noisy selinux messages on tmpfs mount.

Dave Jones
2015-01-08T19:08:32Z

systemd has started mounting a tmpfs in /run/user/<uid> every time a
session begins. So after ssh'ing into a box a number of times, dmesg
looks like this..

[ 929.892760] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[ 4529.025836] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[ 8129.170484] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[11729.313034] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[15329.471269] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[18929.613781] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[22529.759596] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[26129.890709] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[26669.001664] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[33328.937304] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[36929.064927] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[40529.178574] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[44129.301952] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[47729.424882] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[51329.287032] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[54929.563390] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[58529.857740] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[62128.992792] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs

What's a good solution to stopping this spew ? printk_once doesn't seem like
a good fit, in case someone is doing different labelling behaviours between mounts.

Could we only print it if the mount is being done with non-default behaviour perhaps?

Dave