[PATCH] lockdep: annotate DECLARE_WAIT_QUEUE_HEAD

kernel: INFO: trying to register non-static key.
kernel: the code is fine but needs lockdep annotation.
kernel: turning off the locking correctness validator.
kernel:  [<c04051ed>] show_trace_log_lvl+0x58/0x16a
kernel:  [<c04057fa>] show_trace+0xd/0x10
kernel:  [<c0405913>] dump_stack+0x19/0x1b
kernel:  [<c043b1e2>] __lock_acquire+0xf0/0x90d
kernel:  [<c043bf70>] lock_acquire+0x4b/0x6b
kernel:  [<c061472f>] _spin_lock_irqsave+0x22/0x32
kernel:  [<c04363d3>] prepare_to_wait+0x17/0x4b
kernel:  [<f89a24b6>] lpfc_do_work+0xdd/0xcc2 [lpfc]
kernel:  [<c04361b9>] kthread+0xc3/0xf2
kernel:  [<c0402005>] kernel_thread_helper+0x5/0xb

Another case of non-static lockdep keys; duplicate the paradigm set by
DECLARE_COMPLETION_ONSTACK and introduce DECLARE_WAIT_QUEUE_HEAD_ONSTACK.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg KH <gregkh@suse.de>
Cc: Markus Lidel <markus.lidel@shadowconnect.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/wait.h b/include/linux/wait.h
index b3b9048421d8..e820d00e1383 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -79,6 +79,15 @@ struct task_struct;
 
 extern void init_waitqueue_head(wait_queue_head_t *q);
 
+#ifdef CONFIG_LOCKDEP
+# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
+        ({ init_waitqueue_head(&name); name; })
+# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
+        wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
+#else
+# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
+#endif
+
 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
 {
         q->flags = 0;