For COMEDI_BUFINFO ioctl, check for locked or busy subdevice.

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index 0e9bf33b9cc1610fd6df030f0cc2fdd874c98aad..d63302d6e67256096e1398081f38061238319f5d 100644 (file)
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -76,7 +76,7 @@ static int do_devinfo_ioctl(comedi_device * dev, comedi_devinfo * arg,
 static int do_subdinfo_ioctl(comedi_device * dev, comedi_subdinfo * arg,
        void *file);
 static int do_chaninfo_ioctl(comedi_device * dev, comedi_chaninfo * arg);
-static int do_bufinfo_ioctl(comedi_device * dev, void *arg);
+static int do_bufinfo_ioctl(comedi_device * dev, void *arg, void *file);
 static int do_cmd_ioctl(comedi_device * dev, void *arg, void *file);
 static int do_lock_ioctl(comedi_device * dev, unsigned int arg, void *file);
 static int do_unlock_ioctl(comedi_device * dev, unsigned int arg, void *file);
@@ -193,7 +193,7 @@ static int comedi_ioctl(struct inode *inode, struct file *file,
                rc = do_rangeinfo_ioctl(dev, (void *)arg);
                break;
        case COMEDI_BUFINFO:
-               rc = do_bufinfo_ioctl(dev, (void *)arg);
+               rc = do_bufinfo_ioctl(dev, (void *)arg, file);
                break;
        case COMEDI_LOCK:
                rc = do_lock_ioctl(dev, arg, file);
@@ -573,7 +573,7 @@ static int do_chaninfo_ioctl(comedi_device * dev, comedi_chaninfo * arg)
     modified bufinfo at arg
 
   */
-static int do_bufinfo_ioctl(comedi_device * dev, void *arg)
+static int do_bufinfo_ioctl(comedi_device * dev, void *arg, void *file)
 {
        comedi_bufinfo bi;
        comedi_subdevice *s;
@@ -586,8 +586,11 @@ static int do_bufinfo_ioctl(comedi_device * dev, void *arg)
                return -EINVAL;
 
        s = dev->subdevices + bi.subdevice;
-       async = s->async;
 
+       if (s->lock && s->lock != file)
+               return -EACCES;
+
+       async = s->async;
        if (!async) {
                DPRINTK("subdevice does not have async capability\n");
                bi.buf_write_ptr = 0;
@@ -598,6 +601,13 @@ static int do_bufinfo_ioctl(comedi_device * dev, void *arg)
                bi.bytes_written = 0;
                goto copyback;
        }
+       if (!s->busy) {
+               bi.bytes_read = 0;
+               bi.bytes_written = 0;
+               goto copyback;
+       }
+       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);