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Commit dbf717fd authored by Grant Grundler's avatar Grant Grundler Committed by Greg Kroah-Hartman
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staging:iio:tsl2563 rewrite probe error handling 

tsl2563 probe function has two minor issues with it's error handling paths:
1) it is silent (did not report errors to dmesg)
2) did not return failure code (mixed up use of ret and err)

and two major issues:
3) goto fail2 would corrupt a free memory pool ("double free")
4) device registration failure did NOT cancel/flush delayed work.
   (and thus dereference a freed data structure later)

The "double free" is subtle and was introduced with this change:
    Author: Jonathan Cameron <jic23@cam.ac.uk>
    Date:   Mon Apr 18 12:58:55 2011 +0100
    staging:iio:tsl2563 take advantage of new iio_device_allocate private data.

Originally, chip was allocated seperately. Now it's appended to the
indio_dev by iio_allocate_device(sizeof(*chip)). So we only need one
kfree call as well (in iio_free_device()).

Gory details of tracking this down are here:
   http://crosbug.com/26819



Despite iio_device_registration failing, system can at least now boot.
Will follow up with a fix to "double register : in_intensity_both_raw"
error that is included in the bug report.

Signed-off-by: default avatarGrant Grundler <grundler@chromium.org>
Acked-by: default avatarJonathan Cameron <jic23@kernel.org>
Reviewed-by: default avatarBryan Freed <bfreed@chromium.org>
Reviewed-by: default avatarBenson Leung <bleung@chromium.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ee6aeff7

drivers/staging/iio/light/tsl2563.c

+26 −13
Original line number Diff line number Diff line
@@ -708,7 +708,6 @@ static int __devinit tsl2563_probe(struct i2c_client *client, 
	struct tsl2563_chip *chip;

	struct tsl2563_platform_data *pdata = client->dev.platform_data;

	int err = 0;

	int ret;

	u8 id = 0;



	indio_dev = iio_allocate_device(sizeof(*chip));
@@ -722,13 +721,15 @@ static int __devinit tsl2563_probe(struct i2c_client *client, 


	err = tsl2563_detect(chip);

	if (err) {

		dev_err(&client->dev, "device not found, error %d\n", -err);

		dev_err(&client->dev, "detect error %d\n", -err);

		goto fail1;

	}



	err = tsl2563_read_id(chip, &id);

	if (err)

	if (err) {

		dev_err(&client->dev, "read id error %d\n", -err);

		goto fail1;

	}



	mutex_init(&chip->lock);
@@ -751,40 +752,52 @@ static int __devinit tsl2563_probe(struct i2c_client *client, 
	indio_dev->num_channels = ARRAY_SIZE(tsl2563_channels);

	indio_dev->dev.parent = &client->dev;

	indio_dev->modes = INDIO_DIRECT_MODE;



	if (client->irq)

		indio_dev->info = &tsl2563_info;

	else

		indio_dev->info = &tsl2563_info_no_irq;



	if (client->irq) {

		ret = request_threaded_irq(client->irq,

		err = request_threaded_irq(client->irq,

					   NULL,

					   &tsl2563_event_handler,

					   IRQF_TRIGGER_RISING | IRQF_ONESHOT,

					   "tsl2563_event",

					   indio_dev);

		if (ret)

			goto fail2;

		if (err) {

			dev_err(&client->dev, "irq request error %d\n", -err);

			goto fail1;

		}

	}



	err = tsl2563_configure(chip);

	if (err)

		goto fail3;

	if (err) {

		dev_err(&client->dev, "configure error %d\n", -err);

		goto fail2;

	}



	INIT_DELAYED_WORK(&chip->poweroff_work, tsl2563_poweroff_work);



	/* The interrupt cannot yet be enabled so this is fine without lock */

	schedule_delayed_work(&chip->poweroff_work, 5 * HZ);



	ret = iio_device_register(indio_dev);

	if (ret)

	err = iio_device_register(indio_dev);

	if (err) {

		dev_err(&client->dev, "iio registration error %d\n", -err);

		goto fail3;

	}



	return 0;



fail3:

	cancel_delayed_work(&chip->poweroff_work);

	flush_scheduled_work();

fail2:

	if (client->irq)

		free_irq(client->irq, indio_dev);

fail2:

	iio_free_device(indio_dev);

fail1:

	kfree(chip);

	iio_free_device(indio_dev);

	return err;

}