On Thu, Jan 19, 2023 at 01:22:40PM -0800, Rick Edgecombe wrote:

From: Yu-cheng Yu <redacted>

Shadow stack provides protection for applications against function return
address corruption. It is active when the processor supports it, the
kernel has CONFIG_X86_SHADOW_STACK enabled, and the application is built
for the feature. This is only implemented for the 64-bit kernel. When it
is enabled, legacy non-shadow stack applications continue to work, but
without protection.

Since there is another feature that utilizes CET (Kernel IBT) that will
share implementation with shadow stacks, create CONFIG_CET to signify
that at least one CET feature is configured.

Tested-by: Pengfei Xu <redacted>
Tested-by: John Allen <john.allen@amd.com>
Signed-off-by: Yu-cheng Yu <redacted>

Reviewed-by: Kees Cook <redacted>

-- 
Kees Cook