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

[Kay Sievers]

On Sat, Jul 25, 2015 at 6:11 PM, SF Markus Elfring
<elfring at users.sourceforge.net> wrote:
> 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.

Can you try to run it under gdb?

$ gdb /home/elfring/Projekte/Bau/systemd/systemd-udev

Type "r" at the prompt to run it.

if it shows the same error here as when it runs without gdb, type "bt
full" at the prompt

It should print the backtrace with the location where the error
happened. Please paste that output into an email.

Thanks,
Kay