Livepatching With Linux 5.1 To Support Atomic Replace & Cumulative Patches

With the Linux 5.1 kernel cycle that should get underway in just over one month's time, there will now be the long in development work (it's been through 15+ rounds of public code review!) for supporting atomic replace and cumulative patches.

The atomic replace support to the kernel's common livepatch infrastructure allows for replacing/reverting an existing kernel live patch and for handling of multiple patches in a series as "cumulative patches." This code also improves the behavior around the patching order/stacking and allows recovering from the overhead of functions no longer being patched. The documentation describes the inner-workings of atomic replace in much more detail.

Following this work by Akamai, SUSE, and other developers, the atomic replace / cumulative patches series was merged to livepatching for-next this week making it staged material for the upcoming Linux 5.1 cycle. Depending upon how quickly the Linux 5.0 cycle settles down and is cleared for release, the Linux 5.1 merge window should formally open up around the start of March while the 5.1 stable release would likely debut around early May.