** Tags added: sts ** Description changed:
- In Ubuntu 12.04.5 LTS (procps 1:3.2.8-11ubuntu6.3), the following worked - fine: + [Impact] + ps -o thcount doesn't print out an error (error: unknown user-defined format specifier "thcount") + + [Description] + The Xenial version of procps has a bug in the thcount format specifier. ps doesn't recognize it, and complains about an unknown user-defined format. + This is due to the format specifier table in ps/output.c, which is queried with a binary search. Since the "thcount" entry appears out of order in Xenial, it can't be looked up and the program fails with the "unknown user-defined format specifier" error. + + This has been fixed upstream by the commit below: + - Fix for Bug:1174313 (3a52dfa34027) + + $ git describe --contains 3a52dfa34027 + v3.3.12~58^2 + + $ rmadison procps + procps | 2:3.3.10-4ubuntu2 | xenial | source, ... + procps | 2:3.3.10-4ubuntu2.4 | xenial-security | source, ... + procps | 2:3.3.10-4ubuntu2.4 | xenial-updates | source, ... <-------- + procps | 2:3.3.12-3ubuntu1 | bionic | source, ... + procps | 2:3.3.12-3ubuntu1.1 | bionic-security | source, ... + procps | 2:3.3.12-3ubuntu1.2 | bionic-updates | source, ... + + Releases starting with Bionic already have this fix, so it's only needed + for Xenial. + + [Test case] + 1. Boot up a Xenial environment with e.g. an lxd container: + # lxc launch images:ubuntu/xenial xenial + + 2. Execute ps with the '-o thcount' options: + # lxc exec xenial -- ps -o thcount + error: unknown user-defined format specifier "thcount" + + Usage: + ps [options] + + Try 'ps --help <simple|list|output|threads|misc|all>' + or 'ps --help <s|l|o|t|m|a>' + for additional help text. + + For more details see ps(1). + + [Regression Potential] + The fix just fixes the order of two entries in the format specifier array, so the regression potential is very low. Furthermore, the patch has been present and tested in up-to-date versions of procps since Bionic. Any new regressions introduced in Xenial will be checked with autopkgtest. + + [Original Description] + In Ubuntu 12.04.5 LTS (procps 1:3.2.8-11ubuntu6.3), the following worked fine: $ export PS_FORMAT=thcount $ ps THCNT - 1 - 1 + 1 + 1 In Ubuntu 14.04.1 LTS (procps 1:3.3.9-1ubuntu2), it does not work anymore: $ export PS_FORMAT=thcount $ ps warning: $PS_FORMAT ignored. (unknown user-defined format specifier "thcount") - PID TTY TIME CMD - 6593 pts/1 00:00:00 ps + PID TTY TIME CMD + 6593 pts/1 00:00:00 ps 16633 pts/1 00:00:00 bash Other PS_FORMAT specifiers still work fine (I have tried many, but not all). In real-life usage, a more complex PS_FORMAT would of course be used, such as PS_FORMAT=pid,s,thcount,nice,euser,egroup,etime,cputime,%mem,rssize:6,size:7,vsize:7,command Workaround: use nlwp instead of thcount (they are alias to the same data, and nlwp works fine in both versions). ** Also affects: procps (Ubuntu Xenial) Importance: Undecided Status: New ** Changed in: procps (Ubuntu) Status: Confirmed => Fix Released ** Changed in: procps (Ubuntu Xenial) Status: New => In Progress ** Changed in: procps (Ubuntu Xenial) Assignee: (unassigned) => Heitor Alves de Siqueira (halves) ** Summary changed: - PS_FORMAT=thcount does not work anymore + ps doesn't support "thcount" format specifier on Xenial -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1410558 Title: ps doesn't support "thcount" format specifier on Xenial To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/procps/+bug/1410558/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs