From 3b8e73ec822cecf62e68e12c5320cf329d69923a Mon Sep 17 00:00:00 2001 From: Crestez Dan Leonard Date: Mon, 23 May 2016 21:40:01 +0300 Subject: [PATCH] iio: Refuse to register triggers with duplicate names The trigger name is documented as unique but drivers are currently allowed to register triggers with duplicate names. This should be considered a bug since it makes the 'current_trigger' interface unusable. Signed-off-by: Crestez Dan Leonard Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-trigger.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c index 672911293987..b3ca30896fd8 100644 --- a/drivers/iio/industrialio-trigger.c +++ b/drivers/iio/industrialio-trigger.c @@ -64,6 +64,8 @@ static struct attribute *iio_trig_dev_attrs[] = { }; ATTRIBUTE_GROUPS(iio_trig_dev); +static struct iio_trigger *__iio_trigger_find_by_name(const char *name); + int iio_trigger_register(struct iio_trigger *trig_info) { int ret; @@ -86,11 +88,19 @@ int iio_trigger_register(struct iio_trigger *trig_info) /* Add to list of available triggers held by the IIO core */ mutex_lock(&iio_trigger_list_lock); + if (__iio_trigger_find_by_name(trig_info->name)) { + pr_err("Duplicate trigger name '%s'\n", trig_info->name); + ret = -EEXIST; + goto error_device_del; + } list_add_tail(&trig_info->list, &iio_trigger_list); mutex_unlock(&iio_trigger_list_lock); return 0; +error_device_del: + mutex_unlock(&iio_trigger_list_lock); + device_del(&trig_info->dev); error_unregister_id: ida_simple_remove(&iio_trigger_ida, trig_info->id); return ret; @@ -109,6 +119,18 @@ void iio_trigger_unregister(struct iio_trigger *trig_info) } EXPORT_SYMBOL(iio_trigger_unregister); +/* Search for trigger by name, assuming iio_trigger_list_lock held */ +static struct iio_trigger *__iio_trigger_find_by_name(const char *name) +{ + struct iio_trigger *iter; + + list_for_each_entry(iter, &iio_trigger_list, list) + if (!strcmp(iter->name, name)) + return iter; + + return NULL; +} + static struct iio_trigger *iio_trigger_find_by_name(const char *name, size_t len) { -- 2.20.1