Bug 1238151 - 'virt_to_phys' fail with sparse memory.
Summary: 'virt_to_phys' fail with sparse memory.
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: crash
Version: 23
Hardware: arm
OS: Linux
unspecified
medium
Target Milestone: ---
Assignee: Dave Anderson
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2015-07-01 09:51 UTC by a.krasnov
Modified: 2016-12-20 13:52 UTC (History)
1 user (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2016-12-20 13:52:35 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)

Description a.krasnov 2015-07-01 09:51:09 UTC
Description of problem: crash failed reading 'memory_section' symbol with sparse mem.

Version-Release number of selected component (if applicable):
7.1.1

How reproducible:
I have board with sparse memory. When i'm trying to load coredump of this board,
i get the following message:

crash: read error: kernel virtual address: dc98f400  type: "memory section"

This happens because 'arm_kvtop' translates virtual to physical just using offset,
while mentioned board has the following physical memory layout(from, size):
0x20000000, 0xf800000
0x40000000, 0x2c000000
0x84800000, 0x2b000000
So when crash substracts offset from 0xdc98f400 it gets 0x3c98f400, which is
out of physical addresses of coredump program segments. I've prepared simple
patch which parses device tree in order to read these memory regions and use
them instead of offset substraction during virtual to physical address
translation.

Steps to Reproduce:
1. Just load coredump.
2.
3.

Actual results:


Expected results:


Additional info:

Comment 2 Dave Anderson 2015-07-01 12:17:42 UTC
32-bit ARM is not supported in RHEL.

Comment 3 Dave Anderson 2015-07-01 12:21:46 UTC
> I've prepared simple patch which parses device tree in order to read these
> memory regions and use them instead of offset substraction during virtual
> to physical address

You can certainly post your patch here, but it would be more helpful if this
were discussed/posted on the upstream crash utility mailing list:

  https://www.redhat.com/mailman/listinfo/crash-utility

Comment 4 Dave Anderson 2015-07-01 12:40:19 UTC
BTW, what kind of dumpfile is this?  (i.e., ELF kdump, compressed kdump, or
ramdump)

Comment 5 Dave Anderson 2015-07-01 13:05:23 UTC
I don't do any ARM32 support, but rather I depend upon several developers
that are on the crash-utility mailing list who post, review and accept
patches, which I then take in.  For general testing purposes, I have about a
dozen ARM32 dumpfiles that they have given me, but I note that all of them
are from kernels that were configured with FLATMEM, which I am presuming
is the crux of the problem.  The ARM32 VTOP() function simply reflects
the kernel's FLATMEM __virt_to_phys() function.   (There is no "virt_to_phys"
function in the crash utility)

That being the case, in addition to your proposed patch, I am also going to
need a sample dumpfile from a kernel configured with SPARSEMEM.

Comment 6 a.krasnov 2015-07-01 13:27:58 UTC
dumpfile is ELF kdump, ok i'll post patch to mail list as soon as possible.

Comment 7 Jan Kurik 2015-07-15 13:52:32 UTC
This bug appears to have been reported against 'rawhide' during the Fedora 23 development cycle.
Changing version to '23'.

(As we did not run this process for some time, it could affect also pre-Fedora 23 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 23 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora23

Comment 8 Fedora End Of Life 2016-11-24 11:58:47 UTC
This message is a reminder that Fedora 23 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 23. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '23'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 23 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Comment 9 Fedora End Of Life 2016-12-20 13:52:35 UTC
Fedora 23 changed to end-of-life (EOL) status on 2016-12-20. Fedora 23 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
bug.

Thank you for reporting this bug and we are sorry it could not be fixed.


Note You need to log in before you can comment on or make changes to this bug.