diff options
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep.c | 89 |
1 files changed, 48 insertions, 41 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 64ea69f94b3a..47e3acb6b5c9 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -84,12 +84,39 @@ module_param(lock_stat, int, 0644); * to use a raw spinlock - we really dont want the spinlock * code to recurse back into the lockdep code... */ -static arch_spinlock_t lockdep_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; +static arch_spinlock_t __lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; +static struct task_struct *__owner; + +static inline void lockdep_lock(void) +{ + DEBUG_LOCKS_WARN_ON(!irqs_disabled()); + + arch_spin_lock(&__lock); + __owner = current; + current->lockdep_recursion++; +} + +static inline void lockdep_unlock(void) +{ + if (debug_locks && DEBUG_LOCKS_WARN_ON(__owner != current)) + return; + + current->lockdep_recursion--; + __owner = NULL; + arch_spin_unlock(&__lock); +} + +static inline bool lockdep_assert_locked(void) +{ + return DEBUG_LOCKS_WARN_ON(__owner != current); +} + static struct task_struct *lockdep_selftest_task_struct; + static int graph_lock(void) { - arch_spin_lock(&lockdep_lock); + lockdep_lock(); /* * Make sure that if another CPU detected a bug while * walking the graph we dont change it (while the other @@ -97,27 +124,15 @@ static int graph_lock(void) * dropped already) */ if (!debug_locks) { - arch_spin_unlock(&lockdep_lock); + lockdep_unlock(); return 0; } - /* prevent any recursions within lockdep from causing deadlocks */ - current->lockdep_recursion++; return 1; } -static inline int graph_unlock(void) +static inline void graph_unlock(void) { - if (debug_locks && !arch_spin_is_locked(&lockdep_lock)) { - /* - * The lockdep graph lock isn't locked while we expect it to - * be, we're confused now, bye! - */ - return DEBUG_LOCKS_WARN_ON(1); - } - - current->lockdep_recursion--; - arch_spin_unlock(&lockdep_lock); - return 0; + lockdep_unlock(); } /* @@ -128,7 +143,7 @@ static inline int debug_locks_off_graph_unlock(void) { int ret = debug_locks_off(); - arch_spin_unlock(&lockdep_lock); + lockdep_unlock(); return ret; } @@ -1479,6 +1494,8 @@ static int __bfs(struct lock_list *source_entry, struct circular_queue *cq = &lock_cq; int ret = 1; + lockdep_assert_locked(); + if (match(source_entry, data)) { *target_entry = source_entry; ret = 0; @@ -1501,8 +1518,6 @@ static int __bfs(struct lock_list *source_entry, head = get_dep_list(lock, offset); - DEBUG_LOCKS_WARN_ON(!irqs_disabled()); - list_for_each_entry_rcu(entry, head, entry) { if (!lock_accessed(entry)) { unsigned int cq_depth; @@ -1729,11 +1744,9 @@ unsigned long lockdep_count_forward_deps(struct lock_class *class) this.class = class; raw_local_irq_save(flags); - current->lockdep_recursion++; - arch_spin_lock(&lockdep_lock); + lockdep_lock(); ret = __lockdep_count_forward_deps(&this); - arch_spin_unlock(&lockdep_lock); - current->lockdep_recursion--; + lockdep_unlock(); raw_local_irq_restore(flags); return ret; @@ -1758,11 +1771,9 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class) this.class = class; raw_local_irq_save(flags); - current->lockdep_recursion++; - arch_spin_lock(&lockdep_lock); + lockdep_lock(); ret = __lockdep_count_backward_deps(&this); - arch_spin_unlock(&lockdep_lock); - current->lockdep_recursion--; + lockdep_unlock(); raw_local_irq_restore(flags); return ret; @@ -3046,7 +3057,7 @@ static inline int add_chain_cache(struct task_struct *curr, * disabled to make this an IRQ-safe lock.. for recursion reasons * lockdep won't complain about its own locking errors. */ - if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) + if (lockdep_assert_locked()) return 0; chain = alloc_lock_chain(); @@ -5181,8 +5192,7 @@ static void free_zapped_rcu(struct rcu_head *ch) return; raw_local_irq_save(flags); - arch_spin_lock(&lockdep_lock); - current->lockdep_recursion++; + lockdep_lock(); /* closed head */ pf = delayed_free.pf + (delayed_free.index ^ 1); @@ -5194,8 +5204,7 @@ static void free_zapped_rcu(struct rcu_head *ch) */ call_rcu_zapped(delayed_free.pf + delayed_free.index); - current->lockdep_recursion--; - arch_spin_unlock(&lockdep_lock); + lockdep_unlock(); raw_local_irq_restore(flags); } @@ -5240,13 +5249,11 @@ static void lockdep_free_key_range_reg(void *start, unsigned long size) init_data_structures_once(); raw_local_irq_save(flags); - arch_spin_lock(&lockdep_lock); - current->lockdep_recursion++; + lockdep_lock(); pf = get_pending_free(); __lockdep_free_key_range(pf, start, size); call_rcu_zapped(pf); - current->lockdep_recursion--; - arch_spin_unlock(&lockdep_lock); + lockdep_unlock(); raw_local_irq_restore(flags); /* @@ -5268,10 +5275,10 @@ static void lockdep_free_key_range_imm(void *start, unsigned long size) init_data_structures_once(); raw_local_irq_save(flags); - arch_spin_lock(&lockdep_lock); + lockdep_lock(); __lockdep_free_key_range(pf, start, size); __free_zapped_classes(pf); - arch_spin_unlock(&lockdep_lock); + lockdep_unlock(); raw_local_irq_restore(flags); } @@ -5367,10 +5374,10 @@ static void lockdep_reset_lock_imm(struct lockdep_map *lock) unsigned long flags; raw_local_irq_save(flags); - arch_spin_lock(&lockdep_lock); + lockdep_lock(); __lockdep_reset_lock(pf, lock); __free_zapped_classes(pf); - arch_spin_unlock(&lockdep_lock); + lockdep_unlock(); raw_local_irq_restore(flags); } |