Function poll_with_restart 

pub fn poll_with_restart(
    current_task: &mut CurrentTask,
    user_fds: UserRef<pollfd>,
    num_fds: i32,
    deadline: MonotonicInstant,
) -> Result<usize, Errno>

Calls poll and arranges for an interrupted call to be restarted unless a signal handler runs.

Reporting EINTR directly would surface interruptions that userspace never asked about, as poll cannot tell whether the signal that interrupted it was delivered at all.