Signals

How signals work on Peios — the access-mask model that gates signal sending, PIP dominance, and the carve-out for kernel-originated signals.

The 31 POSIX-defined standard signals — number, name, default action, and which process access mask is required to send each.

The real-time signal range (SIGRTMIN to SIGRTMAX) — queued delivery, payloads, priority ordering, and how POSIX timer expiry uses them.

How a process registers signal handlers, controls which signals are blocked, runs handlers on a separate stack, and waits for signals synchronously.

The siginfo_t struct delivered to a signal handler — what each field means, how senders are identified, and how to obtain Peios-strength sender identity.