diff options
Diffstat (limited to 'package/mac80211/patches/100-cfg80211-fix-deadlock.patch')
| -rw-r--r-- | package/mac80211/patches/100-cfg80211-fix-deadlock.patch | 108 |
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 6e2a2b1d1..000000000 --- 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))) |