[PATCH] lockdep: annotate on-stack completions

lockdep needs to have the waitqueue lock initialized for on-stack waitqueues
implicitly initialized by DECLARE_COMPLETION(). Annotate on-stack completions
accordingly.

Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/x86_64/kernel/smpboot.c

···
 	};
 	DECLARE_WORK(work, do_fork_idle, &c_idle);
 
+	lockdep_set_class(&c_idle.done.wait.lock, &waitqueue_lock_key);
+
 	/* allocate memory for gdts of secondary cpus. Hotplug is considered */
 	if (!cpu_gdt_descr[cpu].address &&
 		!(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) {

block/ll_rw_blk.c

···
 int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
 		   struct request *rq, int at_head)
 {
-	DECLARE_COMPLETION(wait);
+	DECLARE_COMPLETION_ONSTACK(wait);
 	char sense[SCSI_SENSE_BUFFERSIZE];
 	int err = 0;
 

drivers/ide/ide-io.c

···
 {
 	unsigned long flags;
 	ide_hwgroup_t *hwgroup = HWGROUP(drive);
-	DECLARE_COMPLETION(wait);
+	DECLARE_COMPLETION_ONSTACK(wait);
 	int where = ELEVATOR_INSERT_BACK, err;
 	int must_wait = (action == ide_wait || action == ide_head_wait);
 

drivers/scsi/libata-core.c

···
 	struct ata_queued_cmd *qc;
 	unsigned int tag, preempted_tag;
 	u32 preempted_sactive, preempted_qc_active;
-	DECLARE_COMPLETION(wait);
+	DECLARE_COMPLETION_ONSTACK(wait);
 	unsigned long flags;
 	unsigned int err_mask;
 	int rc;

drivers/spi/spi.c

···
  */
 int spi_sync(struct spi_device *spi, struct spi_message *message)
 {
-	DECLARE_COMPLETION(done);
+	DECLARE_COMPLETION_ONSTACK(done);
 	int status;
 
 	message->complete = spi_complete;

kernel/kmod.c

···
 int call_usermodehelper_keys(char *path, char **argv, char **envp,
 			     struct key *session_keyring, int wait)
 {
-	DECLARE_COMPLETION(done);
+	DECLARE_COMPLETION_ONSTACK(done);
 	struct subprocess_info sub_info = {
 		.complete	= &done,
 		.path		= path,