| From foo@baz Sun Aug 26 09:13:00 CEST 2018 |
| From: Peter Rosin <peda@axentia.se> |
| Date: Fri, 20 Jul 2018 10:39:13 +0200 |
| Subject: locking/rtmutex: Allow specifying a subclass for nested locking |
| |
| From: Peter Rosin <peda@axentia.se> |
| |
| [ Upstream commit 62cedf3e60af03e47849fe2bd6a03ec179422a8a ] |
| |
| Needed for annotating rt_mutex locks. |
| |
| Tested-by: John Sperbeck <jsperbeck@google.com> |
| Signed-off-by: Peter Rosin <peda@axentia.se> |
| Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
| Cc: Davidlohr Bueso <dave@stgolabs.net> |
| Cc: Deepa Dinamani <deepadinamani@google.com> |
| Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Peter Chang <dpf@google.com> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Philippe Ombredanne <pombredanne@nexb.com> |
| Cc: Thomas Gleixner <tglx@linutronix.de> |
| Cc: Will Deacon <will.deacon@arm.com> |
| Cc: Wolfram Sang <wsa@the-dreams.de> |
| Link: http://lkml.kernel.org/r/20180720083914.1950-2-peda@axentia.se |
| Signed-off-by: Ingo Molnar <mingo@kernel.org> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| include/linux/rtmutex.h | 7 +++++++ |
| kernel/locking/rtmutex.c | 29 +++++++++++++++++++++++++---- |
| 2 files changed, 32 insertions(+), 4 deletions(-) |
| |
| --- a/include/linux/rtmutex.h |
| +++ b/include/linux/rtmutex.h |
| @@ -106,7 +106,14 @@ static inline int rt_mutex_is_locked(str |
| extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key); |
| extern void rt_mutex_destroy(struct rt_mutex *lock); |
| |
| +#ifdef CONFIG_DEBUG_LOCK_ALLOC |
| +extern void rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass); |
| +#define rt_mutex_lock(lock) rt_mutex_lock_nested(lock, 0) |
| +#else |
| extern void rt_mutex_lock(struct rt_mutex *lock); |
| +#define rt_mutex_lock_nested(lock, subclass) rt_mutex_lock(lock) |
| +#endif |
| + |
| extern int rt_mutex_lock_interruptible(struct rt_mutex *lock); |
| extern int rt_mutex_timed_lock(struct rt_mutex *lock, |
| struct hrtimer_sleeper *timeout); |
| --- a/kernel/locking/rtmutex.c |
| +++ b/kernel/locking/rtmutex.c |
| @@ -1466,6 +1466,29 @@ rt_mutex_fastunlock(struct rt_mutex *loc |
| rt_mutex_postunlock(&wake_q); |
| } |
| |
| +static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass) |
| +{ |
| + might_sleep(); |
| + |
| + mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); |
| + rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock); |
| +} |
| + |
| +#ifdef CONFIG_DEBUG_LOCK_ALLOC |
| +/** |
| + * rt_mutex_lock_nested - lock a rt_mutex |
| + * |
| + * @lock: the rt_mutex to be locked |
| + * @subclass: the lockdep subclass |
| + */ |
| +void __sched rt_mutex_lock_nested(struct rt_mutex *lock, unsigned int subclass) |
| +{ |
| + __rt_mutex_lock(lock, subclass); |
| +} |
| +EXPORT_SYMBOL_GPL(rt_mutex_lock_nested); |
| +#endif |
| + |
| +#ifndef CONFIG_DEBUG_LOCK_ALLOC |
| /** |
| * rt_mutex_lock - lock a rt_mutex |
| * |
| @@ -1473,12 +1496,10 @@ rt_mutex_fastunlock(struct rt_mutex *loc |
| */ |
| void __sched rt_mutex_lock(struct rt_mutex *lock) |
| { |
| - might_sleep(); |
| - |
| - mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
| - rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock); |
| + __rt_mutex_lock(lock, 0); |
| } |
| EXPORT_SYMBOL_GPL(rt_mutex_lock); |
| +#endif |
| |
| /** |
| * rt_mutex_lock_interruptible - lock a rt_mutex interruptible |