[v3,11/13] iio: core: Move the currentmode entry to the opaque structure

Commit Message

Miquel Raynal Feb. 7, 2022, 2:38 p.m. UTC

This entry should, under no situation, be modified by device
drivers. Now that we have limited its read access to device drivers
really needing it and did so through a dedicated helper, we can
easily move this variable to the opaque structure in order to
prevent any further modification from non-authorized code (out of the
core, basically).

Signed-off-by: Miquel Raynal <[e-mail]>
Reviewed-by: Alexandru Ardelean <[e-mail]>
---
 drivers/iio/industrialio-buffer.c  | 12 ++++++------
 drivers/iio/industrialio-core.c    | 10 +++++++---
 drivers/iio/industrialio-trigger.c |  2 +-
 include/linux/iio/iio-opaque.h     |  4 ++++
 include/linux/iio/iio.h            |  4 ----
 5 files changed, 18 insertions(+), 14 deletions(-)

Patch

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 94eb9f6cf128..2a5a09693b08 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -1065,7 +1065,7 @@  static int iio_enable_buffers(struct iio_dev *indio_dev,
 	indio_dev->active_scan_mask = config->scan_mask;
 	indio_dev->scan_timestamp = config->scan_timestamp;
 	indio_dev->scan_bytes = config->scan_bytes;
-	indio_dev->currentmode = config->mode;
+	iio_dev_opaque->currentmode = config->mode;
 
 	iio_update_demux(indio_dev);
 
@@ -1101,7 +1101,7 @@  static int iio_enable_buffers(struct iio_dev *indio_dev,
 			goto err_disable_buffers;
 	}
 
-	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+	if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
 		ret = iio_trigger_attach_poll_func(indio_dev->trig,
 						   indio_dev->pollfunc);
 		if (ret)
@@ -1120,7 +1120,7 @@  static int iio_enable_buffers(struct iio_dev *indio_dev,
 	return 0;
 
 err_detach_pollfunc:
-	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+	if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
 		iio_trigger_detach_poll_func(indio_dev->trig,
 					     indio_dev->pollfunc);
 	}
@@ -1132,7 +1132,7 @@  static int iio_enable_buffers(struct iio_dev *indio_dev,
 	if (indio_dev->setup_ops->postdisable)
 		indio_dev->setup_ops->postdisable(indio_dev);
 err_undo_config:
-	indio_dev->currentmode = INDIO_DIRECT_MODE;
+	iio_dev_opaque->currentmode = INDIO_DIRECT_MODE;
 	indio_dev->active_scan_mask = NULL;
 
 	return ret;
@@ -1162,7 +1162,7 @@  static int iio_disable_buffers(struct iio_dev *indio_dev)
 			ret = ret2;
 	}
 
-	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+	if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
 		iio_trigger_detach_poll_func(indio_dev->trig,
 					     indio_dev->pollfunc);
 	}
@@ -1181,7 +1181,7 @@  static int iio_disable_buffers(struct iio_dev *indio_dev)
 
 	iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
 	indio_dev->active_scan_mask = NULL;
-	indio_dev->currentmode = INDIO_DIRECT_MODE;
+	iio_dev_opaque->currentmode = INDIO_DIRECT_MODE;
 
 	return ret;
 }
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index f8fcfe12dfa2..b757273e6652 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -190,7 +190,9 @@  EXPORT_SYMBOL_GPL(iio_device_id);
  */
 bool iio_buffer_enabled(struct iio_dev *indio_dev)
 {
-	return indio_dev->currentmode
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+
+	return iio_dev_opaque->currentmode
 		& (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
 		   INDIO_BUFFER_SOFTWARE);
 }
@@ -2073,12 +2075,14 @@  EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
 
 /**
  * iio_device_get_current_mode() - helper function providing read-only access to
- *				   the @currentmode variable
+ *				   the opaque @currentmode variable
  * @indio_dev:			   IIO device structure for device
  */
 int iio_device_get_current_mode(struct iio_dev *indio_dev)
 {
-	return indio_dev->currentmode;
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+
+	return iio_dev_opaque->currentmode;
 }
 EXPORT_SYMBOL_GPL(iio_device_get_current_mode);
 
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index f504ed351b3e..585b6cef8fcc 100644
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -444,7 +444,7 @@  static ssize_t iio_trigger_write_current(struct device *dev,
 	int ret;
 
 	mutex_lock(&indio_dev->mlock);
-	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+	if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
 		mutex_unlock(&indio_dev->mlock);
 		return -EBUSY;
 	}
diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h
index 2be12b7b5dc5..6b3586b3f952 100644
--- a/include/linux/iio/iio-opaque.h
+++ b/include/linux/iio/iio-opaque.h
@@ -7,6 +7,9 @@ 
  * struct iio_dev_opaque - industrial I/O device opaque information
  * @indio_dev:			public industrial I/O device information
  * @id:			used to identify device internally
+ * @currentmode:		operating mode currently in use, may be eventually
+ *				checked by device drivers but should be considered
+ *				read-only as this is a core internal bit
  * @driver_module:		used to make it harder to undercut users
  * @info_exist_lock:		lock to prevent use during removal
  * @trig_readonly:		mark the current trigger immutable
@@ -36,6 +39,7 @@ 
  */
 struct iio_dev_opaque {
 	struct iio_dev			indio_dev;
+	int				currentmode;
 	int				id;
 	struct module			*driver_module;
 	struct mutex			info_exist_lock;
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 31098ffa7dc9..85cb924debd9 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -494,9 +494,6 @@  struct iio_buffer_setup_ops {
  *			also be filed up by the IIO core, as a result of
  *			enabling particular features in the driver
  *			(see iio_triggered_event_setup()).
- * @currentmode:	[INTERN] operating mode currently in use, may be
- *			eventually checked by device drivers but should be
- *			considered read-only as this is a core internal bit
  * @dev:		[DRIVER] device structure, should be assigned a parent
  *			and owner
  * @buffer:		[DRIVER] any buffer present
@@ -523,7 +520,6 @@  struct iio_buffer_setup_ops {
  */
 struct iio_dev {
 	int				modes;
-	int				currentmode;
 	struct device			dev;
 
 	struct iio_buffer		*buffer;