From: Coiby Xu on
gitlab.com
https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1442#note_7199...
Oh, I make a mistake. KEXEC_SIG doesn't exist for POWER. So it's indeed an NO-
OP.
Btw, POWER uses IMA appraise to verify the signature appended to the kernel
image. So it doesn't need it.