version check fails on RHEL / CentOS 7.x

[sspans]

Installing the openvswitch datapath modules via DKMS fails on redhat/centos 7 because the original modules are tagged with a checksum in the srcversion field:

# modinfo /lib/modules/3.10.0-514.el7.x86_64/kernel/net/openvswitch/openvswitch.ko
filename:       /lib/modules/3.10.0-514.el7.x86_64/kernel/net/openvswitch/openvswitch.ko
license:        GPL
description:    Open vSwitch switching datapath
rhelversion:    7.3
srcversion:     B31AE95554C9D9A0067F935
depends:        nf_conntrack,nf_nat,libcrc32c,nf_nat_ipv6,nf_nat_ipv4,nf_defrag_ipv6
intree:         Y
vermagic:       3.10.0-514.el7.x86_64 SMP mod_unload modversions
signer:         CentOS Linux kernel signing key
sig_key:        D4:88:63:A7:C1:6F:CC:27:41:23:E6:29:8F:74:F0:57:AF:19:FC:54
sig_hashalgo:   sha256

Resulting failure:

#dkms autoinstall openvswitch/2.6.2

openvswitch:
Running module version sanity check.
Error! Module version 2.6.2 for openvswitch.ko
is not newer than what is already found in kernel 3.10.0-514.el7.x86_64 (B31AE95554C9D9A0067F935).
You may override by specifying --force.

Quick hack which resolves the issue for me:

--- /usr/sbin/dkms.orig	2016-12-20 11:31:59.368461247 +0100
+++ /usr/sbin/dkms	2016-12-20 11:32:03.059461265 +0100
@@ -723,7 +723,7 @@
             res[2]=${vals[2]}
             ;;
         srcversion:)
-        res[1]=${vals[1]}
+        #res[1]=${vals[1]}
         ;;
     esac
     done < <(modinfo $1)

[GoPerry]

`#dkms autoinstall openvswitch/2.6.2

openvswitch:
Running module version sanity check.
Error! Module version 2.6.2 for openvswitch.ko
is not newer than what is already found in kernel 3.10.0-514.el7.x86_64 (B31AE95554C9D9A0067F935).
You may override by specifying --force.`

I want to know which kernel version you are using to build the openvswitch.ko module ?

[sspans]

The default kernel from RHEL 7.3 version: 3.10.0-514.el7.x86_64

However this issue seems to hit every RHEL7 / CentOS 7 kernel, they all have similar modinfo output.

[scaronni]

Same issue as here: #5

[sspans]

It would make sense to make dkms handle 'broken' modules, given that this affects the mainline kernels from RHEL/CentOS. POLA and all.

[GoPerry]

@sspans @scaronni
Could you help to provide the broken modules source code to test ？

[GoPerry]

I have the RHEL7.3 build environment to reproduce the installing error，if the issue can be reproduced and make sure it is a dkms bug ,we will find out the workable solution to fix it .

[superm1]

@yuzaipiaofei I believe this should be the source https://github.com/openvswitch/ovs/tree/master/datapath

Here's the DKMS package spec file:
https://github.com/openvswitch/ovs/blob/75e2077e0c43224bcca92746b28b01a4936fc101/rhel/openvswitch-dkms.spec.in

@sspans You might be able to provide something a little more direct about the exact version you are failing with, but it sounds like this should be a generic failure.

[sspans]

The failure is triggered by the upstream openvswitch kernel module - it's not dependend on the dkms source tarball. A sample of affected kernels would be:

kernel-3.10.0-514.2.2.el7.x86_64
kernel-3.10.0-327.el7.x86_64
kernel-3.10.0-327.36.3.el7.x86_64

Modinfo which triggers the issue looks like this:

> modinfo /var/lib/dkms/openvswitch/2.6.2/3.10.0-514.2.2.el7.x86_64/x86_64/module/openvswitch.ko
filename:       /var/lib/dkms/openvswitch/2.6.2/3.10.0-514.2.2.el7.x86_64/x86_64/module/openvswitch.ko
version:        2.6.2
license:        GPL
description:    Open vSwitch switching datapath
rhelversion:    7.3
srcversion:     3A8FCA763C880FAD0F8AD6A
depends:        nf_conntrack,nf_nat,nf_defrag_ipv6,udp_tunnel,libcrc32c,nf_nat_ipv6,nf_nat_ipv4
vermagic:       3.10.0-514.2.2.el7.x86_64 SMP mod_unload modversions

[sspans]

@superm1 please see issue #5 for a longer description. There are upstream modules in distribution kernels which trigger DKMS failures because the modules lack a version field.

Fixing the upstream modules is a noble goal, but would not help for the kernels already out there.
The fix to DKMS mentionedi in issue #5 is trivial and would solve the issue.

[jared-dominguez]

@sspans I already stated why the patch in #5 will not be accepted and gave acceptable alternatives, including other changes to DKMS (even though openvswitch really should fix their module). Also, for what it's worth, distributions update kernels more frequently than DKMS, so I don't follow your argument about kernels already in the field, especially since the bug is in openvswitch anyway.

[sspans]

I'm pretty sure this will not be changed on the rhel/centos side.

What would be an acceptable change to DKMS to deal with this?

[GoPerry]

Before change i also can get below install error
[root@localhost src]# dkms install openvswitch -v 1.4

openvswitch:
Running module version sanity check.
Error! Module version B31AE95554C9D9A0067F935 for openvswitch.ko
is not newer than what is already found in kernel 3.10.0-514.el7.x86_64 (B31AE95554C9D9A0067F935).
You may override by specifying --force.
Adding any weak-modules

depmod...

Backing up initramfs-3.10.0-514.el7.x86_64.img to /boot/initramfs-3.10.0-514.el7.x86_64.img.old-dkms
Making new initramfs-3.10.0-514.el7.x86_64.img
(If next boot fails, revert to initramfs-3.10.0-514.el7.x86_64.img.old-dkms image)
dracut..........

DKMS: install completed.

[GoPerry]

apply patch code :

diff --git a/dkms b/dkms
index 65286de..a66af89 100644
--- a/dkms
+++ b/dkms
@@ -803,7 +803,7 @@ check_version_sanity()
return 1
fi

• if [[ $kernels_info && $dkms_info && ! ( $(VER $dkms_info) > $(VER $kernels_info) ) && ! $force ]]; then

• if [[ $kernels_info && $dkms_info && ! ( $(VER $dkms_info) -ge $(VER $kernels_info) ) && ! $force ]]; then
  error $"Module version $dkms_info for ${4}$module_suffix"
  $"is not newer than what is already found in kernel $1 ($kernels_info)."
  $"You may override by specifying --force."
  @@ -3681,7 +3681,7 @@ while (($# > 0)); do
  exec >/dev/null 2>&1
  ;;
  --version|-V)

[GoPerry]

Then install the module again :
[root@localhost src]# dkms install openvswitch -v 1.4

openvswitch:
Running module version sanity check.

• Original module
  • Found /lib/modules/3.10.0-514.el7.x86_64/updates/openvswitch.ko
  • Storing in /var/lib/dkms/openvswitch/original_module/3.10.0-514.el7.x86_64/x86_64/
  • Archiving for uninstallation purposes
• Installation
  • Installing to /lib/modules/3.10.0-514.el7.x86_64/extra/
    Adding any weak-modules

depmod...

Backing up initramfs-3.10.0-514.el7.x86_64.img to /boot/initramfs-3.10.0-514.el7.x86_64.img.old-dkms
Making new initramfs-3.10.0-514.el7.x86_64.img
(If next boot fails, revert to initramfs-3.10.0-514.el7.x86_64.img.old-dkms image)
dracut..........

DKMS: install completed.