Re: [BUG] x86 : i486 reporting to be vulnerable to Meltdown/Spectre_V1/Spectre_V2

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Feb 06, 2018 at 07:10:27PM +0000, David Woodhouse wrote:
> 
> 
> On Tue, 2018-02-06 at 11:02 -0800, Greg Kroah-Hartman wrote:
> > .
> > > 
> > > David
> > >   I believe I got the patch(es) you mention in in the stable 4.15.1 kernel:
> > > 
> > > Pull x86/pti updates from Thomas Gleixner: "Another set of melted
> > > spectrum related changes"
> > > (commit 6304672b7f0a5c010002e63a075160856dc4f88d).
> > > 
> > > Unfortunately, the symptoms I reported remain on at least the i486 and i686.
> > 
> > Can you try 4.15.2-rc1?  Or how about Linus's kernel tree now?  There
> > was a lot of spectrum patches merged just this week that were not in
> > 4.15.1.
> 
> No, for the 486 it *should* have worked. The interesting commit
> is fec9434a12 ("x86/pti: Do not enable PTI on CPUs which are not
> vulnerable to Meltdown") which is indeed pulled in with the merge
> commit that Matthew mentions.
> 

I disagree.

$ git describe
v4.15.1-61-g7ab5513e4cbc
$ git log --oneline v4.15.1.. | grep Melt
3472b3689bab x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown

Guenter