Commit 6b7c93c1 authored by Benjamin Berg's avatar Benjamin Berg Committed by Johannes Berg
Browse files

wifi: cfg80211: keep bss_lock held when informing 



It is reasonable to hold bss_lock for a little bit longer after
cfg80211_bss_update is done. Right now, this does not make any big
difference, but doing so in preparation for the next patch which adds
a call to the driver.

Signed-off-by: default avatarBenjamin Berg <benjamin.berg@intel.com>
Signed-off-by: default avatarGregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094948.61701884ff0d.I3358228209eb6766202aff04d1bae0b8fdff611f@changeid


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent c2edd301

net/wireless/scan.c

+42 −24
Original line number Diff line number Diff line
@@ -1701,8 +1701,8 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev, 
}



/* Returned bss is reference counted and must be cleaned up appropriately. */

struct cfg80211_internal_bss *

cfg80211_bss_update(struct cfg80211_registered_device *rdev,

static struct cfg80211_internal_bss *

__cfg80211_bss_update(struct cfg80211_registered_device *rdev,

		      struct cfg80211_internal_bss *tmp,

		      bool signal_valid, unsigned long ts)

{
@@ -1713,10 +1713,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, 


	tmp->ts = ts;



	spin_lock_bh(&rdev->bss_lock);



	if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {

		spin_unlock_bh(&rdev->bss_lock);

		return NULL;

	}
@@ -1724,7 +1721,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, 


	if (found) {

		if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid))

			goto drop;

			return NULL;

	} else {

		struct cfg80211_internal_bss *new;

		struct cfg80211_internal_bss *hidden;
@@ -1744,7 +1741,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, 
			ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);

			if (ies)

				kfree_rcu(ies, rcu_head);

			goto drop;

			return NULL;

		}

		memcpy(new, tmp, sizeof(*new));

		new->refcount = 1;
@@ -1775,14 +1772,14 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, 
			 */

			if (!cfg80211_combine_bsses(rdev, new)) {

				bss_ref_put(rdev, new);

				goto drop;

				return NULL;

			}

		}



		if (rdev->bss_entries >= bss_entries_limit &&

		    !cfg80211_bss_expire_oldest(rdev)) {

			bss_ref_put(rdev, new);

			goto drop;

			return NULL;

		}



		/* This must be before the call to bss_ref_get */
@@ -1799,12 +1796,22 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, 


	rdev->bss_generation++;

	bss_ref_get(rdev, found);

	spin_unlock_bh(&rdev->bss_lock);



	return found;

 drop:

}



struct cfg80211_internal_bss *

cfg80211_bss_update(struct cfg80211_registered_device *rdev,

		    struct cfg80211_internal_bss *tmp,

		    bool signal_valid, unsigned long ts)

{

	struct cfg80211_internal_bss *res;



	spin_lock_bh(&rdev->bss_lock);

	res = __cfg80211_bss_update(rdev, tmp, signal_valid, ts);

	spin_unlock_bh(&rdev->bss_lock);

	return NULL;



	return res;

}



int cfg80211_get_ies_channel_number(const u8 *ie, size_t ielen,
@@ -2015,15 +2022,15 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, 
	rcu_assign_pointer(tmp.pub.ies, ies);



	signal_valid = data->chan == channel;

	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, ts);

	spin_lock_bh(&rdev->bss_lock);

	res = __cfg80211_bss_update(rdev, &tmp, signal_valid, ts);

	if (!res)

		return NULL;

		goto drop;



	if (non_tx_data) {

		/* this is a nontransmitting bss, we need to add it to

		 * transmitting bss' list if it is not there

		 */

		spin_lock_bh(&rdev->bss_lock);

		if (cfg80211_add_nontrans_list(non_tx_data->tx_bss,

					       &res->pub)) {

			if (__cfg80211_unlink_bss(rdev, res)) {
@@ -2031,15 +2038,19 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, 
				res = NULL;

			}

		}

		spin_unlock_bh(&rdev->bss_lock);



		if (!res)

			return NULL;

			goto drop;

	}

	spin_unlock_bh(&rdev->bss_lock);



	trace_cfg80211_return_bss(&res->pub);

	/* cfg80211_bss_update gives us a referenced result */

	/* __cfg80211_bss_update gives us a referenced result */

	return &res->pub;



drop:

	spin_unlock_bh(&rdev->bss_lock);

	return NULL;

}



static const struct element
@@ -2376,6 +2387,7 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, 
				      struct ieee80211_mgmt *mgmt, size_t len,

				      gfp_t gfp)

{

	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);

	struct cfg80211_internal_bss tmp = {}, *res;

	struct cfg80211_bss_ies *ies;

	struct ieee80211_channel *channel;
@@ -2485,14 +2497,20 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, 
	ether_addr_copy(tmp.parent_bssid, data->parent_bssid);



	signal_valid = data->chan == channel;

	res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid,

				  jiffies);

	spin_lock_bh(&rdev->bss_lock);

	res = __cfg80211_bss_update(rdev, &tmp, signal_valid, jiffies);

	if (!res)

		return NULL;

		goto drop;



	spin_unlock_bh(&rdev->bss_lock);



	trace_cfg80211_return_bss(&res->pub);

	/* cfg80211_bss_update gives us a referenced result */

	/* __cfg80211_bss_update gives us a referenced result */

	return &res->pub;



drop:

	spin_unlock_bh(&rdev->bss_lock);

	return NULL;

}



struct cfg80211_bss *