diff options
Diffstat (limited to 'package/mac80211/patches/407-debugfs-sta-work-fix.patch')
| -rw-r--r-- | package/mac80211/patches/407-debugfs-sta-work-fix.patch | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/package/mac80211/patches/407-debugfs-sta-work-fix.patch b/package/mac80211/patches/407-debugfs-sta-work-fix.patch new file mode 100644 index 000000000..4dbdba998 --- /dev/null +++ b/package/mac80211/patches/407-debugfs-sta-work-fix.patch @@ -0,0 +1,68 @@ +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 <johannes@sipsolutions.net> +Cc: Robin Holt <holt@sgi.com> +--- + net/mac80211/debugfs_sta.c | 11 +++++++++++ + net/mac80211/sta_info.c | 7 ++++++- + net/mac80211/sta_info.h | 1 + + 3 files changed, 18 insertions(+), 1 deletion(-) + +--- everything.orig/net/mac80211/debugfs_sta.c 2008-10-07 20:05:29.000000000 +0200 ++++ everything/net/mac80211/debugfs_sta.c 2008-10-07 20:06:39.000000000 +0200 +@@ -249,11 +249,22 @@ void ieee80211_sta_debugfs_add(struct st + 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; +--- everything.orig/net/mac80211/sta_info.c 2008-10-07 20:05:29.000000000 +0200 ++++ everything/net/mac80211/sta_info.c 2008-10-07 20:06:39.000000000 +0200 +@@ -635,7 +635,12 @@ static void sta_info_debugfs_add_work(st + + spin_lock_irqsave(&local->sta_lock, flags); + list_for_each_entry(tmp, &local->sta_list, list) { +- if (!tmp->debugfs.dir) { ++ /* ++ * debugfs.add_has_run will be set by ++ * ieee80211_sta_debugfs_add regardless ++ * of what else it does. ++ */ ++ if (!tmp->debugfs.add_has_run) { + sta = tmp; + __sta_info_pin(sta); + break; +--- everything.orig/net/mac80211/sta_info.h 2008-10-07 20:05:29.000000000 +0200 ++++ everything/net/mac80211/sta_info.h 2008-10-07 20:06:39.000000000 +0200 +@@ -300,6 +300,7 @@ struct sta_info { + struct dentry *inactive_ms; + struct dentry *last_seq_ctrl; + struct dentry *agg_status; ++ bool add_has_run; + } debugfs; + #endif + |