7eca1112fb
Closes #185 If vipw is suspended (e.g. via control-Z) and then resumed, it often gets immediately suspended. This is easier to reproduce on a multi-core system. root@buster:~# /usr/sbin/vipw [1]+ Stopped /usr/sbin/vipw root@buster:~# fg /usr/sbin/vipw [1]+ Stopped /usr/sbin/vipw root@buster:~# fg [vipw resumes on the second fg] The problem is that vipw forks a child process and calls waitpid() with the WUNTRACED flag. When the child process (running the editor) is suspended, the parent sends itself SIGSTOP to suspend the main vipw process. However, because the main vipw is in the same process group as the editor which received the ^Z, the kernel already sent the main vipw SIGTSTP. If the main vipw receives SIGTSTP before the child, it will be suspended and then, once resumed, will proceed to suspend itself again. To fix this, run the child process in its own process group as the foreground process group. That way, control-Z will only affect the child process and the parent can use the existing logic to suspend the parent.
Shadow SITES ============ Homepage http://github.com/shadow-maint/shadow Issue tracker http://github.com/shadow-maint/shadow/issues Releases https://github.com/shadow-maint/shadow/releases Mailing lists for general discuss: pkg-shadow-devel@lists.alioth.debian.org commit list: pkg-shadow-commits@lists.alioth.debian.org Mailing lists subscription http://lists.alioth.debian.org/mailman/listinfo/pkg-shadow-devel http://lists.alioth.debian.org/mailman/listinfo/pkg-shadow-commits Mailing lists archives: http://lists.alioth.debian.org/pipermail/pkg-shadow-devel/ http://lists.alioth.debian.org/pipermail/pkg-shadow-commits/ S/Key support: Shadow can be built with S/Key support using the S/Key package from: http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libskey/ or http://gentoo.osuosl.org/distfiles/skey-1.1.5.tar.bz2 Authors and contributors ======================== Thanks to at least the following people for sending patches, bug reports and various comments. This list may be incomplete, I received a lot of mail... Adam Rudnicki <adam@v-lo.krakow.pl> Alan Curry <pacman@tardis.mars.net> Aleksa Sarai <cyphar@cyphar.com> Alexander O. Yuriev <alex@bach.cis.temple.edu> Algis Rudys <arudys@rice.edu> Andreas Jaeger <aj@arthur.rhein-neckar.de> Aniello Del Sorbo <anidel@edu-gw.dia.unisa.it> Anton Gluck <gluc@midway.uchicago.edu> Arkadiusz Miskiewicz <misiek@pld.org.pl> Ben Collins <bcollins@debian.org> Brian R. Gaeke <brg@dgate.org> Calle Karlsson <ckn@kash.se> Chip Rosenthal <chip@unicom.com> Chris Evans <lady0110@sable.ox.ac.uk> Chris Lamb <chris@chris-lamb.co.uk> Cristian Gafton <gafton@sorosis.ro> Dan Walsh <dwalsh@redhat.com> Darcy Boese <possum@chardonnay.niagara.com> Dave Hagewood <admin@arrowweb.com> David A. Holland <dholland@hcs.harvard.edu> David Frey <David.Frey@lugs.ch> Ed Carp <ecarp@netcom.com> Eric W. Biederman" <ebiederm@xmission.com> Floody <flood@evcom.net> Frank Denis <j@4u.net> George Kraft IV <gk4@us.ibm.com> Greg Mortensen <loki@world.std.com> Guido van Rooij Guy Maor <maor@debian.org> Hrvoje Dogan <hdogan@bjesomar.srce.hr> Jakub Hrozek <jhrozek@redhat.com> Janos Farkas <chexum@bankinf.banki.hu> Jay Soffian <jay@lw.net> Jesse Thilo <Jesse.Thilo@pobox.com> Joey Hess <joey@kite.ml.org> John Adelsberger <jja@umr.edu> Jonathan Hankins <jhankins@mailserv.homewood.k12.al.us> Jon Lewis <jlewis@lewis.org> Joshua Cowan <jcowan@hermit.reslife.okstate.edu> Judd Bourgeois <shagboy@bluesky.net> Juergen Heinzl <unicorn@noris.net> Juha Virtanen <jiivee@iki.fi> Julian Pidancet <julian.pidancet@gmail.com> Julianne Frances Haugh <jockgrrl@ix.netcom.com> Leonard N. Zubkoff <lnz@dandelion.com> Luca Berra <bluca@www.polimi.it> Lukáš Kuklínek <lkukline@redhat.com> Lutz Schwalowsky <schwalow@mineralogie.uni-hamburg.de> Marc Ewing <marc@redhat.com> Martin Bene <mb@sime.com> Martin Mares <mj@gts.cz> Michael Meskes <meskes@topsystem.de> Michael Talbot-Wilson <mike@calypso.bns.com.au> Mike Frysinger <vapier@gentoo.org> Mike Pakovic <mpakovic@users.southeast.net> Nicolas François <nicolas.francois@centraliens.net> Nikos Mavroyanopoulos <nmav@i-net.paiko.gr> Pavel Machek <pavel@bug.ucw.cz> Peter Vrabec <pvrabec@redhat.com> Phillip Street Rafał Maszkowski <rzm@icm.edu.pl> Rani Chouha <ranibey@smartec.com> Sami Kerola <kerolasa@rocketmail.com> Scott Garman <scott.a.garman@intel.com> Sebastian Rick Rijkers <srrijkers@gmail.com> Seraphim Mellos <mellos@ceid.upatras.gr> Shane Watts <shane@nexus.mlckew.edu.au> Steve M. Robbins <steve@nyongwa.montreal.qc.ca> Thorsten Kukuk <kukuk@suse.de> Tim Hockin <thockin@eagle.ais.net> Timo Karjalainen <timok@iki.fi> Ulisses Alonso Camaro <ulisses@pusa.eleinf.uv.es> Werner Fink <werner@suse.de> Maintainers =========== Tomasz Kłoczko <kloczek@pld.org.pl> (2000-2007) Nicolas François <nicolas.francois@centraliens.net> (2007-2014) Serge E. Hallyn <serge@hallyn.com> (2014-now) Christian Brauner <christian@brauner.io> (2019-now)