diff options
| -rw-r--r-- | include/linux/lockdep.h | 10 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 80 |
2 files changed, 90 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 066ba4157541..c5b6b5830acf 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -255,6 +255,7 @@ struct held_lock { unsigned int check:1; /* see lock_acquire() comment */ unsigned int hardirqs_off:1; unsigned int references:12; /* 32 bits */ + unsigned int pin_count; }; /* @@ -354,6 +355,9 @@ extern void lockdep_set_current_reclaim_state(gfp_t gfp_mask); extern void lockdep_clear_current_reclaim_state(void); extern void lockdep_trace_alloc(gfp_t mask); +extern void lock_pin_lock(struct lockdep_map *lock); +extern void lock_unpin_lock(struct lockdep_map *lock); + # define INIT_LOCKDEP .lockdep_recursion = 0, .lockdep_reclaim_gfp = 0, #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) @@ -368,6 +372,9 @@ extern void lockdep_trace_alloc(gfp_t mask); #define lockdep_recursing(tsk) ((tsk)->lockdep_recursion) +#define lockdep_pin_lock(l) lock_pin_lock(&(l)->dep_map) +#define lockdep_unpin_lock(l) lock_unpin_lock(&(l)->dep_map) + #else /* !CONFIG_LOCKDEP */ static inline void lockdep_off(void) @@ -420,6 +427,9 @@ struct lock_class_key { }; #define lockdep_recursing(tsk) (0) +#define lockdep_pin_lock(l) do { (void)(l); } while (0) +#define lockdep_unpin_lock(l) do { (void)(l); } while (0) + #endif /* !LOCKDEP */ #ifdef CONFIG_LOCK_STAT diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index a266d5165b63..18f9f434d17e 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -3157,6 +3157,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, hlock->waittime_stamp = 0; hlock->holdtime_stamp = lockstat_clock(); #endif + hlock->pin_count = 0; if (check && !mark_irqflags(curr, hlock)) return 0; @@ -3403,6 +3404,8 @@ found_it: if (hlock->instance == lock) lock_release_holdtime(hlock); + WARN(hlock->pin_count, "releasing a pinned lock\n"); + if (hlock->references) { hlock->references--; if (hlock->references) { @@ -3459,6 +3462,49 @@ static int __lock_is_held(struct lockdep_map *lock) return 0; } +static void __lock_pin_lock(struct lockdep_map *lock) +{ + struct task_struct *curr = current; + int i; + + if (unlikely(!debug_locks)) + return; + + for (i = 0; i < curr->lockdep_depth; i++) { + struct held_lock *hlock = curr->held_locks + i; + + if (match_held_lock(hlock, lock)) { + hlock->pin_count++; + return; + } + } + + WARN(1, "pinning an unheld lock\n"); +} + +static void __lock_unpin_lock(struct lockdep_map *lock) +{ + struct task_struct *curr = current; + int i; + + if (unlikely(!debug_locks)) + return; + + for (i = 0; i < curr->lockdep_depth; i++) { + struct held_lock *hlock = curr->held_locks + i; + + if (match_held_lock(hlock, lock)) { + if (WARN(!hlock->pin_count, "unpinning an unpinned lock\n")) + return; + + hlock->pin_count--; + return; + } + } + + WARN(1, "unpinning an unheld lock\n"); +} + /* * Check whether we follow the irq-flags state precisely: */ @@ -3582,6 +3628,40 @@ int lock_is_held(struct lockdep_map *lock) } EXPORT_SYMBOL_GPL(lock_is_held); +void lock_pin_lock(struct lockdep_map *lock) +{ + unsigned long flags; + + if (unlikely(current->lockdep_recursion)) + return; + + raw_local_irq_save(flags); + check_flags(flags); + + current->lockdep_recursion = 1; + __lock_pin_lock(lock); + current->lockdep_recursion = 0; + raw_local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(lock_pin_lock); + +void lock_unpin_lock(struct lockdep_map *lock) +{ + unsigned long flags; + + if (unlikely(current->lockdep_recursion)) + return; + + raw_local_irq_save(flags); + check_flags(flags); + + current->lockdep_recursion = 1; + __lock_unpin_lock(lock); + current->lockdep_recursion = 0; + raw_local_irq_restore(flags); +} +EXPORT_SYMBOL_GPL(lock_unpin_lock); + void lockdep_set_current_reclaim_state(gfp_t gfp_mask) { current->lockdep_reclaim_gfp = gfp_mask; |