From 63044e9f54b6bac50d2380bf4d14f63e9e7de72b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 7 Oct 2008 12:04:29 +0200 Subject: mac80211: fix debugfs lockup When debugfs_create_dir fails, sta_info_debugfs_add_work will not terminate because it will find the same station again and again. This is possible whenever debugfs fails for whatever reason; one reason is a race condition in mac80211, unfortunately we cannot do much about it, so just document it, it just means some station may be missing from debugfs. Signed-off-by: Johannes Berg Cc: Robin Holt Signed-off-by: John W. Linville --- net/mac80211/debugfs_sta.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'net/mac80211/debugfs_sta.c') diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c index b9902e425f09..189d0bafa91a 100644 --- a/net/mac80211/debugfs_sta.c +++ b/net/mac80211/debugfs_sta.c @@ -249,11 +249,22 @@ void ieee80211_sta_debugfs_add(struct sta_info *sta) DECLARE_MAC_BUF(mbuf); u8 *mac; + sta->debugfs.add_has_run = true; + if (!stations_dir) return; mac = print_mac(mbuf, sta->sta.addr); + /* + * This might fail due to a race condition: + * When mac80211 unlinks a station, the debugfs entries + * remain, but it is already possible to link a new + * station with the same address which triggers adding + * it to debugfs; therefore, if the old station isn't + * destroyed quickly enough the old station's debugfs + * dir might still be around. + */ sta->debugfs.dir = debugfs_create_dir(mac, stations_dir); if (!sta->debugfs.dir) return; -- cgit