diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2010-05-19 18:09:50 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-06-04 13:38:53 -0700 |
| commit | 53fa827e295d8b09a2446b3126577244644d256d (patch) | |
| tree | 38e3ad302db84c0cad2fc714fc494f9d9fecc21f | |
| parent | 4772c018e35b6a21e8a8bde54568b59998540a16 (diff) | |
Staging: comedi: For COMEDI_BUFINFO, check access to command
Don't allow COMEDI_BUFINFO ioctl if some other file object has locked
the subdevice or has an active command. If there is no active command,
just report back the last buffer position.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 75256251250..aeb2c00875c 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -83,7 +83,7 @@ static int do_subdinfo_ioctl(struct comedi_device *dev, static int do_chaninfo_ioctl(struct comedi_device *dev, struct comedi_chaninfo __user *arg); static int do_bufinfo_ioctl(struct comedi_device *dev, - struct comedi_bufinfo __user *arg); + struct comedi_bufinfo __user *arg, void *file); static int do_cmd_ioctl(struct comedi_device *dev, struct comedi_cmd __user *arg, void *file); static int do_lock_ioctl(struct comedi_device *dev, unsigned int arg, @@ -169,7 +169,8 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, break; case COMEDI_BUFINFO: rc = do_bufinfo_ioctl(dev, - (struct comedi_bufinfo __user *)arg); + (struct comedi_bufinfo __user *)arg, + file); break; case COMEDI_LOCK: rc = do_lock_ioctl(dev, arg, file); @@ -563,7 +564,7 @@ static int do_chaninfo_ioctl(struct comedi_device *dev, */ static int do_bufinfo_ioctl(struct comedi_device *dev, - struct comedi_bufinfo __user *arg) + struct comedi_bufinfo __user *arg, void *file) { struct comedi_bufinfo bi; struct comedi_subdevice *s; @@ -576,6 +577,10 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, return -EINVAL; s = dev->subdevices + bi.subdevice; + + if (s->lock && s->lock != file) + return -EACCES; + async = s->async; if (!async) { @@ -588,6 +593,13 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, bi.bytes_written = 0; goto copyback; } + if (!s->busy) { + bi.bytes_read = 0; + bi.bytes_written = 0; + goto copyback_position; + } + if (s->busy != file) + return -EACCES; if (bi.bytes_read && (s->subdev_flags & SDF_CMD_READ)) { bi.bytes_read = comedi_buf_read_alloc(async, bi.bytes_read); @@ -606,6 +618,7 @@ static int do_bufinfo_ioctl(struct comedi_device *dev, comedi_buf_write_free(async, bi.bytes_written); } +copyback_position: bi.buf_write_count = async->buf_write_count; bi.buf_write_ptr = async->buf_write_ptr; bi.buf_read_count = async->buf_read_count; |