Linux Reworks AMD Zen 1 Divide-By-Zero Mitigation After Original Fix Inadequate

Following last week's AMD Inception vulnerability another AMD Zen CPU bug came to light and that was performing a divide by zero on Zen 1 could end up leaking data with this DIV0 speculation bug. The original workaround was performing a dummy division 0/1 within the #DE exception handler but that's now turned out to be inadequate...