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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2023-02-15 17:18:39 +0200
committerHans Verkuil <hverkuil-cisco@xs4all.nl>2023-04-12 09:46:06 +0200
commitecefa105cc44fff6d170ac5f441e76cb229f8e19 (patch)
tree40b1d8cb135dfaf82846f6aa1f4e620ac81bc322 /drivers/media/platform/xilinx/xilinx-dma.c
parenta8ca0cf1ff53c011e7654c4c2e9c1bcf297204b3 (diff)
media: Zero-initialize all structures passed to subdev pad operations
Several drivers call subdev pad operations, passing structures that are not fully zeroed. While the drivers initialize the fields they care about explicitly, this results in reserved fields having uninitialized values. Future kernel API changes that make use of those fields thus risk breaking proper driver operation in ways that could be hard to detect. To avoid this, make the code more robust by zero-initializing all the structures passed to subdev pad operation. Maintain a consistent coding style by preferring designated initializers (which zero-initialize all the fields that are not specified) over memset() where possible, and make variable declarations local to inner scopes where applicable. One notable exception to this rule is in the ipu3 driver, where a memset() is needed as the structure is not a local variable but a function parameter provided by the caller. Not all fields of those structures can be initialized when declaring the variables, as the values for those fields are computed later in the code. Initialize the 'which' field in all cases, and other fields when the variable declaration is so close to the v4l2_subdev_call() call that it keeps all the context easily visible when reading the code, to avoid hindering readability. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Shuah Khan <skhan@linuxfoundation.org> # For vimc Reviewed-by: Lad Prabhakar <prabhakar.csengg@gmail.com> # For am437x Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> # For drivers/staging/media/imx/ Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Diffstat (limited to 'drivers/media/platform/xilinx/xilinx-dma.c')
-rw-r--r--drivers/media/platform/xilinx/xilinx-dma.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
index fee02c8c85fd..80d6f5b072ea 100644
--- a/drivers/media/platform/xilinx/xilinx-dma.c
+++ b/drivers/media/platform/xilinx/xilinx-dma.c
@@ -56,7 +56,9 @@ xvip_dma_remote_subdev(struct media_pad *local, u32 *pad)
static int xvip_dma_verify_format(struct xvip_dma *dma)
{
- struct v4l2_subdev_format fmt;
+ struct v4l2_subdev_format fmt = {
+ .which = V4L2_SUBDEV_FORMAT_ACTIVE,
+ };
struct v4l2_subdev *subdev;
int ret;
@@ -64,7 +66,6 @@ static int xvip_dma_verify_format(struct xvip_dma *dma)
if (subdev == NULL)
return -EPIPE;
- fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
if (ret < 0)
return ret == -ENOIOCTLCMD ? -EINVAL : ret;