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Commit ac917a81 authored by Jonathan Cameron's avatar Jonathan Cameron Committed by Greg Kroah-Hartman
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staging:iio:core set the iio_dev.info pointer to null on unregister under lock. 



This prevents use of provider callbacks after it has been unregistered.
Note that all code using this that can be called from a consumer *must*
check the pointer before using and hold the info_exist_lock throughout
the usage of the callbacks in info.

Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 08cd9ef4

drivers/staging/iio/iio.h

+2 −0
Original line number Diff line number Diff line
@@ -310,6 +310,7 @@ struct iio_buffer_setup_ops { 
 * @chan_attr_group:	[INTERN] group for all attrs in base directory

 * @name:		[DRIVER] name of the device.

 * @info:		[DRIVER] callbacks and constant info from driver

 * @info_exist_lock:	[INTERN] lock to prevent use during removal

 * @chrdev:		[INTERN] associated character device

 * @groups:		[INTERN] attribute groups

 * @groupcounter:	[INTERN] index of next attribute group
@@ -340,6 +341,7 @@ struct iio_dev { 
	struct attribute_group		chan_attr_group;

	const char			*name;

	const struct iio_info		*info;

	struct mutex			info_exist_lock;

	const struct iio_buffer_setup_ops	*setup_ops;

	struct cdev			chrdev;

#define IIO_MAX_GROUPS 6

drivers/staging/iio/industrialio-core.c

+4 −0
Original line number Diff line number Diff line
@@ -594,6 +594,7 @@ struct iio_dev *iio_allocate_device(int sizeof_priv) 
		device_initialize(&dev->dev);

		dev_set_drvdata(&dev->dev, (void *)dev);

		mutex_init(&dev->mlock);

		mutex_init(&dev->info_exist_lock);



		dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);

		if (dev->id < 0) {
@@ -718,6 +719,9 @@ EXPORT_SYMBOL(iio_device_register); 


void iio_device_unregister(struct iio_dev *indio_dev)

{

	mutex_lock(&indio_dev->info_exist_lock);

	indio_dev->info = NULL;

	mutex_unlock(&indio_dev->info_exist_lock);

	device_unregister(&indio_dev->dev);

}

EXPORT_SYMBOL(iio_device_unregister);