Hi, On Thu, 15 Dec 2011, Henrique de Moraes Holschuh wrote: > > <503 pcew80@reincke:~> ps -aef | grep amavis > > amavis 2299 1 0 00:47 ? 00:00:01 amavisd (master) > > amavis 2496 2299 0 00:47 ? 00:00:00 amavisd (ch7-avail) > > amavis 2497 2299 0 00:47 ? 00:00:00 amavisd (ch7-avail) > > amavis 2498 2299 0 00:47 ? 00:00:00 amavisd (ch6-avail) > > reincke 7749 7078 0 08:32 pts/1 00:00:00 grep amavis > > > > <504 pcew80@reincke:~> cat /proc/2299/stat > > 2299 (amavisd (master) S 1 2299 2299 0 -1 4202560 9771 0 4 0 119 5 0 > > 0 20 0 1 0 22660083 221208576 22204 18446744073709551615 1 1 0 0 0 0 > > 0 4224 81927 18446744073709551615 0 0 17 2 0 0 7 0 0 > > Crap. The kernel has done us in. Reassigning to dpkg to get some input on > what should be done. Raising severity because it will cause some services > to not be stopped or restarted properly, which has security implications. > > Guys, 3.1 changes /proc/<pid>/stat, and breaks anything using > start-stop-daemon --name that also messes with the name of the process. Due > to the chage in /proc/<pid>/stat, the executable name is not matched > anymore.
What are those changes exactly? Because the kernel doesn't seem to always respect the name that the process sets for itself. I run 3.1.0-1-amd64 here and I have this: ┏rivendell:~/deb/core/dpkg (test-build) ┗(706)$ ps axf|grep 1758 1758 ? S 0:00 \_ avahi-daemon: chroot helper 4660 pts/8 S+ 0:00 | \_ grep 1758 ┏rivendell:~/deb/core/dpkg (test-build) ┗(707)$ sudo cat /proc/1758/stat 1758 (avahi-daemon) S 1756 1754 1754 0 -1 4202560 83 0 1 0 0 0 0 0 20 0 1 0 2639 3158016 21 18446744073709551615 134512640 134630244 4292694960 4292694424 4151297072 0 0 0 0 0 0 0 17 1 0 0 0 0 0 > This probably affects only processes that change their "visible identity" > (or whatever the string output by ps -aef is called) like amavisd-new does. > > Unfortunately, using --exec is not enough when you're dealing with perl, > python or other scripts. > > How should we proceed? Drop use of start-stop-daemon --name in amavisd-new > and document this kernel ABI issue in start-stop-daemon(8)? Reassign to the > kernel on the grounds that it broke the userspace ABI? Enhance > start-stop-daemon to take a --namere (regexp) and use that in amavisd-new > instead? I would first like to understand the problem because you said "probably" multiple times and I prefer to decide in full knowledge. Can anyone from the kernel team say us if there have been relevant changes here? Henrique, what lead you to conclude that there was a kernel change? I tried to look at http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=history;f=fs/proc/array.c;hb=refs/heads/master but did not find any relevant change. Cheers, -- Raphaël Hertzog ◈ Debian Developer Pre-order a copy of the Debian Administrator's Handbook and help liberate it: http://debian-handbook.info/liberation/ -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20111216101520.ga4...@rivendell.home.ouaza.com
