[46/80] staging: comedi: fix oops for USB DAQ devices.

Greg KH
2011-12-07T16:17:58Z

From: Bernd Porr <berndporr@f2s.com>

commit 3ffab428f40849ed5f21bcfd7285bdef7902f9ca upstream.

This fixes kernel oops when an USB DAQ device is plugged out while it's
communicating with the userspace software.

Signed-off-by: Bernd Porr <berndporr@f2s.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/staging/comedi/comedi_fops.c | 73 +++++++++++++++++++++++++----------
1 file changed, 54 insertions(+), 19 deletions(-)

--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -1452,9 +1452,6 @@ static struct vm_operations_struct comed
static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_device_file_info *dev_file_info =
- comedi_get_device_file_info(minor);
- struct comedi_device *dev = dev_file_info->device;
struct comedi_async *async = NULL;
unsigned long start = vma->vm_start;
unsigned long size;
@@ -1462,6 +1459,15 @@ static int comedi_mmap(struct file *file
int i;
int retval;
struct comedi_subdevice *s;
+ struct comedi_device_file_info *dev_file_info;
+ struct comedi_device *dev;
+
+ dev_file_info = comedi_get_device_file_info(minor);
+ if (dev_file_info == NULL)
+ return -ENODEV;
+ dev = dev_file_info->device;
+ if (dev == NULL)
+ return -ENODEV;

mutex_lock(&dev->mutex);
if (!dev->attached) {
@@ -1528,11 +1534,17 @@ static unsigned int comedi_poll(struct f
{
unsigned int mask = 0;
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_device_file_info *dev_file_info =
- comedi_get_device_file_info(minor);
- struct comedi_device *dev = dev_file_info->device;
struct comedi_subdevice *read_subdev;
struct comedi_subdevice *write_subdev;
+ struct comedi_device_file_info *dev_file_info;
+ struct comedi_device *dev;
+ dev_file_info = comedi_get_device_file_info(minor);
+
+ if (dev_file_info == NULL)
+ return -ENODEV;
+ dev = dev_file_info->device;
+ if (dev == NULL)
+ return -ENODEV;

mutex_lock(&dev->mutex);
if (!dev->attached) {
@@ -1578,9 +1590,15 @@ static ssize_t comedi_write(struct file
int n, m, count = 0, retval = 0;
DECLARE_WAITQUEUE(wait, current);
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_device_file_info *dev_file_info =
- comedi_get_device_file_info(minor);
- struct comedi_device *dev = dev_file_info->device;
+ struct comedi_device_file_info *dev_file_info;
+ struct comedi_device *dev;
+ dev_file_info = comedi_get_device_file_info(minor);
+
+ if (dev_file_info == NULL)
+ return -ENODEV;
+ dev = dev_file_info->device;
+ if (dev == NULL)
+ return -ENODEV;

if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
@@ -1683,9 +1701,15 @@ static ssize_t comedi_read(struct file *
int n, m, count = 0, retval = 0;
DECLARE_WAITQUEUE(wait, current);
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_device_file_info *dev_file_info =
- comedi_get_device_file_info(minor);
- struct comedi_device *dev = dev_file_info->device;
+ struct comedi_device_file_info *dev_file_info;
+ struct comedi_device *dev;
+ dev_file_info = comedi_get_device_file_info(minor);
+
+ if (dev_file_info == NULL)
+ return -ENODEV;
+ dev = dev_file_info->device;
+ if (dev == NULL)
+ return -ENODEV;

if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
@@ -1885,11 +1909,17 @@ ok:
static int comedi_close(struct inode *inode, struct file *file)
{
const unsigned minor = iminor(inode);
- struct comedi_device_file_info *dev_file_info =
- comedi_get_device_file_info(minor);
- struct comedi_device *dev = dev_file_info->device;
struct comedi_subdevice *s = NULL;
int i;
+ struct comedi_device_file_info *dev_file_info;
+ struct comedi_device *dev;
+ dev_file_info = comedi_get_device_file_info(minor);
+
+ if (dev_file_info == NULL)
+ return -ENODEV;
+ dev = dev_file_info->device;
+ if (dev == NULL)
+ return -ENODEV;

mutex_lock(&dev->mutex);

@@ -1923,10 +1953,15 @@ static int comedi_close(struct inode *in
static int comedi_fasync(int fd, struct file *file, int on)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
- struct comedi_device_file_info *dev_file_info =
- comedi_get_device_file_info(minor);
-
- struct comedi_device *dev = dev_file_info->device;
+ struct comedi_device_file_info *dev_file_info;
+ struct comedi_device *dev;
+ dev_file_info = comedi_get_device_file_info(minor);
+
+ if (dev_file_info == NULL)
+ return -ENODEV;
+ dev = dev_file_info->device;
+ if (dev == NULL)
+ return -ENODEV;

return fasync_helper(fd, file, on, &dev->async_queue);
}