Hi,
This patch is to fix the kernel error
[ 46.271811] debugfs: File 'force_bredr_smp' in directory 'hci0'
already present!
When powering off and on the bluetooth, the smp_register will try to create the
force_bredr_smp entry again.
Move the creation to hci_debugfs_create_bredr so the force_bredr_smp entry will
only be created when HCI_SETUP and HCI_CONFIG are not set.
Thanks,
Claire
On Tue, Sep 29, 2020 at 4:03 PM Claire Chang <tientzu@xxxxxxxxxxxx> wrote:
>
> Avoid multiple attempts to create the debugfs entry, force_bredr_smp,
> by moving it from the SMP registration to the BR/EDR controller init
> section. hci_debugfs_create_bredr is only called when HCI_SETUP and
> HCI_CONFIG is not set.
>
> Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx>
> ---
> v2: correct a typo in commit message
>
> net/bluetooth/hci_debugfs.c | 50 +++++++++++++++++++++++++++++++++++++
> net/bluetooth/smp.c | 44 ++------------------------------
> net/bluetooth/smp.h | 2 ++
> 3 files changed, 54 insertions(+), 42 deletions(-)
>
> diff --git a/net/bluetooth/hci_debugfs.c b/net/bluetooth/hci_debugfs.c
> index 5e8af2658e44..4626e0289a97 100644
> --- a/net/bluetooth/hci_debugfs.c
> +++ b/net/bluetooth/hci_debugfs.c
> @@ -494,6 +494,45 @@ static int auto_accept_delay_get(void *data, u64 *val)
> DEFINE_SIMPLE_ATTRIBUTE(auto_accept_delay_fops, auto_accept_delay_get,
> auto_accept_delay_set, "%llu\n");
>
> +static ssize_t force_bredr_smp_read(struct file *file,
> + char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct hci_dev *hdev = file->private_data;
> + char buf[3];
> +
> + buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y' : 'N';
> + buf[1] = '\n';
> + buf[2] = '\0';
> + return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
> +}
> +
> +static ssize_t force_bredr_smp_write(struct file *file,
> + const char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct hci_dev *hdev = file->private_data;
> + bool enable;
> + int err;
> +
> + err = kstrtobool_from_user(user_buf, count, &enable);
> + if (err)
> + return err;
> +
> + err = smp_force_bredr(hdev, enable);
> + if (err)
> + return err;
> +
> + return count;
> +}
> +
> +static const struct file_operations force_bredr_smp_fops = {
> + .open = simple_open,
> + .read = force_bredr_smp_read,
> + .write = force_bredr_smp_write,
> + .llseek = default_llseek,
> +};
> +
> static int idle_timeout_set(void *data, u64 val)
> {
> struct hci_dev *hdev = data;
> @@ -589,6 +628,17 @@ void hci_debugfs_create_bredr(struct hci_dev *hdev)
> debugfs_create_file("voice_setting", 0444, hdev->debugfs, hdev,
> &voice_setting_fops);
>
> + /* If the controller does not support BR/EDR Secure Connections
> + * feature, then the BR/EDR SMP channel shall not be present.
> + *
> + * To test this with Bluetooth 4.0 controllers, create a debugfs
> + * switch that allows forcing BR/EDR SMP support and accepting
> + * cross-transport pairing on non-AES encrypted connections.
> + */
> + if (!lmp_sc_capable(hdev))
> + debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
> + hdev, &force_bredr_smp_fops);
> +
> if (lmp_ssp_capable(hdev)) {
> debugfs_create_file("ssp_debug_mode", 0444, hdev->debugfs,
> hdev, &ssp_debug_mode_fops);
> diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
> index 433227f96c73..8b817e4358fd 100644
> --- a/net/bluetooth/smp.c
> +++ b/net/bluetooth/smp.c
> @@ -3353,31 +3353,8 @@ static void smp_del_chan(struct l2cap_chan *chan)
> l2cap_chan_put(chan);
> }
>
> -static ssize_t force_bredr_smp_read(struct file *file,
> - char __user *user_buf,
> - size_t count, loff_t *ppos)
> +int smp_force_bredr(struct hci_dev *hdev, bool enable)
> {
> - struct hci_dev *hdev = file->private_data;
> - char buf[3];
> -
> - buf[0] = hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP) ? 'Y': 'N';
> - buf[1] = '\n';
> - buf[2] = '\0';
> - return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
> -}
> -
> -static ssize_t force_bredr_smp_write(struct file *file,
> - const char __user *user_buf,
> - size_t count, loff_t *ppos)
> -{
> - struct hci_dev *hdev = file->private_data;
> - bool enable;
> - int err;
> -
> - err = kstrtobool_from_user(user_buf, count, &enable);
> - if (err)
> - return err;
> -
> if (enable == hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
> return -EALREADY;
>
> @@ -3399,16 +3376,9 @@ static ssize_t force_bredr_smp_write(struct file *file,
>
> hci_dev_change_flag(hdev, HCI_FORCE_BREDR_SMP);
>
> - return count;
> + return 0;
> }
>
> -static const struct file_operations force_bredr_smp_fops = {
> - .open = simple_open,
> - .read = force_bredr_smp_read,
> - .write = force_bredr_smp_write,
> - .llseek = default_llseek,
> -};
> -
> int smp_register(struct hci_dev *hdev)
> {
> struct l2cap_chan *chan;
> @@ -3433,17 +3403,7 @@ int smp_register(struct hci_dev *hdev)
>
> hdev->smp_data = chan;
>
> - /* If the controller does not support BR/EDR Secure Connections
> - * feature, then the BR/EDR SMP channel shall not be present.
> - *
> - * To test this with Bluetooth 4.0 controllers, create a debugfs
> - * switch that allows forcing BR/EDR SMP support and accepting
> - * cross-transport pairing on non-AES encrypted connections.
> - */
> if (!lmp_sc_capable(hdev)) {
> - debugfs_create_file("force_bredr_smp", 0644, hdev->debugfs,
> - hdev, &force_bredr_smp_fops);
> -
> /* Flag can be already set here (due to power toggle) */
> if (!hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP))
> return 0;
> diff --git a/net/bluetooth/smp.h b/net/bluetooth/smp.h
> index 121edadd5f8d..fc35a8bf358e 100644
> --- a/net/bluetooth/smp.h
> +++ b/net/bluetooth/smp.h
> @@ -193,6 +193,8 @@ bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
> int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa);
> int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]);
>
> +int smp_force_bredr(struct hci_dev *hdev, bool enable);
> +
> int smp_register(struct hci_dev *hdev);
> void smp_unregister(struct hci_dev *hdev);
>
> --
> 2.28.0.618.gf4bc123cb7-goog
>
