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I am trying to start a crash kernel using Linux's Kernel Crash Dump. Both of the host and crash kernel are compiled linux-4.13.16 kernel. Unfortunately, the crash kernel fails to start after the crash occurs.

iomem reports reserved space for crash kernel and kdump reports its ready for kdump:

28000000-37ffffff : Crash kernel

$ sudo kdump-config show
DUMP_MODE:        kdump
USE_KDUMP:        1
KDUMP_SYSCTL:     kernel.panic_on_oops=1
KDUMP_COREDIR:    /var/crash
crashkernel addr: 0x28000000
   /var/lib/kdump/vmlinuz: symbolic link to /boot/vmlinuz-4.13.16ksa
kdump initrd:
   /var/lib/kdump/initrd.img: symbolic link to /var/lib/kdump/initrd.img-4.13.16ksa
current state:    ready to kdump
kexec command:
  /sbin/kexec -p --command-line="BOOT_IMAGE=/boot/vmlinuz-4.13.16ksa root=UUID=3254c608-d885-4dfc-b20b-fa4e69564dca ro quiet splash vt.handoff=7 irqpoll noirqdistrib nr_cpus=1 nousb systemd.unit=kdump-tools.service" --initrd=/var/lib/kdump/initrd.img /var/lib/kdump/vmlinuz

$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.13.16ksa root=UUID=3254c608-d885-4dfc-b20b-fa4e69564dca ro quiet splash crashkernel=384M-2G:128M,2G-:256M vt.handoff=7

After triggering crash using sysrq-trigger, it doesn't load crash kernel.

I have tested with a generic kernel, linux-4.8.0-36-generic, which successfully works.

Syslog file are here.

Both linux-4.8.0-36-generic and linux-4.13.16ksa has same .config file. Only difference I can see is that during boot, for linux-4.13.0-38, it loads the efi.signed vmlinuz(vmlinuz-4.13.0-38-generic.efi.signed) where as the compiled linux-4.13.16ksa is not efi signed.

Can it be an issue? How can I resolve this?

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