[RndTbl] retbleed

[Trevor Cordes]

Oh joy, Spectre is back.  New kernels are out to fix the new retbleed.
Retbleed preys upon the fix for Spectre-2 that we all had fun with a
few years ago.

Some people thought the retpoline wasn't enough of a fix and that
returns could also be a target for these gadget & sidechannel attacks.
Turns out they were right.

Unlike past vulns that were only, or worse, on Intel, this one is
slightly worse on AMD.

Anyhow, early numbers predict a 12-25% slowdown of your box once you
update and reboot.  Joy indeed!

Info: just google retbleed