Live Patching Now Available For Linux 117
New submitter cyranix writes "You may never have to reboot your Linux machine ever again, even for kernel patching," and excerpts from the long (and nicely human-readable) description of newly merged kernel code that does what Ksplice has for quite a while (namely, offer live updating for Linux systems, no downtime required), but without Oracle's control.
It provides a basic infrastructure for function "live patching" (i.e. code
redirection), including API for kernel modules containing the actual
patches, and API/ABI for userspace to be able to operate on the patches
(look up what patches are applied, enable/disable them, etc). It's
relatively simple and minimalistic, as it's making use of existing kernel
infrastructure (namely ftrace) as much as possible. It's also
self-contained, in a sense that it doesn't hook itself in any other kernel
subsystem (it doesn't even touch any other code). It's now implemented for
x86 only as a reference architecture, but support for powerpc, s390 and
arm is already in the works (adding arch-specific support basically boils
down to teaching ftrace about regs-saving).