josch/mmdebstrap
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be more verbose when sending SIGHUP to the process group

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Johannes Schauer Marin Rodrigues 2023-10-23 11:51:41 +02:00
parent 1a62ccec46
commit 16c7276921
Signed by: josch
GPG key ID: F2CBA5C78FBD83E1
1 changed files with 23 additions and 1 deletions
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@ -6265,8 +6265,30 @@ sub main() {
# running tar and this process itself) to reliably tear down
# all running child processes. The main process is not affected
# because we are ignoring SIGHUP.
#
# FIXME: this codepath becomes dangerous in case mmdebstrap is not
# run in its own process group. When run from the terminal, the
# shell creates a new process group as part of its job control, so
# sending SIGHUP to all processes in our own process group should
# not be dangerous. But for example, on debci, lxc will run in the
# same process group as mmdebstrap and sending SIGHUP to the whole
# process group will also kill lxc. Creating a new process group
# for $pid will break things because only the foreground job is
# allowed to read from the terminal. If a background job does it,
# i will be suspended with SIGTTIN. Even though apt could be told
# to not read from the terminal by opening STDIN from /dev/null,
# this would make --chrooted-customize-hook=bash impossible.
# Making the $pid process group the foreground job will destroy all
# the signal handling we have set up for when the user presses
# ctrl+c in a terminal. Even if we fix the signal handling we now
# find ourselves in the opposite situation: the $pid process must
# now clean up the former main process tree reliably. And we cannot
# create a new process group for everything all-in-one because that
# would also destroy CTRL+C handling from the terminal.
warning "creating tarball failed: $@";
kill HUP => -getpgrp();
my $pgroup = getpgrp();
warning "sending SIGHUP to all processes in process group $pgroup";
kill HUP => -$pgroup;
$exitstatus = 1;
}
} else {