diff options
| author | Davidlohr Bueso <dave@stgolabs.net> | 2019-10-24 20:36:34 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-10-29 12:22:52 +0100 |
| commit | a0855d24fc22d49cdc25664fb224caee16998683 (patch) | |
| tree | dd119b46e9fc2214fc272b2b878799614b728257 | |
| parent | 751459043cc87c3f0098034b15ca5252d12539ab (diff) | |
| download | linux-a0855d24fc22d49cdc25664fb224caee16998683.tar.bz2 | |
locking/mutex: Complain upon mutex API misuse in IRQ contexts
Add warning checks if mutex_trylock() or mutex_unlock() are used in
IRQ contexts, under CONFIG_DEBUG_MUTEXES=y.
While the mutex rules and semantics are explicitly documented, this allows
to expose any abusers and robustifies the whole thing.
While trylock and unlock are non-blocking, calling from IRQ context
is still forbidden (lock must be within the same context as unlock).
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Link: https://lkml.kernel.org/r/20191025033634.3330-1-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/locking/mutex.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 5352ce50a97e..54cc5f9286e9 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -733,6 +733,9 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne */ void __sched mutex_unlock(struct mutex *lock) { +#ifdef CONFIG_DEBUG_MUTEXES + WARN_ON(in_interrupt()); +#endif #ifndef CONFIG_DEBUG_LOCK_ALLOC if (__mutex_unlock_fast(lock)) return; @@ -1413,6 +1416,7 @@ int __sched mutex_trylock(struct mutex *lock) #ifdef CONFIG_DEBUG_MUTEXES DEBUG_LOCKS_WARN_ON(lock->magic != lock); + WARN_ON(in_interrupt()); #endif locked = __mutex_trylock(lock); |