Re: Non-random RDRAND Re: [PATCH] x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h

[Neil Horman]

On Thu, Aug 15, 2019 at 11:12:24AM -0400, Theodore Y. Ts'o wrote:
> On Thu, Aug 15, 2019 at 01:24:35AM +0200, Pavel Machek wrote:
> > Burn it with fire!
> > 
> > I mean... people were afraid RDRAND would be backdoored, and you now
> > confirm ... it indeed _is_ backdoored? /., here's news for you!
> 
> To be fair to AMD, I wouldn't call it a backdoor.  Hanlon's razor is
> applicable here:
> 
> 	"Never attribute to malice that which can be adequately
> 	explained by neglect."
> 
> (Sometimes other words are used instead of neglect, but i'm trying to
> be nice.)
> 
Is it worth setting up a quirk for the Excavator era cpus, that triggers
a call to rdseed on resume?  Working under the assumption that calling
rdseed would kick the rdrand instruction back into gear.

Neil

> 
> 					- Ted
> 
> P.S.   Also applicable:
> 
> 	https://www.youtube.com/watch?v=XZxzJGgox_E
>