[PATCH v7 22/39] arm64/gcs: Implement shadow stack prctl() interface

[Thiago Jung Bauermann]

Mark Brown <broonie at kernel.org> writes:

> Implement the architecture neutral prtctl() interface for setting the
> shadow stack status, this supports setting and reading the current GCS
> configuration for the current thread.
>
> Userspace can enable basic GCS functionality and additionally also
> support for GCS pushes and arbatrary GCS stores.  It is expected that

s/arbatrary/arbitrary/

> this prctl() will be called very early in application startup, for
> example by the dynamic linker, and not subsequently adjusted during
> normal operation.  Users should carefully note that after enabling GCS
> for a thread GCS will become active with no call stack so it is not
> normally possible to return from the function that invoked the prctl().

-- 
Thiago