pidfd_pid
struct pid *pid = pidfd_pid(f);
struct pid *pid = pidfd_pid(file);
struct pid *pid = pidfd_pid(file);
task = get_pid_task(pidfd_pid(file), PIDTYPE_PID);
struct pid *pidfd_pid(const struct file *file);
} else if (!IS_ERR(pidfd_pid(fd_file(f)))) {
err = validate_nsset(&nsset, pidfd_pid(fd_file(f)));
pid = pidfd_pid(fd_file(f));
pid = pidfd_pid(fd_file(f));
pid = pidfd_pid(file);