Re: [PATCH] x86/retpoline: Avoid return buffer underflows on context switch

[David Woodhouse]

On Tue, 2018-01-09 at 00:44 +0000, Woodhouse, David wrote:
> On IRC, Arjan assures me that 'pause' here really is sufficient as a
> speculation trap. If we do end up returning back here as a
> misprediction, that 'pause' will stop the speculative execution on
> affected CPUs even though it isn't *architecturally* documented to do
> so.
> 
> Arjan, can you confirm that in email please?


That actually doesn't make sense to me. If 'pause' alone is sufficient,
then why in $DEITY's name would we need a '1:pause;jmp 1b' loop in the
retpoline itself?

Arjan?

Attachment: smime.p7s
Description: S/MIME cryptographic signature