p5pRT
commented
10 years ago From dlarochelle@cyber.law.harvard.edu
Created by dlarochelle@cyber.law.harvard.edu
The Perl 5.18.2 build failed the ../ext/POSIX/t/wrappers.t test on our production Ubuntu 12.04 server.
Investigation reveals that calling getgrdid with an LDAP based group id breaks subsequent calls to fork(). Using strace\, it appears that the child process dies immediately after the fork() and the main process recieves a SIGCHLD when the child dies. However\, things work fine if the gid isn't LDAP based.
The bug can be reproduced on an LDAP system with the following code:
#!/usr/bin/env perl
use strict;
my $id = $(; say STDERR "group id: $id"; my $getgrgid_result = getgrgid $id; say STDERR "getgrgid: $getgrgid_result";
my $pid = fork();
fail("fork failed: $!") unless defined $pid;
if ($pid) { print STDERR "MAIN PROCESS\n"; } else { # Child print STDERR "CHILD PROCESS\n"; }
EXPECTED RESULT: group id: 10030 113 10006 10010 10030 getgrgid: mediacloud MAIN PROCESS CHILD PROCESS
ACTUAL RESULT: group id: 10030 113 10006 10010 10030 getgrgid: mediacloud MAIN PROCESS
Things work fine with Perl 5.14. If the call to getgrgid is commented out\, both the child and parent processes print out. Things also work if we call getgrgid with an id that is in /etc/groups instead of using $(.
Migrated from rt.perl.org#121485 (status was 'open')
Searchable as RT121485$