Comment 127 for bug 1835660

1) checking that reproducer still fails

sudo qemu-system-x86_64 -kernel ./vmlinuz-5.4.0-64-generic -initrd ./initrd-pad4-5.4.0-64-generic -append 'break=top quiet console=ttyS0' -m 2G -nograt

[ 3.581106] Initramfs unpacking failed: Decoding failed
Spawning shell within the initramfs

BusyBox v1.30.1 (Ubuntu 1:1.30.1-4ubuntu6.3) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs) cat /test-file
cat: can't open '/test-file': No such file or directory
(initramfs) uname -a
Linux (none) 5.4.0-64-generic #72-Ubuntu SMP Fri Jan 15 10:27:54 UTC 2021 x86_64 GNU/Linux
(initramfs)

As expected, error message shown and file from second initrd is not accessible

2) checking that #65 ABI build of v5.4 is good

Verifying v5.4 using a custom test case:

sudo qemu-system-x86_64 -kernel ./vmlinuz-5.4.0-65-generic -initrd ./initrd-pad4-5.4.0-65-generic -append 'break=top quiet console=ttyS0' -m 2G -nograt

Spawning shell within the initramfs

BusyBox v1.30.1 (Ubuntu 1:1.30.1-4ubuntu6.3) built-in shell (ash)
Enter 'help' for a list of built-in commands.

(initramfs) cat /test-file
second
(initramfs) uname -a
Linux (none) 5.4.0-65-generic #73-Ubuntu SMP Mon Jan 18 17:25:17 UTC 2021 x86_64 GNU/Linux
(initramfs) QEMU 5.0.0 monitor - type 'help' for more information
(qemu) quit

All is good.