Spectre V1 Mitigation, IBPB Support Sent In For Linux 4.16

[phoronix]

Phoronix: Spectre V1 Mitigation, IBPB Support Sent In For Linux 4.16

Last week Meltdown/Spectrum patch wrangler Thomas Gleixner sent in various code clean-ups for Retpolines and KPTI with Linux 4.16 while today more feature work has been submitted. This initial initial mitigation work for Spectre v1 as well as IBPB support...

http://www.phoronix.com/scan.php?page=news_item&px=Spectre-v1-IBPB-Linux-4.16-Pull

[NateHubbard]

Well, at least we're getting there. Let's just hope they don't find any more weaknesses in our processors.
Also, this sentence could use some work:

"This initial initial mitigation work for Spectre v1 as well as IBPB support."

[Adarion]

The x86 Centaur/VIA and NSC CPUs are also being whitelisted.

Ah, pure goodness, yeah! Hehehe, I knew my old boxes were too simple for it.
Well, still no reason not to keep shields up, at least a little.

In other news intel also release new ucode, I'd still keep my fingers off it. (Not that I really have affected CPUs here (AMD only and some ancient stuff), but in my family a notebook refused to boot early Jan. this year, just after a ucode update by intel hit SuSE's repos... Better wait for the first fallout.)


Is there any easy to use tool around that can check if meltdown and the spectre(s) work on a CPU? I mean actually testing, not checking for mitigations. I do my own kernels so I already rather know what I selected and if I used gcc < or > 7.3.x.
Meltdown should be easier to check for, but spectres might be more CPU specific (and e.g. AMD itself needed some time to get the one variant halfway working on their CPUs, and they have full documentation). Still, it would be nice, because nobody really writes anything about the rare CPUs and I could test a few.

[numacross]

In other news intel also release new ucode, I'd still keep my fingers off it. (Not that I really have affected CPUs here (AMD only and some ancient stuff), but in my family a notebook refused to boot early Jan. this year, just after a ucode update by intel hit SuSE's repos... Better wait for the first fallout.)

Those updates to microcode made all major motherboard vendors recall their BIOS updates. Even Microsoft has disabled the mitigations relying on the microcode to stop the... how did they PR spin it? Oh yeah... "as they may introduce higher than expected reboots and other unpredictable system behavior".

Well done Intel on leaving every generation since Haswell still broken (https://newsroom.intel.com/wp-content/uploads/sites/11/2018/01/microcode-update-guidance.pdf), we're eagerly expecting new microcode for even older CPUs

Is there any easy to use tool around that can check if meltdown and the spectre(s) work on a CPU? I mean actually testing, not checking for mitigations. I do my own kernels so I already rather know what I selected and if I used gcc < or > 7.3.x.
Meltdown should be easier to check for, but spectres might be more CPU specific (and e.g. AMD itself needed some time to get the one variant halfway working on their CPUs, and they have full documentation). Still, it would be nice, because nobody really writes anything about the rare CPUs and I could test a few.

Maybe those will help https://it.slashdot.org/comments.pl?...3&cid=56066735

[jb.1234abcd]

Malware Exploiting Spectre, Meltdown CPU Flaws Emerges

https://it.slashdot.org/story/18/02/04/045214/malware-exploiting-spectre-meltdown-cpu-flaws-emerges

[dungeon]

Cool Only question is in what scenarios we are slower, now are benchmarks needed

> cat /proc/sys/kernel/osrelease
4.15.0-next-20180205
> cat /sys/devices/system/cpu/vulnerabilities/*
Not affected
Mitigation: __user pointer sanitization
Mitigation: Full AMD retpoline

[rene]

so with all the mitigation slowdown of Intel CPUs, are AMD CPUs faster in all benchmarks already?

[numacross]

Intel’s latest microcode works fine for me on all my Lenovo laptops, must just be buggy Dell desktop computers. 🤪

And Lenovo did withdraw the updates as well.

I haven't hit the bug yet on multiple generations of Dell and HP gear with those updates. I guess we are just that lucky