linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Johannes Berg <johannes@sipsolutions.net>
To: "McGinn, Dan" <dan.mcginn@imperial.ac.uk>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Cc: Denis Kenzior <denkenz@gmail.com>
Subject: Re: [BUG] mac80211: Using smp_processor_id() in preemptible code: iwd
Date: Fri, 15 Jun 2018 14:30:43 +0200	[thread overview]
Message-ID: <1529065843.10037.22.camel@sipsolutions.net> (raw)
In-Reply-To: <DB5PR06MB106451FE83810B8A129CE1E4A47C0@DB5PR06MB1064.eurprd06.prod.outlook.com> (sfid-20180615_133718_270290_EB030DCF)

On Fri, 2018-06-15 at 11:09 +0000, McGinn, Dan wrote:
> Hi, I'm newly trying out Intel iwd daemon but I experience regular kernel errors in 4.17, although WPA2-PSK connection remains stable.  These errors don't seem to be experienced with wpa_supplicant.  The errors reliably appear around the following events:
> netdev_unicast_notify()
> netdev_control_port_frame_event()
> netdev_set_rekey_offload()
> netdev_set_gtk()
> 
> @Denkenz in IRC helpfully suggests Johannes could follow the finger of suspicion to this commit:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=911806491425d79107cadddbde11b42bbdfe38c8

It's his code ;-)

Clearly this comes from cfg80211 without any locking other than rtnl, so
you don't have preemption disabled. That's the minimum needed to get rid
of the warning you found.

I was thinking this is also wrong because of locking assumptions, but I
don't see that in the code now, so I guess it's fine.

johannes

  reply	other threads:[~2018-06-15 12:30 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-15 11:09 [BUG] mac80211: Using smp_processor_id() in preemptible code: iwd McGinn, Dan
2018-06-15 12:30 ` Johannes Berg [this message]
2018-06-20  3:04   ` Denis Kenzior
2018-06-20  7:01     ` Johannes Berg

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=1529065843.10037.22.camel@sipsolutions.net \
    --to=johannes@sipsolutions.net \
    --cc=dan.mcginn@imperial.ac.uk \
    --cc=denkenz@gmail.com \
    --cc=linux-wireless@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).