Photon update forcing rdrand-rng

REF: https://github.com/vmware/photon/issues/774

I just ran security updates on my Photon install and upon checking to see if all my system d services restarted, I found the following...

[ ~ ]$ systemctl status systemd-modules-load
● systemd-modules-load.service - Load Kernel Modules
   Loaded: loaded (/lib/systemd/system/systemd-modules-load.service; static; vendor preset: ena>
   Active: failed (Result: exit-code) since Mon 2020-12-21 12:35:59 EST; 44min ago
     Docs: man:systemd-modules-load.service(8)
           man:modules-load.d(5)
  Process: 397 ExecStart=/lib/systemd/systemd-modules-load (code=exited, status=1/FAILURE)
 Main PID: 397 (code=exited, status=1/FAILURE)

I investigated the PID...

[ ~ ]$ sudo journalctl _PID=397
[sudo] password for rstewart
-- Logs begin at Wed 2020-10-28 12:28:38 EDT, end at Mon 2020-12-21 13:21:40 EST. --
Dec 21 12:35:59 photon-1 systemd-modules-load[397]: Failed to insert 'rdrand_rng': No such devi>
lines 1-2/2 (END)

After a thorough search I found the issue above. I checked /etc/modules-load.d/ and found the file adding the rdrand-rng module to the kernal. I verified in dmesg that this is not supported on my CPU...

[ ~ ]$ sudo dmesg | grep rdrand
[    1.575933] rdrand_rng: Cannot load module, as your CPU does not support RDSEED or RDRAND instructions.
[    3.502349] rdrand_rng: Cannot load module, as your CPU does not support RDSEED or RDRAND instructions.

I commented out the rdrand-rng statement in the config file and rebooted. System came back up without the failed kernal module statement notice in systemctl. Not sure what change fixed this the first time, but this appears to be a regression. My install is only 30 days old and I am not completely sure if the problem was present on install.
The final state after work-around...

[ ~ ]$ systemctl status systemd-modules-load
● systemd-modules-load.service - Load Kernel Modules
   Loaded: loaded (/lib/systemd/system/systemd-modules-load.service; static; vendor preset: ena>
   Active: active (exited) since Mon 2020-12-21 13:27:46 EST; 4min 17s ago
     Docs: man:systemd-modules-load.service(8)
           man:modules-load.d(5)
  Process: 390 ExecStart=/lib/systemd/systemd-modules-load (code=exited, status=0/SUCCESS)
 Main PID: 390 (code=exited, status=0/SUCCESS)

Cheers,

Raymond

Start by inspecting the /etc/modules-load.d/ file that adds rdrand-rng and compare it with the referenced issue 774 and the kernel messages showing unsupported RDSEED or RDRAND instructions. Confirm the appropriate behavior on CPUs without those instructions and verify that systemd-modules-load finishes successfully without the failed module notice.