os_read_file
err = os_read_file(state->fd, kbuf, count);
ret = os_read_file(random_fd, buf, max);
os_read_file(uml_rtc_irq_fd, &c, sizeof(c));
res = os_read_file(
res = os_read_file(ffd, bpf, statbuf.st_size);
r = os_read_file(irqfd, &v, sizeof(v));
rc = os_read_file(fd, buf, len);
rc = os_read_file(info->call_fd, &n, sizeof(n));
extern int os_read_file(int fd, void *buf, int len);
EXPORT_SYMBOL(os_read_file);
n = os_read_file(fd, buf, size);
ret = os_read_file(time_travel_ext_fd, msg, sizeof(*msg));