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authorMarcel Holtmann <marcel@holtmann.org>2015-06-06 06:06:49 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-08-03 09:28:58 -0700
commit2bd8b830dafea36e902518dd4be77e9432634c2d (patch)
tree5cc1c85c7c3c2c94e1ce878960972c253389e635 /net/bluetooth
parent4c3c2d140a873c9330dd51119aa9e13225cd65ef (diff)
Bluetooth: Fix race condition with user channel and setup stage
commit 781f899f2f9d8b71e35225a087f90052059486c5 upstream. During the initial setup stage of a controller, the low-level transport is actually active. This means that HCI_UP is true. To avoid toggling the transport off and back on again for normal operation the kernel holds a grace period with HCI_AUTO_OFF that will turn the low-level transport off in case no user is present. The idea of the grace period is important to avoid having to initialize all of the controller twice. So legacy ioctl and the new management interface knows how to clear this grace period and then start normal operation. For the user channel operation this grace period has not been taken into account which results in the problem that HCI_UP and HCI_AUTO_OFF are set and the kernel will return EBUSY. However from a system point of view the controller is ready to be grabbed by either the ioctl, the management interface or the user channel. This patch brings the user channel to the same level as the other two entries for operating a controller. Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/hci_sock.c26
1 files changed, 19 insertions, 7 deletions
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 56f9edbf3d05..e11a5cfda4b1 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -741,10 +741,11 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
goto done;
}
- if (test_bit(HCI_UP, &hdev->flags) ||
- test_bit(HCI_INIT, &hdev->flags) ||
+ if (test_bit(HCI_INIT, &hdev->flags) ||
hci_dev_test_flag(hdev, HCI_SETUP) ||
- hci_dev_test_flag(hdev, HCI_CONFIG)) {
+ hci_dev_test_flag(hdev, HCI_CONFIG) ||
+ (!hci_dev_test_flag(hdev, HCI_AUTO_OFF) &&
+ test_bit(HCI_UP, &hdev->flags))) {
err = -EBUSY;
hci_dev_put(hdev);
goto done;
@@ -760,10 +761,21 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
err = hci_dev_open(hdev->id);
if (err) {
- hci_dev_clear_flag(hdev, HCI_USER_CHANNEL);
- mgmt_index_added(hdev);
- hci_dev_put(hdev);
- goto done;
+ if (err == -EALREADY) {
+ /* In case the transport is already up and
+ * running, clear the error here.
+ *
+ * This can happen when opening an user
+ * channel and HCI_AUTO_OFF grace period
+ * is still active.
+ */
+ err = 0;
+ } else {
+ hci_dev_clear_flag(hdev, HCI_USER_CHANNEL);
+ mgmt_index_added(hdev);
+ hci_dev_put(hdev);
+ goto done;
+ }
}
atomic_inc(&hdev->promisc);