[Crash-utility] regression with System.map handling on 4.14 +?

[Jinpu Wang]

Hi Dave, hi co,

I noticed a behaviour change regarding System.map handling regarding
newer kernel like 4.14+

As a example:
below command works:
crash -d 1 vmlinux-4.14.43-1-pserver ps402a-30-dump.201806041421 > good.txt

below command report error:
crash -d 1 vmlinux-4.14.43-1-pserver System.map-4.14.43-1-pserver
ps402a-30-dump.201806041421 > bad.txt

crash: page excluded: kernel virtual address: ffffffff82237f18  type:
"page_offset_base"

When compare the difference between good.txt and bad.txt, I noticed
following only in good.txt:
KASLR:
  _stext from vmlinux-4.14.43-1-pserver: ffffffff81000000
  _stext from vmcoreinfo: ffffffff9e000000
  relocate: 1d000000 (464MB)

I tried also on latest Ubuntu 1804, crash reports same error when run
with System.map file.

Is this expected?

Thanks,
-- 
Jack Wang
Linux Kernel Developer

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