Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!caen!uwm.edu!psuvax1!news From: flee@cs.psu.edu (Felix Lee) Newsgroups: comp.unix.programmer Subject: Re: Writing a program that cannot be killed except by reboot Message-ID: Date: 24 Apr 91 08:44:02 GMT References: <444@wrdis01.af.mil> <1991Apr15.113041.3069@ghost.unimi.it> <1991Apr17.181315.14184@sco.COM> Sender: news@cs.psu.edu (Usenet) Organization: ~/News/org Lines: 9 Nntp-Posting-Host: dictionopolis.cs.psu.edu > If a process is ptraced, a SIGKILL delivered to it will cause it to > stop and awaken its parent. Hmm. Then it may be possible for two procesess to mutually ptrace each other (using PTRACE_ATTACH) such that they both intercept and ignore KILL signals. You can still stun the processes if you can deliver signals to both of them quickly enough. -- Felix Lee flee@cs.psu.edu