| Message ID | 20220524181150.9240-2-ddrokosov@sberdevices.ru (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | iio: treewide: rearrange iio trig get/register | expand |
On Tue, May 24, 2022 at 8:14 PM Dmitry Rokosov <DDRokosov@sberdevices.ru> wrote: > > IIO trigger interface function iio_trigger_get() should be called after > iio_trigger_register() (or its devm analogue) strictly, because of > iio_trigger_get() acquires module refcnt based on the trigger->owner > pointer, which is initialized inside iio_trigger_register() to > THIS_MODULE. > If this call order is wrong, the next iio_trigger_put() (from sysfs > callback or "delete module" path) will dereference "default" module > refcnt, which is incorrect behaviour. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > Fixes: 0668a4e4d297 ("iio: accel: bma180: Fix indio_dev->trig assignment") > Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> > --- > drivers/iio/accel/bma180.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c > index d8a454c266d5..5d0bd0fc3018 100644 > --- a/drivers/iio/accel/bma180.c > +++ b/drivers/iio/accel/bma180.c > @@ -1006,11 +1006,12 @@ static int bma180_probe(struct i2c_client *client, > > data->trig->ops = &bma180_trigger_ops; > iio_trigger_set_drvdata(data->trig, indio_dev); > - indio_dev->trig = iio_trigger_get(data->trig); > > ret = iio_trigger_register(data->trig); > if (ret) > goto err_trigger_free; > + > + indio_dev->trig = iio_trigger_get(data->trig); > } > > ret = iio_triggered_buffer_setup(indio_dev, NULL, > -- > 2.36.0
diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c index d8a454c266d5..5d0bd0fc3018 100644 --- a/drivers/iio/accel/bma180.c +++ b/drivers/iio/accel/bma180.c @@ -1006,11 +1006,12 @@ static int bma180_probe(struct i2c_client *client, data->trig->ops = &bma180_trigger_ops; iio_trigger_set_drvdata(data->trig, indio_dev); - indio_dev->trig = iio_trigger_get(data->trig); ret = iio_trigger_register(data->trig); if (ret) goto err_trigger_free; + + indio_dev->trig = iio_trigger_get(data->trig); } ret = iio_triggered_buffer_setup(indio_dev, NULL,
IIO trigger interface function iio_trigger_get() should be called after iio_trigger_register() (or its devm analogue) strictly, because of iio_trigger_get() acquires module refcnt based on the trigger->owner pointer, which is initialized inside iio_trigger_register() to THIS_MODULE. If this call order is wrong, the next iio_trigger_put() (from sysfs callback or "delete module" path) will dereference "default" module refcnt, which is incorrect behaviour. Fixes: 0668a4e4d297 ("iio: accel: bma180: Fix indio_dev->trig assignment") Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> --- drivers/iio/accel/bma180.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)