diff options
| -rw-r--r-- | include/linux/completion.h | 45 | ||||
| -rw-r--r-- | kernel/sched/completion.c | 11 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 9 |
3 files changed, 64 insertions, 1 deletions
diff --git a/include/linux/completion.h b/include/linux/completion.h index 5d5aaae3af43..9bcebf509b4d 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -9,6 +9,9 @@ */ #include <linux/wait.h> +#ifdef CONFIG_LOCKDEP_COMPLETE +#include <linux/lockdep.h> +#endif /* * struct completion - structure used to maintain state for a "completion" @@ -25,10 +28,50 @@ struct completion { unsigned int done; wait_queue_head_t wait; +#ifdef CONFIG_LOCKDEP_COMPLETE + struct lockdep_map_cross map; +#endif }; +#ifdef CONFIG_LOCKDEP_COMPLETE +static inline void complete_acquire(struct completion *x) +{ + lock_acquire_exclusive((struct lockdep_map *)&x->map, 0, 0, NULL, _RET_IP_); +} + +static inline void complete_release(struct completion *x) +{ + lock_release((struct lockdep_map *)&x->map, 0, _RET_IP_); +} + +static inline void complete_release_commit(struct completion *x) +{ + lock_commit_crosslock((struct lockdep_map *)&x->map); +} + +#define init_completion(x) \ +do { \ + static struct lock_class_key __key; \ + lockdep_init_map_crosslock((struct lockdep_map *)&(x)->map, \ + "(complete)" #x, \ + &__key, 0); \ + __init_completion(x); \ +} while (0) +#else +#define init_completion(x) __init_completion(x) +static inline void complete_acquire(struct completion *x) {} +static inline void complete_release(struct completion *x) {} +static inline void complete_release_commit(struct completion *x) {} +#endif + +#ifdef CONFIG_LOCKDEP_COMPLETE +#define COMPLETION_INITIALIZER(work) \ + { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait), \ + STATIC_CROSS_LOCKDEP_MAP_INIT("(complete)" #work, &(work)) } +#else #define COMPLETION_INITIALIZER(work) \ { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) } +#endif #define COMPLETION_INITIALIZER_ONSTACK(work) \ ({ init_completion(&work); work; }) @@ -70,7 +113,7 @@ struct completion { * This inline function will initialize a dynamically created completion * structure. */ -static inline void init_completion(struct completion *x) +static inline void __init_completion(struct completion *x) { x->done = 0; init_waitqueue_head(&x->wait); diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c index 13fc5ae9bf2f..566b6ec7b6fe 100644 --- a/kernel/sched/completion.c +++ b/kernel/sched/completion.c @@ -32,6 +32,12 @@ void complete(struct completion *x) unsigned long flags; spin_lock_irqsave(&x->wait.lock, flags); + + /* + * Perform commit of crossrelease here. + */ + complete_release_commit(x); + if (x->done != UINT_MAX) x->done++; __wake_up_locked(&x->wait, TASK_NORMAL, 1); @@ -92,9 +98,14 @@ __wait_for_common(struct completion *x, { might_sleep(); + complete_acquire(x); + spin_lock_irq(&x->wait.lock); timeout = do_wait_for_common(x, action, timeout, state); spin_unlock_irq(&x->wait.lock); + + complete_release(x); + return timeout; } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c6038f23bb1a..ebd40d3b0b28 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1162,6 +1162,15 @@ config LOCKDEP_CROSSRELEASE such as page locks or completions can use the lock correctness detector, lockdep. +config LOCKDEP_COMPLETE + bool "Lock debugging: allow completions to use deadlock detector" + depends on PROVE_LOCKING + select LOCKDEP_CROSSRELEASE + default n + help + A deadlock caused by wait_for_completion() and complete() can be + detected by lockdep using crossrelease feature. + config DEBUG_LOCKDEP bool "Lock dependency engine debugging" depends on DEBUG_KERNEL && LOCKDEP |