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

On 11/30/2020 11:56 AM, Nick Desaulniers wrote:

In response to https://lore.kernel.org/lkml/20201110162211.9207-6-yu-cheng.yu@intel.com/ (local).

Hi Yu-cheng,
This feature reminds me very much of
ARCH_SUPPORTS_SHADOW_CALL_STACK/CC_HAVE_SHADOW_CALL_STACK implemented in
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5287569a790d2546a06db07e391bf84b8bd6cf51.

Do you think it would be worthwhile to share the same config name between x86
and aarch64?

The CET series has ARCH_HAS_SHADOW_STACK.  In response to Boris' earlier 
comment, I think this maybe eliminated.  In case it is still needed, I 
think it is better to have different names (but I am open to changing it).

(Though, it seems on x86 there will be a distinction between kernel mode and
user mode configs, if I understand correctly?)

Yes, on x86, kernel and user-mode can be enabled separately.

Yu-cheng