lockdep: Print more info when MAX_LOCK_DEPTH is exceeded

This helps debug cases where a lock is acquired over and
over without being released.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1360176979-4421-1-git-send-email-greearb@candelatech.com
[ Changed the printout ordering. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 5cf12e791603..8a0efac4f99d 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3190,9 +3190,14 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 #endif
         if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
                 debug_locks_off();
-                printk("BUG: MAX_LOCK_DEPTH too low!\n");
+                printk("BUG: MAX_LOCK_DEPTH too low, depth: %i  max: %lu!\n",
+                       curr->lockdep_depth, MAX_LOCK_DEPTH);
                 printk("turning off the locking correctness validator.\n");
+
+                lockdep_print_held_locks(current);
+                debug_show_all_locks();
                 dump_stack();
+
                 return 0;
         }