diff options
| author | David Herrmann <dh.herrmann@gmail.com> | 2013-04-06 18:28:39 (GMT) |
|---|---|---|
| committer | Gustavo Padovan <gustavo.padovan@collabora.co.uk> | 2013-04-17 05:45:22 (GMT) |
| commit | 8d12356f33f819ec0d064e233f7ca8e59eaa38ef (patch) | |
| tree | b976b1efc17d3f9d207212253d6cb5167c6b755c /net/bluetooth | |
| parent | fc225c3f5d1b6aa6f99c5c300af4605e4923ce79 (diff) | |
| download | linux-8d12356f33f819ec0d064e233f7ca8e59eaa38ef.tar.xz | |
Bluetooth: introduce hci_conn ref-counting
We currently do not allow using hci_conn from outside of HCI-core.
However, several other users could make great use of it. This includes
HIDP, rfcomm and all other sub-protocols that rely on an active
connection.
Hence, we now introduce hci_conn ref-counting. We currently never call
get_device(). put_device() is exclusively used in hci_conn_del_sysfs().
Hence, we currently never have a greater device-refcnt than 1.
Therefore, it is safe to move the put_device() call from
hci_conn_del_sysfs() to hci_conn_del() (it's the only caller). In fact,
this even fixes a "use-after-free" bug as we access hci_conn after calling
hci_conn_del_sysfs() in hci_conn_del().
From now on we can add references to hci_conn objects in other layers
(like l2cap_sock, HIDP, rfcomm, ...) and grab a reference via
hci_conn_get(). This does _not_ guarantee, that the connection is still
alive. But, this isn't what we want. We can simply lock the hci_conn
device and use "device_is_registered(hci_conn->dev)" to test that.
However, this is hardly necessary as outside users should never rely on
the HCI connection to be alive, anyway. Instead, they should solely rely
on the device-object to be available.
But if sub-devices want the hci_conn object as sysfs parent, they need to
be notified when the connection drops. This will be introduced in later
patches with l2cap_users.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/hci_conn.c | 3 | ||||
| -rw-r--r-- | net/bluetooth/hci_sysfs.c | 1 |
2 files changed, 1 insertions, 3 deletions
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 6b5b8e7..6c7f363 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -462,8 +462,7 @@ int hci_conn_del(struct hci_conn *conn) hci_dev_put(hdev); - if (conn->handle == 0) - kfree(conn); + hci_conn_put(conn); return 0; } diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c index ff38561..6fe15c8 100644 --- a/net/bluetooth/hci_sysfs.c +++ b/net/bluetooth/hci_sysfs.c @@ -146,7 +146,6 @@ void hci_conn_del_sysfs(struct hci_conn *conn) } device_del(&conn->dev); - put_device(&conn->dev); hci_dev_put(hdev); } |