Re: [PATCH v2 01/10] devm-helpers: introduce devm_mutex_init
From: Christophe Leroy <hidden>
Date: 2023-12-04 23:05:57
Also in:
linux-leds, lkml
Le 04/12/2023 à 19:05, George Stark a écrit :
Using of devm API leads to certain order of releasing resources. So all dependent resources which are not devm-wrapped should be deleted with respect to devm-release order. Mutex is one of such objects that often is bound to other resources and has no own devm wrapping. Since mutex_destroy() actually does nothing in non-debug builds frequently calling mutex_destroy() is just ignored which is safe for now but wrong formally and can lead to a problem if mutex_destroy() is extended so introduce devm_mutex_init().
This is not needed for patch 2. Should patch 2 go first ?
quoted hunk ↗ jump to hunk
Signed-off-by: George Stark <redacted> --- include/linux/devm-helpers.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)diff --git a/include/linux/devm-helpers.h b/include/linux/devm-helpers.h index 74891802200d..2f56e476776f 100644 --- a/include/linux/devm-helpers.h +++ b/include/linux/devm-helpers.h@@ -76,4 +76,22 @@ static inline int devm_work_autocancel(struct device *dev, return devm_add_action(dev, devm_work_drop, w); } +static inline void devm_mutex_release(void *res) +{ + mutex_destroy(res); +} + +/** + * devm_mutex_init - Resource-managed mutex initialization + * @dev: Device which lifetime work is bound to + * @lock: Pointer to a mutex + * + * Initialize mutex which is automatically destroyed when driver is detached. + */ +static inline int devm_mutex_init(struct device *dev, struct mutex *lock) +{ + mutex_init(lock); + return devm_add_action_or_reset(dev, devm_mutex_release, lock); +} + #endif