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iPhone update for Meltdown-Spectre: before/after performance benchmarks

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Re: iPhone update for Meltdown-Spectre: before/after performance benchmarks

#31

Post by perlgeek »

brador wrote: post #24

Is this a "bug" we can recover from (in future hardware or software) or are we going to collectively take a lifetime -18 hit to our Moore's Law progress and lose the gains from this technique forever?

At least for Meltdown there are CPU microcode updates out there that should mitigate it, which means the OS level mitigations can be rolled back. And I haven't measured it yet, but I suspect the microcode mitigates are faster.

Regarding Spectre, I think it's too early to tell.

Re: iPhone update for Meltdown-Spectre: before/after performance benchmarks

#32

Post by MBCook »

tn_ wrote: post #8

This might sound dumb but.. with these Meltdown + Spectre bugs would an attacker be able to penetrate to gain full access only if a user downloads a native app or would it be possible through the browser/js?

Not if their browser hasn’t been patched.

Re: iPhone update for Meltdown-Spectre: before/after performance benchmarks

#35

Post by anvandare »

tn_ wrote: post #8

This might sound dumb but.. with these Meltdown + Spectre bugs would an attacker be able to penetrate to gain full access only if a user downloads a native app or would it be possible through the browser/js?

Spectre can give you read-access to the browser process via Javascript, yes, as they described in the original article: https://spectreattack.com/spectre.pdf (section 4.3 on page 6). No write access, or access to the OS internals.

Re: iPhone update for Meltdown-Spectre: before/after performance benchmarks

#36

Post by FBISurveillance »

bfrog wrote: post #9
FBISurveillance wrote: post #2

I've went through Denial, Anger, Bargaining, and now in an Acceptance stage after taking up to 31% performance hit on some of services managed by my team. Worst case has been Elasticsearch so far with our load pattern, taking that 31% hit. Oh well, too bad, enjoying the ride.

Time to switch to an Epyc host?

We're actually using those new 24-core Epyc hosts for our data science pipeline (HDP/Spark cluster) and they work much better than our previous generation Xeon-based builds.

Unfortunately, with those things it takes plenty of time to re-evaluate hardware + in our case we're mostly in the cloud where Skylakes on GCP is the most we can get.

Re: iPhone update for Meltdown-Spectre: before/after performance benchmarks

#39

Post by dogma1138 »

JoachimSchipper wrote: post #26
sschueller wrote: post #22

Is the Samsung S8 CPU also affected? I saw that some ARMs are not affected. EDIT: It appears not the be on the list of affected ARMs [1]. The S8 Exynos 9 Octa 8895 is based on the Cortex-A53 [1] https://developer.arm.com/support/security-update EDIT2: The Snapdragon 820 and 835 do appear to be affected which are the CPU in the US version of the S8

Assume that [EDIT: high-end - dogma1138 is right] smartphone-class processors and above are affected. Raspberry Pi and microcontroller-class ARMs are fine, though (but much slower!)

Most of them aren't affected mid range ARM and below aren't vulnerable, basically if you have a flagship product you should worry.

If we take the snapdragon example the 6XX's aren't affected while the 8XX are.

Re: iPhone update for Meltdown-Spectre: before/after performance benchmarks

#40

Post by mrpippy »

sschueller wrote: post #22

Is the Samsung S8 CPU also affected? I saw that some ARMs are not affected. EDIT: It appears not the be on the list of affected ARMs [1]. The S8 Exynos 9 Octa 8895 is based on the Cortex-A53 [1] https://developer.arm.com/support/security-update EDIT2: The Snapdragon 820 and 835 do appear to be affected which are the CPU in the US version of the S8

It looks like the Exynos 9 Octa 8895's 4 main (big) cores are a custom Samsung architecture which is almost certainly out-of-order, and is probably affected. The "little" cores are Cortex-A53, which is in-order and not affected.
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