releases/3.18.85/iio-iio-trig-periodic-rtc-free-trigger-resource-correctly.patch

From ben.hutchings@codethink.co.uk  Tue Nov 28 10:18:28 2017
From: Ben Hutchings <ben.hutchings@codethink.co.uk>
Date: Wed, 22 Nov 2017 17:12:41 +0000
Subject: iio: iio-trig-periodic-rtc: Free trigger resource correctly
To: stable@vger.kernel.org
Cc: Alison Schofield <amsfield22@gmail.com>, Jonathan Cameron <jic23@kernel.org>
Message-ID: <20171122171231.lr54tqp3umbuexbs@xylophone.i.decadent.org.uk>
Content-Disposition: inline

From: Ben Hutchings <ben.hutchings@codethink.co.uk>

This is based on upstream commit 10e840dfb0b7, which did not touch the
iio-trig-periodic-rtc driver because it has been removed upstream.

The following explanation comes from that commit:

    These stand-alone trigger drivers were using iio_trigger_put()
    where they should have been using iio_trigger_free().  The
    iio_trigger_put() adds a module_put which is bad since they
    never did a module_get.

    In the sysfs driver, module_get/put's are used as triggers are
    added & removed. This extra module_put() occurs on an error path
    in the probe routine (probably rare).

    In the bfin-timer & interrupt trigger drivers, the module resources
    are not explicitly managed, so it's doing a put on something that
    was never get'd.  It occurs on the probe error path and on the
    remove path (not so rare).

    Tested with the sysfs trigger driver.
    The bfin & interrupt drivers were build tested & inspected only.

This was build tested only.

Cc: Alison Schofield <amsfield22@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/iio/trigger/iio-trig-periodic-rtc.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c
+++ b/drivers/staging/iio/trigger/iio-trig-periodic-rtc.c
@@ -137,7 +137,7 @@ static int iio_trig_periodic_rtc_probe(s
 		trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
 		if (!trig_info) {
 			ret = -ENOMEM;
-			goto error_put_trigger_and_remove_from_list;
+			goto error_free_trigger_and_remove_from_list;
 		}
 		iio_trigger_set_drvdata(trig, trig_info);
 		trig->ops = &iio_prtc_trigger_ops;
@@ -164,9 +164,9 @@ error_close_rtc:
 	rtc_class_close(trig_info->rtc);
 error_free_trig_info:
 	kfree(trig_info);
-error_put_trigger_and_remove_from_list:
+error_free_trigger_and_remove_from_list:
 	list_del(&trig->alloc_list);
-	iio_trigger_put(trig);
+	iio_trigger_free(trig);
 error_free_completed_registrations:
 	list_for_each_entry_safe(trig,
 				 trig2,