Messages in this thread Patch in this message | | | From | Dmitry Rokosov <> | Subject | [PATCH v1] iio: trigger: warn about non-registered iio trigger getting attempt | Date | Tue, 31 May 2022 18:15:05 +0000 |
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As a part of patch series about wrong trigger register() and get() calls order in the some IIO drivers trigger initialization path:
https://lore.kernel.org/all/20220524181150.9240-1-ddrokosov@sberdevices.ru/
runtime WARN() is added to alarm IIO driver authors who make such a mistake.
When IIO driver allocates a new IIO trigger, it should register it before calling get() operation. Otherwise, the next iio_trigger_put() will upset refcnt balance.
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> --- include/linux/iio/trigger.h | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h index 4c69b144677b..4a008b952710 100644 --- a/include/linux/iio/trigger.h +++ b/include/linux/iio/trigger.h @@ -93,6 +93,15 @@ static inline void iio_trigger_put(struct iio_trigger *trig) static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig) { get_device(&trig->dev); + + /* + * If driver hasn't called iio_trigger_register() before and trig->owner + * wasn't initialized properly, trigger will have wrong number of users + */ + WARN(!trig->owner, + "Ignore module getting for non-registered iio trigger %s\n", + trig->name); + __module_get(trig->owner); return trig; -- 2.36.0
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