dkms script is missing function find_module

Bug was introduced in by 2.3-3ubuntu9.4 the following commit: https://git.launchpad.net/ubuntu/+source/dkms/commit/?id=4cfc905dc605628eb6d3ceddb21fb12cac9543d5:

Relevant diff:
- read -a kernels_module < <(find $lib_tree -name ${4}$module_suffix)
+ read -a kernels_module < <(find_module "$lib_tree" "${4}")

Reverting this should fix this bug

But there is another bug: The following line reads `[ -z $kernels_module ] || return 0`

Previously the related section was:

    if [ -z $kernels_module ]; then
        # Magic split into array syntax saves trivial awk and cut calls.
        local -a obs=(${3//-/ })
        local -a my=(${1//-/ })
        local obsolete=0
        if [[ ${obs} && ${my} ]]; then
            if [[ $(VER ${obs}) == $(VER ${my}) && ! $force ]]; then
                # They get obsoleted possibly in this kernel release
                if [[ ! ${obs[1]} ]]; then
                    # They were obsoleted in this upstream kernel
                    obsolete=1
                elif [[ $(VER ${my[1]}) > $(VER ${obs[1]}) ]]; then
                    # They were obsoleted in an earlier ABI bump of the kernel
                    obsolete=1
                elif [[ $(VER ${my[1]}) = $(VER ${obs[1]}) ]]; then
                    # They were obsoleted in this ABI bump of the kernel
                    obsolete=1
                fi
            elif [[ $(VER ${my}) > $(VER ${obs}) && ! $force ]]; then
                # They were obsoleted in an earlier kernel release
                obsolete=1
            fi
        fi

        if ((obsolete == 1)); then
            echo $"" >&2
            echo $"Module has been obsoleted due to being included" >&2
            echo $"in kernel $3. We will avoid installing" >&2
            echo $"for future kernels above $3." >&2
            echo $"You may override by specifying --force." >&2
            return 1
  else
          return 0
        fi
    fi

See that misformatted `else`? This probably tricked the patch author. Essence is: If `[ -z $kernels_module ]` then either return with 1 or 0 depending on `obsolete`.

The correct line would hence be: `[ -z $kernels_module ] && return 0`

Status changed to 'Confirmed' because the bug affects multiple users.

indeed, I was tricked by that misformatted `else`.
Thanks for reporting the issue.

I agree the correct line should be `[ -z $kernels_module ] && return 0`, because the following code is used to compare the version of target DKMS and existed module on the system.

So, I'm processing to proposed another patch to fix it.

I tested this patch locally and it (seems to) work:

- read -a kernels_module < <(find_module "$lib_tree" "${4}")
+ read -a kernels_module < <(find $lib_tree -name ${4}$module_suffix)

- [ -z $kernels_module ] || return 0
+ [ -z $kernels_module ] && return 0

the patched package is ready for test, I'll continue to process SRU, please interrupt me if any regression be found.

https://code.launchpad.net/~alextu/+archive/ubuntu/dkms-2.3-lp1838245

btw, the fix already be merged by upstream on github:
https://github.com/dell/dkms/commit/9976fa6c9665d78d4c8125ce4825507cd0dfb247

btw, I plan to land another change in the target SRU, to fix https://github.com/dell/dkms/issues/89
the package on testing ppa already include it.

https://code.launchpad.net/~alextu/+recipe/dkms-2.3-lp1838245
https://code.launchpad.net/~alextu/+archive/ubuntu/dkms-2.3-lp1838245

the case I tested:
install the dkms which already patched (also can be found in my ppa[1])
1. install a dkms which for a kernel module system already installed.
e.g. ath10k of my testing ppa : [1]
1.1. the dkms can be installed well.

2. install a dkms which has OBSOLETE_BY and FORCE
e.g.ath10k of my testing ppa : [1] (source code in [2])
 + the target dkms defined OBSOLETE_BY and FORCE
   - OBSOLETE_BY="4.15.0-1033": https://git.launchpad.net/~alextu/+git/oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms/tree/oem-wifi-qualcomm-ath10k-lp1803647-4.15/dkms.conf?h=lp1838245#n8
   - https://git.launchpad.net/~alextu/+git/oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms/tree/oem-wifi-qualcomm-ath10k-lp1803647-4.15.force?h=lp1838245
 + user install dkms on a system which installed kernel version less than OBSOLETE_BY and another kernel higher than OBSOLETE_BY
  - in my system there're 2 kernels 4.15.0-1030 and 4.15.0-1045
 + the dkms can be installed well with kernel 4.15.0-1030, and not be installed with 4.15.0-1045

also attached the log came from patched dkms script during install dkms [2]

[1]:https://code.launchpad.net/~alextu/+archive/ubuntu/dkms-2.3-lp1838245
[2]:https://code.launchpad.net/~alextu/+git/oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms/+ref/lp1838245

Hello Alex, or anyone else affected,

Accepted dkms into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/dkms/2.3-3ubuntu9.5 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

the proposed version not include the patch of "priority of OBSOLETE_BY should higher than "force". #89 https://github.com/dell/dkms/issues/89" , so I created another ppa [1] to test the regression only

my system installed kernel 4.15.0-1030-oem and 4.15.0-1045-oem and new dkms from #10, then install the oem-wifi-qualcomm-ath10k-lp1803647-4.15-dkms, it works as expected.
 - for kernel 4.15.0-1030-oem, it checked the version of existed module.(line 4763 of my attached log)
 - for kernel 4.15.0-1045-oem, it checked the OBSOLETE_BY.(line 9241 of my attached log)

[1]:https://launchpad.net/~alextu/+archive/ubuntu/lp1838245-test-regression

The verification of the Stable Release Update for dkms has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

This bug was fixed in the package dkms - 2.3-3ubuntu9.5

---------------
dkms (2.3-3ubuntu9.5) bionic; urgency=medium

  * Fixup previous upload: find_module doesn't exist yet, and there's bad
    boolean logic in the check if we've already dealt with obsoleted modules.
    (LP: #1838245)

 -- Mathieu Trudel-Lapierre <email address hidden> Thu, 01 Aug 2019 17:17:58 -0400

this release not include the change of "priority of OBSOLETE_BY should higher than "force". #89 https://github.com/dell/dkms/issues/89" , so I created another ticket for that change:
https://bugs.launchpad.net/oem-priority/+bug/1838921

should be fixed in eoan

I'm still seeing this on Eoan, which has dkms 2.7.1-4ubuntu2 - the symptom is that virtualbox-dkms does not correctly build and install its kernel modules with the message `modinfo: ERROR: missing module or filename.`

For me, the fix is to change line 812 of /usr/sbin/dkms from:

    [ -z $kernels_module ] || return 0

to

    [ -z $kernels_module ] && return 0

This was fixed upstream here:

https://github.com/dell/dkms/commit/b95779938805aca8e98d57492b18dee07d35d285

This changes seems to have been dropped in Ubuntu 19.10 and Focal.

The new feature landing missed that fix.
It impacts eoan and disco.
The bionic carried that fix , and Focal is supposed to just land latest code from upstream, so they will not be impacted.

Sorry for inconvenient, I'll send a new patch to fix it on eoan and disco today.

the patch for eoan is there:
https://code.launchpad.net/~alextu/+git/dkms/+ref/eoan-lp1838245

7db3297 for bump version

b0921f3 for the patch

------------------------------------
the patch for disco is there:
https://code.launchpad.net/~alextu/+git/dkms/+ref/disco-lp1838245

2af553b for bump version

aad29bc for the patch

Thanks to the sponsor,
the patched dkms for eoan is on the queue:
https://launchpad.net/ubuntu/eoan/+queue?queue_state=1
version : 2.7.1-4ubuntu2.1

This patch is not needed for Focal as it got the existed patch from upstream.

Hello Alex, or anyone else affected,

Accepted dkms into eoan-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/dkms/2.7.1-4ubuntu2.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-eoan to verification-done-eoan. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-eoan. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Hello Alex, or anyone else affected,

Accepted dkms into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/dkms/2.6.1-4ubuntu2.5 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

for eoan dkms 2.7.1-4ubuntu2.1:
 + confirmed the patch is there on proposed package
 + verified version-override
  - verbose installation message : http://paste.ubuntu.com/p/YyFBZkhQBR/

 + verified obseleted-by
   - verbose installation message : http://paste.ubuntu.com/p/DvFHkRmrCf/

 + verified force
   - verbose installation message : http://paste.ubuntu.com/p/R5YNPQsKRH/

for disco dkms 2.6.1-4ubuntu2.5:
 + confirmed the patch is there on proposed package
 + verified version-override
  - verbose installation message : http://paste.ubuntu.com/p/PQJXKWSZRC/

 + verified obseleted-by
   - verbose installation message : http://paste.ubuntu.com/p/FrMJFz8KYK/

 + verified force
   - verbose installation message : http://paste.ubuntu.com/p/GDf9zz5btM/

This bug was fixed in the package dkms - 2.7.1-4ubuntu2.1

---------------
dkms (2.7.1-4ubuntu2.1) eoan; urgency=medium

  * cherry-pick from upstream b957799 for LP: #1838245

 -- Alex Tu <email address hidden> Thu, 07 Nov 2019 15:17:48 +0800

This bug was fixed in the package dkms - 2.6.1-4ubuntu2.5

---------------
dkms (2.6.1-4ubuntu2.5) disco; urgency=medium

  * cherry-pick from upstream b957799 for LP: #1838245

 -- Alex Tu <email address hidden> Thu, 07 Nov 2019 15:37:47 +0800