[U-Boot] U-Boot, cache speculation side channel attacks and ARM

[Russell King]

On Sat, Jan 20, 2018 at 11:31:19AM +0000, Marc Zyngier wrote:
> Define enough. These patches allow these CPUs to cope with variant-2,
> and only variant-2. Variant-1 is still work in progress across all
> architectures, variant-3 (aka Meltdown) doesn't concern 32bit ARM
> implementations, and only A15 is susceptible to variant-3a.

I think you need to be really careful about statements like this.

As you know, it is possible to run a 32bit environment in a VM on
the 64bit CPUs.  So, its entirely possible to run a 32bit setup
on a Cortex A72 for example, and that means such a setup _is_
vulnerable to variant 3a.

Do people do this?  That isn't something we can really know, but
I think as long as its allowed, you can bet that someone will,
and someone will end up using it in a production environment.

So, it can't be ignored.

-- 
Russell King