Re: [PATCH v23 00/28] Control-flow Enforcement: Shadow Stack

From: Peter Zijlstra
Date: Tue Mar 16 2021 - 17:52:36 EST


On Tue, Mar 16, 2021 at 08:10:26AM -0700, Yu-cheng Yu wrote:
> Control-flow Enforcement (CET) is a new Intel processor feature that blocks
> return/jump-oriented programming attacks. Details are in "Intel 64 and
> IA-32 Architectures Software Developer's Manual" [1].
>
> CET can protect applications and the kernel. This series enables only
> application-level protection, and has three parts:
>
> - Shadow stack [2],
> - Indirect branch tracking [3], and
> - Selftests [4].

CET is marketing; afaict SS and IBT are 100% independent and there's no
reason what so ever to have them share any code, let alone a Kconfig
knob.

In fact, I think all of this would improve is you remove the CET name
from all of this entirely. Put this series under CONFIG_X86_SHSTK (or
_SS) and use CONFIG_X86_IBT for the other one.

Similarly with the .c file.

All this CET business is just pure confusion.