2023-05-02 23:45:20

by Luiz Augusto von Dentz

[permalink] [raw]
Subject: Re: [PATCH 1/2] Bluetooth: fix debugfs registration

Hi Johan,

On Mon, Apr 24, 2023 at 5:50 AM Johan Hovold <[email protected]> wrote:
>
> Since commit ec6cef9cd98d ("Bluetooth: Fix SMP channel registration for
> unconfigured controllers") the debugfs interface for unconfigured
> controllers will be created when the controller is configured.
>
> There is however currently nothing preventing a controller from being
> configured multiple time (e.g. setting the device address using btmgmt)
> which results in failed attempts to register the already registered
> debugfs entries:
>
> debugfs: File 'features' in directory 'hci0' already present!
> debugfs: File 'manufacturer' in directory 'hci0' already present!
> debugfs: File 'hci_version' in directory 'hci0' already present!
> ...
> debugfs: File 'quirk_simultaneous_discovery' in directory 'hci0' already present!
>
> Add a controller flag to avoid trying to register the debugfs interface
> more than once.
>
> Fixes: ec6cef9cd98d ("Bluetooth: Fix SMP channel registration for unconfigured controllers")
> Cc: [email protected] # 4.0
> Signed-off-by: Johan Hovold <[email protected]>
> ---
> include/net/bluetooth/hci.h | 1 +
> net/bluetooth/hci_sync.c | 3 +++
> 2 files changed, 4 insertions(+)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 400f8a7d0c3f..b8bca65bcd79 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -335,6 +335,7 @@ enum {
> enum {
> HCI_SETUP,
> HCI_CONFIG,
> + HCI_DEBUGFS_CREATED,
> HCI_AUTO_OFF,
> HCI_RFKILLED,
> HCI_MGMT,
> diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
> index 632be1267288..a8785126df75 100644
> --- a/net/bluetooth/hci_sync.c
> +++ b/net/bluetooth/hci_sync.c
> @@ -4501,6 +4501,9 @@ static int hci_init_sync(struct hci_dev *hdev)
> !hci_dev_test_flag(hdev, HCI_CONFIG))
> return 0;
>
> + if (hci_dev_test_and_set_flag(hdev, HCI_DEBUGFS_CREATED))
> + return 0;

Can't we just use HCI_SETUP like we do with in create_basic:

if (hci_dev_test_flag(hdev, HCI_SETUP))
hci_debugfs_create_basic(hdev);

Actually we might as well move these checks directly inside the
hci_debugfs function to make sure these only take effect during the
setup/first init.

> hci_debugfs_create_common(hdev);
>
> if (lmp_bredr_capable(hdev))
> --
> 2.39.2
>


--
Luiz Augusto von Dentz