On 2/5/20 10:19 AM, Yu-cheng Yu wrote:

quoted

Introduce Kconfig option: X86_INTEL_SHADOW_STACK_USER.

Shadow Stack (SHSTK) provides protection against function return address
corruption.  It is active when the kernel has this feature enabled, and
both the processor and the application support it.  When this feature is
enabled, legacy non-SHSTK applications continue to work, but without SHSTK
protection.

The user-mode SHSTK protection is only implemented for the 64-bit kernel.
IA32 applications are supported under the compatibility mode.

I think what you're trying to say here is that the hardware supports
shadow stacks with 32-bit kernels.  However, this series does not
include that support and we have no plans to add it.

Right?

I'll let others weigh in, but I rather dislike the use of acronyms here.
 I'd much rather see the english "shadow stack" everywhere than SHSTK.

For the record, I like "shadow stack" better, too.