There's already been Ksplice for dynamic, live patching of the Linux kernel. Last month SUSE came out with their own form of live kernel patching via kGraft. Last week, Red Hat announced Kpatch.
Kpatch is now available under the GPLv2 license after having been worked on internally at Red Hat for several months. Kpatch allows for patching a Linux kernel without rebooting or restarting processes. Kpatch works at the function level for replacing old functions with new functions via hot patch modules.
Kpatch isn't yet considered production ready but those wishing to learn more can find additional details via the Red Hat blog. The GPL code to Kpatch is currently hosted on GitHub.