Re: [BUG][PATCH -mm] bluetooth : rfcomm add get/put device in del_conn

Dave Young
2007-12-25T10:07:24Z

On Dec 25, 2007 6:03 PM, Dave Young <hidave.darkstar@gmail.com> wrote:
> Due to 2.6.24-rc6-mm1 kernel changes (maybe kobject or driver core), If I exec:
>
> rfcomm connect 0 1
>
> kernel will oops after connect timeout.
>
> hand copy some oops text:
>
> EIP is at driver_sysfs_remove+0x1a/0x40
> Call Trace:
> show_trace_log_lvl+0x1a/0x30
> show_stack_log_lvl+0x9a/0xc0
> show_registers+0xc7/0x270
> die+0x129/0x240
> do_page_fault+0x3a1/0x670
> error_code+0x72/0x78
> __device_release_driver+0x1e/0xa0
> device_release_driver+0x30/0x50
> bus_remove_device+0x63/0x90
> device_del+0x55/0x190
> del_conn+0xb/0x10 [bluetooth]
> run_workqueue+0xe1/0x210
> worker_thread+0x99/0xf0
> kthread+0x5c/0xa0
> kernel_thread_helper+0x7/0x18
>
> (The remote bluetooth device is a mobile phone which is power off)
>
> The reason is that in bus_remobe_dev, the klist_del function will release the device, so just add a get/put pair around the device_del in del_conn.
>
> Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
>
> ---
> net/bluetooth/hci_sysfs.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff -upr linux/net/bluetooth/hci_sysfs.c linux.new/net/bluetooth/hci_sysfs.c
> --- linux/net/bluetooth/hci_sysfs.c 2007-12-25 17:45:09.000000000 +0800
> +++ linux.new/net/bluetooth/hci_sysfs.c 2007-12-25 17:45:51.000000000 +0800
> @@ -319,7 +319,9 @@ void hci_conn_add_sysfs(struct hci_conn
> static void del_conn(struct work_struct *work)
> {
> struct hci_conn *conn = container_of(work, struct hci_conn, work);
> + get_device(&conn->dev);
> device_del(&conn->dev);
> + put_device(&conn->dev);
> }
>
> void hci_conn_del_sysfs(struct hci_conn *conn)
>

Hi greg,

BTW, Is it a possible bug of driver core or kobject ?

Regards
dave