diff options
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index a155bf2c6592..d80060a14977 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -87,6 +87,9 @@ struct comedi_file_info { static DEFINE_SPINLOCK(comedi_file_info_table_lock); static struct comedi_file_info *comedi_file_info_table[COMEDI_NUM_MINORS]; +static struct comedi_file_info *comedi_clear_minor(unsigned minor); +static void comedi_free_board_file_info(struct comedi_file_info *info); + static struct comedi_file_info *comedi_file_info_from_minor(unsigned minor) { struct comedi_file_info *info; @@ -490,6 +493,10 @@ static int do_devconfig_ioctl(struct comedi_device *dev, return -EINVAL; } + if (dev->minor >= comedi_num_legacy_minors) + /* don't re-use dynamically allocated comedi devices */ + return -EBUSY; + ret = comedi_device_attach(dev, &it); if (ret == 0) { if (!try_module_get(dev->driver->module)) { @@ -1635,6 +1642,19 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, } rc = do_devconfig_ioctl(dev, (struct comedi_devconfig __user *)arg); + if (rc == 0) { + if (arg == 0 && + dev->minor >= comedi_num_legacy_minors) { + /* Successfully unconfigured a dynamically + * allocated device. Try and remove it. */ + info = comedi_clear_minor(dev->minor); + if (info) { + mutex_unlock(&dev->mutex); + comedi_free_board_file_info(info); + return rc; + } + } + } goto done; } |