Re: [PATCH v11 4/9] x86/alternatives: Disable LASS when patching kernel code

From: Borislav Petkov

Date: Mon Nov 10 2025 - 14:26:00 EST


On Mon, Nov 10, 2025 at 10:15:23AM -0800, Sohil Mehta wrote:
> lass_clac()/_stac():
> Disable enforcement for kernel data accesses similar to SMAP.
>
> lass_enable()/_disable():
> Disable the entire LASS mechanism (Data and instruction fetch)
> by toggling CR4.LASS
>
> Would that work? Any other suggestions?

Sure, as long as they're documented. And if we decide to change them later for
whatever reason, we can. More than enough bikeshedding we did here.

Thx.

--
Regards/Gruss,
Boris.

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