CONFIG_ARM_KERNMEM_PERMS is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARM_KERNMEM_PERMS.
Result is shown for kernelversion 5.4.229

Restrict kernel memory permissions


Linux Kernel Configuration
└─>Restrict kernel memory permissions
In linux kernel since version 3.19 (release Date: 2015-02-08)  
If this is set, kernel memory other than kernel text (and rodata)
will be made non-executable. The tradeoff is that each region is
padded to section-size (1MiB) boundaries (because their permissions
are different and splitting the 1M pages into 4K ones causes TLB
performance problems), wasting memory.