kexec enable to load/kdump zstd compressed zimg

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 2037398

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

$ sudo /tmp/tmp.u3jP6LAlnj/usr/local/sbin/kexec --debug -l -c /boot/vmlinuz-6.5.0-6-generic
arch_process_options:178: command_line: (null)
arch_process_options:180: initrd: (null)
arch_process_options:182: dtb: (null)
arch_process_options:185: console: (null)
Try gzip decompression.
kernel: 0xffff8e4ef010 kernel_size: 0xda0988
set_phys_offset: phys_offset : 0000000040000000 (method : vmcoreinfo pt_note)
get_memory_ranges:+[0] 0000000040000000 - 000000023c58ffff
get_memory_ranges:- 00000000fa000000 - 00000000ffffffff
get_memory_ranges:- 00000001001dc000 - 00000001001dcfff
get_memory_ranges:- 0000000100210000 - 000000010021ffff
get_memory_ranges:- 0000000100220000 - 000000010022ffff
get_memory_ranges:- 0000000100230000 - 000000010023ffff
get_memory_ranges:- 0000000109540000 - 000000010a0fffff
get_memory_ranges:- 000000022fb50000 - 000000022fb50fff
get_memory_ranges:- 000000022fd5d000 - 000000022fd64fff
get_memory_ranges:- 0000000234400000 - 000000023c3fffff
get_memory_ranges:- 000000023c4a6000 - 000000023c4a6fff
get_memory_ranges:- 000000023c580000 - 000000023c58ffff
get_memory_ranges:+[9] 000000023c730000 - 000000023fbfffff
get_memory_ranges:- 000000023dbf1000 - 000000023e7f1fff
get_memory_ranges:- 000000023eaff000 - 000000023ebbefff
get_memory_ranges:- 000000023ebbf000 - 000000023ebbffff
get_memory_ranges:- 000000023ebc0000 - 000000023ebfffff
get_memory_ranges:- 000000023ec02000 - 000000023ec03fff
get_memory_ranges:- 000000023ec04000 - 000000023ec04fff
get_memory_ranges:- 000000023ec05000 - 000000023fbfffff
get_memory_ranges:+[12] 000000023ffe0000 - 000000023fffffff
get_memory_ranges:- 000000023ffe0000 - 000000023fffffff
System RAM ranges;
0000000040000000-00000000f9ffffff (0)
0000000100000000-00000001001dbfff (0)
00000001001dd000-000000010020ffff (0)
0000000100240000-000000010953ffff (0)
000000010a100000-000000022fb4ffff (0)
000000022fb51000-000000022fd5cfff (0)
000000022fd65000-00000002343fffff (0)
000000023c400000-000000023c4a5fff (0)
000000023c4a7000-000000023c57ffff (0)
000000023c730000-000000023dbf0fff (0)
000000023e7f2000-000000023eafefff (0)
000000023ec00000-000000023ec01fff (0)
elf_arm64_probe: Not an ELF executable.
image_arm64_probe: Bad arm64 image header.
pez_arm64_probe: PROBE.
pez_prepare: kexec can only decompress gziped and lzma images.
Cannot determine the file type of /boot/vmlinuz-6.5.0-6-generic

Even git snapshot of kexec-tools cannot handle zstd commpressed zimg

I have confirmed that this issue with not being able to capture kernel dump with a mantic arm64 kernel is not new. using the arm64 6.5 kernel (6.5.0-5) in the release pocket I captured the following during test.

```
ubuntu@cloudimg:~$ sudo kdump-config show
DUMP_MODE: kdump
USE_KDUMP: 1
KDUMP_COREDIR: /var/crash
crashkernel addr: 0xde000000
   /var/lib/kdump/vmlinuz: symbolic link to /boot/vmlinuz-6.5.0-5-generic
kdump initrd:
   /var/lib/kdump/initrd.img: symbolic link to /var/lib/kdump/initrd.img-6.5.0-5-generic
current state: Not ready to kdump

kexec command:
  no kexec command recorded
ubuntu@cloudimg:~$ uname --all
Linux cloudimg 6.5.0-5-generic #5-Ubuntu SMP PREEMPT_DYNAMIC Wed Sep 6 15:36:23 UTC 2023 aarch64 aarch64 aarch64 GNU/Linux
ubuntu@cloudimg:~$ sudo cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-6.5.0-5-generic root=UUID=e7604ab2-200c-4f34-ab11-47e78ac4b8bd ro console=tty1 console=ttyS0 crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
ubuntu@cloudimg:~$ sudo dmesg | grep -i crash
[ 0.000000] crashkernel reserved: 0x00000000de000000 - 0x00000000fe000000 (512 MB)
[ 0.000000] Kernel command line: BOOT_IMAGE=/vmlinuz-6.5.0-5-generic root=UUID=e7604ab2-200c-4f34-ab11-47e78ac4b8bd ro console=tty1 console=ttyS0 crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
[ 87.054802] pstore: Using crash dump compression: deflate
ubuntu@cloudimg:~$ sudo cat /proc/sys/kernel/sysrq
176
ubuntu@cloudimg:~$ sudo service kdump-tools status
● kdump-tools.service - Kernel crash dump capture service
     Loaded: loaded (/lib/systemd/system/kdump-tools.service; enabled; preset: enabled)
     Active: active (exited) since Tue 2023-09-26 13:44:22 UTC; 7min ago
    Process: 514 ExecStart=/etc/init.d/kdump-tools start (code=exited, status=0/SUCCESS)
   Main PID: 514 (code=exited, status=0/SUCCESS)
        CPU: 4min 46.461s

Sep 26 13:38:21 cloudimg systemd[1]: Starting kdump-tools.service - Kernel crash dump capture service...
Sep 26 13:38:32 cloudimg kdump-tools[514]: Starting kdump-tools:
Sep 26 13:38:32 cloudimg kdump-tools[535]: * Creating symlink /var/lib/kdump/vmlinuz
Sep 26 13:38:41 cloudimg kdump-tools[577]: kdump-tools: Generating /var/lib/kdump/initrd.img-6.5.0-5-generic
Sep 26 13:44:11 cloudimg kdump-tools[535]: * Creating symlink /var/lib/kdump/initrd.img
Sep 26 13:44:22 cloudimg kdump-tools[535]: * failed to load kdump kernel
Sep 26 13:44:22 cloudimg kdump-tools[5536]: failed to load kdump kernel
Sep 26 13:44:22 cloudimg systemd[1]: Finished kdump-tools.service - Kernel crash dump capture service.
ubuntu@cloudimg:~$ sudo ls -al /var/lib/kdump/vmlinuz
lrwxrwxrwx 1 root root 29 Sep 26 13:38 /var/lib/kdump/vmlinuz -> /boot/vmlinuz-6.5.0-5-generic
ubuntu@cloudimg:~$ sudo file /boot/vmlinuz-6.5.0-5-generic
/boot/vmlinuz-6.5.0-5-generic: gzip compressed data, was "vmlinuz-6.5.0-5-generic.efi.signed", last modified: Thu Sep 7 10:43:26 2023, max compression, from Unix, original size modulo 2^32 54989192
```

.. but the `Cannot determine the file type of /var/lib/kdump/vmlinuz` in the `sudo service kdump-tools status` as @xnox has also reproduced with `kexec` is new.

I have also confirm...

-6 kernel is respun, migration of -7 or higher is good

This bug was fixed in the package linux - 6.5.0-7.7

---------------
linux (6.5.0-7.7) mantic; urgency=medium

  * mantic/linux: 6.5.0-7.7 -proposed tracker (LP: #2037611)

  * kexec enable to load/kdump zstd compressed zimg (LP: #2037398)
    - [Packaging] Revert arm64 image format to Image.gz

  * Mantic minimized/minimal cloud images do not receive IP address during
    provisioning (LP: #2036968)
    - [Config] Enable virtio-net as built-in to avoid race

  * Miscellaneous Ubuntu changes
    - SAUCE: Add mdev_set_iommu_device() kABI
    - [Config] update gcc version in annotations

 -- Andrea Righi <email address hidden> Thu, 28 Sep 2023 10:19:24 +0200

This bug is awaiting verification that the linux-oem-6.5/6.5.0-1005.5 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-oem-6.5' to 'verification-done-jammy-linux-oem-6.5'. If the problem still exists, change the tag 'verification-needed-jammy-linux-oem-6.5' to 'verification-failed-jammy-linux-oem-6.5'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!