
2375 m_destructor(data);
[Current thread is 1 (Thread 0x7fe7b49fb840 (LWP 2000))]
(gdb) bt
#0 QMetaType::destruct (data=0x563464af9d00, this=0x5634649ea3b8) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qmetatype.h:2375
#1 QV4::Heap::QQmlValueTypeWrapper::destroy (this=0x7fe79833d460) at qml/qqmlvaluetypewrapper.cpp:100
#2 0x00007fe7b52fa55f in QV4::Chunk::sweep (this=0x7fe798330000, engine=0x56346475ffe0) at memory/qv4mm.cpp:349
#3 0x00007fe7b52fa7f3 in operator() (c=<optimized out>, __closure=<synthetic pointer>) at memory/qv4mm.cpp:630
#4 std::__partition<__gnu_cxx::__normal_iterator<QV4::Chunk**, std::vector<QV4::Chunk*> >, QV4::BlockAllocator::sweep()::<lambda(QV4::Chunk*)> > (__pred=..., __last=0x2, __first=0x7fe798330000) at /usr/include/c++/10/bits/stl_algo.h:1515
#5 std::partition<__gnu_cxx::__normal_iterator<QV4::Chunk**, std::vector<QV4::Chunk*> >, QV4::BlockAllocator::sweep()::<lambda(QV4::Chunk*)> > (__pred=..., __last=..., __first=...) at /usr/include/c++/10/bits/stl_algo.h:4673
#6 QV4::BlockAllocator::sweep (this=***@entry=0x56346442fa60) at memory/qv4mm.cpp:631
#7 0x00007fe7b52fb415 in QV4::MemoryManager::sweep (this=***@entry=0x56346442fa50, lastSweep=***@entry=false, classCountPtr=***@entry=0x0) at memory/qv4mm.cpp:994
#8 0x00007fe7b52fbf2d in QV4::MemoryManager::runGC (this=0x56346442fa50) at memory/qv4mm.cpp:1054
#9 0x00007fe7b52fddb5 in QV4::MemoryManager::allocate (size=32, allocator=0x56346442fa60, this=0x56346442fa50) at ../../include/QtQml/5.15.2/QtQml/private/../../../../../src/qml/memory/qv4mm_p.h:307
#10 QV4::MemoryManager::allocString (this=***@entry=0x56346442fa50, unmanagedSize=<optimized out>) at memory/qv4mm.cpp:791
#11 0x00007fe7b536418e in QV4::MemoryManager::allocWithStringData<QV4::String, QString> (arg1=..., unmanagedSize=<optimized out>, this=0x56346442fa50) at ../../include/QtQml/5.15.2/QtQml/private/../../../../../src/qml/memory/qv4mm_p.h:217
#12 QV4::ExecutionEngine::newString (this=***@entry=0x56346475ffe0, s=...) at jsruntime/qv4engine.cpp:894
#13 0x00007fe7b539f688 in QV4::ErrorPrototype::method_toString (b=<optimized out>, thisObject=0x7fe7986b9508) at jsruntime/qv4errorobject.cpp:352
#14 0x00007fe7b541706f in QV4::FunctionObject::call (argc=0, argv=0x0, thisObject=0x7fe7986b9508, this=0x7fe7986b9530) at jsruntime/qv4functionobject_p.h:172
#15 QV4::RuntimeHelpers::ordinaryToPrimitive (engine=***@entry=0x56346475ffe0, object=***@entry=0x7fe7986b9508, typeHint=***@entry=0x7fe7986b9310) at jsruntime/qv4runtime.cpp:517
#16 0x00007fe7b5417394 in QV4::RuntimeHelpers::objectDefaultValue (object=0x7fe7986b9508, ***@entry=0x7fe7986b9518, typeHint=***@entry=2) at jsruntime/qv4runtime.cpp:495
#17 0x00007fe7b541bd75 in QV4::RuntimeHelpers::toPrimitive (typeHint=QV4::STRING_HINT, value=...) at jsruntime/qv4runtime_p.h:123
#18 QV4::Value::toQStringNoThrow (this=***@entry=0x7fe7986b9508) at jsruntime/qv4value.cpp:150
#19 0x00007fe7b536d5de in QV4::ExecutionEngine::catchExceptionAsQmlError (this=***@entry=0x56346475ffe0) at ../../include/QtQml/5.15.2/QtQml/private/../../../../../src/qml/jsruntime/qv4scopedvalue_p.h:234
#20 0x00007fe7b5518412 in QQmlDelayedError::catchJavaScriptException (engine=0x56346475ffe0, this=0x5634647b3860) at qml/qqmljavascriptexpression.cpp:92
#21 QQmlJavaScriptExpression::evaluate (this=***@entry=0x563464a7ac30, callData=<optimized out>, isUndefined=***@entry=0x7ffe703c9b8f) at qml/qqmljavascriptexpression.cpp:223
#22 0x00007fe7b551d4c4 in QQmlBinding::evaluate (this=***@entry=0x563464a7ac30, isUndefined=***@entry=0x7ffe703c9b8f) at ../../include/QtQml/5.15.2/QtQml/private/../../../../../src/qml/jsruntime/qv4jscall_p.h:95
#23 0x00007fe7b5521367 in QQmlNonbindingBinding::doUpdate (this=0x563464a7ac30, watcher=..., flags=..., scope=...) at qml/qqmlbinding.cpp:254
#24 0x00007fe7b551f144 in QQmlBinding::update (this=0x563464a7ac30, flags=...) at qml/qqmlbinding.cpp:194
#25 0x00007fe7b54fc1ad in QQmlNotifier::emitNotify (endpoint=<optimized out>, a=0x0) at qml/qqmlnotifier.cpp:104
#26 0x00007fe7b47940d5 in doActivate<false> (sender=0x563464767570, signal_index=12, argv=0x0) at kernel/qobject.cpp:3778
#27 0x00007fe7b4794546 in QtPrivate::QSlotObjectBase::call (a=0x7ffe703cb730, r=0x563464767570, this=0x56346479ddf0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#28 doActivate<false> (sender=0x7fe798240140, signal_index=0, argv=***@entry=0x7ffe703cb730) at kernel/qobject.cpp:3886
#29 0x00007fe7b478d8a0 in QMetaObject::activate (sender=***@entry=0x7fe798240140, m=***@entry=0x7fe7b49ea100 <QObject::staticMetaObject>, local_signal_index=***@entry=0, argv=***@entry=0x7ffe703cb730) at kernel/qobject.cpp:3946
#30 0x00007fe7b478d94f in QObject::destroyed (this=***@entry=0x7fe798240140, _t1=<optimized out>, ***@entry=0x7fe798240140) at .moc/moc_qobject.cpp:219
#31 0x00007fe7b47928cd in QObject::~QObject (this=<optimized out>, __in_chrg=<optimized out>) at kernel/qobject.cpp:992
#32 0x00007fe7b41364d7 in __run_exit_handlers (status=0, listp=0x7fe7b42b6718 <__exit_funcs>, run_list_atexit=***@entry=true, run_dtors=***@entry=true) at exit.c:108
#33 0x00007fe7b413667a in __GI_exit (status=<optimized out>) at exit.c:139
#34 0x00007fe7b411ed11 in __libc_start_main (main=0x56346320d860 <main(int, char**)>, argc=5, argv=0x7ffe703cb948, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe703cb938) at ../csu/libc-start.c:342
#35 0x000056346320e04a in _start ()

=> 0x00007fe7b5523ec7 <+23>: call *0x60(%rax)

(gdb) print/x $rax + 0x60
$7 = 0x5634649ea3e0
(gdb) x/1xg $rax + 0x60
0x5634649ea3e0: 0x0070006d006f0063
(gdb) print this->m_destructor
$10 = (QMetaType::Destructor) 0x70006d006f0063
(gdb) x/sh 0x5634649ea3e0-72
0x5634649ea398: u"/usr/share/sddm/themes/debian-theme/components/UserDelegate.qml"

[Lisandro Damián Nicanor Pérez Meyer]

Hi!

Post by Helge Kreutzmann
Hello Bernhard,

Post by Bernhard Übelacker
do you still see these messages in your logging?

For example today.

Post by Bernhard Übelacker
If yes could you maybe add the surrounding logging
journalctl | grep "traps:" -C20

Mär 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:103: TypeError: Cannot read property 'largeSpacing' of null
Mär 20 16:13:35 samd sddm-greeter[2001]: file:///usr/share/sddm/themes/debian-theme/components/UserDelegate.qml:44: TypeError: Cannot read property 'gridUnit' of null

Accroding to the web this is QML being chatty, ie, logging out some
eros that are not necessarily a bug.

Post by Helge Kreutzmann
Mär 20 16:13:35 samd kernel: traps: sddm-greeter[2001] general protection fault ip:7fd51dfe3ec7 sp:7ffccf696ee0 error:0 in libQt5Qml.so.5.15.2[7fd51ddb0000+2cd000]

And I have no idea what could be happening here :-(

[Bernhard Übelacker]

Hello Helge,
do you still see these messages in your logging?
If yes could you maybe add the surrounding logging
of one such fault? E.g. by something like this:
journalctl | grep "traps:" -C20

Kind regards,
Bernhard