CONFIG_ARM64_GCS is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Enable support for Guarded Control Stack (GCS)

modulename: gcs.ko

configname: CONFIG_ARM64_GCS

Linux Kernel Configuration
└─>Kernel Features
└─>v9.4 architectural features
└─>Enable support for Guarded Control Stack (GCS)
In linux kernel since version 6.13 (release Date: 2025-01-19)  
Guarded Control Stack (GCS) provides support for a separate
stack with restricted access which contains only return
addresses. This can be used to harden against some attacks
by comparing return address used by the program with what is
stored in the GCS, and may also be used to efficiently obtain
the call stack for applications such as profiling.

The feature is detected at runtime, and will remain disabled
if the system does not implement the feature.

source code: