BUF_LEN
char buffer[BUF_LEN];
pos += snprintf(buffer + pos, max_t(int, BUF_LEN - pos, 0), args)
BUG_ON(pos >= BUF_LEN - 1);
char buffer[BUF_LEN];
pos += snprintf(buffer + pos, max_t(int, BUF_LEN - pos, 0), args)
BUG_ON(pos >= BUF_LEN - 1);