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>

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 5cf12e791603a58a54d0f4f9cd762543eaf687dc..8a0efac4f99de7c5d0711bea6792db1f385f66eb 100644 (file)
--- 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;
        }