From: Ben Greear <greearb@candelatech.com>
Date: Wed, 6 Feb 2013 18:56:19 +0000 (-0800)
Subject: lockdep: Print more info when MAX_LOCK_DEPTH is exceeded
X-Git-Tag: upstream/snapshot3+hdmi~5673^2~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c0540606837af79b2ae101e5e7b2206e3844d150;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

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 5cf12e7..8a0efac 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;
 	}