fread_tail
static int fread_tail(void *, size_t, size_t);
if (fread_tail(&ktr_header, sizeof(struct ktr_header), 1) == 0 ||
while (fread_tail(&ktr_header, sizeof(struct ktr_header), 1)) {
if (ktrlen && fread_tail(m, ktrlen, 1) == 0)