Re: [PATCH v2 1/2] v2: more sampling fun 1

Thomas Gleixner <[email protected]> Wed, 26 Feb 2020 19:16:33 +0100
Newsgroups org.kernel.lore.historical-speck
Message-ID <[email protected]>
speck for Borislav Petkov <[email protected]> writes:
> On Wed, Feb 26, 2020 at 09:11:03AM -0800, speck for mark gross wrote:
>> Yeah, Andi pointed it out to me on an internal review.  I don't know what tool
>> is using it.
>
> Then how do you write a patch and state in the commit message that
> something is an ABI without knowing what the situation actually is?!
>
>> FWIW doing it this way made a cleaner patch without touching a dozen other
>> files using that structure.  I'd rather stay with the way it is but, if you
>> feel strongly I can do a version of what I had before only adding the new
>> members to the end.  Please let me know.
>
> Looking at that table again - cpu_vuln_whitelist - that is a
> *whitelist*. See how all the bits start with "NO_"? Except maybe
> MSBDS_ONLY.

Well, that was a decision to not have NO_MSDALL and NO_MDSSOMETHING as
it made some of logic in the code simpler.

> What you're doing is, you're misusing it to match models and steppings
> to set SRBDS* bug flags.
>
> What you should actually be doing is setting those bug flags in
> early_init_intel() where you can go wild with the steppings checking and
> then you won't need to touch x86_cpu_id at all.

Either that or add a new cpu_vuln_shitlist beside the whitelist and
stick the new stuff into that. It kinda makes sense to keep all this
vulnerability nonsense in one place.

Thanks,

        tglx