diff options
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 509efd49540..592c576d77a 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -70,6 +70,9 @@ static int graph_lock(void) static inline int graph_unlock(void) { + if (debug_locks && !__raw_spin_is_locked(&lockdep_lock)) + return DEBUG_LOCKS_WARN_ON(1); + __raw_spin_unlock(&lockdep_lock); return 0; } @@ -487,7 +490,7 @@ static void print_lock_dependencies(struct lock_class *class, int depth) * Add a new dependency to the head of the list: */ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, - struct list_head *head, unsigned long ip) + struct list_head *head, unsigned long ip, int distance) { struct lock_list *entry; /* @@ -499,6 +502,7 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, return 0; entry->class = this; + entry->distance = distance; if (!save_trace(&entry->trace)) return 0; @@ -712,6 +716,9 @@ find_usage_backwards(struct lock_class *source, unsigned int depth) struct lock_list *entry; int ret; + if (!__raw_spin_is_locked(&lockdep_lock)) + return DEBUG_LOCKS_WARN_ON(1); + if (depth > max_recursion_depth) max_recursion_depth = depth; if (depth >= RECURSION_LIMIT) @@ -900,7 +907,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next, */ static int check_prev_add(struct task_struct *curr, struct held_lock *prev, - struct held_lock *next) + struct held_lock *next, int distance) { struct lock_list *entry; int ret; @@ -978,8 +985,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * L2 added to its dependency list, due to the first chain.) */ list_for_each_entry(entry, &prev->class->locks_after, entry) { - if (entry->class == next->class) + if (entry->class == next->class) { + if (distance == 1) + entry->distance = 1; return 2; + } } /* @@ -987,12 +997,13 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * to the previous lock's dependency list: */ ret = add_lock_to_list(prev->class, next->class, - &prev->class->locks_after, next->acquire_ip); + &prev->class->locks_after, next->acquire_ip, distance); + if (!ret) return 0; ret = add_lock_to_list(next->class, prev->class, - &next->class->locks_before, next->acquire_ip); + &next->class->locks_before, next->acquire_ip, distance); if (!ret) return 0; @@ -1040,13 +1051,14 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) goto out_bug; for (;;) { + int distance = curr->lockdep_depth - depth + 1; hlock = curr->held_locks + depth-1; /* * Only non-recursive-read entries get new dependencies * added: */ if (hlock->read != 2) { - if (!check_prev_add(curr, hlock, next)) + if (!check_prev_add(curr, hlock, next, distance)) return 0; /* * Stop after the first non-trylock entry, @@ -1293,7 +1305,8 @@ out_unlock_set: if (!subclass || force) lock->class_cache = class; - DEBUG_LOCKS_WARN_ON(class->subclass != subclass); + if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass)) + return NULL; return class; } @@ -1308,7 +1321,8 @@ static inline int lookup_chain_cache(u64 chain_key, struct lock_class *class) struct list_head *hash_head = chainhashentry(chain_key); struct lock_chain *chain; - DEBUG_LOCKS_WARN_ON(!irqs_disabled()); + if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) + return 0; /* * We can walk it lock-free, because entries only get added * to the hash: @@ -1394,7 +1408,9 @@ static void check_chain_key(struct task_struct *curr) return; } id = hlock->class - lock_classes; - DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS); + if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS)) + return; + if (prev_hlock && (prev_hlock->irq_context != hlock->irq_context)) chain_key = 0; @@ -2205,7 +2221,11 @@ out_calc_hash: if (!check_prevs_add(curr, hlock)) return 0; graph_unlock(); - } + } else + /* after lookup_chain_cache(): */ + if (unlikely(!debug_locks)) + return 0; + curr->lockdep_depth++; check_chain_key(curr); if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) { @@ -2214,6 +2234,7 @@ out_calc_hash: printk("turning off the locking correctness validator.\n"); return 0; } + if (unlikely(curr->lockdep_depth > max_lockdep_depth)) max_lockdep_depth = curr->lockdep_depth; @@ -2764,4 +2785,3 @@ void debug_show_held_locks(struct task_struct *task) } EXPORT_SYMBOL_GPL(debug_show_held_locks); - |