3 ms·

Do spectre mitigations already out there fix this?

• ajross 8y ago
  In principle, yes. It's not a different exploit, it's just a different measurement technique for the timing (and one that most people wouldn't have expected to be possible).
  • loeg 8y ago
    Isn't the AVX warmup latency a novel mechanism not docuemnted in existing literature and therefore not mitigated? They also point out that lfence is not a total solution to preventing speculative access (and it isn't being adopted anyway since the performance cost is high).
    • rurban 8y ago
      AVX and esp. AVX2 warmup time is very well known. That's why they tried it over this path at first. But you could use normal instructions also, it's just slower to extract keys.
      • loeg 8y ago
        For ordinary execution, yes, but was it known that the processor warms up the AVX units based on speculated branches?