Comment 27 for bug 1862708

I'm sorry for the slow response Francis, I've been running custom kernels for:
https://bugs.launchpad.net/bugs/1861359
for a while. Thanks for the reminder.

sarnold@millbarge:~$ dmesg | grep -i lockdown
[ 0.000000] Kernel is locked down from EFI Secure Boot mode; see man kernel_lockdown.7
[ 1.009940] Lockdown: swapper/0: hibernation is restricted; see man kernel_lockdown.7
[ 22.929952] Lockdown: systemd: /dev/mem,kmem,port is restricted; see man kernel_lockdown.7
[ 26.152235] Lockdown: Xorg: raw io port access is restricted; see man kernel_lockdown.7
[ 30.333255] Lockdown: rasdaemon: debugfs access is restricted; see man kernel_lockdown.7
sarnold@millbarge:~$ sudo -s
[sudo] password for sarnold:
root@millbarge:/home/sarnold# kprobe-perf -s 'p:shrink_node'
Tracing kprobe shrink_node. Ctrl-C to end.
^C
Ending tracing...
root@millbarge:/home/sarnold# ls -l /sys/kernel/debug/tracing/available_filter_functions
-r--r--r-- 1 root root 0 Apr 3 02:18 /sys/kernel/debug/tracing/available_filter_functions
root@millbarge:/home/sarnold# uname -a
Linux millbarge 5.4.0-21-generic #25-Ubuntu SMP Sat Mar 28 13:10:28 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
root@millbarge:/home/sarnold# dpkg -l 'linux*' | grep ^ii
ii linux-base 4.5ubuntu3 all Linux image base package
ii linux-firmware 1.187 all Firmware for Linux kernel drivers
ii linux-generic 5.4.0.21.25 amd64 Complete Generic Linux kernel and headers
ii linux-headers-5.4.0-18 5.4.0-18.22 all Header files related to Linux kernel version 5.4.0
ii linux-headers-5.4.0-18-generic 5.4.0-18.22 amd64 Linux kernel headers for version 5.4.0 on 64 bit x86 SMP
ii linux-headers-5.4.0-20 5.4.0-20.24 all Header files related to Linux kernel version 5.4.0
ii linux-headers-5.4.0-20-generic 5.4.0-20.24 amd64 Linux kernel headers for version 5.4.0 on 64 bit x86 SMP
ii linux-headers-5.4.0-21 5.4.0-21.25 all Header files related to Linux kernel version 5.4.0
ii linux-headers-5.4.0-21-generic 5.4.0-21.25 amd64 Linux kernel headers for version 5.4.0 on 64 bit x86 SMP
ii linux-headers-generic 5.4.0.21.25 amd64 Generic Linux kernel headers
ii linux-image-5.4.0-20-generic 5.4.0-20.24 amd64 Signed kernel image generic
ii linux-image-5.4.0-21-generic 5.4.0-21.25 amd64 Signed kernel image generic
ii linux-image-generic 5.4.0.21.25 amd64 Generic Linux kernel image
ii linux-image-unsigned-5.4.0-18-generic 5.4.0-18.22 amd64 Linux kernel image for version 5.4.0 on 64 bit x86 SMP
ii linux-libc-dev:amd64 5.4.0-21.25 amd64 Linux Kernel Headers for development
ii linux-modules-5.4.0-18-generic 5.4.0-18.22 amd64 Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii linux-modules-5.4.0-20-generic 5.4.0-20.24 amd64 Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii linux-modules-5.4.0-21-generic 5.4.0-21.25 amd64 Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii linux-modules-extra-5.4.0-18-generic 5.4.0-18.22 amd64 Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii linux-modules-extra-5.4.0-20-generic 5.4.0-20.24 amd64 Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii linux-modules-extra-5.4.0-21-generic 5.4.0-21.25 amd64 Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
ii linux-tools-5.4.0-18 5.4.0-18.22 amd64 Linux kernel version specific tools for version 5.4.0-18
ii linux-tools-5.4.0-18-generic 5.4.0-18.22 amd64 Linux kernel version specific tools for version 5.4.0-18
ii linux-tools-5.4.0-20 5.4.0-20.24 amd64 Linux kernel version specific tools for version 5.4.0-20
ii linux-tools-5.4.0-20-generic 5.4.0-20.24 amd64 Linux kernel version specific tools for version 5.4.0-20
ii linux-tools-5.4.0-21 5.4.0-21.25 amd64 Linux kernel version specific tools for version 5.4.0-21
ii linux-tools-5.4.0-21-generic 5.4.0-21.25 amd64 Linux kernel version specific tools for version 5.4.0-21
ii linux-tools-common 5.4.0-21.25 all Linux kernel version specific tools for version 5.4.0
ii linux-tools-generic 5.4.0.21.25 amd64 Generic Linux kernel tools
root@millbarge:/home/sarnold# man kernel_lockdown
No manual entry for kernel_lockdown
root@millbarge:/home/sarnold#

Other tools also work now:

root@millbarge:/home/sarnold# tcpconnect-bpfcc
Tracing connect ... Hit Ctrl-C to end
PID COMM IP SADDR DADDR DPORT
6781 ssh 4 192.168.0.34 192.168.0.8 22

Thanks