[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>
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 @@
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);
