Bug 2193456 - Systemd logs "System is tainted: cgroupsv1" on OpenShift 4.13
Summary: Systemd logs "System is tainted: cgroupsv1" on OpenShift 4.13
Keywords:
Status: VERIFIED
Alias: None
Product: Red Hat Enterprise Linux 9
Classification: Red Hat
Component: systemd
Version: 9.2
Hardware: All
OS: Linux
unspecified
high
Target Milestone: rc
: ---
Assignee: Jan Macku
QA Contact: Frantisek Sumsal
URL:
Whiteboard:
Depends On:
Blocks: 2196479
TreeView+ depends on / blocked
 
Reported: 2023-05-05 16:52 UTC by Ryan Phillips
Modified: 2023-07-26 10:34 UTC (History)
3 users (show)

Fixed In Version: systemd-252-16.el9
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Doc Text:
Clone Of:
: 2196479 (view as bug list)
Environment:
Last Closed:
Type: Bug
Target Upstream Version:
Embargoed:


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System ID Private Priority Status Summary Last Updated
Github redhat-plumbers systemd-rhel9 pull 162 0 None open (#2193456) manager: don't taint the host if cgroups v1 is used 2023-05-09 11:23:50 UTC
Red Hat Issue Tracker RHELPLAN-156547 0 None None None 2023-05-05 16:55:06 UTC

Description Ryan Phillips 2023-05-05 16:52:36 UTC
Description of problem:

Node Team on OpenShift received a report while testing OpenShift 4.13 that the RHEL 9.2 systemd is tainting the kernel when cgroupsv1 is enabled on the node. OpenShift and the Kernel Team will be supporting cgroupsv1 on OpenShift 4.13.

Version-Release number of selected component (if applicable):
RHEL 9.2

How reproducible:
Every time.

Steps to Reproduce:
1. Boots an OpenShift 4.13 node using cgroupsv1
2.
3.

Actual results:

Kernel is tainted.

Expected results:

Systemd should not taint cgroupsv1 enabled nodes on OpenShift 4.13.

Additional info:

Relevant code line:

https://github.com/systemd/systemd/blob/d685a5f6a4ae8f9eaea1d1c5c78171a915f3b16d/src/core/manager.c#L4728

Comment 1 josearod 2023-05-05 18:24:35 UTC
Having this taint in place affects the results of the CNF certification tools like: https://github.com/test-network-function/test-network-function
Workload certifications won't pass if the platform is tainted. 

Thanks!

Comment 3 Lukáš Nykrýn 2023-05-09 11:33:24 UTC
If you check the code, the manager only calls the function you have
mentioned here https://github.com/redhat-plumbers/systemd-rhel9/blob/main/src/core/manager.c#L3449
So, we only put a message into the logs. So, in the end, there is probably something else tainting the kernel.

[root@ci-vm-10-0-138-58 ~]# cat /proc/cmdline
BOOT_IMAGE=(hd0,msdos1)/boot/vmlinuz-5.14.0-306.el9.x86_64
root=UUID=462f9b3b-7b7e-4e25-beeb-ca2768fe9b47 ro rhgb quiet
crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M net.ifnames=0
systemd.unified_cgroup_hierarchy=0

[root@ci-vm-10-0-138-58 ~]# journalctl --grep taint
May 09 04:50:08 localhost systemd[1]: System is tainted: cgroupsv1

[root@ci-vm-10-0-138-58 ~]# cat /proc/sys/kernel/tainted
0


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