[systemd-devel] Clarification around a segmentation fault from an udevd worker

[SF Markus Elfring]

Hello,

I would like to clarify the setting of device file permissions
for my needs.

So I extended the debug output at some source code places to see
also better which lines are executed during my tests.
I built these extensions for calls of the function "log_debug"
on the current source files (last commit: 3460810e8c61986a4605ad80c9e4805eb95cb5a1)
with the software "GCC 5.2.0" on my openSUSE Tumbleweed system.

I am experimenting a bit with this fresh server program.

Sonne:~ # systemctl stop systemd-udevd.service systemd-udevd-kernel.socket systemd-udevd-control.socket && /home/elfring/Projekte/Bau/systemd/systemd-udevd --debug


Now I wonder about an error message like the following.

…
adding watch on '/dev/dm-0'
…
seq 2633 forked new worker [19879]
seq 2633 running
IMPORT builtin 'usb_id' /usr/lib/udev/rules.d/40-libgphoto2.rules:9
unable to access usb_interface device of '/sys/devices/pci0000:00/0000:00:02.0/usb3/3-2/3-2:1.0'
IMPORT builtin 'usb_id' returned non-zero
IMPORT builtin 'hwdb' /usr/lib/udev/rules.d/50-udev-default.rules:11
worker [19879] terminated by signal 11 (Segmentation fault)
worker [19879] failed while handling '/devices/pci0000:00/0000:00:02.0/usb3/3-2/3-2:1.0'
…

I would appreciate your advices.

I hope that I do not need to extend all log messages with additional
information details.
It would be nice if I could find the failure place easier within
a session with the help of a graphical debugger, wouldn't it?

Regards,
Markus