From mboxrd@z Thu Jan 1 00:00:00 1970 From: dot@dotat.at (Tony Finch) Date: Thu, 24 Mar 2016 14:24:22 +0000 Subject: [TUHS] self-reproducing programs In-Reply-To: References: Message-ID: Not quite a fork bomb... I was deploying some new software on a production server. (There wasn't a good place to test it.) I somehow screwed up the restart logic so it continuously restarted itself. The process forked, the parent exited, and the child looped to restart again. There was only ever one instance of the program running, but its pid changed hundreds of times per second. Since it had daemonized, I couldn't use process groups to kill it. Since it was running as root, I couldn't use `kill -TERM -1` to kill just one user's processes. Since it was a production server, I reslly didn't want to reboot. I tried picking a pid somewhat larger than the program's rapidly increasing pid, and ran a script: while !kill $pid; do :; done No dice, it just blew straight past. I wrote a C program to kill that one pid even faster. Still no luck. In the end I managed to kill it by running about 5 or 10 concurrent copies of my C program on a set of adjacent pids. Only fallout was a few FTP server connection failures... Tony. -- f.anthony.n.finch http://dotat.at/ - I xn--zr8h punycode Lundy, Fastnet, Irish Sea: Southwest 5 to 7, veering northwest, then backing southwest later, 4 or 5. Moderate or rough, becoming slight in Irish Sea. Rain for a time. Good, becoming moderate or poor for a time.