Bug#891233: Bug #891233: kamoso: segmentation fault in kamoso in Debian 9 stable. Buster not affected
Dear Maintainer, I guess the actual segmentation fault is fixed since kamoso 3.2.4-1. Instead it should print this message: The webcam controller was unable to find or load wrappercamerabinsrc plugin; please make sure all required gstreamer plugins are installed. The last question would be, is this sufficient to close the bug, or does kamoso need a dependency or recommends to gstreamer1.0-plugins-bad? Kind regards, Bernhard
Bug#891233: Bug #891233: kamoso: segmentation fault in kamoso in Debian 9 stable. Buster not affected
Hello Bernhard, maintainers Thanks for your help. I'm attaching the result of the gdb command, and the result of the coredumpctl command. As you suggested, I have installed gstreamer1.0-plugins-bad, and after that, I can confirm that kamoso runs well. Note that together with gstreamer1.0-plugins-bad all these packages were installed: freepats gir1.2-gstreamer-1.0 gstreamer1.0-doc gstreamer1.0-plugins-bad gstreamer1.0-plugins-bad-dbg gstreamer1.0-plugins-bad-doc gstreamer1.0-plugins-base-doc libde265-0 libglib2.0-dev libglib2.0-doc libgstreamer1.0-dev libmjpegutils-2.1-0 libmms0 libmodplug1 libmpeg2encpp-2.1-0 libmplex2-2.1-0 libofa0 libpcre3-dev libpcre32-3 libpcrecpp0v5 libsbc1 libvo-aacenc0 libvo-amrwbenc0 libwildmidi-config libwildmidi2 libzbar0 zlib1g-dev Hope that helps. Kind regards, -- Laura Arjona Reina https://wiki.debian.org/LauraArjona This is the result of the coredumpctl gdb: PID: 23446 (kamoso) UID: 1000 (larjona) GID: 1000 (larjona) Signal: 11 (SEGV) Timestamp: Sat 2018-12-08 19:58:05 CET (44s ago) Command Line: /usr/bin/kamoso Executable: /usr/bin/kamoso Control Group: /user.slice/user-1000.slice/session-3.scope Unit: session-3.scope Slice: user-1000.slice Session: 3 Owner UID: 1000 (larjona) Boot ID: 5dd3b27588124948b42e2636b2a6f660 Machine ID: be0c47ee1011441c88e47eac003d0c5f Hostname: larjona-lena Storage: /var/lib/systemd/coredump/core.kamoso.1000.5dd3b27588124948b42e2636b2a6f660.23446.1544295485.lz4 Message: Process 23446 (kamoso) of user 1000 dumped core. Stack trace of thread 23446: #0 0x55568fd5 _ZN13WebcamControl4playEP6Device (kamoso) #1 0x55569bfd _ZN13WebcamControlC2Ev (kamoso) #2 0x5556171f main (kamoso) #3 0x743bc2e1 __libc_start_main (libc.so.6) #4 0x55561a6a _start (kamoso) Stack trace of thread 23452: #0 0x7447b67d __poll (libc.so.6) #1 0x70da09f6 n/a (libglib-2.0.so.0) #2 0x70da0b0c g_main_context_iteration (libglib-2.0.so.0) #3 0x74fa404f _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5) #4 0x74f4d9ca _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5) #5 0x74d7b0f3 _ZN7QThread4execEv (libQt5Core.so.5) #6 0x758e86a5 n/a (libQt5Qml.so.5) #7 0x74d7fda8 n/a (libQt5Core.so.5) #8 0x7267f494 start_thread (libpthread.so.0) #9 0x74484acf __clone (libc.so.6) Stack trace of thread 23450: #0 0x7447b67d __poll (libc.so.6) #1 0x7fffee817150 n/a (libxcb.so.1) #2 0x7fffee818ee9 xcb_wait_for_event (libxcb.so.1) #3 0x7fffe806fb69 n/a (libQt5XcbQpa.so.5) #4 0x74d7fda8 n/a (libQt5Core.so.5) #5 0x7267f494 start_thread (libpthread.so.0) #6 0x74484acf __clone (libc.so.6) Stack trace of thread 23453: #0 0x7447b67d __poll (libc.so.6) #1 0x70da09f6 n/a (libglib-2.0.so.0) #2 0x70da0b0c g_main_context_iteration (libglib-2.0.so.0) #3 0x74fa404f _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5) #4 0x74f4d9ca _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5) #5 0x74d7b0f3 _ZN7QThread4execEv (libQt5Core.so.5) #6 0x758e86a5 n/a (libQt5Qml.so.5) #7 0x74d7fda8 n/a (libQt5Core.so.5) #8 0x7267f494 start_thread (libpthread.so.0) #9 0x74484acf __clone (libc.so.6) Stack trace of thread 23451: #0 0x7447b67d __poll (libc.so.6) #1 0x70da09f6 n/a (libglib-2.0.so.0) #2 0x70da0b0c g_main_context_iteration (libglib-2.0.so.0) #3 0x74fa404f _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5) #4 0x74f4d9ca _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5) #5 0x74d7b0f3 _ZN7QThread4execEv (libQt5Core.so.5) #6 0x72db66d5 n/a (libQt5DBus.so.5) #7 0x74d7fda8 n/a (libQt5Core.so.5) #8 0x7267f494 start_thread
Bug#891233: Bug #891233: kamoso: segmentation fault in kamoso in Debian 9 stable. Buster not affected
Dear Maintainer, hello Laura Arjona Reina,
I just tried to have a look at this crash.
Unfortunately given information point to no exact location.
In that case the line from dmesg would already be helpful:
[ 609.690904] kamoso[28487]: segfault at 0 ip 55bc679e7fd5 sp
7ffc474fd950 error 4 in kamoso[55bc679d3000+2b000]
A good information would be just to run it that way:
gdb -q -ex run -ex bt -ex detach -ex quit --args kamoso
Another way would be to install a core dump collector like systemd-coredump
and execute something like this:
coredumpctl list
coredumpctl gdb
Even better when debug symbols are installed like described in [1].
Nevertheless I could reproduce a crash in a minimal stretch amd64 qemu VM,
with a forwarded usb webcam.
(gdb) bt
#0 0x55bc679e7fd5 in WebcamControl::play (this=this@entry=0x7ffc474fdc80,
device=0x55bc68b82220) at ./src/video/webcamcontrol.cpp:135
#1 0x55bc679e8bfd in WebcamControl::WebcamControl (this=0x7ffc474fdc80) at
./src/video/webcamcontrol.cpp:86
#2 0x55bc679e071f in main (argc=, argv=0x7ffc474fdde8) at
./src/main.cpp:43
(gdb) print cameraSource
$1 = {m_class = 0x0}
134 auto cameraSource =
QGst::ElementFactory::make("wrappercamerabinsrc", "video_balance");
135 cameraSource->setProperty("video-source-filter", bin);
That "wrappercamerabinsrc" points to a missing package gstreamer1.0-plugins-bad.
Maybe you can confirm that installing that package avoids the crash,
if you still run a stretch installation that shows it.
This crash got fixed upstream in [2].
Kind regards,
Bernhard
[1] https://wiki.debian.org/HowToGetABacktrace
[2]
https://cgit.kde.org/kamoso.git/commit/?id=1ff5f14fedd42bfa61ae181e0c598ec991ba4407
Bug#891233: kamoso: segmentation fault in kamoso in Debian 9 stable. Buster not affected
Hello I've installed a virtual machine with Debian testing (Buster), KDE Plasma, and kamoso, and I cannot reproduce the bug there. In testing (buster), when I start kamoso, the program launches well. It shows a dancing banana because my VM has no access to the laptop's camera, but I think that is irrelevant to the problem. My question now is if it's possible to backport the fix to Debian 9 stable, because the program is unusable in Debian stable. Or remove kamoso in Debian 9, and maybe backport the new version to debian-backports? (I'm not sure which is the policy here). For what I've searched and found, looks like the commit fixing the problem is this one: https://cgit.kde.org/kamoso.git/commit/?id=68c0ec95b4f3f0c51ffab558298758eeeae8c489 Thanks -- Laura Arjona Reina https://wiki.debian.org/LauraArjona
