[PATCH 5.4 326/453] media: ipu3-cio2: Serialise access to pad format

[Greg Kroah-Hartman]

From: Sakari Ailus <sakari.ai...@linux.intel.com>

commit 55a6c6b2be3d6670bf5772364d8208bd8dc17da4 upstream.

Pad format can be accessed from user space. Serialise access to it.

Fixes: c2a6a07afe4a ("media: intel-ipu3: cio2: add new MIPI-CSI2 driver")
Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Reviewed-by: Bingbu Cao <bingbu....@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com>
Cc: sta...@vger.kernel.org # v4.16 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+hua...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/media/pci/intel/ipu3/ipu3-cio2.c |   11 +++++++++++
 drivers/media/pci/intel/ipu3/ipu3-cio2.h |    1 +
 2 files changed, 12 insertions(+)

--- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
+++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
@@ -1245,11 +1245,15 @@ static int cio2_subdev_get_fmt(struct v4
 {
        struct cio2_queue *q = container_of(sd, struct cio2_queue, subdev);
 
+       mutex_lock(&q->subdev_lock);
+
        if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
                fmt->format = *v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
        else
                fmt->format = q->subdev_fmt;
 
+       mutex_unlock(&q->subdev_lock);
+
        return 0;
 }
 
@@ -1273,6 +1277,8 @@ static int cio2_subdev_set_fmt(struct v4
        if (fmt->pad == CIO2_PAD_SOURCE)
                return cio2_subdev_get_fmt(sd, cfg, fmt);
 
+       mutex_lock(&q->subdev_lock);
+
        if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
                *v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
        } else {
@@ -1283,6 +1289,8 @@ static int cio2_subdev_set_fmt(struct v4
                fmt->format = q->subdev_fmt;
        }
 
+       mutex_unlock(&q->subdev_lock);
+
        return 0;
 }
 
@@ -1541,6 +1549,7 @@ static int cio2_queue_init(struct cio2_d
 
        /* Initialize miscellaneous variables */
        mutex_init(&q->lock);
+       mutex_init(&q->subdev_lock);
 
        /* Initialize formats to default values */
        fmt = &q->subdev_fmt;
@@ -1659,6 +1668,7 @@ fail_vdev_media_entity:
 fail_subdev_media_entity:
        cio2_fbpt_exit(q, &cio2->pci_dev->dev);
 fail_fbpt:
+       mutex_destroy(&q->subdev_lock);
        mutex_destroy(&q->lock);
 
        return r;
@@ -1672,6 +1682,7 @@ static void cio2_queue_exit(struct cio2_
        v4l2_device_unregister_subdev(&q->subdev);
        media_entity_cleanup(&q->subdev.entity);
        cio2_fbpt_exit(q, &cio2->pci_dev->dev);
+       mutex_destroy(&q->subdev_lock);
        mutex_destroy(&q->lock);
 }
 
--- a/drivers/media/pci/intel/ipu3/ipu3-cio2.h
+++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.h
@@ -332,6 +332,7 @@ struct cio2_queue {
 
        /* Subdev, /dev/v4l-subdevX */
        struct v4l2_subdev subdev;
+       struct mutex subdev_lock; /* Serialise acces to subdev_fmt field */
        struct media_pad subdev_pads[CIO2_PADS];
        struct v4l2_mbus_framefmt subdev_fmt;
        atomic_t frame_sequence;