man proc /proc/kcore This file represents the physical memory of the system and is stored in the ELF core file format. With this pseudo-file, and an unstripped kernel (/usr/src/linux/vmlinux) bi‐ nary, GDB can be used to examine the current state of any kernel data structures.
The total length of the file is the size of physical memory (RAM) plus 4 KiB.