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mac80211: allow TDLS setup code to take wdev lock

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TDLS off-channel can be allowed in channels marked with GO_CONCURRENT,
provided the device is connected to an AP on the same UNII.
When relaxing the NO-IR requirements for TDLS, we might hit flows in
cfg80211_reg_can_beacon that acquire the wdev lock. Take some measures
to allow this during TDLS setup.
Acquire the RCU read lock later in the flow that invokes
cfg80211_reg_can_beacon.
Avoid taking local->mtx when preparing the setup packet to avoid
circular deadlocks with mac80211 code that is invoked with wdev-mtx
held.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Arik Nemtsov 2015-03-01 09:10:09 +02:00 committed by Johannes Berg
parent 23e370989c
commit ae2e9fba85
1 changed files with 24 additions and 17 deletions
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41
net/mac80211/tdls.c
View file

@ -287,17 +287,6 @@ ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
size_t offset = 0, noffset;
u8 *pos;
rcu_read_lock();
/* we should have the peer STA if we're already responding */
if (action_code == WLAN_TDLS_SETUP_RESPONSE) {
sta = sta_info_get(sdata, peer);
if (WARN_ON_ONCE(!sta)) {
rcu_read_unlock();
return;
}
}
ieee80211_add_srates_ie(sdata, skb, false, band);
ieee80211_add_ext_srates_ie(sdata, skb, false, band);
ieee80211_tdls_add_supp_channels(sdata, skb);
@ -350,6 +339,17 @@ ieee80211_tdls_add_setup_start_ies(struct ieee80211_sub_if_data *sdata,
offset = noffset;
}
rcu_read_lock();
/* we should have the peer STA if we're already responding */
if (action_code == WLAN_TDLS_SETUP_RESPONSE) {
sta = sta_info_get(sdata, peer);
if (WARN_ON_ONCE(!sta)) {
rcu_read_unlock();
return;
}
}
/*
* with TDLS we can switch channels, and HT-caps are not necessarily
* the same on all bands. The specification limits the setup to a
@ -983,7 +983,7 @@ ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
if (!is_zero_ether_addr(sdata->u.mgd.tdls_peer) &&
!ether_addr_equal(sdata->u.mgd.tdls_peer, peer)) {
ret = -EBUSY;
goto exit;
goto out_unlock;
}
/*
@ -998,27 +998,34 @@ ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
if (!sta_info_get(sdata, peer)) {
rcu_read_unlock();
ret = -ENOLINK;
goto exit;
goto out_unlock;
}
rcu_read_unlock();
}
ieee80211_flush_queues(local, sdata, false);
memcpy(sdata->u.mgd.tdls_peer, peer, ETH_ALEN);
mutex_unlock(&local->mtx);
/* we cannot take the mutex while preparing the setup packet */
ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
dialog_token, status_code,
peer_capability, initiator,
extra_ies, extra_ies_len, 0,
NULL);
if (ret < 0)
goto exit;
if (ret < 0) {
mutex_lock(&local->mtx);
eth_zero_addr(sdata->u.mgd.tdls_peer);
mutex_unlock(&local->mtx);
return ret;
}
memcpy(sdata->u.mgd.tdls_peer, peer, ETH_ALEN);
ieee80211_queue_delayed_work(&sdata->local->hw,
&sdata->u.mgd.tdls_peer_del_work,
TDLS_PEER_SETUP_TIMEOUT);
return 0;
exit:
out_unlock:
mutex_unlock(&local->mtx);
return ret;
}