1 files changed, 12 insertions, 7 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 2d616f4d853c..592c576d77a7 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -490,7 +490,7 @@ static void print_lock_dependencies(struct lock_class *class, int depth)
  * 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)
+                            struct list_head *head, unsigned long ip, int distance)
 {
         struct lock_list *entry;
         /*
@@ -502,6 +502,7 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
                 return 0;
 
         entry->class = this;
+        entry->distance = distance;
         if (!save_trace(&entry->trace))
                 return 0;
 
@@ -906,7 +907,7 @@ check_deadlock(struct task_struct *curr, struct held_lock *next,
  */
 static int
 check_prev_add(struct task_struct *curr, struct held_lock *prev,
-               struct held_lock *next)
+               struct held_lock *next, int distance)
 {
         struct lock_list *entry;
         int ret;
@@ -984,8 +985,11 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
          *  L2 added to its dependency list, due to the first chain.)
          */
         list_for_each_entry(entry, &prev->class->locks_after, entry) {
-                if (entry->class == next->class)
+                if (entry->class == next->class) {
+                        if (distance == 1)
+                                entry->distance = 1;
                         return 2;
+                }
         }
 
         /*
@@ -993,12 +997,13 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev,
          * to the previous lock's dependency list:
          */
         ret = add_lock_to_list(prev->class, next->class,
-                               &prev->class->locks_after, next->acquire_ip);
+                               &prev->class->locks_after, next->acquire_ip, distance);
+
         if (!ret)
                 return 0;
 
         ret = add_lock_to_list(next->class, prev->class,
-                               &next->class->locks_before, next->acquire_ip);
+                               &next->class->locks_before, next->acquire_ip, distance);
         if (!ret)
                 return 0;
 
@@ -1046,13 +1051,14 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
                 goto out_bug;
 
         for (;;) {
+                int distance = curr->lockdep_depth - depth + 1;
                 hlock = curr->held_locks + depth-1;
                 /*
                  * Only non-recursive-read entries get new dependencies
                  * added:
                  */
                 if (hlock->read != 2) {
-                        if (!check_prev_add(curr, hlock, next))
+                        if (!check_prev_add(curr, hlock, next, distance))
                                 return 0;
                         /*
                          * Stop after the first non-trylock entry,
@@ -2779,4 +2785,3 @@ void debug_show_held_locks(struct task_struct *task)
 }
 
 EXPORT_SYMBOL_GPL(debug_show_held_locks);
-