Re: [PATCH v15 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack

From: Borislav Petkov
Date: Tue Dec 01 2020 - 11:03:00 EST


On Mon, Nov 30, 2020 at 02:48:09PM -0800, Yu, Yu-cheng wrote:
> Logically, enabling IBT without shadow stack does not make sense, but these
> features have different CPUIDs, and CONFIG_X86_SHADOW_STACK_USER and
> CONFIG_X86_BRANCH_TRACKING_USER can be selected separately.
>
> Do we want to have only one selection for both features? In other words, we
> turn on both or neither.

Question is, do they need to be handled separately at all?

If not and IOW, I like dhansen's X86_FEATURE_CET synthetic feature
suggestion.

Thx.

--
Regards/Gruss,
Boris.

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