Re: UMIP and clearcpuid=

[Borislav Petkov <bp@alien8.de>]

On Wed, Jun 10, 2026 at 07:46:11PM +0000, Ronan Pigott wrote:
> In [1] the clearcpuid= flag was hidden, but afaik this remains the only way to
> disable UMIP.

The reason for wanting to disable it being?

> At the time UMIP was enabled, clearcpuid was apparently determined to be the
> appropriate method of disablement in [2],

Don't confuse "appropriate" with "might be good enough" ;)

> and it remains recommended by the documentation in [3].

That doc says:

"DO NOT USE this cmdline option in production - it is meant to be used only as
a quick’n’dirty debugging aid to rule out a feature-enabling code is the
culprit. If you use it, it’ll taint the kernel."

> If clearcpuid is no good, can we have a sanctioned method to disable UMIP
> protections instead then?

Let's figure out the use case first pls.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette