#include <linux/ftrace.h>
#include <linux/stringify.h>
#include <linux/bitops.h>
+#include <linux/gfp.h>
#include <asm/sections.h>
unsigned long start = (unsigned long) &_stext,
end = (unsigned long) &_end,
addr = (unsigned long) obj;
-#ifdef CONFIG_SMP
- int i;
-#endif
/*
* static variable?
if (arch_is_kernel_data(addr))
return 1;
-#ifdef CONFIG_SMP
/*
- * percpu var?
+ * in-kernel percpu var?
*/
- for_each_possible_cpu(i) {
- start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
- end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
- + per_cpu_offset(i);
-
- if ((addr >= start) && (addr < end))
- return 1;
- }
-#endif
+ if (is_kernel_percpu_address(addr))
+ return 1;
/*
- * module var?
+ * module static or percpu var?
*/
- return is_module_address(addr);
+ return is_module_address(addr) || is_module_percpu_address(addr);
}
/*
* 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:
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: */
}
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:
return 0;
}
+ if (lock->key == &__lockdep_no_validate__)
+ check = 1;
+
if (!subclass)
class = lock->class_cache;
/*
{
unsigned long flags;
- trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
-
if (unlikely(current->lockdep_recursion))
return;
check_flags(flags);
current->lockdep_recursion = 1;
+ trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
__lock_acquire(lock, subclass, trylock, read, check,
irqs_disabled_flags(flags), nest_lock, ip, 0);
current->lockdep_recursion = 0;
{
unsigned long flags;
- trace_lock_release(lock, nested, ip);
-
if (unlikely(current->lockdep_recursion))
return;
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
+ 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) {
{
unsigned long flags;
- trace_lock_contended(lock, ip);
-
if (unlikely(!lock_stat))
return;
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
+ trace_lock_contended(lock, ip);
__lock_contended(lock, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
{
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");
printk("%s:%d invoked rcu_dereference_check() without protection!\n",
file, line);
printk("\nother info that might help us debug this:\n\n");
+ printk("\nrcu_scheduler_active = %d, debug_locks = %d\n", rcu_scheduler_active, debug_locks);
lockdep_print_held_locks(curr);
printk("\nstack backtrace:\n");
dump_stack();