static inline u64 lockstat_clock(void)
{
- return cpu_clock(smp_processor_id());
+ return local_clock();
}
static int lock_point(unsigned long points[], unsigned long ip)
}
#endif
+ if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+ debug_locks_off();
+ printk(KERN_ERR
+ "BUG: looking up invalid subclass: %u\n", subclass);
+ printk(KERN_ERR
+ "turning off the locking correctness validator.\n");
+ dump_stack();
+ return NULL;
+ }
+
/*
* Static locks do not have their class-keys yet - for them the key
* is the lock object itself:
raw_local_irq_restore(flags);
if (!subclass || force)
- lock->class_cache = class;
+ lock->class_cache[0] = class;
+ else if (subclass < NR_LOCKDEP_CACHING_CLASSES)
+ lock->class_cache[subclass] = class;
if (DEBUG_LOCKS_WARN_ON(class->subclass != subclass))
return NULL;
* 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, int distance)
+ struct list_head *head, unsigned long ip,
+ int distance, struct stack_trace *trace)
{
struct lock_list *entry;
/*
if (!entry)
return 0;
- if (!save_trace(&entry->trace))
- return 0;
-
entry->class = this;
entry->distance = distance;
+ entry->trace = *trace;
/*
* Since we never remove from the dependency list, the list can
* be walked lockless by other CPUs, it's only allocation
*/
static int
check_prev_add(struct task_struct *curr, struct held_lock *prev,
- struct held_lock *next, int distance)
+ struct held_lock *next, int distance, int trylock_loop)
{
struct lock_list *entry;
int ret;
struct lock_list this;
struct lock_list *uninitialized_var(target_entry);
+ /*
+ * Static variable, serialized by the graph_lock().
+ *
+ * We use this static variable to save the stack trace in case
+ * we call into this function multiple times due to encountering
+ * trylocks in the held lock stack.
+ */
+ static struct stack_trace trace;
/*
* Prove that the new <prev> -> <next> dependency would not
}
}
+ if (!trylock_loop && !save_trace(&trace))
+ return 0;
+
/*
* Ok, all validations passed, add the new lock
* to the previous lock's dependency list:
*/
ret = add_lock_to_list(hlock_class(prev), hlock_class(next),
&hlock_class(prev)->locks_after,
- next->acquire_ip, distance);
+ next->acquire_ip, distance, &trace);
if (!ret)
return 0;
ret = add_lock_to_list(hlock_class(next), hlock_class(prev),
&hlock_class(next)->locks_before,
- next->acquire_ip, distance);
+ next->acquire_ip, distance, &trace);
if (!ret)
return 0;
check_prevs_add(struct task_struct *curr, struct held_lock *next)
{
int depth = curr->lockdep_depth;
+ int trylock_loop = 0;
struct held_lock *hlock;
/*
* added:
*/
if (hlock->read != 2) {
- if (!check_prev_add(curr, hlock, next, distance))
+ if (!check_prev_add(curr, hlock, next,
+ distance, trylock_loop))
return 0;
/*
* Stop after the first non-trylock entry,
if (curr->held_locks[depth].irq_context !=
curr->held_locks[depth-1].irq_context)
break;
+ trylock_loop = 1;
}
return 1;
out_bug:
}
/*
- * Debugging helper: via this flag we know that we are in
- * 'early bootup code', and will warn about any invalid irqs-on event:
- */
-static int early_boot_irqs_enabled;
-
-void early_boot_irqs_off(void)
-{
- early_boot_irqs_enabled = 0;
-}
-
-void early_boot_irqs_on(void)
-{
- early_boot_irqs_enabled = 1;
-}
-
-/*
* Hardirqs will be enabled:
*/
void trace_hardirqs_on_caller(unsigned long ip)
if (unlikely(!debug_locks || current->lockdep_recursion))
return;
- if (DEBUG_LOCKS_WARN_ON(unlikely(!early_boot_irqs_enabled)))
+ if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
return;
if (unlikely(curr->hardirqs_enabled)) {
- debug_atomic_inc(redundant_hardirqs_on);
+ /*
+ * Neither irq nor preemption are disabled here
+ * so this is racy by nature but loosing one hit
+ * in a stat is not a big deal.
+ */
+ __debug_atomic_inc(redundant_hardirqs_on);
return;
}
/* we'll do an OFF -> ON transition: */
void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key *key, int subclass)
{
- lock->class_cache = NULL;
+ int i;
+
+ for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
+ lock->class_cache[i] = NULL;
+
#ifdef CONFIG_LOCK_STAT
lock->cpu = raw_smp_processor_id();
#endif
}
EXPORT_SYMBOL_GPL(lockdep_init_map);
+struct lock_class_key __lockdep_no_validate__;
+
/*
* This gets called for every mutex_lock*()/spin_lock*() operation.
* We maintain the dependency maps and validate the locking attempt:
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
- if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
- debug_locks_off();
- printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
- printk("turning off the locking correctness validator.\n");
- dump_stack();
- return 0;
- }
+ if (lock->key == &__lockdep_no_validate__)
+ check = 1;
- if (!subclass)
- class = lock->class_cache;
+ if (subclass < NR_LOCKDEP_CACHING_CLASSES)
+ class = lock->class_cache[subclass];
/*
- * Not cached yet or subclass?
+ * Not cached?
*/
if (unlikely(!class)) {
class = register_lock_class(lock, subclass, 0);
return 1;
if (hlock->references) {
- struct lock_class *class = lock->class_cache;
+ struct lock_class *class = lock->class_cache[0];
if (!class)
class = look_up_lock_class(lock, 0);
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
- trace_lock_release(lock, nested, ip);
+ trace_lock_release(lock, ip);
__lock_release(lock, nested, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
hlock->holdtime_stamp = now;
}
- trace_lock_acquired(lock, ip, waittime);
+ trace_lock_acquired(lock, ip);
stats = get_lock_stats(hlock_class(hlock));
if (waittime) {
if (list_empty(head))
continue;
list_for_each_entry_safe(class, next, head, hash_entry) {
- if (unlikely(class == lock->class_cache)) {
+ int match = 0;
+
+ for (j = 0; j < NR_LOCKDEP_CACHING_CLASSES; j++)
+ match |= class == lock->class_cache[j];
+
+ if (unlikely(match)) {
if (debug_locks_off_graph_unlock())
WARN_ON(1);
goto out_restore;
* Careful: only use this function if you are sure that
* the task cannot run in parallel!
*/
-void __debug_show_held_locks(struct task_struct *task)
+void debug_show_held_locks(struct task_struct *task)
{
if (unlikely(!debug_locks)) {
printk("INFO: lockdep is turned off.\n");
}
lockdep_print_held_locks(task);
}
-EXPORT_SYMBOL_GPL(__debug_show_held_locks);
-
-void debug_show_held_locks(struct task_struct *task)
-{
- __debug_show_held_locks(task);
-}
EXPORT_SYMBOL_GPL(debug_show_held_locks);
void lockdep_sys_exit(void)
{
struct task_struct *curr = current;
+#ifndef CONFIG_PROVE_RCU_REPEATEDLY
if (!debug_locks_off())
return;
+#endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */
+ /* Note: the following can be executed concurrently, so be careful. */
printk("\n===================================================\n");
printk( "[ INFO: suspicious rcu_dereference_check() usage. ]\n");
printk( "---------------------------------------------------\n");
projects / linux-flexiantxendom0-natty.git / blobdiff