Atomic Replace / Cumulative Patches Being Worked On For Linux Kernel Livepatching

It's been a while since last having anything new to report with the mainline Linux kernel's livepatching infrastructure, but some improvements are in the works.

Petr Mladek of SUSE has been picking up the work started by Joe Lawrence at Red Hat for atomic replace functionality for the kernel livepatches in working towards cumulative patch support.

Atomic replace and cumulative patches are designed for the use-case of having multiple patches that need to be applied and where those patches may be touching the same function(s) and thus inter-dependencies between patches. With atomic replace and cumulative patches, it allows replacing an older set of (multiple) patches in one instance rather than replacing patch by patch and needing to ensure the correct ordering, etc.

The cumulative patch documentation describes this new functionality to a greater degree for those livepatching their systems and may be encountering more complex patches where atomic replace / cumulative patches would make the effort easier.

For now this few hundred lines of new kernel code for this livepatch update can be found on the kernel mailing list.