Missing documentation for lockdown

[Mathieu Trudel-Lapierre]

When attempting to load unsigned modules and the signatures are enforced, a message shows in dmesg pointing to an inexistant manpage:

[...]
[ 5.154346] Adding 1003516k swap on /dev/mapper/10--3--99--105--vg-swap_1. Priority:-2 extents:1 across:1003516k FS
[ 5.277619] new mount options do not match the existing superblock, will be ignored
[ 95.502081] random: crng init done
[ 110.298603] PKCS#7 signature not signed with a trusted key
[ 110.298628] Lockdown: Loading of unsigned modules is restricted; see man kernel_lockdown.7

ubuntu@sacred-civet:~$ man kernel_lockdown.7
man: can't set the locale; make sure $LC_* and $LANG are correct
No manual entry for kernel_lockdown.7
ubuntu@sacred-civet:~$ man 7 kernel_lockdown
man: can't set the locale; make sure $LC_* and $LANG are correct
No manual entry for kernel_lockdown in section 7
ubuntu@sacred-civet:~$ man kernel_lockdown
man: can't set the locale; make sure $LC_* and $LANG are correct
No manual entry for kernel_lockdown
ubuntu@sacred-civet:~$

ubuntu@sacred-civet:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu Bionic Beaver (development branch)
Release: 18.04
Codename: bionic
ubuntu@sacred-civet:~$ cat /proc/version_signature
Ubuntu 4.15.0-13.14-generic 4.15.10

[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 1765761

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.

[Daniel van Vugt (vanvugt)]

Also:

[ 5.277619] new mount options do not match the existing superblock, will be ignored
[ 95.502081] random: crng init done

is bug 1685794 :)