async-signal-safety-review

Verify async-signal-safety in KSCrash by reviewing diffs, branches, and files touching signal-handling paths, then cross-checking suspect system calls against Apple OSS distributions to confirm safety and gather concrete evidence.

Async-signal-safety ensures functions can execute safely within signal handlers without causing deadlocks or undefined behavior, which is critical for crash handlers and Mach exception handlers to capture crash-time data reliably.

Yes, you can use Apple's open-source distributions as ground-truth reference to verify whether suspect system calls in KSCrash code paths are async-signal-safe rather than guessing, producing evidence-backed safety reports.

The review focuses specifically on KSCrash signal handlers, Mach exception handlers, and monitor code reachable from KSCrash sources, ensuring safety before landing risky changes but scoped to the provided diffs, branches, or files.

Signal handler deadlocks during crash reporting often stem from calling non-async-signal-safe functions; reviewing the code paths against Apple OSS implementations identifies unsafe call sites causing the deadlock.