From ed97d10a8b2c78d1664b01658c5f581e6791ff7d Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 10 Nov 2022 07:24:55 -0800 Subject: [PATCH] thermal/core: Move parameter validation from __thermal_zone_get_temp to thermal_zone_get_temp All callers of __thermal_zone_get_temp() already validated the thermal zone parameters. Move validation to thermal_zone_get_temp() where it is actually needed. Also add kernel documentation for __thermal_zone_get_temp(), listing the requirement that the function must be called with validated parameters and with thermal device mutex held. Signed-off-by: Guenter Roeck Signed-off-by: Rafael J. Wysocki --- drivers/thermal/thermal_helpers.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/thermal_helpers.c b/drivers/thermal/thermal_helpers.c index fca0b23570f9..321f8020082d 100644 --- a/drivers/thermal/thermal_helpers.c +++ b/drivers/thermal/thermal_helpers.c @@ -64,6 +64,20 @@ get_thermal_instance(struct thermal_zone_device *tz, } EXPORT_SYMBOL(get_thermal_instance); +/** + * __thermal_zone_get_temp() - returns the temperature of a thermal zone + * @tz: a valid pointer to a struct thermal_zone_device + * @temp: a valid pointer to where to store the resulting temperature. + * + * When a valid thermal zone reference is passed, it will fetch its + * temperature and fill @temp. + * + * Both tz and tz->ops must be valid pointers when calling this function, + * and the tz->ops->get_temp callback must be provided. + * The function must be called under tz->lock. + * + * Return: On success returns 0, an error code otherwise + */ int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) { int ret = -EINVAL; @@ -73,9 +87,6 @@ int __thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) lockdep_assert_held(&tz->lock); - if (!tz || IS_ERR(tz) || !tz->ops->get_temp) - return -EINVAL; - ret = tz->ops->get_temp(tz, temp); if (IS_ENABLED(CONFIG_THERMAL_EMULATION) && tz->emul_temperature) { @@ -114,13 +125,22 @@ int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp) { int ret; + if (IS_ERR_OR_NULL(tz)) + return -EINVAL; + mutex_lock(&tz->lock); + if (!tz->ops->get_temp) { + ret = -EINVAL; + goto unlock; + } + if (device_is_registered(&tz->device)) ret = __thermal_zone_get_temp(tz, temp); else ret = -ENODEV; +unlock: mutex_unlock(&tz->lock); return ret; -- 2.11.0