UPSTREAM: Revert "Bluetooth: hci_core: Fix sleeping function called from invalid context"

[ Upstream commit ab6ab707a4d060a51c45fc13e3b2228d5f7c0b87 ]

This reverts commit 4d94f05558271654670d18c26c912da0c1c15549 which has
problems (see [1]) and is no longer needed since 581dd2dc168f
("Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating")
has reworked the code where the original bug has been found.

[1] Link: https://lore.kernel.org/linux-bluetooth/877c55ci1r.wl-tiwai@suse.de/T/#t
Fixes: 4d94f0555827 ("Bluetooth: hci_core: Fix sleeping function called from invalid context")
Change-Id: If816d3b42cb7b1c18e250c0a5ee266cdd48b4b01
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 55b098a2be)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

net/bluetooth/hci_core.c

@@ -57,6 +57,7 @@ DEFINE_RWLOCK(hci_dev_list_lock);
 
 /* HCI callback list */
 LIST_HEAD(hci_cb_list);
+DEFINE_MUTEX(hci_cb_list_lock);
 
 /* HCI ID Numbering */
 static DEFINE_IDA(hci_index_ida);
@@ -2994,7 +2995,9 @@ int hci_register_cb(struct hci_cb *cb)
 {
 	BT_DBG("%p name %s", cb, cb->name);
 
-	list_add_tail_rcu(&cb->list, &hci_cb_list);
+	mutex_lock(&hci_cb_list_lock);
+	list_add_tail(&cb->list, &hci_cb_list);
+	mutex_unlock(&hci_cb_list_lock);
 
 	return 0;
 }
@@ -3004,8 +3007,9 @@ int hci_unregister_cb(struct hci_cb *cb)
 {
 	BT_DBG("%p name %s", cb, cb->name);
 
-	list_del_rcu(&cb->list);
-	synchronize_rcu();
+	mutex_lock(&hci_cb_list_lock);
+	list_del(&cb->list);
+	mutex_unlock(&hci_cb_list_lock);
 
 	return 0;
 }

net/bluetooth/iso.c

@@ -2137,11 +2137,6 @@ done:
 	return HCI_LM_ACCEPT;
 }
 
-static bool iso_match(struct hci_conn *hcon)
-{
-	return hcon->type == ISO_LINK || hcon->type == LE_LINK;
-}
-
 static void iso_connect_cfm(struct hci_conn *hcon, __u8 status)
 {
 	if (hcon->type != ISO_LINK) {
@@ -2323,7 +2318,6 @@ drop:
 
 static struct hci_cb iso_cb = {
 	.name		= "ISO",
-	.match		= iso_match,
 	.connect_cfm	= iso_connect_cfm,
 	.disconn_cfm	= iso_disconn_cfm,
 };

net/bluetooth/l2cap_core.c

@@ -7230,11 +7230,6 @@ static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
 	return NULL;
 }
 
-static bool l2cap_match(struct hci_conn *hcon)
-{
-	return hcon->type == ACL_LINK || hcon->type == LE_LINK;
-}
-
 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
 {
 	struct hci_dev *hdev = hcon->hdev;
@@ -7242,6 +7237,9 @@ static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
 	struct l2cap_chan *pchan;
 	u8 dst_type;
 
+	if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
+		return;
+
 	BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
 
 	if (status) {
@@ -7306,6 +7304,9 @@ int l2cap_disconn_ind(struct hci_conn *hcon)
 
 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
 {
+	if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
+		return;
+
 	BT_DBG("hcon %p reason %d", hcon, reason);
 
 	l2cap_conn_del(hcon, bt_to_errno(reason));
@@ -7605,7 +7606,6 @@ drop:
 
 static struct hci_cb l2cap_cb = {
 	.name		= "L2CAP",
-	.match		= l2cap_match,
 	.connect_cfm	= l2cap_connect_cfm,
 	.disconn_cfm	= l2cap_disconn_cfm,
 	.security_cfm	= l2cap_security_cfm,

net/bluetooth/rfcomm/core.c

@@ -2134,11 +2134,6 @@ static int rfcomm_run(void *unused)
 	return 0;
 }
 
-static bool rfcomm_match(struct hci_conn *hcon)
-{
-	return hcon->type == ACL_LINK;
-}
-
 static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
 {
 	struct rfcomm_session *s;
@@ -2185,7 +2180,6 @@ static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
 
 static struct hci_cb rfcomm_cb = {
 	.name		= "RFCOMM",
-	.match		= rfcomm_match,
 	.security_cfm	= rfcomm_security_cfm
 };
 

net/bluetooth/sco.c

@@ -1355,13 +1355,11 @@ int sco_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 	return lm;
 }
 
-static bool sco_match(struct hci_conn *hcon)
-{
-	return hcon->type == SCO_LINK || hcon->type == ESCO_LINK;
-}
-
 static void sco_connect_cfm(struct hci_conn *hcon, __u8 status)
 {
+	if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
+		return;
+
 	BT_DBG("hcon %p bdaddr %pMR status %u", hcon, &hcon->dst, status);
 
 	if (!status) {
@@ -1376,6 +1374,9 @@ static void sco_connect_cfm(struct hci_conn *hcon, __u8 status)
 
 static void sco_disconn_cfm(struct hci_conn *hcon, __u8 reason)
 {
+	if (hcon->type != SCO_LINK && hcon->type != ESCO_LINK)
+		return;
+
 	BT_DBG("hcon %p reason %d", hcon, reason);
 
 	sco_conn_del(hcon, bt_to_errno(reason));
@@ -1401,7 +1402,6 @@ drop:
 
 static struct hci_cb sco_cb = {
 	.name		= "SCO",
-	.match		= sco_match,
 	.connect_cfm	= sco_connect_cfm,
 	.disconn_cfm	= sco_disconn_cfm,
 };