CONFIG_ARM64_UAO is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Enable support for User Access Override (UAO)

configname: CONFIG_ARM64_UAO

Linux Kernel Configuration
└─>Kernel Features
└─>ARMv8.2 architectural features
└─>Enable support for User Access Override (UAO)
In linux kernel since version 4.1 (release Date: 2015-06-21)  
User Access Override (UAO; part of the ARMv8.2 Extensions)
causes the 'unprivileged' variant of the load/store instructions to
be overridden to be privileged.

This option changes get_user() and friends to use the 'unprivileged'
variant of the load/store instructions. This ensures that user-space
really did have access to the supplied memory. When addr_limit is
set to kernel memory the UAO bit will be set, allowing privileged
access to kernel memory.

Choosing this option will cause copy_to_user() et al to use user-space
memory permissions.

The feature is detected at runtime, the kernel will use the
regular load/store instructions if the cpu does not implement the