diff options
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 52 |
1 files changed, 28 insertions, 24 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index c9fefdb1a7d..b02032476dc 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -140,13 +140,6 @@ void lockdep_on(void) EXPORT_SYMBOL(lockdep_on); -int lockdep_internal(void) -{ - return current->lockdep_recursion != 0; -} - -EXPORT_SYMBOL(lockdep_internal); - /* * Debugging switches: */ @@ -228,17 +221,15 @@ static int save_trace(struct stack_trace *trace) trace->skip = 3; trace->all_contexts = 0; - /* Make sure to not recurse in case the the unwinder needs to tak -e locks. */ - lockdep_off(); save_stack_trace(trace, NULL); - lockdep_on(); trace->max_entries = trace->nr_entries; nr_stack_trace_entries += trace->nr_entries; - if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES)) + if (DEBUG_LOCKS_WARN_ON(nr_stack_trace_entries > MAX_STACK_TRACE_ENTRIES)) { + __raw_spin_unlock(&hash_lock); return 0; + } if (nr_stack_trace_entries == MAX_STACK_TRACE_ENTRIES) { __raw_spin_unlock(&hash_lock); @@ -357,7 +348,7 @@ get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4 static void print_lock_name(struct lock_class *class) { - char str[128], c1, c2, c3, c4; + char str[KSYM_NAME_LEN + 1], c1, c2, c3, c4; const char *name; get_usage_chars(class, &c1, &c2, &c3, &c4); @@ -379,7 +370,7 @@ static void print_lock_name(struct lock_class *class) static void print_lockdep_cache(struct lockdep_map *lock) { const char *name; - char str[128]; + char str[KSYM_NAME_LEN + 1]; name = lock->name; if (!name) @@ -449,7 +440,9 @@ static void print_lock_dependencies(struct lock_class *class, int depth) print_lock_class_header(class, depth); list_for_each_entry(entry, &class->locks_after, entry) { - DEBUG_LOCKS_WARN_ON(!entry->class); + if (DEBUG_LOCKS_WARN_ON(!entry->class)) + return; + print_lock_dependencies(entry->class, depth + 1); printk("%*s ... acquired at:\n",depth,""); @@ -474,7 +467,8 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this, return 0; entry->class = this; - save_trace(&entry->trace); + if (!save_trace(&entry->trace)) + return 0; /* * Since we never remove from the dependency list, the list can @@ -562,8 +556,12 @@ static noinline int print_circular_bug_tail(void) if (debug_locks_silent) return 0; + /* hash_lock unlocked by the header */ + __raw_spin_lock(&hash_lock); this.class = check_source->class; - save_trace(&this.trace); + if (!save_trace(&this.trace)) + return 0; + __raw_spin_unlock(&hash_lock); print_circular_bug_entry(&this, 0); printk("\nother info that might help us debug this:\n\n"); @@ -966,14 +964,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, &prev->class->locks_after, next->acquire_ip); if (!ret) return 0; - /* - * Return value of 2 signals 'dependency already added', - * in that case we dont have to add the backlink either. - */ - if (ret == 2) - return 2; + ret = add_lock_to_list(next->class, prev->class, &next->class->locks_before, next->acquire_ip); + if (!ret) + return 0; /* * Debugging printouts: @@ -1025,7 +1020,8 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next) * added: */ if (hlock->read != 2) { - check_prev_add(curr, hlock, next); + if (!check_prev_add(curr, hlock, next)) + return 0; /* * Stop after the first non-trylock entry, * as non-trylock entries have added their @@ -1182,6 +1178,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) struct lockdep_subclass_key *key; struct list_head *hash_head; struct lock_class *class; + unsigned long flags; class = look_up_lock_class(lock, subclass); if (likely(class)) @@ -1203,6 +1200,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) key = lock->key->subkeys + subclass; hash_head = classhashentry(key); + raw_local_irq_save(flags); __raw_spin_lock(&hash_lock); /* * We have to do the hash-walk again, to avoid races @@ -1217,6 +1215,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) */ if (nr_lock_classes >= MAX_LOCKDEP_KEYS) { __raw_spin_unlock(&hash_lock); + raw_local_irq_restore(flags); debug_locks_off(); printk("BUG: MAX_LOCKDEP_KEYS too low!\n"); printk("turning off the locking correctness validator.\n"); @@ -1239,15 +1238,18 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force) if (verbose(class)) { __raw_spin_unlock(&hash_lock); + raw_local_irq_restore(flags); printk("\nnew class %p: %s", class->key, class->name); if (class->name_version > 1) printk("#%d", class->name_version); printk("\n"); dump_stack(); + raw_local_irq_save(flags); __raw_spin_lock(&hash_lock); } out_unlock_set: __raw_spin_unlock(&hash_lock); + raw_local_irq_restore(flags); if (!subclass || force) lock->class_cache = class; @@ -1728,6 +1730,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, debug_atomic_dec(&nr_unused_locks); break; default: + __raw_spin_unlock(&hash_lock); debug_locks_off(); WARN_ON(1); return 0; @@ -2645,6 +2648,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len) } local_irq_restore(flags); } +EXPORT_SYMBOL_GPL(debug_check_no_locks_freed); static void print_held_locks_bug(struct task_struct *curr) { |