Timeout downloading initrd

[dann frazier]

[Impact]
GRUB times out when downloading downloading large files w/ tftp. This notably breaks subiquity based PXE installs which feature a large initrd. (Observed on several arm64 platforms, though the symptom is not arch-specific).

[Test Case]
Simple test case using an x86 UEFI VM:
Place a kernel/ramdisk on a tftp server. Inflate the initrd or kernel to 87M, e.g.:

dd if=/dev/zero of=initrd.img bs=1M count=87
dd if=initrd.img.orig of=initrd.img conv=notrunc

Success looks like:
Shell> fs0:
FS0:\> \efi\grubnetx64.efi
grub> net_dhcp efinet0
grub> linux (tftp,192.168.122.1)/vmlinuz.orig console=ttyS0,115200n8
grub> initrd (tftp,192.168.122.1)/initrd.img
grub>

Failure looks like:

grub> net_dhcp efinet0
grub> linux (tftp,192.168.122.1)/vmlinuz.orig console=ttyS0,115200n8
grub> initrd (tftp,192.168.122.1)/initrd.img
!!!! X64 Exception Type - 06(#UD - Invalid Opcode) CPU Apic ID - 00000000 !!!!
RIP - 0000000000099080, CS - 0000000000000038, RFLAGS - 0000000000010286
RAX - 000000007DC2FF00, RCX - 000000004FF99013, RDX - 000000007BF4CCF4
RBX - 000000007BE43FC0, RSP - 000000007FF25AE8, RBP - 000000007BE3C2A0
RSI - 000000000000000B, RDI - 000000007BE3C340
R8 - 000000007DC21168, R9 - 000000007DC1D4AE, R10 - 0000000000000067
R11 - 0000000000000002, R12 - 000000007BE3CCA0, R13 - 000000007BE3C260
R14 - 0000000000020004, R15 - 000000007DC1A613
DS - 0000000000000030, ES - 0000000000000030, FS - 0000000000000030
GS - 0000000000000030, SS - 0000000000000030
CR0 - 0000000080010033, CR2 - 0000000000000000, CR3 - 000000007FC01000
CR4 - 0000000000000668, CR8 - 0000000000000000
DR0 - 0000000000000000, DR1 - 0000000000000000, DR2 - 0000000000000000
DR3 - 0000000000000000, DR6 - 00000000FFFF0FF0, DR7 - 0000000000000400
GDTR - 000000007F9EE698 0000000000000047, LDTR - 0000000000000000
IDTR - 000000007F4B2018 0000000000000FFF, TR - 0000000000000000
FXSAVE_STATE - 000000007FF25740
!!!! Can't find image information. !!!!

This was originally discovered on a Cavium ThunderX CRB system using subiquity from the groovy arm64 ISO. Failure there looks like:

                         GNU GRUB version 2.04

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 ������������������������������������������������������������������������������

      Use the and keys to select which entry is highlighted.
      Press enter to boot the selected OS, `e' to edit the commands
      before booting or `c' for a command-line.

error: timeout reading `initrd'.

Press any key to continue...

[Fix]
https://git.savannah.gnu.org/cgit/grub.git/commit/?id=a6838bbc6726ad624bd2b94991f690b8e9d23c69

[Where problems could occur]
The fix is to the tftp command, so problems would like appear in the tftp stack, possibly due to inconsistencies between tftp server implementations.

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1900773

[Steve Langasek (vorlon)]

Just to confirm, are you using the initrd as extracted from the .iso?

[Steve Langasek (vorlon)]

And is there something intrinsic to this hardware that leads to the timeout? Or would this perhaps work if the machine had a faster network link to the tftp server?

[dann frazier (dannf)]

On Tue, Oct 20, 2020 at 5:30 PM Steve Langasek
<email address hidden> wrote:
>
> Just to confirm, are you using the initrd as extracted from the .iso?

I am.

[dann frazier (dannf)]

On Tue, Oct 20, 2020 at 5:30 PM Steve Langasek
<email address hidden> wrote:
>
> And is there something intrinsic to this hardware that leads to the
> timeout?

I wonder if there might be a firmware bug. Here's what I see on the wire:

52120 56.958016 10.229.50.135 10.229.50.84 TFTP 78 Read Request, File:
initrd, Transfer type: octet, blksize=1024, tsize=0
52121 56.960144 10.229.50.84 10.229.50.135 TFTP 72 Option
Acknowledgement, blksize=1024, tsize=90771321
<---snip--->
183218 65.602857 10.229.50.84 10.229.50.135 TFTP 1070 Data Packet, Block: 65535
183219 65.603129 10.229.50.135 10.229.50.84 TFTP 60 Acknowledgement,
Block: 65535
<---snip--->
229458 68.561417 10.229.50.135 10.229.50.84 TFTP 60 Acknowledgement,
Block: 88643
229459 68.561466 10.229.50.84 10.229.50.135 TFTP 935 Data Packet,
Block: 88644 (last)
229460 68.561519 10.229.50.135 10.229.50.84 TFTP 60 Acknowledgement,
Block: 88644
229462 68.962413 10.229.50.135 10.229.50.84 TFTP 60 Acknowledgement,
Block: 65535

It looks like the entire initrd was successfully transferred. The
client ACK'd the last block but then, for some reason, it comes back
about half a second later and re-ACKs a block it had already ACK'd.
And that block being number number 65535 is *interesting*.

> Or would this perhaps work if the machine had a faster network
> link to the tftp server?

Perhaps - but these systems are in the same physical location, slowest
link between is 1Gbps.

[Ike Panhc (ikepanhc)]

I hit this issue on Hisilicon d06 when PXE groovy subiquity. System boots without initrd and hang on no rootfs.

error: timeout reading `/casper/initrd'.

Press any key to continue...

[dann frazier (dannf)]

On Wed, Oct 21, 2020, 03:20 Ike Panhc <email address hidden> wrote:

> I hit this issue on Hisilicon d06 when PXE groovy subiquity. System
> boots without initrd and hang on no rootfs.
>
>
> error: timeout reading `/casper/initrd'.
>
> Press any key to continue...
>

Interesting, does recompressing with lzma suffice as a workaround for d06
also?

>

[Ike Panhc (ikepanhc)]

90771321 initrd
44620048 initrd.lzma

Yes. recompress with `lzma -9` and I can finish the installation.

[dann frazier (dannf)]

Since technically GRUB is requesting the initrd file, I tried to rule it out as a possible cause by seeing if the initial payload that UEFI downloads directly would time out if it was the same size. I did this by padding my grubnetaa64.efi binary to be the same size as the installer initrd.

 mv grubnetaa64.efi grubnetaa64.efi.orig
 cp casper/initrd grubnetaa64.efi
 dd if=grubnetaa64.efi.orig of=grubnetaa64 conv=notrunc

This did *not* timeout. So unfortunately we can't obviously rule out GRUB as a factor.

[Ike Panhc (ikepanhc)]

More infomation. I can not reproduce with grubnetaa64.efi from focal.

This is the focal grub I download, which can not reproduce

http://ports.ubuntu.com/ubuntu-ports/dists/focal/main/uefi/grub2-arm64/current/grubnetaa64.efi.signed

This is the groovy grub, which is able to reproduce

http://ports.ubuntu.com/ubuntu-ports/dists/groovy/main/uefi/grub2-arm64/current/grubnetaa64.efi.signed

[Taihsiang Ho (taihsiangho)]

My apologies. The comment#9 https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1900773/comments/9 used the grubnetaa64.efi from focal http://ports.ubuntu.com/ubuntu-ports/dists/focal/main/uefi/grub2-arm64/current/grubnetaa64.efi.signed

If d05 (d05-4) uses the groovy grub, it COULD reproduce this issue as well.

So I would say the testing result of d05 is the same as d06 by @Ike.
    - grub from focal ---> not reproduce this issue
    - grub from groovy --> able to reproduce this issue

My next will be:
    - hide comment#9 to not confuse people
    - also try the initrd.lzma workaround

[Taihsiang Ho (taihsiangho)]

Repacking initrd as initrd.lz is a working workaround on d05. By using initrd.lz, I could not reproduce this issue on d05-4.

[Taihsiang Ho (taihsiangho)]

Groovy rc 20201022 daily image could reproduce on d05 (d05-1) and d06 (kreiken). Besides, the lz workaround still works on both of the platforms.

[dann frazier (dannf)]

Turns out this is a GRUB issue. It was fixed upstream in the following commit, which cleanly cherry-picks to groovy. I prepared a test build in ppa:dannf/test and confirmed it resolves the issue.

commit a6838bbc6726ad624bd2b94991f690b8e9d23c69
Author: Javier Martinez Canillas <email address hidden>
Date: Thu Sep 10 17:17:57 2020 +0200

    tftp: Roll-over block counter to prevent data packets timeouts

    Commit 781b3e5efc3 (tftp: Do not use priority queue) caused a regression
    when fetching files over TFTP whose size is bigger than 65535 * block size.

      grub> linux /images/pxeboot/vmlinuz
      grub> echo $?
      0
      grub> initrd /images/pxeboot/initrd.img
      error: timeout reading '/images/pxeboot/initrd.img'.
      grub> echo $?
      28

[dann frazier (dannf)]

I am able to reproduce w/ focal as well. The above patch is tagged as "Fixes: 781b3e5efc3 (tftp: Do not use priority queue)", which is in focal (d/p/0090-tftp-Do-not-use-priority-queue.patch). However, it wasn't added until 2.04-1ubuntu26.1. My guess is that it was not reproducible in Comment #12 because that test may have used the original GA image from 2.04-1ubuntu26[1] instead of the latest[2]. @Tai can you confirm?

[1] http://ports.ubuntu.com/ubuntu-ports/dists/focal/main/uefi/grub2-arm64/current/grubnetaa64.efi
[2] http://ports.ubuntu.com/ubuntu-ports/dists/focal-updates/main/uefi/grub2-arm64/current/grubnetaa64.efi

[Łukasz Zemczak (sil2100)]

Hello dann, or anyone else affected,

Accepted grub2 into groovy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/grub2/2.04-1ubuntu35.1 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, what testing has been performed on the package and change the tag from verification-needed-groovy to verification-done-groovy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-groovy. 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.

[Łukasz Zemczak (sil2100)]

Hello dann, or anyone else affected,

Accepted grub2 into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/grub2/2.04-1ubuntu26.7 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, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. 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.

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2 - 2.04-1ubuntu36

---------------
grub2 (2.04-1ubuntu36) hirsute; urgency=medium

  * Avoid "EFI stub: FIRMWARE BUG" message when booting >= 5.7 kernels
    on arm64 by setting the image base address before jumping to the
    PE/COFF entry point LP: #1900774
  * Fix tftp timeouts when fetch large files. LP: #1900773

 -- dann frazier <email address hidden> Wed, 11 Nov 2020 07:17:49 -0700

[Łukasz Zemczak (sil2100)]

Hello dann, or anyone else affected,

Accepted grub2 into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/grub2/2.02-2ubuntu8.20 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, what testing has been performed on the package 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.

[Łukasz Zemczak (sil2100)]

Hello dann, or anyone else affected,

Accepted grub2 into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/grub2/2.02~beta2-36ubuntu3.29 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, what testing has been performed on the package and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. 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.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted grub2 (2.04-1ubuntu26.7) for focal have finished running.
The following regressions have been reported in tests triggered by the package:

ubuntu-image/1.10+20.04ubuntu1 (arm64)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/focal/update_excuses.html#grub2

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted grub2 (2.04-1ubuntu35.1) for groovy have finished running.
The following regressions have been reported in tests triggered by the package:

grubzfs-testsuite/unknown (amd64)
ubuntu-image/unknown (amd64)
ubiquity/unknown (amd64)
zsys/unknown (amd64)
grml2usb/unknown (amd64)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/groovy/update_excuses.html#grub2

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[dann frazier (dannf)]

= groovy verification =
                   GNU GRUB GNU GRUB version 2.04buntu3.29

   Minimal BASH-like line editing is supported. For the first word, TAB
   lists possible command completions. Anywhere else TAB lists possible
   device or file completions.

grub> net_dhcp efinet0
grub> linux (tftp,192.168.122.1)/vmlinuz.orig console=ttyS0,115200n8
grub> initrd (tftp,192.168.122.1)/initrd.img
grub>

= focal verification =
                             GNU GRUB version 2.04

   Minimal BASH-like line editing is supported. For the first word, TAB
   lists possible command completions. Anywhere else TAB lists possible
   device or file completions.

grub> net_dhcp efinet0
grub> linux (tftp,192.168.122.1)/vmlinuz.orig console=ttyS0,115200n8
grub> initrd (tftp,192.168.122.1)/initrd.img
grub>

= bionic verification =
                             GNU GRUB version 2.02

   Minimal BASH-like line editing is supported. For the first word, TAB
   lists possible command completions. Anywhere else TAB lists possible
   device or file completions.

grub> net_add_addr test efinet0 192.168.122.86
grub> linux (tftp,192.168.122.1)/vmlinuz.orig console=ttyS0,115200n8
grub> initrd (tftp,192.168.122.1)/initrd.img
grub>

= xenial verification =
                   GNU GRUB version 2.02~beta2-36ubuntu3.29

   Minimal BASH-like line editing is supported. For the first word, TAB
   lists possible command completions. Anywhere else TAB lists possible
   device or file completions.

grub> net_add_addr test efinet0 192.168.122.86
grub> linux (tftp,192.168.122.1)/vmlinuz.orig console=ttyS0,115200n8
grub> initrd (tftp,192.168.122.1)/initrd.img
grub>

[Łukasz Zemczak (sil2100)]

The listed grub versions in the output look weird, but I trust that the right packages from -proposed have been used for validation.

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2 - 2.04-1ubuntu35.1

---------------
grub2 (2.04-1ubuntu35.1) groovy; urgency=medium

  * Avoid "EFI stub: FIRMWARE BUG" message when booting >= 5.7 kernels
    on arm64 by setting the image base address before jumping to the
    PE/COFF entry point LP: #1900774
  * Fix tftp timeouts when fetching large files. LP: #1900773

 -- dann frazier <email address hidden> Thu, 12 Nov 2020 16:08:57 -0700

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for grub2 has completed successfully and the package is now being 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.

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2 - 2.04-1ubuntu26.7

---------------
grub2 (2.04-1ubuntu26.7) focal; urgency=medium

  * Avoid "EFI stub: FIRMWARE BUG" message when booting >= 5.7 kernels
    on arm64 by setting the image base address before jumping to the
    PE/COFF entry point LP: #1900774
  * Fix tftp timeouts when fetching large files. LP: #1900773

 -- dann frazier <email address hidden> Thu, 12 Nov 2020 16:15:13 -0700

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2 - 2.02-2ubuntu8.20

---------------
grub2 (2.02-2ubuntu8.20) bionic; urgency=medium

  * Avoid "EFI stub: FIRMWARE BUG" message when booting >= 5.7 kernels
    on arm64 by setting the image base address before jumping to the
    PE/COFF entry point LP: #1900774
  * Fix tftp timeouts when fetching large files. LP: #1900773

 -- dann frazier <email address hidden> Fri, 13 Nov 2020 17:40:19 -0700

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2 - 2.02~beta2-36ubuntu3.29

---------------
grub2 (2.02~beta2-36ubuntu3.29) xenial; urgency=medium

  * Avoid "EFI stub: FIRMWARE BUG" message when booting >= 5.7 kernels
    on arm64 by setting the image base address before jumping to the
    PE/COFF entry point LP: #1900774
  * Fix tftp timeouts when fetching large files. LP: #1900773

 -- dann frazier <email address hidden> Fri, 13 Nov 2020 18:03:44 -0700