508 	int rv, cntr;  in wdm_read()  local
517 	cntr = READ_ONCE(desc->length);  in wdm_read()
518 	if (cntr == 0) {  in wdm_read()
583 		cntr = desc->length;  in wdm_read()
587 	if (cntr > count)  in wdm_read()
588 		cntr = count;  in wdm_read()
589 	rv = copy_to_user(buffer, desc->ubuf, cntr);  in wdm_read()
597 	for (i = 0; i < desc->length - cntr; i++)  in wdm_read()
598 		desc->ubuf[i] = desc->ubuf[i + cntr];  in wdm_read()
600 	desc->length -= cntr;  in wdm_read()
607 	rv = cntr;  in wdm_read()