On Thu, Sep 19, 2019 at 10:32:47PM +0200, Greg KH wrote:
> On Mon, Sep 09, 2019 at 02:45:01PM +0200, Niklas Cassel wrote:
> > Hello,
> > 
> > I would like to request
> > 2a355ec25729 ("arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field")
> > 
> > to be backported to 4.19 stable.
> > 
> > These CPUs are not susceptible to Meltdown, so enabling the mitigations
> > for Meltdown (kpti) should be redundant, especially since we know that
> > it can have a huge performance penalty for certain workloads.
> > 
> > kpti will still be automatically enabled if KASLR is enabled.
> 
> Now queued up, thanks.
> 

Hello Greg, Will,

How about applying this also to v4.14 stable?
(Since kpti is also enabled on Cortex-A CPUs in v4.14.)

2a355ec25729 does not apply cleanly on v4.14.y,
since a LOT of things have changed in the file.

git log --oneline 2a355ec25729053bb9a1a89b6c1d1cdd6c3b3fb1 --not linux-stable/linux-4.14.y arch/arm64/kernel/cpufeature.c | wc -l
72

However, I've attached a simple backport of the commit.


Kind regards,
Niklas