| Message ID | 20220524181150.9240-6-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: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device") > Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> > --- > drivers/iio/humidity/hts221_buffer.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c > index f29692b9d2db..66b32413cf5e 100644 > --- a/drivers/iio/humidity/hts221_buffer.c > +++ b/drivers/iio/humidity/hts221_buffer.c > @@ -135,9 +135,12 @@ int hts221_allocate_trigger(struct iio_dev *iio_dev) > > iio_trigger_set_drvdata(hw->trig, iio_dev); > hw->trig->ops = &hts221_trigger_ops; > + > + err = devm_iio_trigger_register(hw->dev, hw->trig); > + > iio_dev->trig = iio_trigger_get(hw->trig); > > - return devm_iio_trigger_register(hw->dev, hw->trig); > + return err; > } > > static int hts221_buffer_preenable(struct iio_dev *iio_dev) > -- > 2.36.0
diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c index f29692b9d2db..66b32413cf5e 100644 --- a/drivers/iio/humidity/hts221_buffer.c +++ b/drivers/iio/humidity/hts221_buffer.c @@ -135,9 +135,12 @@ int hts221_allocate_trigger(struct iio_dev *iio_dev) iio_trigger_set_drvdata(hw->trig, iio_dev); hw->trig->ops = &hts221_trigger_ops; + + err = devm_iio_trigger_register(hw->dev, hw->trig); + iio_dev->trig = iio_trigger_get(hw->trig); - return devm_iio_trigger_register(hw->dev, hw->trig); + return err; } static int hts221_buffer_preenable(struct iio_dev *iio_dev)
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: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device") Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> --- drivers/iio/humidity/hts221_buffer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)