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| author | George Stark <gnstark@salutedevices.com> | 2024-04-11 19:10:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-18 14:07:26 +0300 |
| commit | e8053aa2ecc4784311cfdc971c4c58ea1d8edcab (patch) | |
| tree | 6fadc804161a29d14b45acd3e45d6ae0d0ea7de3 /include/linux/mutex.h | |
| parent | 5e3070adafca2b648869310f34438f5d659a2c8e (diff) | |
| download | linux-e8053aa2ecc4784311cfdc971c4c58ea1d8edcab.tar.xz | |
locking/mutex: Introduce devm_mutex_init()
[ Upstream commit 4cd47222e435dec8e3787614924174f53fcfb5ae ]
Using of devm API leads to a 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() will be
extended so introduce devm_mutex_init().
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: George Stark <gnstark@salutedevices.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux/mutex.h')
| -rw-r--r-- | include/linux/mutex.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 8f226d460f51..9ef01b9d2456 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -20,6 +20,8 @@ #include <linux/osq_lock.h> #include <linux/debug_locks.h> +struct device; + #ifdef CONFIG_DEBUG_LOCK_ALLOC # define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ , .dep_map = { \ @@ -170,6 +172,31 @@ do { \ } while (0) #endif /* CONFIG_PREEMPT_RT */ +#ifdef CONFIG_DEBUG_MUTEXES + +int __devm_mutex_init(struct device *dev, struct mutex *lock); + +#else + +static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) +{ + /* + * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so + * no really need to register it in the devm subsystem. + */ + return 0; +} + +#endif + +#define devm_mutex_init(dev, mutex) \ +({ \ + typeof(mutex) mutex_ = (mutex); \ + \ + mutex_init(mutex_); \ + __devm_mutex_init(dev, mutex_); \ +}) + /* * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/locking/mutex-design.rst. |