关于Linux-Kernel-Live-patching-的操作效果演示-kpatch auto-配置

本文为了演示出效果，准备了如下的环境

操作系统：Red Hat Enterprise Linux release 8.7 (Ootpa)

内核版本：4.18.0-372.9.1.el8.x86_64

 

1、关于操作系统版本、内核、内核相关的软件包版本，情况如下：

[root@qq-5201351 ~]# cat /etc/redhat-release
Red Hat Enterprise Linux release 8.7 (Ootpa)
[root@qq-5201351 ~]# uname -r
4.18.0-372.9.1.el8.x86_64
[root@qq-5201351 ~]# rpm -qa |grep kernel
kernel-modules-4.18.0-372.9.1.el8.x86_64
kernel-core-4.18.0-372.9.1.el8.x86_64
kernel-4.18.0-372.9.1.el8.x86_64
kernel-tools-4.18.0-372.9.1.el8.x86_64
kernel-tools-libs-4.18.0-372.9.1.el8.x86_64
[root@qq-5201351 ~]#

2、安装kpatch软件包，用于实现Kernel-Live-patching

[root@qq-5201351 ~]# dnf install kpatch
Updating Subscription Management repositories.
Last metadata expiration check: 0:10:11 ago on Fri 30 Jun 2023 03:18:03 PM CST.
Dependencies resolved.
========================================================================================================================================
 Package                    Architecture           Version                          Repository                                     Size
========================================================================================================================================
Installing:
 kpatch                     noarch                 0.9.7-2.el8                      rhel-8-for-x86_64-baseos-rpms                  18 k
Installing dependencies:
 binutils                   x86_64                 2.30-119.el8                     rhel-8-for-x86_64-baseos-rpms                 5.8 M
Installing weak dependencies:
 kpatch-dnf                 noarch                 0.9.7_0.4-2.el8                  rhel-8-for-x86_64-baseos-rpms                  19 k

Transaction Summary
========================================================================================================================================
Install  3 Packages

Total download size: 5.8 M
Installed size: 24 M
Is this ok [y/N]: y
Downloading Packages:
(1/3): kpatch-0.9.7-2.el8.noarch.rpm                                                                    4.5 kB/s |  18 kB     00:03
(2/3): kpatch-dnf-0.9.7_0.4-2.el8.noarch.rpm                                                            1.7 kB/s |  19 kB     00:11
(3/3): binutils-2.30-119.el8.x86_64.rpm                                                                 410 kB/s | 5.8 MB     00:14
----------------------------------------------------------------------------------------------------------------------------------------
Total                                                                                                   412 kB/s | 5.8 MB     00:14
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                                1/1
  Installing       : kpatch-dnf-0.9.7_0.4-2.el8.noarch                                                                              1/3
  Running scriptlet: kpatch-dnf-0.9.7_0.4-2.el8.noarch                                                                              1/3
To enable automatic kpatch-patch subscription, run:
        $ dnf kpatch auto

  Installing       : binutils-2.30-119.el8.x86_64                                                                                   2/3
  Running scriptlet: binutils-2.30-119.el8.x86_64                                                                                   2/3
  Installing       : kpatch-0.9.7-2.el8.noarch                                                                                      3/3
  Running scriptlet: kpatch-0.9.7-2.el8.noarch                                                                                      3/3
  Verifying        : binutils-2.30-119.el8.x86_64                                                                                   1/3
  Verifying        : kpatch-dnf-0.9.7_0.4-2.el8.noarch                                                                              2/3
  Verifying        : kpatch-0.9.7-2.el8.noarch                                                                                      3/3
Installed products updated.

Installed:
  binutils-2.30-119.el8.x86_64                kpatch-0.9.7-2.el8.noarch                kpatch-dnf-0.9.7_0.4-2.el8.noarch

Complete!

3、此时我们通过 kpatch list 进行查看， 内容为空，如下：

[root@qq-5201351 ~]# kpatch list
Loaded patch modules:

Installed patch modules:
[root@qq-5201351 ~]#

4、内容为空，是因为没有设置yum kpatch 为auto， 接下来进行设置，执行yum kpatch auto 命令即可

[root@qq-5201351 ~]# yum kpatch auto
Updating Subscription Management repositories.
Last metadata expiration check: 0:12:14 ago on Fri 30 Jun 2023 03:18:03 PM CST.
Dependencies resolved.
========================================================================================================================================
 Package                                   Architecture         Version               Repository                                   Size
========================================================================================================================================
Installing:
 kpatch-patch-4_18_0-372_9_1               x86_64               1-3.el8               rhel-8-for-x86_64-baseos-rpms                19 k

Transaction Summary
========================================================================================================================================
Install  1 Package

Total download size: 19 k
Installed size: 32 k
Is this ok [y/N]: y
Downloading Packages:
kpatch-patch-4_18_0-372_9_1-1-3.el8.x86_64.rpm                                                          8.9 kB/s |  19 kB     00:02
----------------------------------------------------------------------------------------------------------------------------------------
Total                                                                                                   8.9 kB/s |  19 kB     00:02
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                                1/1
  Installing       : kpatch-patch-4_18_0-372_9_1-1-3.el8.x86_64                                                                     1/1
  Running scriptlet: kpatch-patch-4_18_0-372_9_1-1-3.el8.x86_64                                                                     1/1
installing /usr/lib/kpatch/4.18.0-372.9.1.el8.x86_64/kpatch-4_18_0-372_9_1-1-3.ko (4.18.0-372.9.1.el8.x86_64)
Created symlink /etc/systemd/system/multi-user.target.wants/kpatch.service → /usr/lib/systemd/system/kpatch.service.
chcon: can't apply partial context to unlabeled file '/var/lib/kpatch/4.18.0-372.9.1.el8.x86_64/kpatch-4_18_0-372_9_1-1-3.ko'
loading patch module: /var/lib/kpatch/4.18.0-372.9.1.el8.x86_64/kpatch-4_18_0-372_9_1-1-3.ko
waiting (up to 15 seconds) for patch transition to complete...
transition complete (1 seconds)

  Verifying        : kpatch-patch-4_18_0-372_9_1-1-3.el8.x86_64                                                                     1/1
Installed products updated.

Installed:
  kpatch-patch-4_18_0-372_9_1-1-3.el8.x86_64

Complete!
[root@qq-5201351 ~]#

5、这时，我们再通过 kpatch list 查看时就能看到关于当前运行内核的实时补丁了，因为上面在设置yum kpatch 为auto时，已经安装上了 kpatch-patch-4_18_0-372_9_1-1-3.el8.x86_64

[root@qq-5201351 ~]# kpatch list
Loaded patch modules:
kpatch_4_18_0_372_9_1_1_3 [enabled]

Installed patch modules:
kpatch_4_18_0_372_9_1_1_3 (4.18.0-372.9.1.el8.x86_64)
[root@qq-5201351 ~]# 

 

其他测试、看一下效果，此时我们升级一下当前内核到当前内核版本的后面一个新版本：

[root@qq-5201351 ~]# yum update kernel-4.18.0-372.13.1.el8_6
Updating Subscription Management repositories.
Last metadata expiration check: 0:14:48 ago on Fri 30 Jun 2023 03:18:03 PM CST.
Dependencies resolved.
========================================================================================================================================
 Package                                Architecture     Version                          Repository                               Size
========================================================================================================================================
Installing:
 kernel                                 x86_64           4.18.0-372.13.1.el8_6            rhel-8-for-x86_64-baseos-rpms           8.0 M
 kernel-core                            x86_64           4.18.0-372.13.1.el8_6            rhel-8-for-x86_64-baseos-rpms            39 M
 kernel-modules                         x86_64           4.18.0-372.13.1.el8_6            rhel-8-for-x86_64-baseos-rpms            32 M
 kpatch-patch-4_18_0-372_13_1           x86_64           1-2.el8_6                        rhel-8-for-x86_64-baseos-rpms            17 k

Transaction Summary
========================================================================================================================================
Install  4 Packages

Total download size: 79 M
Installed size: 92 M
Is this ok [y/N]: y
Downloading Packages:
(1/4): kernel-4.18.0-372.13.1.el8_6.x86_64.rpm                                                          176 kB/s | 8.0 MB     00:46
(2/4): kpatch-patch-4_18_0-372_13_1-1-2.el8_6.x86_64.rpm                                                 35 kB/s |  17 kB     00:00
(3/4): kernel-core-4.18.0-372.13.1.el8_6.x86_64.rpm                                                     658 kB/s |  39 MB     01:01
(4/4): kernel-modules-4.18.0-372.13.1.el8_6.x86_64.rpm                                                  417 kB/s |  32 MB     01:17
----------------------------------------------------------------------------------------------------------------------------------------
Total                                                                                                   1.0 MB/s |  79 MB     01:17
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                                1/1
  Installing       : kernel-core-4.18.0-372.13.1.el8_6.x86_64                                                                       1/4
  Running scriptlet: kernel-core-4.18.0-372.13.1.el8_6.x86_64                                                                       1/4
  Installing       : kernel-modules-4.18.0-372.13.1.el8_6.x86_64                                                                    2/4
  Running scriptlet: kernel-modules-4.18.0-372.13.1.el8_6.x86_64                                                                    2/4
  Installing       : kernel-4.18.0-372.13.1.el8_6.x86_64                                                                            3/4
  Installing       : kpatch-patch-4_18_0-372_13_1-1-2.el8_6.x86_64                                                                  4/4
  Running scriptlet: kpatch-patch-4_18_0-372_13_1-1-2.el8_6.x86_64                                                                  4/4
installing /usr/lib/kpatch/4.18.0-372.13.1.el8_6.x86_64/kpatch-4_18_0-372_13_1-1-2.ko (4.18.0-372.13.1.el8_6.x86_64)
chcon: can't apply partial context to unlabeled file '/var/lib/kpatch/4.18.0-372.13.1.el8_6.x86_64/kpatch-4_18_0-372_13_1-1-2.ko'

  Running scriptlet: kernel-core-4.18.0-372.13.1.el8_6.x86_64                                                                       4/4
/etc/dracut.conf.d/xen.conf:add_drivers+="xen_netfront xen_blkfront "

dracut: WARNING: <key>+=" <values> ": <values> should have surrounding white spaces!
dracut: WARNING: This will lead to unwanted side effects! Please fix the configuration file.


  Running scriptlet: kpatch-patch-4_18_0-372_13_1-1-2.el8_6.x86_64                                                                  4/4
  Verifying        : kernel-modules-4.18.0-372.13.1.el8_6.x86_64                                                                    1/4
  Verifying        : kernel-4.18.0-372.13.1.el8_6.x86_64                                                                            2/4
  Verifying        : kernel-core-4.18.0-372.13.1.el8_6.x86_64                                                                       3/4
  Verifying        : kpatch-patch-4_18_0-372_13_1-1-2.el8_6.x86_64                                                                  4/4
Installed products updated.

Installed:
  kernel-4.18.0-372.13.1.el8_6.x86_64            kernel-core-4.18.0-372.13.1.el8_6.x86_64  kernel-modules-4.18.0-372.13.1.el8_6.x86_64
  kpatch-patch-4_18_0-372_13_1-1-2.el8_6.x86_64

Complete!
[root@qq-5201351 ~]# 

这时我们再查看kpatch list 还是只开启了当前内核的热补丁

[root@qq-5201351 ~]# kpatch list
Loaded patch modules:
kpatch_4_18_0_372_9_1_1_3 [enabled]

Installed patch modules:
kpatch_4_18_0_372_13_1_1_2 (4.18.0-372.13.1.el8_6.x86_64)
kpatch_4_18_0_372_9_1_1_3 (4.18.0-372.9.1.el8.x86_64)
[root@qq-5201351 ~]# yum kpatch auto
Updating Subscription Management repositories.
Last metadata expiration check: 0:18:11 ago on Fri 30 Jun 2023 03:18:03 PM CST.
Dependencies resolved.
Nothing to do.
Complete!
[root@qq-5201351 ~]# 

这里可以看到当前 Loaded patch modules 里，还是当前运行内核版本的热补丁模块，但上面我们升级内核时，其实也已经安装了新版本内核的热补丁模块

但不会被Load， 因为只会加载开启当前运行内核的热补丁，笔者测试重启OS后，再通过kpatch list 查看就能看到新版本的内核热补丁就会出现在Loaded patch modules 当中了

当然只要不重启OS，当前的内核版本、始终都还是之前运行的内核版本

[root@qq-5201351 ~]# uname -r
4.18.0-372.9.1.el8.x86_64
[root@qq-5201351 ~]# 

 

最后也附上关于 4.18.0-372 版本的内核Kernel 与 kpatch-patch 的版本情况，先是内核版本

kernel.x86_64        4.18.0-372.9.1.el8           rhel-8-for-x86_64-baseos-rpms
kernel.x86_64        4.18.0-372.13.1.el8_6        rhel-8-for-x86_64-baseos-rpms
kernel.x86_64        4.18.0-372.16.1.el8_6        rhel-8-for-x86_64-baseos-rpms
kernel.x86_64        4.18.0-372.19.1.el8_6        rhel-8-for-x86_64-baseos-rpms
kernel.x86_64        4.18.0-372.26.1.el8_6        rhel-8-for-x86_64-baseos-rpms
kernel.x86_64        4.18.0-372.32.1.el8_6        rhel-8-for-x86_64-baseos-rpms

然后也附上4.18.0-372 版本的 kpatch-patch的小版本

kpatch-patch-4_18_0-372_9_1.x86_64                     1-3.el8                         rhel-8-for-x86_64-baseos-rpms
kpatch-patch-4_18_0-372_13_1.x86_64                    1-2.el8_6                       rhel-8-for-x86_64-baseos-rpms
kpatch-patch-4_18_0-372_16_1.x86_64                    1-2.el8_6                       rhel-8-for-x86_64-baseos-rpms
kpatch-patch-4_18_0-372_19_1.x86_64                    1-1.el8_6                       rhel-8-for-x86_64-baseos-rpms
kpatch-patch-4_18_0-372_26_1.x86_64                    1-1.el8_6                       rhel-8-for-x86_64-baseos-rpms
kpatch-patch-4_18_0-372_32_1.x86_64                    0-0.el8_6                       rhel-8-for-x86_64-baseos-rpms

说明：其中关于kpatch-patch 最后是0-0的、是代表当前包是空的，没有热补丁模块，笔者查看了一下当前版本的内核，也是一样，空的，(contains no files) ~

 

 

 

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