aboutsummaryrefslogtreecommitdiffstats
path: root/package/mac80211/patches/100-cfg80211-fix-deadlock.patch
diff options
context:
space:
mode:
Diffstat (limited to 'package/mac80211/patches/100-cfg80211-fix-deadlock.patch')
-rw-r--r--package/mac80211/patches/100-cfg80211-fix-deadlock.patch108
1 files changed, 0 insertions, 108 deletions
diff --git a/package/mac80211/patches/100-cfg80211-fix-deadlock.patch b/package/mac80211/patches/100-cfg80211-fix-deadlock.patch
deleted file mode 100644
index 6e2a2b1d1f..0000000000
--- a/package/mac80211/patches/100-cfg80211-fix-deadlock.patch
+++ /dev/null
@@ -1,108 +0,0 @@
-Subject: [PATCH] cfg80211: fix deadlock
-From: Johannes Berg <johannes@sipsolutions.net>
-To: John Linville <linville@tuxdriver.com>
-Cc: linux-wireless <linux-wireless@vger.kernel.org>,
- Christian Lamparter <chunkeey@web.de>
-Content-Type: text/plain
-Date: Sun, 16 Aug 2009 13:32:38 +0200
-Message-Id: <1250422358.17522.0.camel@johannes.local>
-Mime-Version: 1.0
-X-Mailer: Evolution 2.27.90
-Content-Transfer-Encoding: 7bit
-Sender: linux-wireless-owner@vger.kernel.org
-Precedence: bulk
-List-ID: <linux-wireless.vger.kernel.org>
-X-Mailing-List: linux-wireless@vger.kernel.org
-
-When removing an interface with nl80211, cfg80211 will
-deadlock in the netdev notifier because we're already
-holding rdev->mtx and try to acquire it again to verify
-the scan has been done.
-
-This bug was introduced by my patch
-"cfg80211: check for and abort dangling scan requests".
-
-To fix this, move the dangling scan request check into
-wiphy_unregister(). This will not be able to catch all
-cases right away, but if the scan problem happens with
-a manual ifdown or so it will be possible to remedy it
-by removing the module/device.
-
-Additionally, add comments about the deadlock scenario.
-
-Reported-by: Christian Lamparter <chunkeey@web.de>
-Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
----
- net/wireless/core.c | 32 +++++++++++++++++++-------------
- 1 file changed, 19 insertions(+), 13 deletions(-)
-
---- a/net/wireless/core.c
-+++ b/net/wireless/core.c
-@@ -586,9 +586,15 @@ void wiphy_unregister(struct wiphy *wiph
- * get to lock contention here if userspace issues a command
- * that identified the hardware by wiphy index.
- */
-- mutex_lock(&rdev->mtx);
-- /* unlock again before freeing */
-- mutex_unlock(&rdev->mtx);
-+ cfg80211_lock_rdev(rdev);
-+
-+ if (WARN_ON(rdev->scan_req)) {
-+ rdev->scan_req->aborted = true;
-+ ___cfg80211_scan_done(rdev);
-+ }
-+
-+ cfg80211_unlock_rdev(rdev);
-+ flush_work(&rdev->scan_done_wk);
-
- cfg80211_debugfs_rdev_del(rdev);
-
-@@ -603,9 +609,7 @@ void wiphy_unregister(struct wiphy *wiph
-
- mutex_unlock(&cfg80211_mutex);
-
-- flush_work(&rdev->scan_done_wk);
- cancel_work_sync(&rdev->conn_work);
-- kfree(rdev->scan_req);
- flush_work(&rdev->event_work);
- }
- EXPORT_SYMBOL(wiphy_unregister);
-@@ -653,6 +657,11 @@ static int cfg80211_netdev_notifier_call
-
- switch (state) {
- case NETDEV_REGISTER:
-+ /*
-+ * NB: cannot take rdev->mtx here because this may be
-+ * called within code protected by it when interfaces
-+ * are added with nl80211.
-+ */
- mutex_init(&wdev->mtx);
- INIT_LIST_HEAD(&wdev->event_list);
- spin_lock_init(&wdev->event_lock);
-@@ -730,13 +739,11 @@ static int cfg80211_netdev_notifier_call
- #endif
- break;
- case NETDEV_UNREGISTER:
-- cfg80211_lock_rdev(rdev);
--
-- if (WARN_ON(rdev->scan_req && rdev->scan_req->dev == dev)) {
-- rdev->scan_req->aborted = true;
-- ___cfg80211_scan_done(rdev);
-- }
--
-+ /*
-+ * NB: cannot take rdev->mtx here because this may be
-+ * called within code protected by it when interfaces
-+ * are removed with nl80211.
-+ */
- mutex_lock(&rdev->devlist_mtx);
- /*
- * It is possible to get NETDEV_UNREGISTER
-@@ -755,7 +762,6 @@ static int cfg80211_netdev_notifier_call
- #endif
- }
- mutex_unlock(&rdev->devlist_mtx);
-- cfg80211_unlock_rdev(rdev);
- break;
- case NETDEV_PRE_UP:
- if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))