On Wed, 2023-11-22 at 09:42 +0000, Mark Brown wrote: > These features are expected to be inherited by new threads and > cleared > on exec(), unknown features should be rejected for enable but > accepted > for locking (in order to allow for future proofing). The reason why I stuck with arch_prctl when this came up is that CRIU (and probably other ptracers) needs a way to unlock via ptrace. ptrace arch_prctl() can do this. Did you have a plan for unlocking via ptrace?