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SubjectRe: [BUG] x86 : i486 reporting to be vulnerable to Meltdown/Spectre_V1/Spectre_V2
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On Tuesday 06 February 2018, tedheadster wrote:
> On Tue, Feb 6, 2018 at 3:54 PM, David Woodhouse <dwmw2@infradead.org> wrote:
> > On Tue, 2018-02-06 at 15:45 -0500, tedheadster wrote:
> >> If that is correct (and I might be wrong), then I am up to date and I
> >> am still getting the following in /proc/cpuinfo on my Pentium 4M i686:
> >>
> >> bugs : cpu_meltdown spectre_v1 spectre_v2
> >
> > That's expected for now. The CPUs we exempt are as follows:
> >
> > static const __initdata struct x86_cpu_id cpu_no_speculation[] = {
> > { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW,
> > X86_FEATURE_ANY }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW,
> > X86_FEATURE_ANY }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT,
> > X86_FEATURE_ANY }, { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL,
> > X86_FEATURE_ANY }, { X86_VENDOR_INTEL, 6,
> > INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY }, { X86_VENDOR_CENTAUR, 5
> > },
> > { X86_VENDOR_INTEL, 5 },
> > { X86_VENDOR_NSC, 5 },
> > { X86_VENDOR_ANY, 4 },
> > {}
> > };
> >
> > Alan is going to improve that list, but your Pentium 4 isn't on it yet.
> >
> > The bugs went away on the 486 though, right?
>
> Okay, recompiled for the i486 and it reports no bugs.
>
> As for the i686, it is really a "Mobile Pentium 4 HT" Prescott series
> (https://ark.intel.com/products/27368/Mobile-Intel-Pentium-4-Processor-532-
>supporting-HT-Technology-1M-Cache-3_06-GHz-533-MHz-FSB). Does that make it a
> 'speculative execution' processor?
>
> Thank you for the help and I'll test more of the museum pieces.
>
> - Matthew

What about Pentium II and 3? I'm using 5 such machines (and also a Pentium
MMX). I've tried a spectre test before and it wasn't reading anything useful.
Don't know about meltdown. Is there a complete test program? (The web is so
full of crap that even google can't find anything useful.)

--
Ondrej Zary

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