media: i2c: max9286: Allocate v4l2_async_subdev dynamically

v4l2_async_notifier_add_subdev() requires the asd to be allocated
dynamically, but the max9286 driver embeds it in the max9286_source
structure. This causes memory corruption when the notifier is destroyed
at remove time with v4l2_async_notifier_cleanup().

Fix this issue by registering the asd with
v4l2_async_notifier_add_fwnode_subdev(), which allocates it dynamically
internally. A new max9286_asd structure is introduced, to store a
pointer to the corresonding max9286_source that needs to be accessed
from bound and unbind callbacks. There's no need to take an extra
explicit reference to the fwnode anymore as
v4l2_async_notifier_add_fwnode_subdev() does so internally.

While at it, use %u instead of %d to print the unsigned index in the
error message from the v4l2_async_notifier_add_fwnode_subdev() error
path.

Fixes: 66d8c9d242 ("media: i2c: Add MAX9286 driver")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Laurent Pinchart 2020-08-11 22:59:39 +02:00 committed by Mauro Carvalho Chehab
parent 2cac7cbfb4
commit 86d37bf31a
1 changed files with 20 additions and 18 deletions

View File

@ -135,13 +135,19 @@
#define MAX9286_SRC_PAD 4
struct max9286_source {
struct v4l2_async_subdev asd;
struct v4l2_subdev *sd;
struct fwnode_handle *fwnode;
};
#define asd_to_max9286_source(_asd) \
container_of(_asd, struct max9286_source, asd)
struct max9286_asd {
struct v4l2_async_subdev base;
struct max9286_source *source;
};
static inline struct max9286_asd *to_max9286_asd(struct v4l2_async_subdev *asd)
{
return container_of(asd, struct max9286_asd, base);
}
struct max9286_priv {
struct i2c_client *client;
@ -481,7 +487,7 @@ static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd)
{
struct max9286_priv *priv = sd_to_max9286(notifier->sd);
struct max9286_source *source = asd_to_max9286_source(asd);
struct max9286_source *source = to_max9286_asd(asd)->source;
unsigned int index = to_index(priv, source);
unsigned int src_pad;
int ret;
@ -545,7 +551,7 @@ static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
struct v4l2_async_subdev *asd)
{
struct max9286_priv *priv = sd_to_max9286(notifier->sd);
struct max9286_source *source = asd_to_max9286_source(asd);
struct max9286_source *source = to_max9286_asd(asd)->source;
unsigned int index = to_index(priv, source);
source->sd = NULL;
@ -570,23 +576,19 @@ static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
for_each_source(priv, source) {
unsigned int i = to_index(priv, source);
struct v4l2_async_subdev *asd;
source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
source->asd.match.fwnode = source->fwnode;
ret = v4l2_async_notifier_add_subdev(&priv->notifier,
&source->asd);
if (ret) {
dev_err(dev, "Failed to add subdev for source %d", i);
asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier,
source->fwnode,
sizeof(*asd));
if (IS_ERR(asd)) {
dev_err(dev, "Failed to add subdev for source %u: %ld",
i, PTR_ERR(asd));
v4l2_async_notifier_cleanup(&priv->notifier);
return ret;
return PTR_ERR(asd);
}
/*
* Balance the reference counting handled through
* v4l2_async_notifier_cleanup()
*/
fwnode_handle_get(source->fwnode);
to_max9286_asd(asd)->source = source;
}
priv->notifier.ops = &max9286_notify_ops;