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notfred
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Location: Ottawa, Canada

Intel Speculative Execution - yet another flaw

Thu Jun 14, 2018 12:01 pm

Lazy FP state restore leaks state, including potentially your crypto keys:

https://www.intel.com/content/www/us/en ... 00145.html

https://twitter.com/cperciva/status/1007010583244230656

So far Intel only, not AMD.

Guess I need to wait a bit longer to build a new PC:
https://techreport.com/discussion/33699 ... 01#1080001
 
srg86
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Posts: 239
Joined: Tue Apr 25, 2006 7:57 am
Location: Madison, WI

Re: Intel Speculative Execution - yet another flaw

Thu Jun 14, 2018 12:47 pm

Compared to Meltdown and Spectre, this one is a non-issue, as most modern OSs (Windows and Linux 4.9 and later) already use Eager FP state save/restore anyway. I wouldn't let this one hold off a purchase.

Lazy FP save/restore comes from an age of separate Math Co-processor chips where most of the overhead was simply transferring data between the CPU, FPU and RAM. Especially since XSAVEOPT which does optimizations in hardware, Eager FP is now the norm from what I understand.
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