Hi Zhengping,
On Wed, Jul 20, 2022 at 4:36 PM Zhengping Jiang <jiangzp@xxxxxxxxxx> wrote:
>
> If connection exists, set the connection data before calling
> get_clock_info_sync, so it can be verified the connection is still
> connected, before retrieving clock info.
>
> Signed-off-by: Zhengping Jiang <jiangzp@xxxxxxxxxx>
> ---
>
> Changes in v1:
> - Fix input connection data
>
> net/bluetooth/mgmt.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index ef8371975c4eb..947d700574c54 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -6971,11 +6971,16 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
> }
>
> cmd = mgmt_pending_new(sk, MGMT_OP_GET_CLOCK_INFO, hdev, data, len);
> - if (!cmd)
> + if (!cmd) {
> err = -ENOMEM;
> - else
> + } else {
> + if (conn) {
> + hci_conn_hold(conn);
> + cmd->user_data = hci_conn_get(conn);
> + }
> err = hci_cmd_sync_queue(hdev, get_clock_info_sync, cmd,
> get_clock_info_complete);
> + }
Having seconds though if this is actually the right thing to do,
hci_cmd_sync_queue will queue the command so get_clock_info_sync
shouldn't execute immediately if that happens that actually would be
quite a problem since we are holding the hci_dev_lock so if the
callback executes and blocks waiting a command that would likely cause
a deadlock because no command can be completed while hci_dev_lock is
being held, in fact I don't really like the idea of holding hci_conn
reference either since we are doing a lookup by address on
get_clock_info_sync Id probably just remove this code as it seem
unnecessary.
Btw, there are tests for this command in mgmt-tester so if this is
actually attempting to fix a problem Id like to have a test to
reproduce it.
> if (err < 0) {
> err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_CLOCK_INFO,
> @@ -6984,12 +6989,8 @@ static int get_clock_info(struct sock *sk, struct hci_dev *hdev, void *data,
> if (cmd)
> mgmt_pending_free(cmd);
>
> - } else if (conn) {
> - hci_conn_hold(conn);
> - cmd->user_data = hci_conn_get(conn);
> }
>
> -
> unlock:
> hci_dev_unlock(hdev);
> return err;
> --
> 2.37.0.170.g444d1eabd0-goog
>
--
Luiz Augusto von Dentz
