2 files changed, 38 insertions, 5 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 07a8b4281a39..14d7221b8ac0 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -64,7 +64,7 @@ static DEFINE_IDA(hci_index_ida);
 
 /* Get HCI device by index.
  * Device is held on return. */
-struct hci_dev *hci_dev_get(int index)
+static struct hci_dev *__hci_dev_get(int index, int *srcu_index)
 {
 	struct hci_dev *hdev = NULL, *d;
 
@@ -77,6 +77,8 @@ struct hci_dev *hci_dev_get(int index)
 	list_for_each_entry(d, &hci_dev_list, list) {
 		if (d->id == index) {
 			hdev = hci_dev_hold(d);
+			if (srcu_index)
+				*srcu_index = srcu_read_lock(&d->srcu);
 			break;
 		}
 	}
@@ -84,6 +86,22 @@ struct hci_dev *hci_dev_get(int index)
 	return hdev;
 }
 
+struct hci_dev *hci_dev_get(int index)
+{
+	return __hci_dev_get(index, NULL);
+}
+
+static struct hci_dev *hci_dev_get_srcu(int index, int *srcu_index)
+{
+	return __hci_dev_get(index, srcu_index);
+}
+
+static void hci_dev_put_srcu(struct hci_dev *hdev, int srcu_index)
+{
+	srcu_read_unlock(&hdev->srcu, srcu_index);
+	hci_dev_put(hdev);
+}
+
 /* ---- Inquiry support ---- */
 
 bool hci_discovery_active(struct hci_dev *hdev)
@@ -568,9 +586,9 @@ static int hci_dev_do_reset(struct hci_dev *hdev)
 int hci_dev_reset(__u16 dev)
 {
 	struct hci_dev *hdev;
-	int err;
+	int err, srcu_index;
 
-	hdev = hci_dev_get(dev);
+	hdev = hci_dev_get_srcu(dev, &srcu_index);
 	if (!hdev)
 		return -ENODEV;
 
@@ -592,7 +610,7 @@ int hci_dev_reset(__u16 dev)
 	err = hci_dev_do_reset(hdev);
 
 done:
-	hci_dev_put(hdev);
+	hci_dev_put_srcu(hdev, srcu_index);
 	return err;
 }
 
@@ -2433,6 +2451,11 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv)
 	if (!hdev)
 		return NULL;
 
+	if (init_srcu_struct(&hdev->srcu)) {
+		kfree(hdev);
+		return NULL;
+	}
+
 	hdev->pkt_type  = (HCI_DM1 | HCI_DH1 | HCI_HV1);
 	hdev->esco_type = (ESCO_HV1);
 	hdev->link_mode = (HCI_LM_ACCEPT);
@@ -2678,6 +2701,9 @@ void hci_unregister_dev(struct hci_dev *hdev)
 	list_del(&hdev->list);
 	write_unlock(&hci_dev_list_lock);
 
+	synchronize_srcu(&hdev->srcu);
+	cleanup_srcu_struct(&hdev->srcu);
+
 	disable_work_sync(&hdev->rx_work);
 	disable_work_sync(&hdev->cmd_work);
 	disable_work_sync(&hdev->tx_work);
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index a5bde5db58ef..40daa38276f3 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3415,7 +3415,7 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data
 	struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
 	struct l2cap_conf_efs efs;
 	u8 remote_efs = 0;
-	u16 mtu = L2CAP_DEFAULT_MTU;
+	u16 mtu = 0;
 	u16 result = L2CAP_CONF_SUCCESS;
 	u16 size;
 
@@ -3520,6 +3520,13 @@ done:
 		/* Configure output options and let the other side know
 		 * which ones we don't like. */
 
+		/* If MTU is not provided in configure request, use the most recently
+		 * explicitly or implicitly accepted value for the other direction,
+		 * or the default value.
+		 */
+		if (mtu == 0)
+			mtu = chan->imtu ? chan->imtu : L2CAP_DEFAULT_MTU;
+
 		if (mtu < L2CAP_DEFAULT_MIN_MTU)
 			result = L2CAP_CONF_UNACCEPT;
 		else {