linux/drivers/media/test-drivers
Laurent Pinchart ecefa105cc 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>
2023-04-12 09:46:06 +02:00
..
vicodec media: vicodec-core: Convert to platform remove callback returning void 2023-04-11 16:59:21 +02:00
vidtv media: vidtv_bridge: Convert to platform remove callback returning void 2023-04-11 16:59:21 +02:00
vimc media: Zero-initialize all structures passed to subdev pad operations 2023-04-12 09:46:06 +02:00
visl media: visl-core: Convert to platform remove callback returning void 2023-04-11 16:59:21 +02:00
vivid media: vivid-core: Convert to platform remove callback returning void 2023-04-11 16:59:21 +02:00
Kconfig media: visl: add virtual stateless decoder driver 2022-11-25 07:32:16 +00:00
Makefile media: visl: add virtual stateless decoder driver 2022-11-25 07:32:16 +00:00
vim2m.c media: vim2m: Convert to platform remove callback returning void 2023-04-11 16:59:21 +02:00