Re: [PATCH v2] x86/amd: Disable RDSEED on AMD Zen5 because of an error.

[Jason A. Donenfeld]

On Wed, Nov 05, 2025 at 08:41:01AM -0800, Thiago Macieira wrote:
> > Oh yea, good question. Well, with every major OS now having a mechanism
> > to skip syscalls for random numbers, I guess you could indeed just alias
> > global() to system() and call it a day. Then users really cannot shoot
> > themselves in the foot. That would be simpler too. Seems like the best
> > option.
> 
> Indeed.
> 
> But consider people who haven't upgraded Linux (yes, we get people asking to 
> keep everything intact in their system, but upgrade Qt only, then complain 
> when our dependency minimums change). How much of an impact would they have?

I suppose you could benchmark it and see if it matters. The syscall is
obviously slower than the megafast vDSO code, so it will probably also
be a bit slower than the MT code. But I suspect for most use cases maybe
it doesn't matter that much? It's worth a try and seeing if anybody
complains.

Jason