ide-cd: use the new object_is_in_stack() helper

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-cd.c

@@ -1164,13 +1164,12 @@ static void cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
 	if (rq->bio || ((rq->cmd_type == REQ_TYPE_ATA_PC) && rq->data_len)) {
 		struct request_queue *q = drive->queue;
 		unsigned int alignment;
-		unsigned long addr;
-		unsigned long stack_mask = ~(THREAD_SIZE - 1);
+		char *buf;
 
 		if (rq->bio)
-			addr = (unsigned long)bio_data(rq->bio);
+			buf = bio_data(rq->bio);
 		else
-			addr = (unsigned long)rq->data;
+			buf = rq->data;
 
 		info->dma = drive->using_dma;
 
@@ -1181,11 +1180,8 @@ static void cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
 		 * separate masks.
 		 */
 		alignment = queue_dma_alignment(q) | q->dma_pad_mask;
-		if (addr & alignment || rq->data_len & alignment)
-			info->dma = 0;
-
-		if (!((addr & stack_mask) ^
-		      ((unsigned long)current->stack & stack_mask)))
+		if ((unsigned long)buf & alignment || rq->data_len & alignment
+		    || object_is_on_stack(buf))
 			info->dma = 0;
 	}
 }