Re: Meltdown workaround enabled?

Mike Larkin [mlarkin@azathoth.net] wrote:
>
> I'm not sure whether or not I believe what your machine is reporting, I was
> under the assumption that new hardware was needed to fix this. Shrug.
>

There is a public PoC for meltdown and spectre on OpenBSD:

https://github.com/genua/meltdown

Here's what it looks like with the current meltdown work-around:

danka# ./meltdown -qv
CPU has RDTSCP
CPU has TSX
Access time: memory 401, cache 121 -> threshold 261
Using addr 0xffffffff818e4f30 for symbol '_version'.
0000 ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??????????
matched 0% (0 of 10 bytes)
System is not vulnerable to meltdown
0000 53 70 65 63 69 ?? 6c 20 45 78 Speci?l Ex
matched 90% (9 of 10 bytes)
System is vulnerable to spectre

here's a 6.1 system with no patches:

meltdown# ./meltdown -qv
WARNING: CPU has no RDTSCP support!
CPU has no TSX support!
Access time: memory 347, cache 98 -> threshold 222
Using addr 0xffffffff816bc1a0 for symbol '_version'.
0000 4f 70 65 6e 42 53 44 20 36 2e OpenBSD 6.
matched 100% (10 of 10 bytes)
System is vulnerable to meltdown
0000 53 70 65 63 69 61 6c 20 45 78 Special Ex
matched 100% (10 of 10 bytes)
Segmentation fault (core dumped)