[RndTbl] Horrific CPU flaws (Meltdown / Spectre)

Trevor Cordes trevor at tecnopolis.ca
Thu Jan 4 18:38:28 CST 2018


On 2018-01-04 Adam Thompson wrote:
> I don't know what's being fixed, but there are already microcode
> updates available for some Haswell Xeon E5 chips, according to OVH's
> (probably the 4th or 5th largest consumer of them) CEO on Twitter. In
> same tweet, said older chips (no idea how old) would get updates
> within weeks. YMMV. -Adam

Oh ya, that's right... as I said in my original post, the very very
latest Intel chips have new instructions that can mitigate this.
Perhaps they are changing microcode to auto-run the new instruction
when it would be prudent.  Not sure how they can do that fix for older
chips without the instruction though.

News is so sparse, poor quality, and often conflicting at the mo.
We'll see how the dust settles.

Everyone seems to be focusing on Meltdown (kernel RAM) but nothing I'm
looking at seems to solve Spectre (user RAM).  Man your JS blockers!

That link from Linus has a good technical write up, with code:
https://googleprojectzero.blogspot.ca/2018/01/reading-privileged-memory-with-side.html
Haven't waded through it all yet, but I'm eager to toy with the C code
and see what I can see on my own box.


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