Linux kernel live patching

kexec (kernel execute), analogous to the Unix/Linux kernel call exec, is a mechanism of the Linux kernel that allows booting of a new kernel from the currently running one.

Ksplice is an open-source extension of the Linux kernel that allows security patches to be applied to a running kernel without the need for reboots, avoiding downtimes and improving availability (a technique broadly referred to as dynamic software updating). Ksplice supports only the patches that do not make significant semantic changes to kernel's data structures.