红帽全球峰会8.4. 实时对内核打补丁的过程
kpatch 内核打补丁解决方案使用 livepatch 内核子系统将过时的功能重定向到更新的功能。将实时内核补丁应用到系统会触发以下进程：
-
内核补丁模块复制到
/var/lib/kpatch/目录中，并在下次引导时由systemd注册以重新应用到内核。 -
kpatch模块加载到运行的内核中，新的功能使用指向新代码在内存中的位置的指针被注册到ftrace机制中。
当内核访问打了补丁的功能时，ftrace 机制会重定向它，绕过原始功能，并将内核引导到打了补丁的函数版本。
图 8.1. 内核实时补丁如何工作
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