Index: sys/cam/cam_ccb.h
===================================================================
--- sys/cam/cam_ccb.h
+++ sys/cam/cam_ccb.h
@@ -62,6 +62,9 @@
 /* CCB memory allocation flags */
 typedef enum {
 	CAM_CCB_FROM_UMA	= 0x00000001,/* CCB from a periph UMA zone */
+	CAM_CCB_FROM_STACK	= 0x00000002,/* CCB lives on the stack */
+	CAM_CCB_FROM_MALLOC	= 0x00000004,/* CCB Obtained from malloc */
+	CAM_CCB_FROM_MASK	= 0x00000007,/* Mask of all CCB from types */
 } ccb_alloc_flags;
 
 /* CAM CCB flags */
Index: sys/cam/cam_xpt.h
===================================================================
--- sys/cam/cam_xpt.h
+++ sys/cam/cam_xpt.h
@@ -85,6 +85,10 @@
 void			xpt_setup_ccb(struct ccb_hdr *ccb_h,
 				      struct cam_path *path,
 				      u_int32_t priority);
+void			xpt_setup_stack_ccb(struct ccb_hdr *ccb_h,
+					    size_t len,
+					    struct cam_path *path,
+					    u_int32_t priority);
 void			xpt_merge_ccb(union ccb *dst_ccb,
 				      union ccb *src_ccb);
 cam_status		xpt_create_path(struct cam_path **new_path_ptr,
Index: sys/cam/cam_xpt.c
===================================================================
--- sys/cam/cam_xpt.c
+++ sys/cam/cam_xpt.c
@@ -3556,6 +3556,8 @@
 {
 
 	CAM_DEBUG(path, CAM_DEBUG_TRACE, ("xpt_setup_ccb\n"));
+	KASSERT((ccb_h->alloc_flags & CAM_CCB_FROM_MASK) != 0,
+	    ("CCB alloc mask not set."));
 	ccb_h->pinfo.priority = priority;
 	ccb_h->path = path;
 	ccb_h->path_id = path->bus->path_id;
@@ -3580,6 +3582,15 @@
 	xpt_setup_ccb_flags(ccb_h, path, priority, /*flags*/ 0);
 }
 
+void
+xpt_setup_stack_ccb(struct ccb_hdr *ccb_h, size_t len, struct cam_path *path,
+    u_int32_t priority)
+{
+	memset(ccb_h, 0, len);
+	ccb_h->alloc_flags |= CAM_CCB_FROM_STACK;
+	xpt_setup_ccb_flags(ccb_h, path, priority, 0);
+}
+
 /* Path manipulation functions */
 cam_status
 xpt_create_path(struct cam_path **new_path_ptr, struct cam_periph *perph,
@@ -4678,6 +4689,7 @@
 	union ccb *new_ccb;
 
 	new_ccb = malloc(sizeof(*new_ccb), M_CAMCCB, M_ZERO|M_WAITOK);
+	new_ccb->alloc_flags |= CAM_CCB_FROM_MALLOC;
 	return (new_ccb);
 }
 
@@ -4687,6 +4699,8 @@
 	union ccb *new_ccb;
 
 	new_ccb = malloc(sizeof(*new_ccb), M_CAMCCB, M_ZERO|M_NOWAIT);
+	if (new_ccb != NULL)
+		new_ccb->alloc_flags |= CAM_CCB_FROM_MALLOC;
 	return (new_ccb);
 }
 
Index: sys/cam/scsi/scsi_da.c
===================================================================
--- sys/cam/scsi/scsi_da.c
+++ sys/cam/scsi/scsi_da.c
@@ -1931,9 +1931,9 @@
 	if ((softc->flags & DA_FLAG_PACK_INVALID) != 0)
 		return (ENXIO);
 
-	memset(&csio, 0, sizeof(csio));
 	if (length > 0) {
-		xpt_setup_ccb(&csio.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_stack_ccb(&csio.ccb_h, sizeof(csio), periph->path,
+		    CAM_PRIORITY_NORMAL);
 		csio.ccb_h.ccb_state = DA_CCB_DUMP;
 		scsi_read_write(&csio,
 				/*retries*/0,
@@ -1959,7 +1959,8 @@
 	 * Sync the disk cache contents to the physical media.
 	 */
 	if ((softc->quirks & DA_Q_NO_SYNC_CACHE) == 0) {
-		xpt_setup_ccb(&csio.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_stack_ccb(&csio.ccb_h, sizeof(csio), periph->path,
+		    CAM_PRIORITY_NORMAL);
 		csio.ccb_h.ccb_state = DA_CCB_DUMP;
 		scsi_synchronize_cache(&csio,
 				       /*retries*/0,
@@ -2373,8 +2374,8 @@
 	/*
 	 * Add some addressing info.
 	 */
-	memset(&cts, 0, sizeof (cts));
-	xpt_setup_ccb(&cts.ccb_h, periph->path, CAM_PRIORITY_NONE);
+	xpt_setup_stack_ccb(&cts.ccb_h, sizeof(cts), periph->path,
+	    CAM_PRIORITY_NONE);
 	cts.ccb_h.func_code = XPT_GET_TRAN_SETTINGS;
 	cts.type = CTS_TYPE_CURRENT_SETTINGS;
 	cam_periph_lock(periph);
@@ -4897,9 +4898,8 @@
 						 /*timeout*/0,
 						 /*getcount_only*/0);
 
-			memset(&cgd, 0, sizeof(cgd));
-			xpt_setup_ccb(&cgd.ccb_h, done_ccb->ccb_h.path,
-				      CAM_PRIORITY_NORMAL);
+			xpt_setup_stack_ccb(&cgd.ccb_h, sizeof(cgd),
+			    done_ccb->ccb_h.path, CAM_PRIORITY_NORMAL);
 			cgd.ccb_h.func_code = XPT_GDEV_TYPE;
 			xpt_action((union ccb *)&cgd);
 
@@ -6144,8 +6144,8 @@
 	 * up with something that will make this a bootable
 	 * device.
 	 */
-	memset(&ccg, 0, sizeof(ccg));
-	xpt_setup_ccb(&ccg.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+	xpt_setup_stack_ccb(&ccg.ccb_h, sizeof(ccg), periph->path,
+	    CAM_PRIORITY_NORMAL);
 	ccg.ccb_h.func_code = XPT_CALC_GEOMETRY;
 	ccg.block_size = dp->secsize;
 	ccg.volume_size = dp->sectors;
@@ -6182,8 +6182,8 @@
 		  min(sizeof(softc->rcaplong), rcap_len)) != 0)) {
 		struct ccb_dev_advinfo cdai;
 
-		memset(&cdai, 0, sizeof(cdai));
-		xpt_setup_ccb(&cdai.ccb_h, periph->path, CAM_PRIORITY_NORMAL);
+		xpt_setup_stack_ccb(&cdai.ccb_h, sizeof(cdai), periph->path,
+		    CAM_PRIORITY_NORMAL);
 		cdai.ccb_h.func_code = XPT_DEV_ADVINFO;
 		cdai.buftype = CDAI_TYPE_RCAPLONG;
 		cdai.flags = CDAI_FLAG_STORE;