Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

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dnessett
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Joined: 2019/04/24 23:24:39

Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by dnessett » 2019/05/22 23:45:51

I think there is a bug in Centos 7.6 kernel.x86_64 3.10.0-957.12.2.el7. In particular name -r is not returning the correct information.

First, here is listed pertinent information from Centos 7, 3.10.0-957.12.1.el7:

===================

[dnessett@localhost ~]$ yum list | grep kernel
abrt-addon-kerneloops.x86_64 2.1.11-52.el7.centos @base
kernel.x86_64 3.10.0-862.14.4.el7 @updates
kernel.x86_64 3.10.0-957.1.3.el7 @updates
kernel.x86_64 3.10.0-957.5.1.el7 @updates
kernel.x86_64 3.10.0-957.10.1.el7 @updates
kernel.x86_64 3.10.0-957.12.1.el7 @updates
kernel-abi-whitelists.noarch 3.10.0-957.12.1.el7 @updates
kernel-devel.x86_64 3.10.0-957.10.1.el7 @updates
kernel-devel.x86_64 3.10.0-957.12.1.el7 @updates
kernel-headers.x86_64 3.10.0-957.12.1.el7 @updates
kernel-tools.x86_64 3.10.0-957.12.1.el7 @updates
kernel-tools-libs.x86_64 3.10.0-957.12.1.el7 @updates
texlive-l3kernel.noarch 2:svn29409.SVN_4469-43.el7 @base
erlang-kernel.x86_64 R16B-03.18.el7 epel
kernel.x86_64 3.10.0-957.12.2.el7 updates
kernel-abi-whitelists.noarch 3.10.0-957.12.2.el7 updates
kernel-debug.x86_64 3.10.0-957.12.2.el7 updates
kernel-debug-devel.x86_64 3.10.0-957.12.2.el7 updates
kernel-devel.x86_64 3.10.0-957.12.2.el7 updates
kernel-doc.noarch 3.10.0-957.12.2.el7 updates
kernel-headers.x86_64 3.10.0-957.12.2.el7 updates
kernel-tools.x86_64 3.10.0-957.12.2.el7 updates
kernel-tools-libs.x86_64 3.10.0-957.12.2.el7 updates
kernel-tools-libs-devel.x86_64 3.10.0-957.12.2.el7 updates
libreport-plugin-kerneloops.x86_64 2.1.11-42.el7.centos base
lirc-disable-kernel-rc.x86_64 0.9.0-21.el7.nux nux-dextop
lirc-disable-kernel-rc.noarch 0.10.0-16.el7 epel
php-symfony-http-kernel.noarch 2.8.12-2.el7 epel
texlive-l3kernel-doc.noarch 2:svn29409.SVN_4469-43.el7 base
[dnessett@localhost ~]$

[dnessett@localhost ~]$ uname -r
3.10.0-957.12.1.el7.x86_64
[dnessett@localhost ~]$

[dnessett@localhost generated]$ pwd
/usr/src/kernels/3.10.0-957.12.1.el7.x86_64/include/generated
[dnessett@localhost generated]$ cat utsrelease.h
#define UTS_RELEASE "3.10.0-957.12.1.el7.x86_64"

[dnessett@localhost proc]$ pwd
/proc
[dnessett@localhost proc]$ cat version
Linux version 3.10.0-957.12.1.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-36) (GCC) ) #1 SMP Mon Apr 29 14:59:59 UTC 2019

===================

Notice that "name -r" returns the OS minor release (or whatever it is called) of 12.1 in 3.10.0-957.12.1.el7.x86_64. Here is the same information from Centos 7, 3.10.0-957.12.2.el7:

=======================

[dnessett@niDAQmx ~]$ yum list | grep kernel
abrt-addon-kerneloops.x86_64 2.1.11-52.el7.centos @anaconda
kernel.x86_64 3.10.0-957.el7 @anaconda
kernel.x86_64 3.10.0-957.12.2.el7 @updates
kernel-debug-devel.x86_64 3.10.0-957.12.2.el7 @updates
kernel-devel.x86_64 3.10.0-957.12.2.el7 @updates
kernel-headers.x86_64 3.10.0-957.12.2.el7 @updates
kernel-tools.x86_64 3.10.0-957.12.2.el7 @updates
kernel-tools-libs.x86_64 3.10.0-957.12.2.el7 @updates
erlang-kernel.x86_64 R16B-03.18.el7 epel
kernel-abi-whitelists.noarch 3.10.0-957.12.2.el7 updates
kernel-debug.x86_64 3.10.0-957.12.2.el7 updates
kernel-doc.noarch 3.10.0-957.12.2.el7 updates
kernel-tools-libs-devel.x86_64 3.10.0-957.12.2.el7 updates
libreport-plugin-kerneloops.x86_64 2.1.11-42.el7.centos base
lirc-disable-kernel-rc.noarch 0.10.0-16.el7 epel
php-symfony-http-kernel.noarch 2.8.12-2.el7 epel
texlive-l3kernel.noarch 2:svn29409.SVN_4469-43.el7 base
texlive-l3kernel-doc.noarch 2:svn29409.SVN_4469-43.el7 base
[dnessett@niDAQmx ~]$

[dnessett@niDAQmx ~]$ uname -r
3.10.0-957.el7.x86_64
[dnessett@niDAQmx ~]$

[dnessett@niDAQmx generated]$ pwd
/usr/src/kernels/3.10.0-957.12.2.el7.x86_64/include/generated
[dnessett@niDAQmx generated]$ cat utsrelease.h
#define UTS_RELEASE "3.10.0-957.12.2.el7.x86_64"
[dnessett@niDAQmx generated]$

[dnessett@niDAQmx proc]$ cat version
Linux version 3.10.0-957.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-36) (GCC) ) #1 SMP Thu Nov 8 23:39:32 UTC 2018
[dnessett@niDAQmx proc]$

==================

Notice that "name -r" returns 3.10.0-957.el7.x86_64, not 3.10.0-957.12.2.el7.x86_64. This difference is apparent in utsrelease.h compared with /proc/version. For some reason the uname system call is returning the wrong information.

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avij
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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by avij » 2019/05/23 04:49:34

uname -r shows information of the running kernel. In the latter case you have the new kernel installed, but you have not rebooted that system yet. After you reboot, uname -r will also show 957.12.2.

What is in/usr/src/kernels/3.10.0-957.12.[12].el7.x86_64/include/generated is irrelevant, because that comes from the kernel-devel package. The actual kernel that you run is in the "kernel" package.

dnessett
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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by dnessett » 2019/05/23 04:55:30

I installed Centos 7.6 on Monday and have rebooted several times since then.

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avij
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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by avij » 2019/05/23 05:08:22

The problem is not that uname -r (or cat /proc/version) reports wrong information, the problem is that you are not running the new kernel. Maybe there is something wrong with your boot configuration. See your /etc/grub2.cfg or /etc/grub2-efi.cfg. Reinstalling the new kernel may help.

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TrevorH
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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by TrevorH » 2019/05/23 06:17:02

Just to confirm what avij says, on my machine here after updating I get

Code: Select all

$ uname -r
3.10.0-957.12.2.el7.x86_64
so you are definitely booting the wrong kernel.
CentOS 5 died in March 2017 - migrate NOW!
Full time Geek, part time moderator. Use the FAQ Luke

dnessett
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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by dnessett » 2019/05/23 22:32:13

Found the problem. I am multi-booting the machine on which CentOS 7.6 is installed and running grub2 from another CentOS installation (kernel 3.10.0-957.12.1.el7). When I run grub2-mkconfig on (the other) CentOS, it only finds the CentOS 7.6 kernel created during installation. It isn't figuring out that there are multiple kernels and creating boot menu options for each. Since I am not a grub2 expert, it may be that grub2 can only find multiple kernels on the partition on which its OS is installed.

Here is the output from grub2-mkconfig (running on the "other" CentOS installation):

[dnessett@localhost ~]$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
[sudo] password for dnessett:
Generating grub configuration file ...
Found background: /boot/Windbuchencom.tga
Found linux image: /boot/vmlinuz-3.10.0-957.12.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.12.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.10.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.10.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.5.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.5.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.1.3.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.1.3.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-862.14.4.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-862.14.4.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-74546d29fe0647aab72add633b8d3390
Found initrd image: /boot/initramfs-0-rescue-74546d29fe0647aab72add633b8d3390.img
Found Dell Utility Partition on /dev/sda1
Found Ubuntu 14.04.1 LTS (14.04) on /dev/sda2
Found Windows 8 (loader) on /dev/sda3
Found Ubuntu 14.04.1 LTS (14.04) on /dev/sdb2
Found Ubuntu 14.04.1 LTS (14.04) on /dev/sdb5
Found CentOS Linux release 7.6.1810 (Core) on /dev/mapper/centos-root
done
[dnessett@localhost ~]$

desertcat
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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by desertcat » 2019/05/23 22:41:45

TrevorH wrote:
2019/05/23 06:17:02
Just to confirm what avij says, on my machine here after updating I get

Code: Select all

$ uname -r
3.10.0-957.12.2.el7.x86_64
so you are definitely booting the wrong kernel.
Just to confirm what TrevorH said I too ran uname -r and here is what I got:
3.10.0-957.12.2.el7.x86_64

Hope you find the problem.

dnessett
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Joined: 2019/04/24 23:24:39

Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by dnessett » 2019/05/24 04:38:55

Solved. The grub2 menu includes an "advanced options" entry that when selected shows 3 entries for CentOS 7.6. The middle entry boots into 3.10.0-957.12.2.el7.x86_64.

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Re: Bug in Centos 7.6 kernel 3.10.0-957.12.2.el7

Post by hunter86_bg » 2019/05/25 07:45:09

In such case rebuild the grub menu via 'grub2-mkconfig -o'.
Also , to check running kernel always run:

Code: Select all

cat /proc/cmdline

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