查看内核版本：
root@ubuntu:~# uname -a

Linux ubuntu 4.15.0-44-generic #47-Ubuntu SMP Mon Jan 14 11:26:59 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

查看源码包名称：

root@ubuntu:~# apt-cache search linux-source

linux-source - Linux kernel source with Ubuntu patches

linux-source-4.15.0 - Linux kernel source for version 4.15.0 with Ubuntu patches

linux-source-4.18.0 - Linux kernel source for version 4.18.0 with Ubuntu patches

获取源码， 默认安装在/usr/src目录下：

root@ubuntu:~# apt-get install linux-source-4.15.0