Sigwire: a live TUI for tracing every Linux signal

Sigwire is a terminal dashboard that hooks into the Linux kernel's signal_generate and signal_deliver tracepoints to show every signal on a machine in real time, without strace or ptrace. Instead of tracking a single process, it captures signals from any source — kill(2), tgkill, POSIX timers, or kernel-raised faults — across all processes at once.

Each line shows how a signal was raised, whether the target caught it, how long the handler ran, and whether it tore a blocked syscall out with EINTR. Repeated bursts collapse into a single ×N line, and genuinely fatal signals are flagged separately from ones that were likely caught or ignored. Pausing the feed and selecting a row reveals sigaction flags, handler address, and which signals the target was blocking at that moment.

By correlating rt_sigreturn(2) and syscall-exit tracepoints with the delivery side, sigwire can time handlers precisely and surface EINTR interruptions — a classic source of timing-dependent bugs. For engineers debugging signal handling, supervisors, or runtime internals, it offers system-wide, process-agnostic visibility that traditional tracing tools don't provide.