mac80211: make scan_sdata pointer usable with RCU
Making the scan_sdata pointer usable with RCU makes it possible to dereference it in the RX path to see if a received frame actually matches the interface that is scanning. This is just preparations, making the pointer __rcu. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Родитель
d811b3d556
Коммит
e2fd5dbc1c
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@ -972,7 +972,7 @@ struct ieee80211_local {
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unsigned long leave_oper_channel_time;
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enum mac80211_scan_state next_scan_state;
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struct delayed_work scan_work;
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struct ieee80211_sub_if_data *scan_sdata;
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struct ieee80211_sub_if_data __rcu *scan_sdata;
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enum nl80211_channel_type _oper_channel_type;
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struct ieee80211_channel *oper_channel, *csa_channel;
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@ -112,10 +112,11 @@ static u32 __ieee80211_recalc_idle(struct ieee80211_local *local)
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}
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}
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if (local->scan_sdata &&
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!(local->hw.flags & IEEE80211_HW_SCAN_WHILE_IDLE)) {
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sdata = rcu_dereference_protected(local->scan_sdata,
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lockdep_is_held(&local->mtx));
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if (sdata && !(local->hw.flags & IEEE80211_HW_SCAN_WHILE_IDLE)) {
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scanning = true;
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local->scan_sdata->vif.bss_conf.idle = false;
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sdata->vif.bss_conf.idle = false;
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}
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list_for_each_entry(sdata, &local->interfaces, list) {
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@ -628,7 +629,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata,
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clear_bit(SDATA_STATE_RUNNING, &sdata->state);
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if (local->scan_sdata == sdata)
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if (rcu_access_pointer(local->scan_sdata) == sdata)
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ieee80211_scan_cancel(local);
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/*
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@ -293,7 +293,13 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
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return;
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if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
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int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req);
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int rc;
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rc = drv_hw_scan(local,
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rcu_dereference_protected(local->scan_sdata,
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lockdep_is_held(&local->mtx)),
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local->hw_scan_req);
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if (rc == 0)
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return;
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}
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@ -394,7 +400,10 @@ void ieee80211_run_deferred_scan(struct ieee80211_local *local)
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if (!local->scan_req || local->scanning)
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return;
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if (!ieee80211_can_scan(local, local->scan_sdata))
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if (!ieee80211_can_scan(local,
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rcu_dereference_protected(
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local->scan_sdata,
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lockdep_is_held(&local->mtx))))
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return;
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ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
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@ -405,9 +414,12 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
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unsigned long *next_delay)
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{
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int i;
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struct ieee80211_sub_if_data *sdata = local->scan_sdata;
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struct ieee80211_sub_if_data *sdata;
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enum ieee80211_band band = local->hw.conf.channel->band;
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sdata = rcu_dereference_protected(local->scan_sdata,
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lockdep_is_held(&local->mtx));;
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for (i = 0; i < local->scan_req->n_ssids; i++)
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ieee80211_send_probe_req(
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sdata, NULL,
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@ -439,7 +451,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
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if (!ieee80211_can_scan(local, sdata)) {
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/* wait for the work to finish/time out */
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local->scan_req = req;
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local->scan_sdata = sdata;
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rcu_assign_pointer(local->scan_sdata, sdata);
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return 0;
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}
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@ -473,7 +485,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
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}
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local->scan_req = req;
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local->scan_sdata = sdata;
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rcu_assign_pointer(local->scan_sdata, sdata);
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if (local->ops->hw_scan) {
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__set_bit(SCAN_HW_SCANNING, &local->scanning);
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@ -533,7 +545,7 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
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ieee80211_recalc_idle(local);
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local->scan_req = NULL;
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local->scan_sdata = NULL;
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rcu_assign_pointer(local->scan_sdata, NULL);
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}
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return rc;
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@ -720,7 +732,8 @@ void ieee80211_scan_work(struct work_struct *work)
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mutex_lock(&local->mtx);
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sdata = local->scan_sdata;
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sdata = rcu_dereference_protected(local->scan_sdata,
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lockdep_is_held(&local->mtx));
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/* When scanning on-channel, the first-callback means completed. */
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if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
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@ -741,7 +754,7 @@ void ieee80211_scan_work(struct work_struct *work)
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int rc;
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local->scan_req = NULL;
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local->scan_sdata = NULL;
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rcu_assign_pointer(local->scan_sdata, NULL);
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rc = __ieee80211_start_scan(sdata, req);
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if (rc) {
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@ -893,7 +906,9 @@ void ieee80211_scan_cancel(struct ieee80211_local *local)
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if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
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if (local->ops->cancel_hw_scan)
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drv_cancel_hw_scan(local, local->scan_sdata);
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drv_cancel_hw_scan(local,
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rcu_dereference_protected(local->scan_sdata,
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lockdep_is_held(&local->mtx)));
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goto out;
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}
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