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Bug 1901739

Summary: crash fails to print blk_mq_ctx struct member
Product: Red Hat Enterprise Linux 8 Reporter: John Pittman <jpittman>
Component: crashAssignee: lijiang
Status: CLOSED ERRATA QA Contact: Jie Li <jieli>
Severity: medium Docs Contact:
Priority: medium    
Version: 8.2CC: djeffery, jieli, loberman, ruyang
Target Milestone: rcKeywords: Triaged
Target Release: 8.0Flags: pm-rhel: mirror+
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: crash-7.3.0-2.el8 Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-11-09 18:08:37 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description John Pittman 2020-11-25 22:08:27 UTC 
Description of problem:

crash fails to print struct member (array of unsigned longs)

MAJOR GENDISK            NAME       REQUEST_QUEUE      TOTAL ASYNC  SYNC
  253 ffff8c5a7ba06000   dm-35      ffff8c5a81a4cec0     576   576     0
 
crash> struct request_queue.queue_ctx ffff8c5a81a4cec0
  queue_ctx = 0x4640df42ed80
 
crash> kmem -o | head -n2
PER-CPU OFFSET VALUES:
  CPU 0: ffff8c5a9fc00000
 
crash> eval ffff8c5a9fc00000 + 0x4640df42ed80
hexadecimal: ffffd29b7f02ed80  
    decimal: 18446694164025503104  (-49909684048512)
      octal: 1777776451557700566600
     binary: 1111111111111111110100101001101101111111000000101110110110000000
 
And something strange...
 
crash> struct blk_mq_ctx.rq_completed
struct blk_mq_ctx {
  [128] unsigned long rq_completed[2];
}
 
crash> struct blk_mq_ctx.rq_completed ffffd29b7f02ed80  <===== no value?
crash>

crash> struct blk_mq_ctx ffffd29b7f02ed80 | grep rq_completed  <=== but grep works
  rq_completed = {1523, 677}, 

Version-Release number of selected component (if applicable):

crash 7.2.7-3.el8
kernel-4.18.0-193.28.1.el8_2

How reproducible:

Every time on this core

Steps to Reproduce:

Run struct command against prior mentioned member

Actual results:

struct command does not return values of member array

Expected results:

struct command should return values of member array
Comment 10 errata-xmlrpc 2021-11-09 18:08:37 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (crash bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2021:4199