From: greearb@candelatech.com
To: linux-wireless@vger.kernel.org
Cc: Ben Greear <greearb@candelatech.com>
Subject: [PATCH] mac80211: Fix deadlock in ieee80211_do_stop.
Date: Fri, 12 Nov 2010 12:07:06 -0800 [thread overview]
Message-ID: <1289592426-5367-1-git-send-email-greearb@candelatech.com> (raw)
From: Ben Greear <greearb@candelatech.com>
We cannot call flush_work here because we are holding
RTNL and the worker thread(s) that will be called upon to
do the flushing might already be running a piece of work
that is blocking on RTNL. That leads to deadlock and/or
OOM.
The ieee80211_iface_work method does nothing when sdata
is stopped (as it would be when the flush_work was called)
so it shouldn't be any big change to just cancel the work
entirely.
Signed-off-by: Ben Greear <greearb@candelatech.com>
---
:100644 100644 7aa8559... 073b42a... M net/mac80211/iface.c
net/mac80211/iface.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 7aa8559..073b42a 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -516,7 +516,13 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
}
/* fall through */
default:
- flush_work(&sdata->work);
+ /* Cannot call flush_work here because we are holding
+ * RTNL and the worker thread(s) that will be called upon to
+ * do the flushing might already be running a piece of work
+ * that is blocking on RTNL. That leads to deadlock and/or
+ * OOM.
+ */
+ cancel_work_sync(&sdata->work);
/*
* When we get here, the interface is marked down.
* Call synchronize_rcu() to wait for the RX path
--
1.7.2.3
next reply other threads:[~2010-11-12 20:07 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-12 20:07 greearb [this message]
2010-11-12 20:08 ` [PATCH] mac80211: Fix deadlock in ieee80211_do_stop Luis R. Rodriguez
2010-11-12 20:16 ` Ben Greear
2010-11-12 20:49 ` Johannes Berg
2010-11-12 20:57 ` Ben Greear
2010-11-12 21:08 ` Johannes Berg
2010-11-12 21:51 ` Ben Greear
2010-11-13 10:34 ` Tejun Heo
2010-11-15 21:16 ` Ben Greear
2010-11-16 14:19 ` Tejun Heo
2010-11-16 16:51 ` Ben Greear
2010-11-17 8:55 ` Tejun Heo
2010-11-17 17:37 ` Ben Greear
2010-11-16 17:40 ` Johannes Berg
2010-11-17 8:47 ` Tejun Heo
2010-11-17 18:53 ` Johannes Berg
2010-11-17 18:59 ` Ben Greear
2010-11-17 19:03 ` Johannes Berg
2010-11-18 6:34 ` Tejun Heo
2010-11-18 7:07 ` Johannes Berg
2010-11-18 7:22 ` Tejun Heo
2010-11-18 16:59 ` Johannes Berg
2010-11-19 14:34 ` Tejun Heo
2010-11-19 17:57 ` Johannes Berg
2010-11-19 20:55 ` Ben Greear
2010-11-19 22:27 ` Luis R. Rodriguez
2010-12-08 17:36 ` Ben Greear
2010-12-08 18:19 ` Ben Greear
2010-12-08 18:28 ` Ben Greear
2010-12-09 14:34 ` Tejun Heo
2010-12-09 14:42 ` Johannes Berg
2010-12-09 14:46 ` Tejun Heo
2010-12-09 16:17 ` Tejun Heo
[not found] ` <4D0156F6.4000306@candelate ch.com>
2010-12-09 17:27 ` Ben Greear
2010-12-09 22:23 ` Ben Greear
2010-12-10 15:11 ` Tejun Heo
2010-12-10 16:35 ` Ben Greear
2010-11-18 17:55 ` Ben Greear
2010-11-18 18:04 ` Tejun Heo
2010-11-18 18:11 ` Ben Greear
2010-11-17 20:13 ` Ben Greear
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=1289592426-5367-1-git-send-email-greearb@candelatech.com \
--to=greearb@candelatech.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).