diff options
| author | Thomas Weißschuh <linux@weissschuh.net> | 2025-06-17 19:08:14 +0200 |
|---|---|---|
| committer | Boqun Feng <boqun.feng@gmail.com> | 2025-07-11 15:11:54 -0700 |
| commit | daec29dcc8731b7596690ab9f647839e4584a86d (patch) | |
| tree | 1af9d7f03fe3024ad096621ecaa5d545c6f16835 | |
| parent | 3b07bb900af7f43f13f9ff398b4c6ca1dee217cd (diff) | |
locking/mutex: Mark devm_mutex_init() as __must_check
devm_mutex_init() can fail. With CONFIG_DEBUG_MUTEXES=y the mutex will be
marked as unusable and trigger errors on usage.
Enforce all callers check the return value through the compiler.
As devm_mutex_init() itself is a macro, it can not be annotated
directly. Annotate __devm_mutex_init() instead.
Unfortunately __must_check/warn_unused_result don't propagate through
statement expression. So move the statement expression into the argument
list of the call to __devm_mutex_init() through a helper macro.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250617-must_check-devm_mutex_init-v7-3-d9e449f4d224@weissschuh.net
| -rw-r--r-- | include/linux/mutex.h | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/include/linux/mutex.h b/include/linux/mutex.h index a039fa8c1780..00afd341d293 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -126,11 +126,11 @@ do { \ #ifdef CONFIG_DEBUG_MUTEXES -int __devm_mutex_init(struct device *dev, struct mutex *lock); +int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock); #else -static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) +static inline int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock) { /* * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so @@ -141,14 +141,17 @@ static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) #endif -#define devm_mutex_init(dev, mutex) \ +#define __mutex_init_ret(mutex) \ ({ \ typeof(mutex) mutex_ = (mutex); \ \ mutex_init(mutex_); \ - __devm_mutex_init(dev, mutex_); \ + mutex_; \ }) +#define devm_mutex_init(dev, mutex) \ + __devm_mutex_init(dev, __mutex_init_ret(mutex)) + /* * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/locking/mutex-design.rst. |