KGDB: kernel debugger

modulename: kgdb.ko

and/or

debug_core.ko

configname: CONFIG_KGDB

Linux Kernel Configuration
└─>Kernel hacking
└─>KGDB: kernel debugger
In linux kernel since version 2.6.12  
If you say Y here, it will be possible to remotely debug the
kernel using gdb. It is recommended but not required, that
you also turn on the kernel config option
CONFIG_FRAME_POINTER to aid in producing more reliable stack
backtraces in the external debugger. Documentation of
kernel debugger is available at http://kgdb.sourceforge.net
as well as in Documentation/dev-tools/kgdb.rst. If
unsure, say N.

source code: