linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ming Lei <ming.lei@redhat.com>
To: Daniel Wagner <dwagner@suse.de>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	Jens Axboe <axboe@kernel.dk>, Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH 2/2] block: hold queue lock while iterating in diskstats_show
Date: Thu, 20 Jan 2022 21:51:18 +0800	[thread overview]
Message-ID: <Yelo1gx5cp1l4npK@T590> (raw)
In-Reply-To: <20220120131936.mlug7nhnoe73abx5@carbon.lan>

On Thu, Jan 20, 2022 at 02:19:36PM +0100, Daniel Wagner wrote:
> Hi Ming,
> 
> On Thu, Jan 20, 2022 at 08:56:03PM +0800, Ming Lei wrote:
> [323467.255527] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [323467.255538] #PF: supervisor read access in kernel mode
> [323467.255541] #PF: error_code(0x0000) - not-present page
> [323467.255544] PGD 0 P4D 0 
> [323467.255550] Oops: 0000 [#1] SMP PTI
> [323467.255555] CPU: 13 PID: 17640 Comm: iostat Kdump: loaded Tainted: G          IOE  X    5.3.18-59.27-default #1 SLE15-SP3
> [323467.255559] Hardware name: Dell Inc. PowerEdge R940xa/08XR9M, BIOS 2.12.2 07/12/2021
> [323467.255569] RIP: 0010:blk_mq_queue_tag_busy_iter+0x1e4/0x2e0

Then Can you figure out where blk_mq_queue_tag_busy_iter+0x1e4 points to
in source code? And what is NULL pointer?

With this kind of info, we may know the root cause.

Thanks,
Ming


  reply	other threads:[~2022-01-20 13:51 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-20 10:52 [PATCH 0/2] fix crash by reading /proc/diskstats Daniel Wagner
2022-01-20 10:52 ` [PATCH 1/2] block: remove commented out code from diskstats_show Daniel Wagner
2022-01-20 11:02   ` Hannes Reinecke
2022-03-04 15:38     ` Daniel Wagner
2022-01-20 10:52 ` [PATCH 2/2] block: hold queue lock while iterating in diskstats_show Daniel Wagner
2022-01-20 11:18   ` Hannes Reinecke
2022-01-20 12:41     ` Daniel Wagner
2022-01-20 12:56   ` Ming Lei
2022-01-20 13:19     ` Daniel Wagner
2022-01-20 13:51       ` Ming Lei [this message]
2022-01-20 14:01         ` Daniel Wagner
2022-01-20 14:06           ` Daniel Wagner
2022-01-20 14:21           ` Christoph Hellwig
2022-01-20 14:34             ` Daniel Wagner
2022-01-20 15:37           ` Ming Lei
2022-01-20 16:29             ` Daniel Wagner
2022-03-04 14:53               ` Daniel Wagner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=Yelo1gx5cp1l4npK@T590 \
    --to=ming.lei@redhat.com \
    --cc=axboe@kernel.dk \
    --cc=dwagner@suse.de \
    --cc=hare@suse.de \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).