There was some discussion about the order in which debugfs entries are removed in context of IEEE 802.11w implementation couple of months ago. The problem that I was seeing ended up leaving the netdev:mon.wlan0 directory in debugfs behind when the monitor interface was removed. This happened because mac80211 tried to remove the netdev directory before making sure that all files were removed from the directory. This did not show up before, but with IEEE 802.11w implementation, the netdev:mon.wlan0 directory may actually contain a key symlink and that prevented the directory from being removed. It looks like someone has cleaned up the netdev uninit sequence (which was quite a mess at the time I looked at it last and ended up just delaying the fix till now..) and that seems to make it trivial to fix the deinit order issue. The key part in fixing this is to make sure that the possible key symlinks are removed before the netdev directory and this is now easy to do by just changing the order of the function calls in ieee80211_teardown_sdata(). I did not find any reason why they would need to be in the other order, so this looks like a safe change. Did I miss something there or would the following change be acceptable way of fixing the issue? I did not notice any problems in my tests and this allows the debugfs directories to be removed properly with my IEEE 802.11w patches applied. ieee80211_free_keys() must be called before ieee80211_debugfs_remove_netdev() in order to make sure that the possible default_key symlink is removed before the netdev debugfs directory is removed. This fixes an issue where a monitor interface may be left behind when being removed if there is a key symlink in it. This does not happen with the current mac80211 code, but could happen in future after IEEE 802.11w (management frame protection) is added with its additional default_mgmt_key symlink. Signed-off-by: Jouni Malinen <jouni.malinen@xxxxxxxxxxx> Index: wireless-testing/net/mac80211/iface.c =================================================================== --- wireless-testing.orig/net/mac80211/iface.c +++ wireless-testing/net/mac80211/iface.c @@ -31,11 +31,11 @@ static void ieee80211_teardown_sdata(str int flushed; int i; - ieee80211_debugfs_remove_netdev(sdata); - /* free extra data */ ieee80211_free_keys(sdata); + ieee80211_debugfs_remove_netdev(sdata); + for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) __skb_queue_purge(&sdata->fragments[i].skb_list); sdata->fragment_next = 0; -- Jouni Malinen PGP id EFC895FA -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
