Commit 0378b597 authored by Johan Hedberg's avatar Johan Hedberg Committed by Marcel Holtmann
Browse files

Bluetooth: Convert link keys list to use RCU 



This patch converts the hdev->link_keys list to be protected through
RCU, thereby eliminating the need to hold the hdev lock while accessing
the list.

Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent cb6f3f7a

include/net/bluetooth/hci_core.h

+1 −0
Original line number Diff line number Diff line
@@ -130,6 +130,7 @@ struct smp_irk { 


struct link_key {

	struct list_head list;

	struct rcu_head rcu;

	bdaddr_t bdaddr;

	u8 type;

	u8 val[HCI_LINK_KEY_SIZE];

net/bluetooth/hci_core.c

+18 −19
Original line number Diff line number Diff line
@@ -274,15 +274,13 @@ static const struct file_operations inquiry_cache_fops = { 
static int link_keys_show(struct seq_file *f, void *ptr)

{

	struct hci_dev *hdev = f->private;

	struct list_head *p, *n;

	struct link_key *key;



	hci_dev_lock(hdev);

	list_for_each_safe(p, n, &hdev->link_keys) {

		struct link_key *key = list_entry(p, struct link_key, list);

	rcu_read_lock();

	list_for_each_entry_rcu(key, &hdev->link_keys, list)

		seq_printf(f, "%pMR %u %*phN %u\n", &key->bdaddr, key->type,

			   HCI_LINK_KEY_SIZE, key->val, key->pin_len);

	}

	hci_dev_unlock(hdev);

	rcu_read_unlock();



	return 0;

}
@@ -3101,15 +3099,11 @@ void hci_uuids_clear(struct hci_dev *hdev) 


void hci_link_keys_clear(struct hci_dev *hdev)

{

	struct list_head *p, *n;



	list_for_each_safe(p, n, &hdev->link_keys) {

	struct link_key *key;



		key = list_entry(p, struct link_key, list);



		list_del(p);

		kfree(key);

	list_for_each_entry_rcu(key, &hdev->link_keys, list) {

		list_del_rcu(&key->list);

		kfree_rcu(key, rcu);

	}

}
@@ -3137,9 +3131,14 @@ struct link_key *hci_find_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr) 
{

	struct link_key *k;



	list_for_each_entry(k, &hdev->link_keys, list)

		if (bacmp(bdaddr, &k->bdaddr) == 0)

	rcu_read_lock();

	list_for_each_entry_rcu(k, &hdev->link_keys, list) {

		if (bacmp(bdaddr, &k->bdaddr) == 0) {

			rcu_read_unlock();

			return k;

		}

	}

	rcu_read_unlock();



	return NULL;

}
@@ -3290,7 +3289,7 @@ struct link_key *hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, 
		key = kzalloc(sizeof(*key), GFP_KERNEL);

		if (!key)

			return NULL;

		list_add(&key->list, &hdev->link_keys);

		list_add_rcu(&key->list, &hdev->link_keys);

	}



	BT_DBG("%s key for %pMR type %u", hdev->name, bdaddr, type);
@@ -3383,8 +3382,8 @@ int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr) 


	BT_DBG("%s removing %pMR", hdev->name, bdaddr);



	list_del(&key->list);

	kfree(key);

	list_del_rcu(&key->list);

	kfree_rcu(key, rcu);



	return 0;

}

net/bluetooth/hci_event.c

+2 −2
Original line number Diff line number Diff line
@@ -3324,8 +3324,8 @@ static void hci_link_key_notify_evt(struct hci_dev *hdev, struct sk_buff *skb) 
	 */

	if (key->type == HCI_LK_DEBUG_COMBINATION &&

	    !test_bit(HCI_KEEP_DEBUG_KEYS, &hdev->dev_flags)) {

		list_del(&key->list);

		kfree(key);

		list_del_rcu(&key->list);

		kfree_rcu(key, rcu);

	} else if (conn) {

		if (persistent)

			clear_bit(HCI_CONN_FLUSH_KEY, &conn->flags);