Boot hangs at "loading initial ramdisk..."

[Krister Swenson]

I cannot load a kernel beyond 4.15.0-32-generic on my machine.
Both 4.15.0-33-generic and 4.15.0-34-generic hang at "loading initial ramdisk...".

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-34-generic 4.15.0-34.37
ProcVersionSignature: Ubuntu 4.15.0-32.35-generic 4.15.18
Uname: Linux 4.15.0-32-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: kms 2233 F.... pulseaudio
 /dev/snd/controlC1: kms 2233 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Wed Sep 12 10:52:00 2018
HibernationDevice: RESUME=UUID=c3d34d19-9e9e-4967-ac45-f1d699cf5eef
InstallationDate: Installed on 2018-01-05 (249 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
MachineType: Dell Inc. Precision Tower 7810
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-32-generic root=UUID=90d43be7-a2f7-4500-8b88-9bd7a549d96d ro quiet splash vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-32-generic N/A
 linux-backports-modules-4.15.0-32-generic N/A
 linux-firmware 1.173.1
SourcePackage: linux
UpgradeStatus: Upgraded to bionic on 2018-05-02 (132 days ago)
dmi.bios.date: 06/25/2018
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A27
dmi.board.name: 0KJCC5
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 7
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA27:bd06/25/2018:svnDellInc.:pnPrecisionTower7810:pvr:rvnDellInc.:rn0KJCC5:rvrA00:cvnDellInc.:ct7:cvr:
dmi.product.name: Precision Tower 7810
dmi.sys.vendor: Dell Inc.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

I built a 4.15.0-35 test kernel.

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test this kernel and see if it resolves this bug?

Note about installing test kernels:
• If the test kernel is prior to 4.15(Bionic) you need to install the linux-image and linux-image-extra .deb packages.
• If the test kernel is 4.15(Bionic) or newer, you need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

Thanks in advance!

[Krister Swenson (thekswenson)]

I get error messages when installing linux-headers:

-- kms@winters:~/Downloads/ubuntu/kernels
=> sudo dpkg -i linux-image-unsigned-4.15.0-35-generic_4.15.0-35.39~lp1792100_amd64.deb linux-modules-* linux-headers-4.15.0-35*
(Reading database ... 599557 files and directories currently installed.)
.
. snip
.
Setting up linux-headers-4.15.0-35-generic (4.15.0-35.39~lp1792100) ...
/etc/kernel/header_postinst.d/dkms:
ERROR (dkms apport): kernel package linux-headers-4.15.0-35-generic is not supported
Error! Bad return status for module build on kernel: 4.15.0-35-generic (x86_64)
Consult /var/lib/dkms/amdgpu/18.20-621984/build/make.log for more information.
Setting up linux-image-unsigned-4.15.0-35-generic (4.15.0-35.39~lp1792100) ...
Setting up linux-modules-extra-4.15.0-35-generic (4.15.0-35.39~lp1792100) ...
Processing triggers for linux-image-unsigned-4.15.0-35-generic (4.15.0-35.39~lp1792100) ...
/etc/kernel/postinst.d/dkms:
ERROR (dkms apport): kernel package linux-headers-4.15.0-35-generic is not supported
Error! Bad return status for module build on kernel: 4.15.0-35-generic (x86_64)
Consult /var/lib/dkms/amdgpu/18.20-621984/build/make.log for more information.
.
. snip
.

[Joseph Salisbury (jsalisbury)]

The linux-headers package shouldn't be needed to test for this bug. You should only need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

[Krister Swenson (thekswenson)]

The 4.15.0-35 test kernel also hangs at "loading initial ramdisk...".

[Joseph Salisbury (jsalisbury)]

I started a kernel bisect between Ubuntu-4.15.--32 and Ubuntu-4.15.0-33. The kernel bisect will require testing of about 7-10 test kernels.

I built the first test kernel, up to the following commit:
77a24c313d21e3765b04d90521e9228a9bb6e332

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

I'll test this tomorrow.

[Krister Swenson (thekswenson)]

The kernel 4.15.0-32-generic #35~lp1792100Commit77a24c313d2 works.

I installed an older kernel to use in case of problems. It turns out the some of the older kernels hang in the same way. Here's the rundown on the kernels from the repository:

4.15.0-30: hangs
4.15.0-29: hangs
4.15.0-24: works
4.15.0-20: works

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
7f36a83df6d4fabe39ba597a4eef5ca1f5bbda99

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commit7f36a83df6d kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
9627b5742a8e8d87f62d29a8ee04ae867ecd3768

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commit9627b5742a8e kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
00c3aa70c712c5f7758370e0cd719ac5e401305e

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The directory http://kernel.ubuntu.com/~jsalisbury/lp1792100 is empty!

[Joseph Salisbury (jsalisbury)]

Sorry, my upload failed. The .debs are there now.

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commit00c3aa70c71 kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
84d28cc43f2d9820bd97e8dc428b00483322f660

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commit84d28cc43f2 kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
d4be7ce8e6324691737b45f336d770245ba07310

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commitd4be7ce8e632 kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
d86a0bd64457a4373623713e93fe8848a9e75ce7

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commitd86a0bd644 kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
f03220fb0122a5aced32a57bcb14dde045fc462c

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commitf03220fb0122 kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
3dfa1c904fcf138e64658c03f054ef102f52c6ec

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commit3dfa1c904fcf138 kernel works.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
19e56be2af5ad5333a32da9595f60ec5045d1ca4

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Krister Swenson (thekswenson)]

The kernel is missing at http://kernel.ubuntu.com/~jsalisbury/lp1792100.

[Joseph Salisbury (jsalisbury)]

Sorry about that. The .debs are there now.

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100Commit19e56be2af5a kernel works.

[Joseph Salisbury (jsalisbury)]

I built a test kernel using the master-next repo.

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not?

[Krister Swenson (thekswenson)]

The 4.15.0-39-generic_4.15.0-39.43~lp1792100MasterNext kernel HANGS.

[Joseph Salisbury (jsalisbury)]

Does it hang at the same point as prior kernels, or does it seem different?

[Krister Swenson (thekswenson)]

It looks (superficially) the same...
   the purple screen says "loading initial ramdisk..." indefinitely.

If you give me instructions, I could look into it further.

[Joseph Salisbury (jsalisbury)]

What's interesting is the test kernel in comment #28 was tested as good. That was built with commit 19e56be2af5 as the tip of the tree. That commit is only one commit behind 22df1539aed9, which is the version tag. However, the bug exists when commit 22df1539aed9 is the tip.

I built a v2 version of 4.15.0-33.

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1792100

Can you test that kernel and report back if it has the bug or not?

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #37~lp1792100v2 kernel works.

[Joseph Salisbury (jsalisbury)]

That was using a stock 4.15.0-33.36 tree that I built. Can you test the official build from the ppa, which is available here:

https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/ppa/+build/15263551

Just be sure to install all three of the required packages:
 linux-modules, linux-modules-extra and linux-image-unsigned .deb packages.

[Krister Swenson (thekswenson)]

The 4.15.0-33-generic #36-Ubuntu kernel works.

[Joseph Salisbury (jsalisbury)]

That is good news, that might indicate this bug is now fixed. Can you apply all the latest updates and the latest kernel to see if the bug still exists?

[Krister Swenson (thekswenson)]

Neither the 4.18.0-10 nor the 4.15.0-39 kernel will boot.

[Joseph Salisbury (jsalisbury)]

Hmm, OK, thanks for the feedback. Let me review the bisect results and see if we went astray at some point.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.20 kernel[0].

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.20-rc3

[Krister Swenson (thekswenson)]

The 4.20.0-042000rc3-generic kernel works.

[Joseph Salisbury (jsalisbury)]

If that is the case, we are better off performing a "Reverse" bisect to identify the fix in mainline versus investigating what went wrong in the first regular bisect.

The steps for a reverse bisect are similar, but we first need to find the last "Bad" kernel and the first "Good" kernel. Can you test the following kernels:

v4.19: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.19/
v4.20-rc1: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.20-rc1

[Krister Swenson (thekswenson)]

Those kernels are OK.

[Joseph Salisbury (jsalisbury)]

Can you test 4.18 final:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.18/

[Krister Swenson (thekswenson)]

The 4.18.0-041800-generic kernel works.

[Joseph Salisbury (jsalisbury)]

Can you test the following kernel? It appears this bug may have been introduced by a SAUCE patch:
-34:

https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/ppa/+build/15307305

[Joseph Salisbury (jsalisbury)]

Also, just to confirm to test this kernel you need to install the linux-modules, linux-modules-extra and linux-image-unsigned .deb packages in that order.

[Joseph Salisbury (jsalisbury)]

Can you also test the following mainline kernels to confirm if this is due to a SAUCE patch or not:

4.15.18: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15.18/
4.16 Final: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.16/

[Krister Swenson (thekswenson)]

The 4.15.0-34-generic downloaded from https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/ppa/+build/15307305 works.

[Krister Swenson (thekswenson)]

The 4.15.18-041518-generic kernel works.

[Krister Swenson (thekswenson)]

The 4.16.0-041600-generic kernel works.

[Nick (nick-power)]

Upgrading to 18.10 works.