Re: [PATCH 2/2] x86/random: Issue a warning if RDRAND or RDSEED fails

From: H. Peter Anvin
Date: Tue Jan 30 2024 - 13:16:43 EST


On January 30, 2024 9:58:09 AM PST, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>On 1/30/24 09:49, Jason A. Donenfeld wrote:
>>> Anybody disagree?
>> Yes, I disagree. I made a trivial test that shows RDSEED breaks easily
>> in a busy loop. So at the very least, your statement holds true only
>> for RDRAND.
>
>Well, darn. :)
>
>Any chance you could share some more information about the environment
>where you're seeing this? It'd be good to reconcile what you're seeing
>with how the hardware is expected to behave.

What CPU is this and could you clarify exactly how you run your busy loop?