From 4a08069461ac9822855116d24fbf11d5fb223cd1 Mon Sep 17 00:00:00 2001 From: Dmitry Rokosov Date: Tue, 7 Jun 2022 18:39:18 +0000 Subject: [PATCH] iio: trigger: warn about non-registered iio trigger getting attempt 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_ONCE() is added to alarm IIO driver authors who make such a mistake. When an IIO driver allocates a new IIO trigger, it should register it before calling the get() operation. In other words, each IIO driver must abide by IIO trigger alloc()/register()/get() calls order. Signed-off-by: Dmitry Rokosov Link: https://lore.kernel.org/r/20220607183907.20017-1-ddrokosov@sberdevices.ru Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-trigger.c | 2 ++ include/linux/iio/trigger.h | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c index d89bf90650d5..26d610d4cbb8 100644 --- a/drivers/iio/industrialio-trigger.c +++ b/drivers/iio/industrialio-trigger.c @@ -576,6 +576,8 @@ struct iio_trigger *viio_trigger_alloc(struct device *parent, if (trig->name == NULL) goto free_descs; + INIT_LIST_HEAD(&trig->list); + trig->subirq_chip.name = trig->name; trig->subirq_chip.irq_mask = &iio_trig_subirqmask; trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask; diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h index 4c69b144677b..03b1d6863436 100644 --- a/include/linux/iio/trigger.h +++ b/include/linux/iio/trigger.h @@ -93,6 +93,11 @@ 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); + + WARN_ONCE(list_empty(&trig->list), + "Getting non-registered iio trigger %s is prohibited\n", + trig->name); + __module_get(trig->owner); return trig;