What Is /proc/kcore?

None of the files in /proc are really there--they're all, "pretend,"
files made up by the kernel, to give you information about the system
and don't take up any hard disk space.

/proc/kcore is like an "alias" for the memory in your computer. Its
size is the same as the amount of RAM you have, and if you read it as
a file, the kernel does memory reads.