Re: [PATCH v5 1/3] x86/cpu: Clear feature bits disabled at compile-time

[Sohil Mehta]

On 2/12/2026 1:51 PM, Borislav Petkov wrote:
> On February 12, 2026 9:34:31 PM UTC, "H. Peter Anvin" <hpa@xxxxxxxxx> wrote:
>> As the original author of the code I'm pretty sure that bug was always there.
> 
> So, we don't need to backport it anywhere, we change it now in 7.0 or whatever and so be it. We can backport a documentation patch if someone is really pounding on it beint precisely correct for whatever reason...
> 
> 

Can we just deprecate the "Flags" bits of /proc/cpuinfo at this point?

No production software can be using this meaningfully. We have always
said that the *absence* of the feature doesn't mean anything. The
feature could be disabled or the kernel doesn't know about it.

And now we've realized that the *presence* of the feature in
/proc/cpuinfo doesn't mean anything either.

Should we come up with a more thought-out mechanism for user space
feature detection?