Subject: linux-next: manual merge of the wireless-next tree with the wireless tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 12 Sep 2023 12:46:23 +1000

Hi all,

Today's linux-next merge of the wireless-next tree got a conflict in:

  net/wireless/nl80211.c

between commit:

  37c20b2effe9 ("wifi: cfg80211: fix cqm_config access race")

from the wireless tree and commit:

  076fc8775daf ("wifi: cfg80211: remove wdev mutex")

from the wireless-next tree.

I fixed it up (I used a supplied resolution from Johannes - see below)
and can carry the fix as necessary. This is now fixed as far as
linux-next is concerned, but any non trivial conflicts should be
mentioned to your upstream maintainer when your tree is submitted for
merging.  You may also want to consider cooperating with the maintainer
of the conflicting tree to minimise any particularly complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc net/wireless/nl80211.c
index 7a88361b3414,ab0aea7dca7d..fe06c238d4ef
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@@ -6191,12 -6135,8 +6150,12 @@@ static int nl80211_start_ap(struct sk_b
  
  	err = nl80211_calculate_ap_params(params);
  	if (err)
- 		goto out_unlock;
+ 		goto out;
  
 +	err = nl80211_validate_ap_phy_operation(params);
 +	if (err)
- 		goto out_unlock;
++		goto out;
 +
  	if (info->attrs[NL80211_ATTR_AP_SETTINGS_FLAGS])
  		params->flags = nla_get_u32(
  			info->attrs[NL80211_ATTR_AP_SETTINGS_FLAGS]);
@@@ -12884,11 -12747,10 +12767,11 @@@ static int nl80211_set_cqm_rssi(struct 
  				u32 hysteresis)
  {
  	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 +	struct cfg80211_cqm_config *cqm_config = NULL, *old;
  	struct net_device *dev = info->user_ptr[1];
  	struct wireless_dev *wdev = dev->ieee80211_ptr;
- 	int i, err;
  	s32 prev = S32_MIN;
 -	int i;
++	int i, err;
  
  	/* Check all values negative and sorted */
  	for (i = 0; i < n_thresholds; i++) {
@@@ -12917,11 -12781,9 +12800,9 @@@
  	if (n_thresholds == 1 && thresholds[0] == 0) /* Disabling */
  		n_thresholds = 0;
  
- 	wdev_lock(wdev);
- 	old = rcu_dereference_protected(wdev->cqm_config,
- 					lockdep_is_held(&wdev->mtx));
 -	if (n_thresholds) {
 -		struct cfg80211_cqm_config *cqm_config;
++	old = wiphy_dereference(wdev->wiphy, wdev->cqm_config);
  
 +	if (n_thresholds) {
  		cqm_config = kzalloc(struct_size(cqm_config, rssi_thresholds,
  						 n_thresholds),
  				     GFP_KERNEL);
@@@ -12936,22 -12796,10 +12815,20 @@@
  		       flex_array_size(cqm_config, rssi_thresholds,
  				       n_thresholds));
  
 -		wdev->cqm_config = cqm_config;
 +		rcu_assign_pointer(wdev->cqm_config, cqm_config);
 +	} else {
 +		RCU_INIT_POINTER(wdev->cqm_config, NULL);
  	}
  
 -	return cfg80211_cqm_rssi_update(rdev, dev);
 +	err = cfg80211_cqm_rssi_update(rdev, dev, cqm_config);
 +	if (err) {
 +		rcu_assign_pointer(wdev->cqm_config, old);
 +		kfree_rcu(cqm_config, rcu_head);
 +	} else {
 +		kfree_rcu(old, rcu_head);
 +	}
- unlock:
- 	wdev_unlock(wdev);
 +
 +	return err;
  }
  
  static int nl80211_set_cqm(struct sk_buff *skb, struct genl_info *info)
@@@ -19107,41 -18879,18 +18907,39 @@@ void cfg80211_cqm_rssi_notify(struct ne
  		    rssi_event != NL80211_CQM_RSSI_THRESHOLD_EVENT_HIGH))
  		return;
  
 -	if (wdev->cqm_config) {
 -		wdev->cqm_config->last_rssi_event_value = rssi_level;
 +	rcu_read_lock();
 +	cqm_config = rcu_dereference(wdev->cqm_config);
 +	if (cqm_config) {
 +		cqm_config->last_rssi_event_value = rssi_level;
 +		cqm_config->last_rssi_event_type = rssi_event;
 +		wiphy_work_queue(wdev->wiphy, &wdev->cqm_rssi_work);
 +	}
 +	rcu_read_unlock();
 +}
 +EXPORT_SYMBOL(cfg80211_cqm_rssi_notify);
 +
 +void cfg80211_cqm_rssi_notify_work(struct wiphy *wiphy, struct wiphy_work *work)
 +{
 +	struct wireless_dev *wdev = container_of(work, struct wireless_dev,
 +						 cqm_rssi_work);
 +	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 +	enum nl80211_cqm_rssi_threshold_event rssi_event;
 +	struct cfg80211_cqm_config *cqm_config;
 +	struct sk_buff *msg;
 +	s32 rssi_level;
 +
- 	wdev_lock(wdev);
- 	cqm_config = rcu_dereference_protected(wdev->cqm_config,
- 					       lockdep_is_held(&wdev->mtx));
++	cqm_config = wiphy_dereference(wdev->wiphy, wdev->cqm_config);
 +	if (!wdev->cqm_config)
- 		goto unlock;
++		return;
  
 -		cfg80211_cqm_rssi_update(rdev, dev);
 +	cfg80211_cqm_rssi_update(rdev, wdev->netdev, cqm_config);
  
 -		if (rssi_level == 0)
 -			rssi_level = wdev->cqm_config->last_rssi_event_value;
 -	}
 +	rssi_level = cqm_config->last_rssi_event_value;
 +	rssi_event = cqm_config->last_rssi_event_type;
  
 -	msg = cfg80211_prepare_cqm(dev, NULL, gfp);
 +	msg = cfg80211_prepare_cqm(wdev->netdev, NULL, GFP_KERNEL);
  	if (!msg)
- 		goto unlock;
+ 		return;
  
  	if (nla_put_u32(msg, NL80211_ATTR_CQM_RSSI_THRESHOLD_EVENT,
  			rssi_event))
@@@ -19151,15 -18900,14 +18949,13 @@@
  				      rssi_level))
  		goto nla_put_failure;
  
 -	cfg80211_send_cqm(msg, gfp);
 +	cfg80211_send_cqm(msg, GFP_KERNEL);
  
- 	goto unlock;
+ 	return;
  
   nla_put_failure:
  	nlmsg_free(msg);
-  unlock:
- 	wdev_unlock(wdev);
  }
 -EXPORT_SYMBOL(cfg80211_cqm_rssi_notify);
  
  void cfg80211_cqm_txe_notify(struct net_device *dev,
  			     const u8 *peer, u32 num_packets,