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

[David Woodhouse]

On Tue, 2018-02-06 at 11:02 -0800, Greg Kroah-Hartman wrote:
> .
> >Â
> > David
> >ÂÂ I believe I got the patch(es) you mention in in the stable 4.15.1 kernel:
> >Â
> > Pull x86/pti updates from Thomas Gleixner: "Another set of melted
> > spectrum related changes"
> > (commit 6304672b7f0a5c010002e63a075160856dc4f88d).
> >Â
> > 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
isÂfec9434a12 ("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.

Matthew, can you show the content of /proc/cpuinfo please? And perhaps
add a printk or two in early_identify_cpu() to work out what's going
on?

Your CPU *should* hit the x86_match_cpu(cpu_no_speculation) case and
not set any of the three bugs, AFAICT.

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