Function rt_sigaction 

pub unsafe fn rt_sigaction(
    signal: Signal,
    new_action: &sigaction,
    old_action: Option<&mut sigaction>,
) -> Result<(), Errno>

Calls the rt_sigaction syscall.

Safety

• new_action’s handler must be safe to call as a signal handler. See signal-safety(7).
• Generally, new_action must have SA_RESTORER set and a suitable restorer, such as sigaction_restorer. (There might be some esoteric way to call this syscall without this property, but I’m not aware of one).