console-conf crashes on UC18 on arm64 (dragonboard and pi3 in 64bit mode)

[Michael Vogt]

[impact]
We are working on the UC18 release right now. The test images can be found at http://people.canonical.com/~mvo/core18/core18-dragonboard-18-beta20181009.img or build using ubuntu-image.

We ran into the issue that console-conf just crashes. We did some face-to-face debugging in brussels but not much progress there. This bug is mostly so that we can track the issue as this is a release blocker.

[test case]
As above, build an UC18 image, install it on a dragonboard and see if console-conf crashes at start up.

A more targeted test:

1. get yourself an arm64 environment which has a wlan device
2. make sure that device is down (ip link set dev $wlan down)
3. install probert
4. run the "probert" command

if it doesn't segfault, we're good (if it doesn't segfault it will crash with an attributeerror which is a bug but not one that console-conf will run into)

[regression potential]
It's a one line patch that can be observed to be correct. Barring things like a toolchain update causing probert to be miscompiled, there is no potential for regression.

[Michael Hudson-Doyle (mwhudson)]

So I've poked at this a bit and basically failed to get anywhere. How should I go about debugging this? I need to be able to run console-conf under gdb on the dragonboard in an environment that has full access to the wifi device (I tried a bionic lxd container on an ubuntu core 16 system but failed on this last point). I'm a bit out of ideas :(

[Michael Hudson-Doyle (mwhudson)]

And of course almost as soon as I post this I manage to cook up a reproduction in my lxd container (you need a privileged lxd container, which isn't very surprising when you think about it). Can debug now, although I'm about to EOW. Will get back to it on Monday.

[Michael Hudson-Doyle (mwhudson)]

ARGH this was a stupid bug I fixed in probert ages ago but somehow never uploaded to the archive :(

[Michael Hudson-Doyle (mwhudson)]

So I've uploaded the fix to cosmic and bionic UNAPPROVED; you can get it from there if you want to get it into a PPA sooner for testing?

[Launchpad Janitor (janitor)]

This bug was fixed in the package probert - 0.0.14.2

---------------
probert (0.0.14.2) cosmic; urgency=medium

  * Correctly mark set_link_flags as METH_KEYWORDS. (LP: #1797342)

 -- Michael Hudson-Doyle <email address hidden> Mon, 15 Oct 2018 10:27:03 +1300

[Łukasz Zemczak (sil2100)]

We're using the PPA for our builds anyway, so I'll pull it in from cosmic today. Thanks!

[Łukasz Zemczak (sil2100)]

Confirmed to work on both dragonboard and raspi3 arm64. All good.

[Łukasz Zemczak (sil2100)]

Hello Michael, or anyone else affected,

Accepted probert into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/probert/0.0.14.1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Michael Hudson-Doyle (mwhudson)]

verified in a lxd bionic image on my dragonboard running ubuntu core 16:

root@fit-ape:~# dpkg -l probert
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-====================================-=======================-=======================-=============================================================================
ii probert 0.0.14.1build2 arm64 Hardware probing tool
root@fit-ape:~# probert
Segmentation fault
root@fit-ape:~# apt install probert/bionic-proposed
Reading package lists... Done
Building dependency tree
Reading state information... Done
Selected version '0.0.14.1.1' (Ubuntu:18.04/bionic-proposed [arm64]) for 'probert'
The following packages will be upgraded:
  probert
1 upgraded, 0 newly installed, 0 to remove and 74 not upgraded.
Need to get 31.8 kB of archives.
After this operation, 1024 B of additional disk space will be used.
Get:1 http://ports.ubuntu.com/ubuntu-ports bionic-proposed/universe arm64 probert arm64 0.0.14.1.1 [31.8 kB]
Fetched 31.8 kB in 1s (34.5 kB/s)
(Reading database ... 35670 files and directories currently installed.)
Preparing to unpack .../probert_0.0.14.1.1_arm64.deb ...
Unpacking probert (0.0.14.1.1) over (0.0.14.1build2) ...
Setting up probert (0.0.14.1.1) ...
root@fit-ape:~# probert
Traceback (most recent call last):
  File "/usr/bin/probert", line 62, in <module>
    main()
  File "/usr/bin/probert", line 56, in main
    p.probe()
  File "/usr/lib/python3/dist-packages/probert/prober.py", line 41, in probe
    getattr(self, fn)()
  File "/usr/lib/python3/dist-packages/probert/prober.py", line 45, in probe_all
    fn()
  File "/usr/lib/python3/dist-packages/probert/prober.py", line 54, in probe_network
    results = network.probe()
  File "/usr/lib/python3/dist-packages/probert/network.py", line 332, in probe
    'ip' : l.ip,
AttributeError: 'NetworkInfo' object has no attribute 'ip'

[Launchpad Janitor (janitor)]

This bug was fixed in the package probert - 0.0.14.1.1

---------------
probert (0.0.14.1.1) bionic; urgency=medium

  * Correctly mark set_link_flags as METH_KEYWORDS. (LP: #1797342)

 -- Michael Hudson-Doyle <email address hidden> Mon, 15 Oct 2018 10:27:03 +1300

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for probert has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.