From d5abe669172f20a4129a711de0f250a4e07db298 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Wed, 6 Dec 2006 20:37:26 -0800
Subject: [PATCH] debug: workqueue locking sanity

Workqueue functions should not leak locks, assert so, printing the
last function ran.

Use macros in lockdep.h to avoid include dependency pains.

[akpm@osdl.org: build fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 kernel/workqueue.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'kernel/workqueue.c')

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 2945b09..5484d6e 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -30,6 +30,8 @@
 #include <linux/hardirq.h>
 #include <linux/mempolicy.h>
 #include <linux/freezer.h>
+#include <linux/kallsyms.h>
+#include <linux/debug_locks.h>
 
 /*
  * The per-CPU workqueue (if single thread, we always use the first
@@ -253,6 +255,17 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
 			work_release(work);
 		f(work);
 
+		if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
+			printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
+					"%s/0x%08x/%d\n",
+					current->comm, preempt_count(),
+				       	current->pid);
+			printk(KERN_ERR "    last function: ");
+			print_symbol("%s\n", (unsigned long)f);
+			debug_show_held_locks(current);
+			dump_stack();
+		}
+
 		spin_lock_irqsave(&cwq->lock, flags);
 		cwq->remove_sequence++;
 		wake_up(&cwq->work_done);
-- 
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