1 files changed, 22 insertions, 6 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index c62ec14609b9..c927a549db2c 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3211,8 +3211,6 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 {
         unsigned long flags;
 
-        trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
-
         if (unlikely(current->lockdep_recursion))
                 return;
 
@@ -3220,6 +3218,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
         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;
@@ -3232,14 +3231,13 @@ void lock_release(struct lockdep_map *lock, int nested,
 {
         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, nested, ip);
         __lock_release(lock, nested, ip);
         current->lockdep_recursion = 0;
         raw_local_irq_restore(flags);
@@ -3413,8 +3411,6 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
 {
         unsigned long flags;
 
-        trace_lock_contended(lock, ip);
-
         if (unlikely(!lock_stat))
                 return;
 
@@ -3424,6 +3420,7 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
         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);
@@ -3809,3 +3806,22 @@ void lockdep_sys_exit(void)
                 lockdep_print_held_locks(curr);
         }
 }
+
+void lockdep_rcu_dereference(const char *file, const int line)
+{
+        struct task_struct *curr = current;
+
+        if (!debug_locks_off())
+                return;
+        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();
+}
+EXPORT_SYMBOL_GPL(lockdep_rcu_dereference);