[PATCH] lockdep: clean up VERY_VERBOSE define
[pandora-kernel.git] / kernel / lockdep.c
index e596525..c4ffd3c 100644 (file)
@@ -140,21 +140,12 @@ void lockdep_on(void)
 
 EXPORT_SYMBOL(lockdep_on);
 
-int lockdep_internal(void)
-{
-       return current->lockdep_recursion != 0;
-}
-
-EXPORT_SYMBOL(lockdep_internal);
-
 /*
  * Debugging switches:
  */
 
 #define VERBOSE                        0
-#ifdef VERBOSE
-# define VERY_VERBOSE          0
-#endif
+#define VERY_VERBOSE           0
 
 #if VERBOSE
 # define HARDIRQ_VERBOSE       1
@@ -179,8 +170,8 @@ static int class_filter(struct lock_class *class)
                        !strcmp(class->name, "&struct->lockfield"))
                return 1;
 #endif
-       /* Allow everything else. 0 would be filter everything else */
-       return 1;
+       /* Filter everything else. 1 would be to allow everything else */
+       return 0;
 }
 #endif
 
@@ -228,17 +219,15 @@ 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 +346,7 @@ 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 +368,7 @@ 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 +438,9 @@ 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 +465,8 @@ 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
@@ -518,9 +510,9 @@ print_circular_bug_entry(struct lock_list *target, unsigned int depth)
 
 static void print_kernel_version(void)
 {
-       printk("%s %.*s\n", system_utsname.release,
-               (int)strcspn(system_utsname.version, " "),
-               system_utsname.version);
+       printk("%s %.*s\n", init_utsname()->release,
+               (int)strcspn(init_utsname()->version, " "),
+               init_utsname()->version);
 }
 
 /*
@@ -562,8 +554,12 @@ 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");
@@ -575,6 +571,8 @@ static noinline int print_circular_bug_tail(void)
        return 0;
 }
 
+#define RECURSION_LIMIT 40
+
 static int noinline print_infinite_recursion_bug(void)
 {
        __raw_spin_unlock(&hash_lock);
@@ -595,7 +593,7 @@ check_noncircular(struct lock_class *source, unsigned int depth)
        debug_atomic_inc(&nr_cyclic_check_recursions);
        if (depth > max_recursion_depth)
                max_recursion_depth = depth;
-       if (depth >= 20)
+       if (depth >= RECURSION_LIMIT)
                return print_infinite_recursion_bug();
        /*
         * Check this lock's dependency list:
@@ -645,7 +643,7 @@ find_usage_forwards(struct lock_class *source, unsigned int depth)
 
        if (depth > max_recursion_depth)
                max_recursion_depth = depth;
-       if (depth >= 20)
+       if (depth >= RECURSION_LIMIT)
                return print_infinite_recursion_bug();
 
        debug_atomic_inc(&nr_find_usage_forwards_checks);
@@ -684,7 +682,7 @@ find_usage_backwards(struct lock_class *source, unsigned int depth)
 
        if (depth > max_recursion_depth)
                max_recursion_depth = depth;
-       if (depth >= 20)
+       if (depth >= RECURSION_LIMIT)
                return print_infinite_recursion_bug();
 
        debug_atomic_inc(&nr_find_usage_backwards_checks);
@@ -964,14 +962,11 @@ 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:
@@ -1023,7 +1018,8 @@ 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
@@ -1079,7 +1075,8 @@ static int static_obj(void *obj)
         */
        for_each_possible_cpu(i) {
                start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
-               end   = (unsigned long) &__per_cpu_end   + per_cpu_offset(i);
+               end   = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
+                                       + per_cpu_offset(i);
 
                if ((addr >= start) && (addr < end))
                        return 1;
@@ -1114,8 +1111,6 @@ static int count_matching_names(struct lock_class *new_class)
        return count + 1;
 }
 
-extern void __error_too_big_MAX_LOCKDEP_SUBCLASSES(void);
-
 /*
  * Register a lock's class in the hash-table, if the class is not present
  * yet. Otherwise we look it up. We cache the result in the lock object
@@ -1153,8 +1148,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
         * (or spin_lock_init()) call - which acts as the key. For static
         * locks we use the lock object itself as the key.
         */
-       if (sizeof(struct lock_class_key) > sizeof(struct lock_class))
-               __error_too_big_MAX_LOCKDEP_SUBCLASSES();
+       BUILD_BUG_ON(sizeof(struct lock_class_key) > sizeof(struct lock_class));
 
        key = lock->key->subkeys + subclass;
 
@@ -1177,11 +1171,12 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
  * itself, so actual lookup of the hash should be once per lock object.
  */
 static inline struct lock_class *
-register_lock_class(struct lockdep_map *lock, unsigned int subclass)
+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 +1198,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
        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 +1213,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
         */
        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");
@@ -1239,17 +1236,20 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
 
        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)
+       if (!subclass || force)
                lock->class_cache = class;
 
        DEBUG_LOCKS_WARN_ON(class->subclass != subclass);
@@ -1262,7 +1262,7 @@ out_unlock_set:
  * add it and return 0 - in this case the new dependency chain is
  * validated. If the key is already hashed, return 1.
  */
-static inline int lookup_chain_cache(u64 chain_key)
+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;
@@ -1284,9 +1284,13 @@ cache_hit:
                        __raw_spin_lock(&hash_lock);
                        return 1;
 #endif
+                       if (very_verbose(class))
+                               printk("\nhash chain already cached, key: %016Lx tail class: [%p] %s\n", chain_key, class->key, class->name);
                        return 0;
                }
        }
+       if (very_verbose(class))
+               printk("\nnew hash chain, key: %016Lx tail class: [%p] %s\n", chain_key, class->key, class->name);
        /*
         * Allocate a new chain entry from the static array, and add
         * it to the hash:
@@ -1728,6 +1732,7 @@ 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;
@@ -1937,7 +1942,7 @@ void trace_softirqs_off(unsigned long ip)
  * Initialize a lock instance's lock-class mapping info:
  */
 void lockdep_init_map(struct lockdep_map *lock, const char *name,
-                     struct lock_class_key *key)
+                     struct lock_class_key *key, int subclass)
 {
        if (unlikely(!debug_locks))
                return;
@@ -1957,6 +1962,8 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
        lock->name = name;
        lock->key = key;
        lock->class_cache = NULL;
+       if (subclass)
+               register_lock_class(lock, subclass, 1);
 }
 
 EXPORT_SYMBOL_GPL(lockdep_init_map);
@@ -1995,7 +2002,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         * Not cached yet or subclass?
         */
        if (unlikely(!class)) {
-               class = register_lock_class(lock, subclass);
+               class = register_lock_class(lock, subclass, 0);
                if (!class)
                        return 0;
        }
@@ -2134,7 +2141,7 @@ out_calc_hash:
         * (If lookup_chain_cache() returns with 1 it acquires
         * hash_lock for us)
         */
-       if (!trylock && (check == 2) && lookup_chain_cache(chain_key)) {
+       if (!trylock && (check == 2) && lookup_chain_cache(chain_key, class)) {
                /*
                 * Check whether last held lock:
                 *
@@ -2428,6 +2435,7 @@ EXPORT_SYMBOL_GPL(lock_release);
 void lockdep_reset(void)
 {
        unsigned long flags;
+       int i;
 
        raw_local_irq_save(flags);
        current->curr_chain_key = 0;
@@ -2438,6 +2446,8 @@ void lockdep_reset(void)
        nr_softirq_chains = 0;
        nr_process_chains = 0;
        debug_locks = 1;
+       for (i = 0; i < CHAINHASH_SIZE; i++)
+               INIT_LIST_HEAD(chainhash_table + i);
        raw_local_irq_restore(flags);
 }
 
@@ -2643,6 +2653,7 @@ 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)
 {