On 3/16/2021 2:15 PM, Peter Zijlstra wrote:
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.
We used to have shadow stack and ibt under separate Kconfig options, but
in a few places they actually share same code path, such as the XSAVES
supervisor states and ELF header for example. Anyways I will be happy
to make changes again if there is agreement.
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.
