From: Jakub Kicinski <kuba@kernel.org>
To: Zbynek Michl <zbynek.michl@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: [regression] Kernel panic on resume from sleep
Date: Thu, 4 Mar 2021 09:51:10 -0800 [thread overview]
Message-ID: <20210304095110.7830dce4@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> (raw)
In-Reply-To: <CAJH0kmyTgLp4rJGL1EYo4hQ_qcd3t3JQS-s-e9FY8ERTPrmwqQ@mail.gmail.com>
On Thu, 4 Mar 2021 13:50:01 +0100 Zbynek Michl wrote:
> Looks good so far, but need to wait some more time as the issue was irregular.
>
> Do you have any explanation why the calls disorder caused the panic
> just occasionally?
Depends if kernel attempts to try to send a packet before __alx_open()
finishes. You can probably make it more likely by running trafgen, iperf
or such while suspending and resuming?
> Also, the same (wrong) order I can see in the 3.16 kernel code, but it
> has worked fine with this kernel in all cases. So what is different in
> 5.10?
At some point in between those versions the driver got modified to
allocate and free the NAPI structures dynamically.
I didn't look too closely to find out if things indeed worked 100%
correctly before, but now they will reliably crash on a NULL pointer
dereference if transmission comes before open is done.
next prev parent reply other threads:[~2021-03-04 17:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-01 22:11 [regression] Kernel panic on resume from sleep Zbynek Michl
2021-03-03 1:44 ` Jakub Kicinski
2021-03-04 12:50 ` Zbynek Michl
2021-03-04 17:51 ` Jakub Kicinski [this message]
2021-03-05 12:50 ` Zbynek Michl
2021-03-05 22:18 ` Jakub Kicinski
2021-03-06 18:36 ` Zbynek Michl
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=20210304095110.7830dce4@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com \
--to=kuba@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=zbynek.michl@gmail.com \
/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).