lxc-test-unpriv test failed on s390x instances with cgmanager

[Po-Hsu Lin]

Update2: Switching from cgroup-lite to cgmanager will trigger this failure, see comment #4

Update1: this can be reproduced with kernel downgraded to 4.4.0-98, see comment #1

This test has passed with older kernels (4.4.0-98, 4.4.0-97, 4.4.0-96), but this time it failed.
Issue can be seen on zKVM, zVM and Ubuntu on LPAR

Steps:
1. Install lxc-tests
2. Run sudo /usr/bin/lxc-test-unpriv

Result:
  ---
  mount: wrong fs type, bad option, bad superblock on none,
         missing codepage or helper program, or other error

         In some cases useful info is found in syslog - try
         dmesg | tail or so.
  umount: /tmp/tmp.uMnoGYXJSH/ovl_symlink_test/overlayfs: not mounted
  /usr/sbin/deluser: The user `lxcunpriv' does not exist.
  Path existed
  Using image from local cache
  Unpacking the rootfs

  ---
  You just created an Ubuntu container (release=xenial, arch=s390x, variant=default)

  To enable sshd, run: apt-get install openssh-server

  For security reason, container images ship without user accounts
  and without a root password.

  Use lxc-attach or chroot directly into the rootfs to set a root password
  or create user accounts.
  Name: c1
  State: RUNNING
  PID: 5846
  CPU use: 0.05 seconds
  BlkIO use: 0 bytes
  Memory use: 10.04 MiB
  KMem use: 0 bytes
  Link: vethV2EVRI
   TX bytes: 0 bytes
   RX bytes: 0 bytes
   Total bytes: 0 bytes
  Name: c1
  State: RUNNING
  PID: 6218
  CPU use: 0.03 seconds
  BlkIO use: 0 bytes
  Memory use: 1.50 MiB
  KMem use: 0 bytes
  Link: vethA54DMR
   TX bytes: 0 bytes
   RX bytes: 0 bytes
   Total bytes: 0 bytes
  Testing containers under different cgroups per subsystem
  call to cgmanager_move_pid_main_sync failed: invalid request
  c2 is not running
  c1 is not running
  Removing user `lxcunpriv' ...
  Warning: group `lxcunpriv' has no more members.
  Done.
  FAIL
  ---

The mount error (bug 1730915) is not the cause, it looks like the failure was caused by:
  call to cgmanager_move_pid_main_sync failed: invalid request

In that shell script, this line account for the error:
    cgm movepid freezer x1 $$

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-100-generic 4.4.0-100.123
ProcVersionSignature: Ubuntu 4.4.0-100.123-generic 4.4.95
Uname: Linux 4.4.0-100-generic s390x
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access '/dev/snd/': No such file or directory
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: s390x
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Date: Wed Nov 8 04:39:12 2017
HibernationDevice: RESUME=UUID=ca468a9c-9563-442c-85c6-6055e800a66e
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lspci:

Lsusb: Error: command ['lsusb'] failed with exit code 1:
PciMultimedia:

ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C
 SHELL=/bin/bash
ProcFB: Error: [Errno 2] No such file or directory: '/proc/fb'
ProcKernelCmdLine: root=UUID=b65b756a-ba4e-4c53-aa32-0db2bdb50bb3 crashkernel=196M
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-100-generic N/A
 linux-backports-modules-4.4.0-100-generic N/A
 linux-firmware 1.157.13
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1730926

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Po-Hsu Lin (cypressyew)]

This test still fail with 4.4.0-101 on s2lp6g001 (zKVM).
However, I have switched to 4.4.0-98, lxc-test-unpriv failed too.

This error message (call to cgmanager_move_pid_main_sync failed: invalid request) seems to be caused by command:
    cgm movepid freezer x1 $$

[Po-Hsu Lin (cypressyew)]

I have found the cause.

It was running the cgm command from cgroup-lite package.
But during the last SRU cycle, it got replaced by cgmanager package.

If you switch to the cgroup-lite, the SUT will pass with this test.