Merge branch 'topic/kbuild-fixes-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media build fixes from Mauro Carvalho Chehab:
 "A series of patches that fix compilation on non-x86 archs.

  While most of them are just build fixes, there are some fixes for real
  bugs, as there are a number of drivers using dynamic stack allocation.
  A few of those might be considered a security risk, if the i2c-dev
  module is loaded, as someone could be sending very long I2C data that
  could potentially overflow the Kernel stack.  Ok, as using /dev/i2c-*
  devnodes usually requires root on usual distros, and exploiting it
  would require a DVB board or USB stick, the risk is not high"

* 'topic/kbuild-fixes-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (28 commits)
  [media] platform drivers: Fix build on frv arch
  [media] lirc_zilog: Don't use dynamic static allocation
  [media] mxl111sf: Don't use dynamic static allocation
  [media] af9035: Don't use dynamic static allocation
  [media] af9015: Don't use dynamic static allocation
  [media] dw2102: Don't use dynamic static allocation
  [media] dibusb-common: Don't use dynamic static allocation
  [media] cxusb: Don't use dynamic static allocation
  [media] v4l2-async: Don't use dynamic static allocation
  [media] cimax2: Don't use dynamic static allocation
  [media] tuner-xc2028: Don't use dynamic static allocation
  [media] tuners: Don't use dynamic static allocation
  [media] av7110_hw: Don't use dynamic static allocation
  [media] stv090x: Don't use dynamic static allocation
  [media] stv0367: Don't use dynamic static allocation
  [media] stb0899_drv: Don't use dynamic static allocation
  [media] dvb-frontends: Don't use dynamic static allocation
  [media] dvb-frontends: Don't use dynamic static allocation
  [media] s5h1420: Don't use dynamic static allocation
  [media] uvc/lirc_serial: Fix some warnings on parisc arch
  ...

1 files changed, 27 insertions, 3 deletions

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index c85d69da35b..85a6a34128a 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -189,30 +189,53 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 	struct v4l2_subdev *sd, *tmp;
 	unsigned int notif_n_subdev = notifier->num_subdevs;
 	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
-	struct device *dev[n_subdev];
+	struct device **dev;
 	int i = 0;
 
 	if (!notifier->v4l2_dev)
 		return;
 
+	dev = kmalloc(n_subdev * sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(notifier->v4l2_dev->dev,
+			"Failed to allocate device cache!\n");
+	}
+
 	mutex_lock(&list_lock);
 
 	list_del(&notifier->list);
 
 	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
-		dev[i] = get_device(sd->dev);
+		struct device *d;
+
+		d = get_device(sd->dev);
 
 		v4l2_async_cleanup(sd);
 
 		/* If we handled USB devices, we'd have to lock the parent too */
-		device_release_driver(dev[i++]);
+		device_release_driver(d);
 
 		if (notifier->unbind)
 			notifier->unbind(notifier, sd, sd->asd);
+
+		/*
+		 * Store device at the device cache, in order to call
+		 * put_device() on the final step
+		 */
+		if (dev)
+			dev[i++] = d;
+		else
+			put_device(d);
 	}
 
 	mutex_unlock(&list_lock);
 
+	/*
+	 * Call device_attach() to reprobe devices
+	 *
+	 * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
+	 * executed.
+	 */
 	while (i--) {
 		struct device *d = dev[i];
 
@@ -228,6 +251,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
 		}
 		put_device(d);
 	}
+	kfree(dev);
 
 	notifier->v4l2_dev = NULL;