[RFC 09/10] x86/enter: Create macros to restrict/unrestrict Indirect Branch Speculation

[Greg Kroah-Hartman]

On Thu, Jan 25, 2018 at 05:19:04PM +0100, Mason wrote:
> On 23/01/2018 10:30, David Woodhouse wrote:
> 
> > Skylake takes predictions from the generic branch target buffer when
> > the RSB underflows.
> 
> Adding LAKML.
> 
> AFAIU, some ARM Cortex cores have the same optimization.
> (A9 maybe, A17 probably, some recent 64-bit cores)
> 
> Are there software work-arounds for Spectre planned for arm32 and arm64?

Yes, I think they are currently burried in one of the arm64 trees, and
they have been posted to the mailing list a few times in the past.

thanks,

greg k-h