Hmmm...Just found <https://www.securecoding.cert.org/confluence/display/seccode/void+SIG33-C.+Do+not+recursively+invoke+the+raise%28%29+function>, the bottom part "Compliant Solution (POSIX)" does raise() in the signal handler.
However, I can't find it in the POSIX standard at <http://pubs.opengroup.org/onlinepubs/009695399/functions/sigaction.html>.
But <https://www.securecoding.cert.org/confluence/display/seccode/SIG30-C.+Call+only+asynchronous-safe+functions+within+signal+handlers> lists the async-safe functions. raise() and sigaction() are in it. But _Exit() is, too.
