From: Johannes Berg Date: Tue, 19 Apr 2011 18:44:04 +0000 (+0200) Subject: mac80211: fix SMPS debugfs locking X-Git-Url: http://git.alex.org.uk mac80211: fix SMPS debugfs locking BugLink: http://bugs.launchpad.net/bugs/780546 commit 243e6df4ed919880d079d717641ad699c6530a03 upstream. The locking with SMPS requests means that the debugs file should lock the mgd mutex, not the iflist mutex. Calls to __ieee80211_request_smps() need to hold that mutex, so add an assertion. This has always been wrong, but for some reason never been noticed, probably because the locking error only happens while unassociated. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman Signed-off-by: Tim Gardner --- diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 9cd73b1..40f7357 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1471,6 +1471,8 @@ int __ieee80211_request_smps(struct ieee80211_sub_if_data *sdata, enum ieee80211_smps_mode old_req; int err; + lockdep_assert_held(&sdata->u.mgd.mtx); + old_req = sdata->u.mgd.req_smps; sdata->u.mgd.req_smps = smps_mode; diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c index 2dabdf7..bae23ad 100644 --- a/net/mac80211/debugfs_netdev.c +++ b/net/mac80211/debugfs_netdev.c @@ -172,9 +172,9 @@ static int ieee80211_set_smps(struct ieee80211_sub_if_data *sdata, if (sdata->vif.type != NL80211_IFTYPE_STATION) return -EOPNOTSUPP; - mutex_lock(&local->iflist_mtx); + mutex_lock(&sdata->u.mgd.mtx); err = __ieee80211_request_smps(sdata, smps_mode); - mutex_unlock(&local->iflist_mtx); + mutex_unlock(&sdata->u.mgd.mtx); return err; }