diff options
Diffstat (limited to 'package')
| -rw-r--r-- | package/kernel/mac80211/patches/subsys/310-mac80211-agg-tx-don-t-schedule_and_wake_txq-under-st.patch | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/package/kernel/mac80211/patches/subsys/310-mac80211-agg-tx-don-t-schedule_and_wake_txq-under-st.patch b/package/kernel/mac80211/patches/subsys/310-mac80211-agg-tx-don-t-schedule_and_wake_txq-under-st.patch new file mode 100644 index 0000000000..008ee49cfb --- /dev/null +++ b/package/kernel/mac80211/patches/subsys/310-mac80211-agg-tx-don-t-schedule_and_wake_txq-under-st.patch @@ -0,0 +1,79 @@ +From: Johannes Berg <johannes.berg@intel.com> +Date: Mon, 29 Nov 2021 15:32:47 +0200 +Subject: [PATCH] mac80211: agg-tx: don't schedule_and_wake_txq() under + sta->lock + +When we call ieee80211_agg_start_txq(), that will in turn call +schedule_and_wake_txq(). Called from ieee80211_stop_tx_ba_cb() +this is done under sta->lock, which leads to certain circular +lock dependencies, as reported by Chris Murphy: +https://lore.kernel.org/r/CAJCQCtSXJ5qA4bqSPY=oLRMbv-irihVvP7A2uGutEbXQVkoNaw@mail.gmail.com + +In general, ieee80211_agg_start_txq() is usually not called +with sta->lock held, only in this one place. But it's always +called with sta->ampdu_mlme.mtx held, and that's therefore +clearly sufficient. + +Change ieee80211_stop_tx_ba_cb() to also call it without the +sta->lock held, by factoring it out of ieee80211_remove_tid_tx() +(which is only called in this one place). + +This breaks the locking chain and makes it less likely that +we'll have similar locking chain problems in the future. + +Reported-by: Chris Murphy <lists@colorremedies.com> +Signed-off-by: Johannes Berg <johannes.berg@intel.com> +Signed-off-by: Luca Coelho <luciano.coelho@intel.com> +--- + +--- a/net/mac80211/agg-tx.c ++++ b/net/mac80211/agg-tx.c +@@ -9,7 +9,7 @@ + * Copyright 2007, Michael Wu <flamingice@sourmilk.net> + * Copyright 2007-2010, Intel Corporation + * Copyright(c) 2015-2017 Intel Deutschland GmbH +- * Copyright (C) 2018 - 2020 Intel Corporation ++ * Copyright (C) 2018 - 2021 Intel Corporation + */ + + #include <linux/ieee80211.h> +@@ -213,6 +213,8 @@ ieee80211_agg_start_txq(struct sta_info + struct ieee80211_txq *txq = sta->sta.txq[tid]; + struct txq_info *txqi; + ++ lockdep_assert_held(&sta->ampdu_mlme.mtx); ++ + if (!txq) + return; + +@@ -290,7 +292,6 @@ static void ieee80211_remove_tid_tx(stru + ieee80211_assign_tid_tx(sta, tid, NULL); + + ieee80211_agg_splice_finish(sta->sdata, tid); +- ieee80211_agg_start_txq(sta, tid, false); + + kfree_rcu(tid_tx, rcu_head); + } +@@ -889,6 +890,7 @@ void ieee80211_stop_tx_ba_cb(struct sta_ + { + struct ieee80211_sub_if_data *sdata = sta->sdata; + bool send_delba = false; ++ bool start_txq = false; + + ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", + sta->sta.addr, tid); +@@ -906,10 +908,14 @@ void ieee80211_stop_tx_ba_cb(struct sta_ + send_delba = true; + + ieee80211_remove_tid_tx(sta, tid); ++ start_txq = true; + + unlock_sta: + spin_unlock_bh(&sta->lock); + ++ if (start_txq) ++ ieee80211_agg_start_txq(sta, tid, false); ++ + if (send_delba) + ieee80211_send_delba(sdata, sta->sta.addr, tid, + WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); |