Running a stable x86 platform, with Perl and dev-perl/Term-ReadLine-Perl installed, a process which uses Term::ReadLine will segfault on exit with an error like: *** glibc detected *** double free or corruption (!prev): 0x0829dc18 *** Steps to Reproduce contains a very short perl script which demonstrates this problem. This broke on a glibc update a while back (I forget when, sorry). I have reinstalled both Perl and Term-ReadLine-Perl since then. I have installed the module after installing Perl. ithreads is not enabled as a Perl use-flag. Reproducible: Always Steps to Reproduce: #!/usr/bin/perl # Run this script, provide some input when asked. use strict; use warnings; use Term::ReadLine; my $term = new Term::ReadLine "check_readline"; die "No terminal initialisation" unless defined $term; my $foo = $term->readline('Enter your foo text here: '); my $len = length $foo; print "Input was $len chars long: {$foo}\n"; exit 0; Actual Results: normal_prompt% ./check_readline Enter your foo text here: foo Input was 3 chars long: {foo} *** glibc detected *** double free or corruption (!prev): 0x08193c20 *** zsh: abort (core dumped) ./check_readline {SIGABRT}-prompt% gdb /usr/bin/perl core.check_readline.30748 [...] (gdb) bt #0 0xffffe410 in __kernel_vsyscall () #1 0xb7e6bd21 in raise () from /lib/tls/libc.so.6 #2 0xb7e6d3e8 in abort () from /lib/tls/libc.so.6 #3 0xbfffea54 in ?? () [...] #38 0xbfffeaf4 in ?? () #39 0xb7ea514b in free () from /lib/tls/libc.so.6 Previous frame inner to this frame (corrupt stack?) (gdb) Expected Results: Clean process exit, exit-status 0. No glibc warnings. No shell warnings of signal death and core-dump. No core-dump. # qpkg -I dev-lang/perl -v dev-lang/perl-5.8.5-r5 * # qpkg -I dev-perl/Term-ReadLine-Perl -v dev-perl/Term-ReadLine-Perl-1.0203 * # emerge -pv dev-lang/perl dev-perl/Term-ReadLine-Perl [...] [ebuild R ] dev-lang/perl-5.8.5-r5 +berkdb -debug +doc +gdbm -ithreads -perlsuid 0 kB [ebuild R ] dev-perl/Term-ReadLine-Perl-1.0203 0 kB Portage 2.0.51.19 (default-linux/x86/2005.0, gcc-3.3.5-20050130, glibc-2.3.4.20041102-r1, 2.6.11-gentoo-r6 i686) ================================================================= System uname: 2.6.11-gentoo-r6 i686 Intel(R) Pentium(R) 4 CPU 2.80GHz Gentoo Base System version 1.4.16 Python: dev-lang/python-2.3.5 [2.3.5 (#1, May 4 2005, 10:25:59)] ccache version 2.3 [enabled] dev-lang/python: 2.3.5 sys-apps/sandbox: [Not Present] sys-devel/autoconf: 2.59-r6, 2.13 sys-devel/automake: 1.7.9-r1, 1.8.5-r3, 1.5, 1.4_p6, 1.6.3, 1.9.5 sys-devel/binutils: 2.15.92.0.2-r7 sys-devel/libtool: 1.5.16 virtual/os-headers: 2.6.8.1-r2 ACCEPT_KEYWORDS="x86" AUTOCLEAN="yes" CFLAGS="-O2 -mcpu=pentium4 -march=pentium4 -mmmx -msse -msse2 -mfpmath=sse,387 -pipe" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3/share/config /usr/lib/X11/xkb /usr/lib/mozilla/defaults/pref /usr/share/config /usr/share/texmf/dvipdfm/config/ /usr/share/texmf/dvips/config/ /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/texmf/xdvi/ /var/qmail/control" CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d" CXXFLAGS="-O2 -mcpu=pentium4 -march=pentium4 -mmmx -msse -msse2 -mfpmath=sse,387 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoaddcvs autoconfig ccache distlocks nostrip sandbox sfperms strict" GENTOO_MIRRORS="http://ftp.easynet.nl/mirror/gentoo/ http://ftp.snt.utwente.nl/pub/os/linux/gentoo http://ftp-stud.fht-esslingen.de/pub/Mirrors/gentoo/ http://pandemonium.tiscali.de/pub/gentoo/ http://ftp.du.se/pub/os/gentoo" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" SYNC="rsync://rsync4.nl.gentoo.org/gentoo-portage" USE="x86 X acl acpi adns alsa apache2 apm avi berkdb bitmap-fonts bzlib caps cdb cdr cjk crypt cscope cups curl curlwrappers doc dvd eds emboss encode evo fam flac foomaticdb fortran gd gdbm ggi gif gmp gnome gnutls gpm gstreamer gtk gtk2 hardenedphp iconv imagemagick imap imlib imlib2 ipv6 java jpeg kerberos lcms ldap libg++ libwww lzo mad maildir matrox mbox mcal memlimit mhash mikmod mime mmx mng motif mozilla mp3 mpeg mysql ncurses netcdf nptl odbc offensive ogg oggvorbis opengl pam pcre pdflib perl pic plotutils png postgres ppds python quicktime readline real recode ruby samba sasl sdl silc slang sndfile snmp sockets speex spell sse sse2 ssl svg tcpd tetex theora tiff truetype truetype-fonts type1-fonts unicode usb vhosts vorbis win32codecs wmf xanim xine xml xml2 xmms xprint xv xvid zlib userland_GNU kernel_linux elibc_glibc" Unset: ASFLAGS, CBUILD, CTARGET, LANG, LC_ALL, LDFLAGS, LINGUAS, PORTDIR_OVERLAY
Doesn't dup over here Enter your foo text here: ahlo Input was 4 chars long: {ahlo} mcummings@randombox $ Like you said - this looks like a problem between you and glibc, not the perl module. (glibc-2.3.4.20040808-r1, tried it on 3 boxes, fwiw)
use the nomalloccheck USE flag when emerging glibc to avoid these errors.
(In reply to comment #1) > Like you said - this looks like a problem between you and glibc, not the perl > module. (glibc-2.3.4.20040808-r1, tried it on 3 boxes, fwiw) The glibc check is a diagnostic to highlight a bug. Unfortunately, I can't see a way to turn it off without a re-emerge, as suggested by R.Hill; that's underway now. (FreeBSD's /etc/malloc.conf | $MALLOC_OPTIONS wins here.) Unless there's a glibc bug in the free() checks, this means that there's a bug either in the readline library or the Term::ReadLine perl module (and its XS wrapping). I have sys-devel/bc installed with the 'readline' USE-flag and ldd(1) confirms that it links against libreadline; bc does not core-dump on exit. This suggests that the problem lies with Term::ReadLine itself. Hence the bug-report. As a real-world example of an affected program: cpan(1)
glibc no longer provides the nomalloccheck USE-flag on either x86 or ~x86. As such, the complaints about double-free can no longer be avoided and any perl script using Term::ReadLine is dying with SIGABRT on exit: *** glibc detected *** double free or corruption (!prev): 0x083ac0d8 *** sys-libs/glibc-2.3.5 -build -debug -erandom -hardened (-multilib) -nls +nptl -nptlonly +pic (-selinux) +userlocales dev-lang/perl-5.8.6-r5 +berkdb -build -debug +doc +gdbm -ithreads -minimal -perlsuid dev-perl/Term-ReadLine-Perl-1.0203 If using the current Gentoo glibc on x86, can anyone else duplicate this? Thanks,
sys-libs/glibc-2.3.5 no sign of this bug. Enter your foo text here: hi me Input was 5 chars long: {hi me} mcummings@nomad%
Sorry, bug report is in error. I hadn't remembered that when I'd installed Gentoo, I'd used Term::ReadLine::Gnu which isn't in Portage, because I wanted the advanced features available from the libreadline implementation. I'd forgotten that although "use Term::ReadLine" will use the ...::Gnu version if it's available, it's not included by default. The port is fine. I had failed to rebuild Term::ReadLine::Gnu after an update of Perl, because I'd forgotten that I'd installed some stuff before I learnt about g-cpan.pl; I've now used g-cpan.pl so that this mistake should not be repeated. I'm sorry to have wasted peoples' time. Thank you for being so patient with me whilst I was a complete twit.
