CONFIG_ADDRESS_MASKING is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

Linear Address Masking support

configname: CONFIG_ADDRESS_MASKING

Linux Kernel Configuration
└─>Processor type and features
└─>Linear Address Masking support
In linux kernel since version 6.4 (release Date: 2023-06-25)  
Linear Address Masking (LAM) modifies the checking that is applied
to 64-bit linear addresses, allowing software to use of the
untranslated address bits for metadata.

The capability can be used for efficient address sanitizers (ASAN)
implementation and for optimizations in JITs.

depends
CONFIG_X86_64