/kdump-playground

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Kernel dump testing

A few simple steps and scripts to force a kernelpanic or kernelpanic on softlockup to explore kernel dump debugging with the help of some kernel modules. Only tested on Ubuntu20.04 and uses Vagrant+Hyper-V/VirtualBox to quickly spin up a VM for testing. You can also use any other generic Ubuntu20.04 install.

Launch VM:

cd vagrant
vagrant up --provider hyperv
#or
vagrant up --provider virtualbox

Enable kernel.softlockup_panic and kernel.panic:

sudo vim /etc/sysctl.d/panic.conf
### Add line: kernel.softlockup_panic = 1 and kernel.panic = 20 then save.
sudo sysctl -p /etc/sysctl.d/panic.conf
sudo reboot now

Install and configure kernel crash dump:

sudo apt-get install linux-crashdump

Install prerequisites to build kernel modules:

sudo apt-get update
sudo apt-get install build-essential

Copy files in the softlockup or kernelpanic directory to the VM and build kernel module:

make

Install the kernelmodule:

sudo insmod softlockup.ko
# Or
sudo insmod kernelpanic.ko

Now wait between 30 to 60 seconds for the machine to reboot, kernel dump can now be found inside /var/crash

More information about kernel dump debugging here