On 2013/01/07 11:35 PM, Greg Kroah-Hartman wrote: > On Mon, Jan 07, 2013 at 05:34:28PM -0600, H Hartley Sweeten wrote: >> On Monday, January 07, 2013 4:23 PM, Greg Kroah-Hartman wrote: >>> On Wed, Jan 02, 2013 at 04:21:23PM +0000, Ian Abbott wrote: >>>> When a low-level comedi driver auto-configures a device, a `struct >>>> comedi_dev_file_info` is allocated (as well as a `struct >>>> comedi_device`) by `comedi_alloc_board_minor()`. A pointer to the >>>> hardware `struct device` is stored as a cookie in the `struct >>>> comedi_dev_file_info`. When the low-level comedi driver >>>> auto-unconfigures the device, `comedi_auto_unconfig()` uses the cookie >>>> to find the `struct comedi_dev_file_info` so it can detach the comedi >>>> device from the driver, clean it up and free it. >>>> >>>> A problem arises if the user manually unconfigures and reconfigures the >>>> comedi device using the `COMEDI_DEVCONFIG` ioctl so that is no longer >>>> associated with the original hardware device. The problem is that the >>>> cookie is not cleared, so that a call to `comedi_auto_unconfig()` from >>>> the low-level driver will still find it, detach it, clean it up and free >>>> it. >>>> >>>> Stop this problem occurring by always clearing the `hardware_device` >>>> cookie in the `struct comedi_dev_file_info` whenever the >>>> `COMEDI_DEVCONFIG` ioctl call is successful. >>>> >>>> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> >>>> Cc: stable@xxxxxxxxxxxxxxx >>>> --- >>>> @Greg: This was originally sent on 4th December. It clashes with >>>> Hartley's "[PATCH 04/26] staging: comedi: use comedi_dev_from_minor()" >>>> of 19th December. It would be nice if my patch takes precedence so that >>>> it can be used as-is in the stable kernels, though unfortunately that >>>> would require a slight re-work of Hartley's patch. >>> >>> I've applied this, and Hartley's patches, and merged the branches >>> together. I've fixed up the obvious build error, can both of you verify >>> that I didn't do anything wrong? It should be in the staging-next >>> branch now. >> >> Look good to me. > > Great, thanks for checking. The merge looks good to me too. -- -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=- -=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=- _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
