Hi Luiz,
> This adds a debugfs entry to set msft_opcode enabling vhci to emulate
> controllers with MSFT extention support.
>
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> ---
> drivers/bluetooth/hci_vhci.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
> index 56c6b22be10b..ac122299bacc 100644
> --- a/drivers/bluetooth/hci_vhci.c
> +++ b/drivers/bluetooth/hci_vhci.c
> @@ -194,6 +194,34 @@ static const struct file_operations force_wakeup_fops = {
> .llseek = default_llseek,
> };
>
> +
> +static int msft_opcode_set(void *data, u64 val)
> +{
> + struct vhci_data *vhci = data;
> + uint16_t ogf = (val & 0xffff >> 10);
> +
> + if (val > 0xffff || ogf != 0x3f)
I would actually just include it here to avoid any 16-bit overflow.
if (val > 0xffff || (val & 0xffff >> 10) != 0x3f)
> + return -EINVAL;
> +
> + hci_set_msft_opcode(vhci->hdev, val);
> +
> + return 0;
> +}
> +
> +static int msft_opcode_get(void *data, u64 *val)
> +{
> + struct vhci_data *vhci = data;
> +
> + hci_dev_lock(vhci->hdev);
> + *val = vhci->hdev->msft_opcode;
> + hci_dev_unlock(vhci->hdev);
> +
> + return 0;
> +}
> +
> +DEFINE_DEBUGFS_ATTRIBUTE(msft_opcode_fops, msft_opcode_get, msft_opcode_set,
> + "%llu\n");
> +
> static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
> {
> struct hci_dev *hdev;
> @@ -259,6 +287,10 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
> debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
> &force_wakeup_fops);
>
> + if (IS_ENABLED(CONFIG_BT_MSFTEXT))
> + debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
> + &msft_opcode_fops);
> +
So my concern is that you can modify this value when the device is up and running. That will cause havoc.
Just checking HCI_UP is kinda bad since we just removed that access from the drivers.
Regards
Marcel
