Patching kernel functions in memory on a live machine. Taken from samples/livepatch.
This livepatch kernel module creates a replacement for cmdline_proc_show() from fs/proc/cmdline.c to simply print a message out instead of the usual cmdline.
To use:
- Check the output of
cat /proc/cmdline - Build with
make, and load into the kernel withinsmod livepatch-sample.ko - Check the output again of
cat /proc/cmdline - Disable the livepatch with
echo 0 | sudo tee /sys/kernel/livepatch/livepatch-sample/enabled - Unload from the kernel with
rmmod livepatch-sample.ko
Tested on Ubuntu 20.04 running under Vagrant.