use encoding "utf8" causes segfault

[p5pRT]

Migrated from rt.perl.org#31923 (status was 'resolved')

Searchable as RT31923$

[p5pRT]

From hatta@yandex.ru

Hello,
Today I was playing with gtk2-perl and found that for some reason my
program, running two threads - gui and worker - crashed when thread->new
was executed. So i began investigating this and found, that gtk2-perl
was not the cause of segfault, i found that it was all use encoding
"utf8" statement​:

---

this code gives segmentation fault on my Fedora Core 2/linux-2.6.8.1

#!/usr/bin/perl -w
use strict;
use warnings;
use threads;
use threads​::shared;
use encoding "utf8"; # no segfault if remove

my $t = threads->new(\&fn);

sub fn {
  print "hello\n";
}

---

Output from perlbug -d (I cannot send email from my local machine)

---

Flags​:
  category=
  severity=

---

Site configuration information for perl v5.8.3​:

Configured by bhcompile at Thu Apr 15 13​:08​:28 EDT 2004.

Summary of my perl5 (revision 5.0 version 8 subversion 3) configuration​:
  Platform​:
  osname=linux, osvers=2.4.21-4.elsmp, archname=i386-linux-thread-multi
  uname='linux tweety.devel.redhat.com 2.4.21-4.elsmp #1 smp fri oct
3 17​:52​:56 edt 2003 i686 i686 i386 gnulinux '
  config_args='-des -Doptimize=-O2 -g -pipe -march=i386 -mcpu=i686
-Dversion=5.8.3 -Dmyhostname=localhost -Dperladmin=root@​localhost
-Dcc=gcc -Dcf_by=Red Hat, Inc. -Dinstallprefix=/usr -Dprefix=/usr
-Darchname=i386-linux -Dvendorprefix=/usr -Dsiteprefix=/usr -Duseshrplib
-Dusethreads -Duseithreads -Duselargefiles -Dd_dosuid -Dd_semctl_semun
-Di_db -Ui_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dman3ext=3pm -Duseperlio
-Dinstallusrbinperl -Ubincompat5005 -Uversiononly -Dpager=/usr/bin/less
-isr -Dinc_version_list=5.8.2 5.8.1 5.8.0'
  hint=recommended, useposix=true, d_sigaction=define
  usethreads=define use5005threads=undef useithreads=define
usemultiplicity=define
  useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
  use64bitint=undef use64bitall=undef uselongdouble=undef
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS
-DDEBUGGING -fno-strict-aliasing -I/usr/local/include
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm',
  optimize='-O2 -g -pipe -march=i386 -mcpu=i686',
  cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS
-DDEBUGGING -fno-strict-aliasing -I/usr/local/include -I/usr/include/gdbm'
  ccversion='', gccversion='3.3.3 20040412 (Red Hat Linux 3.3.3-7)',
gccosandvers=''
  intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
  ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t',
lseeksize=8
  alignbytes=4, prototype=define
  Linker and Libraries​:
  ld='gcc', ldflags =' -L/usr/local/lib'
  libpth=/usr/local/lib /lib /usr/lib
  libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lpthread -lc
  perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
  libc=/lib/libc-2.3.3.so, so=so, useshrplib=true, libperl=libperl.so
  gnulibc_version='2.3.3'
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic
-Wl,-rpath,/usr/lib/perl5/5.8.3/i386-linux-thread-multi/CORE'
  cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'

Locally applied patches​:

---

@​INC for perl v5.8.3​:
  /usr/lib/perl5/5.8.3/i386-linux-thread-multi
  /usr/lib/perl5/5.8.3
  /usr/lib/perl5/site_perl/5.8.3/i386-linux-thread-multi
  /usr/lib/perl5/site_perl/5.8.2/i386-linux-thread-multi
  /usr/lib/perl5/site_perl/5.8.1/i386-linux-thread-multi
  /usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi
  /usr/lib/perl5/site_perl/5.8.3
  /usr/lib/perl5/site_perl/5.8.2
  /usr/lib/perl5/site_perl/5.8.1
  /usr/lib/perl5/site_perl/5.8.0
  /usr/lib/perl5/site_perl
  /usr/lib/perl5/vendor_perl/5.8.3/i386-linux-thread-multi
  /usr/lib/perl5/vendor_perl/5.8.2/i386-linux-thread-multi
  /usr/lib/perl5/vendor_perl/5.8.1/i386-linux-thread-multi
  /usr/lib/perl5/vendor_perl/5.8.0/i386-linux-thread-multi
  /usr/lib/perl5/vendor_perl/5.8.3
  /usr/lib/perl5/vendor_perl/5.8.2
  /usr/lib/perl5/vendor_perl/5.8.1
  /usr/lib/perl5/vendor_perl/5.8.0
  /usr/lib/perl5/vendor_perl
  .

---

Environment for perl v5.8.3​:
  HOME=/home/hatta
  LANG=ru_RU.UTF-8
  LANGUAGE (unset)
  LD_LIBRARY_PATH (unset)
  LOGDIR (unset)

PATH=/usr/kerberos/bin​:/usr/local/bin​:/usr/bin​:/bin​:/usr/X11R6/bin​:/usr/lib/java/jre/bin​:/usr/lib/java/bin​:/usr/local/Wine/bin
  PERL_BADLANG (unset)
  SHELL=/bin/bash

---

Goodbye.

--
K. S. <mailto​:hatta@​NOT-FOR-SPAM.yandex.ru>
ICQ​: 224295216
Jabber​: hatta@​jabber.ru

[p5pRT]

From @rgs

Konstantin Stopani (via RT) wrote​:

this code gives segmentation fault on my Fedora Core 2/linux-2.6.8.1

#!/usr/bin/perl -w
use strict;
use warnings;
use threads;
use threads​::shared;
use encoding "utf8"; # no segfault if remove

my $t = threads->new(\&fn);

sub fn {
print "hello\n";
}

Reproduced here with bleadperl; apparently this comes from this bit in
ext/PerlIO/encoding/encoding.xs (function PerlIOEncode_getarg()) :

  /* Not 100% sure stack swap is right thing to do during dup ... */
  PUSHSTACKi(PERLSI_MAGIC);

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From nick@ing-simmons.net

Rafael Garcia-Suarez <rgarciasuarez@​mandrakesoft.com> writes​:

Konstantin Stopani (via RT) wrote​:

this code gives segmentation fault on my Fedora Core 2/linux-2.6.8.1

#!/usr/bin/perl -w
use strict;
use warnings;
use threads;
use threads​::shared;
use encoding "utf8"; # no segfault if remove

my $t = threads->new(\&fn);

sub fn {
print "hello\n";
}

Reproduced here with bleadperl; apparently this comes from this bit in
ext/PerlIO/encoding/encoding.xs (function PerlIOEncode_getarg()) :

   /\* Not 100% sure stack swap is right thing to do during dup \.\.\. \*/

Seems like it isn't ;-)

   PUSHSTACKi\(PERLSI\_MAGIC\);

Someone could experiment with commenting out the stack swap,
that isn't the right total fix but if it made segfault go away it would
be a hint.

[p5pRT]

From @kimurakoichi

Hi, I use perl with sjis encoding.
Segfault occures when use encoding with thread.

This cause by the script above.

use v5.8.0;
use strict;
use threads;
use encoding 'ascii';

my $thread1 = threads->new(\&main, "One");
my $thread2 = threads->new(\&main, "Two");

$thread1->join;
$thread2->join;

print "done.\n";

sub main {
  my ($name) = @​_;
  for (1..10) {
  print "I am $name ($_)\n";
  threads->yield();
  }
}

Summary of my perl5 (revision 5 version 8 subversion 6) configuration​:
  Platform​:
  osname=cygwin, osvers=1.5.12(0.11642),
archname=cygwin-thread-multi-64int
  uname='cygwin_nt-4.0 loreley 1.5.12(0.11642) 2004-11-10 08​:34 i686
unknown unknown cygwin '
  config_args='-de -Dmksymlinks -Duse64bitint -Dusethreads
-Doptimize=-O3 -Dman3ext=3pm'
  hint=recommended, useposix=true, d_sigaction=define
  usethreads=define use5005threads=undef useithreads=define
usemultiplicity=define
  useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
  use64bitint=define use64bitall=undef uselongdouble=undef
  usemymalloc=y, bincompat5005=undef
  Compiler​:
  cc='gcc', ccflags ='-DPERL_USE_SAFE_PUTENV -fno-strict-aliasing
-pipe -I/usr/local/include',
  optimize='-O3',
  cppflags='-DPERL_USE_SAFE_PUTENV -fno-strict-aliasing -pipe
-I/usr/local/include'
  ccversion='', gccversion='3.4.1 (cygming special)', gccosandvers=''
  intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
  ivtype='long long', ivsize=8, nvtype='double', nvsize=8,
Off_t='off_t', lseeksize=8
  alignbytes=8, prototype=define
  Linker and Libraries​:
  ld='ld2', ldflags =' -s -L/usr/local/lib'
  libpth=/usr/local/lib /usr/lib /lib
  libs=-lgdbm -ldb -lcrypt -lgdbm_compat
  perllibs=-lcrypt -lgdbm_compat
  libc=/usr/lib/libc.a, so=dll, useshrplib=true, libperl=libperl.a
  gnulibc_version=''
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' -s'
  cccdlflags=' ', lddlflags=' -s -L/usr/local/lib'

Characteristics of this binary (from libperl)​:
  Compile-time options​: MULTIPLICITY USE_ITHREADS USE_64_BIT_INT
USE_LARGE_FILES PERL_IMPLICIT_CONTEXT
  Built under cygwin
  Compiled at Jan 12 2005 01​:07​:08
  %ENV​:
  PERL5LIB="d​:/home/perl"
  CYGWIN=""
  @​INC​:
  d
  /home/perl
  /usr/lib/perl5/5.8/cygwin
  /usr/lib/perl5/5.8
  /usr/lib/perl5/site_perl/5.8/cygwin
  /usr/lib/perl5/site_perl/5.8
  /usr/lib/perl5/site_perl/5.8
  /usr/lib/perl5/vendor_perl/5.8/cygwin
  /usr/lib/perl5/vendor_perl/5.8
  /usr/lib/perl5/vendor_perl/5.8
  .

thanks,

--
Koichi Kimura
  I thought what I'd do was, I'd pretend I was one of those deaf-mutes.
  mail kbk@​kt.rim.or.jp
  web www.kt.rim.or.jp/~kbk/index.html#zakkicho
  homepage3.nifty.com/farstar/

[p5pRT]

From rkitover@walmart.com

Created by rkitover@rkitover-linux.walmart.com

As reported by DawnFantasy on IRC (FreeNode #perl)​:
/usr/local/bin/perl -Mthreads -e 'binmode STDOUT, "​:encoding(UTF-8)"; threads->new( sub {sleep 3;print "K\n";}); sleep 5'

produces a core dump.

5.8.8 (Debian unstable version) produces a core dump as well.

Perl Info

Flags:
    category=library
    severity=medium

Site configuration information for perl 5.9.5:

Configured by rkitover at Thu Aug 23 02:54:48 PDT 2007.

Summary of my perl5 (revision 5 version 9 subversion 5 patch 31749) configuration:
  Platform:
    osname=linux, osvers=2.6.18-4-amd64, archname=x86_64-linux-thread-multi
    uname='linux rkitover-linux 2.6.18-4-amd64 #1 smp mon mar 26 11:36:53 cest 2007 x86_64 gnulinux '
    config_args='-Dusedevel -Dprefix=/usr/local/stow/bleadperl -Dmad=y -Dusethreads -des'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.1.3 20070718 (prerelease) (Debian 4.1.2-14)', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64 /usr/local/lib64
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lpthread -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=/lib/libc-2.6.1.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.6.1'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib'

Locally applied patches:
    DEVEL


@INC for perl 5.9.5:
    /usr/local/stow/bleadperl/lib/5.9.5/x86_64-linux-thread-multi
    /usr/local/stow/bleadperl/lib/5.9.5
    /usr/local/stow/bleadperl/lib/site_perl/5.9.5/x86_64-linux-thread-multi
    /usr/local/stow/bleadperl/lib/site_perl/5.9.5
    .


Environment for perl 5.9.5:
    HOME=/home/rkitover
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LC_CTYPE=en_US.utf8
    LD_LIBRARY_PATH=/lib:/usr/lib:/usr/local/lib:/home/oracle/instantclient_10_2
    LOGDIR (unset)
    PATH=/home/rkitover/bin:/usr/local/bin:/usr/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/bin/X11:/usr/games:/home/oracle/instantclient_10_2
    PERL_BADLANG (unset)
    SHELL=zsh

[p5pRT]

From @jdhedden

As reported by DawnFantasy on IRC (FreeNode #perl)​:
/usr/local/bin/perl -Mthreads -e 'binmode STDOUT, "​:encoding(UTF-8)"; threads->new( sub {sleep 3;print "K\n";}); sleep 5'

produces a core dump.

5.8.8 (Debian unstable version) produces a core dump as well.

Produces a seg fault with blead under Cygwin on Windows.

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From shouldbedomo@mac.com

On 2007–08–23, at 13​:52, Jerry D. Hedden wrote​:

As reported by DawnFantasy on IRC (FreeNode #perl)​:
/usr/local/bin/perl -Mthreads -e 'binmode STDOUT, "​:encoding
(UTF-8)"; threads->new( sub {sleep 3;print "K\n";}); sleep 5'

produces a core dump.

5.8.8 (Debian unstable version) produces a core dump as well.

Produces a seg fault with blead under Cygwin on Windows.

And on Mac OS 10.4.10 with both 5.8.8 and bleadperl (5.10 to be).
Here's the log from 5.8.8 (that from blead is very similar indeed)​:

Host Name​: Tullamore
Date/Time​: 2007-08-23 14​:22​:22.390 +0200
OS Version​: 10.4.10 (Build 8R218)
Report Version​: 4

Command​: perl
Path​: /usr/local/bin/perl
Parent​: bash [8591]

Version​: ??? (???)

PID​: 11777
Thread​: 0

Exception​: EXC_BAD_ACCESS (0x0001)
Codes​: KERN_PROTECTION_FAILURE (0x0002) at 0x00000018

Thread 0 Crashed​:
0 encoding.bundle 0x000262ac PerlIOEncode_getarg + 76
1 libperl.dylib 0x002ee548 PerlIOBase_dup + 248
2 encoding.bundle 0x00028c10 PerlIOEncode_dup + 32
3 libperl.dylib 0x0027e80c Perl_fp_dup + 156
4 libperl.dylib 0x002f0f30 PerlIO_clone + 560
5 libperl.dylib 0x002874d8 perl_clone + 3352
6 threads.bundle 0x0001efd4 XS_threads_create + 4852
7 libperl.dylib 0x0027cdb4 Perl_pp_entersub + 1764
8 libperl.dylib 0x00273f08 Perl_runops_standard + 88
9 libperl.dylib 0x0020926c perl_run + 524
10 perl 0x00002910 main + 240
11 perl 0x0000243c _start + 760
12 perl 0x00002140 start + 48

Thread 0 crashed with PPC Thread State 64​:
  srr0​: 0x00000000000262ac srr1​:
0x100000000200f030 vrsave​: 0x0000000000000000
  cr​: 0x22008274 xer​: 0x0000000000000000 lr​:
0x00000000000262a8 ctr​: 0x00000000002f7030
  r0​: 0x00000000000262a8 r1​: 0x00000000bffff0e0 r2​:
0x0000000000000000 r3​: 0x0000000001841b88
  r4​: 0x0000000000401ac8 r5​: 0x00000000bffff318 r6​:
0x0000000000000001 r7​: 0x00000000bffff318
  r8​: 0x0000000000000000 r9​: 0x00000000003212e4 r10​:
0x0000000000000600 r11​: 0x000000000002a0b8
  r12​: 0x00000000002f7030 r13​: 0x000000000043fae0 r14​:
0x000000000182a4a8 r15​: 0x0000000000000000
  r16​: 0x000000000043fa80 r17​: 0x0000000000000002 r18​:
0x0000000001842344 r19​: 0x0000000001842350
  r20​: 0x000000000184235c r21​: 0x0000000000000001 r22​:
0x0000000001800400 r23​: 0x0000000001800400
  r24​: 0x0000000000000001 r25​: 0x0000000001842344 r26​:
0x0000000000440e80 r27​: 0x0000000000000000
  r28​: 0x0000000001841a00 r29​: 0x000000000002a004 r30​:
0x0000000000441c68 r31​: 0x0000000000026270

Binary Images Description​:
  0x1000 - 0x3fff perl /usr/local/bin/perl
  0x1a000 - 0x21fff threads.bundle /usr/local/lib/perl5/5.8.8/
darwin-thread-multi-2level/auto/threads/threads.bundle
  0x25000 - 0x29fff encoding.bundle /usr/local/lib/perl5/5.8.8/
darwin-thread-multi-2level/auto/PerlIO/encoding/encoding.bundle
  0x2d000 - 0x33fff Encode.bundle /usr/local/lib/perl5/5.8.8/
darwin-thread-multi-2level/auto/Encode/Encode.bundle
  0x205000 - 0x317fff libperl.dylib /usr/local/lib/perl5/5.8.8/
darwin-thread-multi-2level/CORE/libperl.dylib
0x8fe00000 - 0x8fe52fff dyld 46.12 /usr/lib/dyld
0x90000000 - 0x901bcfff libSystem.B.dylib /usr/lib/libSystem.B.dylib
0x94c90000 - 0x94cb0fff libmx.A.dylib /usr/lib/libmx.A.dylib
0x9611d000 - 0x96122fff libmathCommon.A.dylib /usr/lib/system/
libmathCommon.A.dylib

--
Dominic Dunlop

[p5pRT]

From @smpeters

On Thu, Aug 23, 2007 at 03​:45​:26AM -0700, Rafael Kitover wrote​:

# New Ticket Created by "Rafael Kitover"
# Please include the string​: [perl #44887]
# in the subject line of all future correspondence about this issue.
# <URL​: http​://rt.perl.org/rt3/Ticket/Display.html?id=44887 >

This is a bug report for perl from rkitover@​rkitover-linux.walmart.com,
generated with the help of perlbug 1.36 running under perl 5.9.5.

-----------------------------------------------------------------
[Please enter your report here]

As reported by DawnFantasy on IRC (FreeNode #perl)​:
/usr/local/bin/perl -Mthreads -e 'binmode STDOUT, "​:encoding(UTF-8)"; threads->new( sub {sleep 3;print "K\n";}); sleep 5'

produces a core dump.

5.8.8 (Debian unstable version) produces a core dump as well.

Here's the backtrace with blead....

Program terminated with signal 11, Segmentation fault.
#0 0x00c0afa1 in PerlIOEncode_getarg (my_perl=0x8e44108, f=0x8dfffec,
  param=0xbfb7d6e4, flags=1) at encoding.xs​:64
64 PUSHSTACKi(PERLSI_MAGIC);
(gdb) bt
#0 0x00c0afa1 in PerlIOEncode_getarg (my_perl=0x8e44108, f=0x8dfffec,
  param=0xbfb7d6e4, flags=1) at encoding.xs​:64
#1 0x0822f988 in PerlIOBase_dup (my_perl=0x8e44108, f=0x8e685b4, o=0x8dfffec,
  param=0xbfb7d6e4, flags=1) at perlio.c​:2269
#2 0x00c125af in PerlIOEncode_dup (my_perl=0x8e44108, f=0x8e685b4,
  o=0x8dfffec, params=0xbfb7d6e4, flags=1) at encoding.xs​:554
#3 0x0822bedf in PerlIO_fdupopen (my_perl=0x8e44108, f=0x8dfffec,
  param=0xbfb7d6e4, flags=1) at perlio.c​:569
#4 0x08153680 in Perl_fp_dup (my_perl=0x8e44108, fp=0x8dfffec, type=0 '\0',
  param=0xbfb7d6e4) at sv.c​:9669
#5 0x0822c32a in PerlIO_clone (my_perl=0x8e44108, proto=0x8de7008,
  param=0xbfb7d6e4) at perlio.c​:685
#6 0x0815a576 in perl_clone (proto_perl=0x8de7008, flags=2) at sv.c​:11049
#7 0x004e7588 in S_ithread_create (my_perl=0x8de7008,
  init_function=0x8deb7b4, stack_size=0, gimme=128, exit_opt=0,
  params=0x8e463a4) at threads.xs​:666
#8 0x004eade4 in XS_threads_create (my_perl=0x8de7008, cv=0x8e45ca4)
  at threads.xs​:953
#9 0x0811d764 in Perl_pp_entersub (my_perl=0x8de7008) at pp_hot.c​:2823
#10 0x080c3e78 in Perl_runops_debug (my_perl=0x8de7008) at dump.c​:1918
#11 0x080fe0e8 in S_run_body (my_perl=0x8de7008, oldscope=1) at perl.c​:2429
#12 0x080fd54d in perl_run (my_perl=0x8de7008) at perl.c​:2347
#13 0x0806068c in main (argc=5, argv=0xbfb7dd44, env=0xbfb7dd5c)

[p5pRT]

From @smpeters

On Thu, Aug 23, 2007 at 08​:01​:56AM -0500, Steve Peters wrote​:

On Thu, Aug 23, 2007 at 03​:45​:26AM -0700, Rafael Kitover wrote​:

# New Ticket Created by "Rafael Kitover"
# Please include the string​: [perl #44887]
# in the subject line of all future correspondence about this issue.
# <URL​: http​://rt.perl.org/rt3/Ticket/Display.html?id=44887 >

This is a bug report for perl from rkitover@​rkitover-linux.walmart.com,
generated with the help of perlbug 1.36 running under perl 5.9.5.

-----------------------------------------------------------------
[Please enter your report here]

As reported by DawnFantasy on IRC (FreeNode #perl)​:
/usr/local/bin/perl -Mthreads -e 'binmode STDOUT, "​:encoding(UTF-8)"; threads->new( sub {sleep 3;print "K\n";}); sleep 5'

produces a core dump.

5.8.8 (Debian unstable version) produces a core dump as well.

Here's the backtrace with blead....

Program terminated with signal 11, Segmentation fault.
#0 0x00c0afa1 in PerlIOEncode_getarg (my_perl=0x8e44108, f=0x8dfffec,
param=0xbfb7d6e4, flags=1) at encoding.xs​:64
64 PUSHSTACKi(PERLSI_MAGIC);
(gdb) bt
#0 0x00c0afa1 in PerlIOEncode_getarg (my_perl=0x8e44108, f=0x8dfffec,
param=0xbfb7d6e4, flags=1) at encoding.xs​:64
#1 0x0822f988 in PerlIOBase_dup (my_perl=0x8e44108, f=0x8e685b4, o=0x8dfffec,
param=0xbfb7d6e4, flags=1) at perlio.c​:2269
#2 0x00c125af in PerlIOEncode_dup (my_perl=0x8e44108, f=0x8e685b4,
o=0x8dfffec, params=0xbfb7d6e4, flags=1) at encoding.xs​:554
#3 0x0822bedf in PerlIO_fdupopen (my_perl=0x8e44108, f=0x8dfffec,
param=0xbfb7d6e4, flags=1) at perlio.c​:569
#4 0x08153680 in Perl_fp_dup (my_perl=0x8e44108, fp=0x8dfffec, type=0 '\0',
param=0xbfb7d6e4) at sv.c​:9669
#5 0x0822c32a in PerlIO_clone (my_perl=0x8e44108, proto=0x8de7008,
param=0xbfb7d6e4) at perlio.c​:685
#6 0x0815a576 in perl_clone (proto_perl=0x8de7008, flags=2) at sv.c​:11049
#7 0x004e7588 in S_ithread_create (my_perl=0x8de7008,
init_function=0x8deb7b4, stack_size=0, gimme=128, exit_opt=0,
params=0x8e463a4) at threads.xs​:666
#8 0x004eade4 in XS_threads_create (my_perl=0x8de7008, cv=0x8e45ca4)
at threads.xs​:953
#9 0x0811d764 in Perl_pp_entersub (my_perl=0x8de7008) at pp_hot.c​:2823
#10 0x080c3e78 in Perl_runops_debug (my_perl=0x8de7008) at dump.c​:1918
#11 0x080fe0e8 in S_run_body (my_perl=0x8de7008, oldscope=1) at perl.c​:2429
#12 0x080fd54d in perl_run (my_perl=0x8de7008) at perl.c​:2347
#13 0x0806068c in main (argc=5, argv=0xbfb7dd44, env=0xbfb7dd5c)

Now that I look at the code, this is a known bug. I'll merge this in with
RT #31923.

Steve Peters
steve@​fisharerojo.org

[p5pRT]

From blgl@hagernas.com

In article <20070823130816.GA3683@​kirk.peters.homeunix.org>,
steve@​fisharerojo.org (Steve Peters) wrote​:

Now that I look at the code, this is a known bug. I'll merge this in with
RT #31923.

It's related to #41106 as well.

/Bo Lindbergh

[p5pRT]

From @nwc10

Created by @nwc10

$ valgrind ./perl -Ilib -Mthreads -e '{use encoding "latin1"} threads->new(sub {})->join()'
==17052== Memcheck, a memory error detector.
==17052== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al.
==17052== Using LibVEX rev 1854, a library for dynamic binary translation.
==17052== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP.
==17052== Using valgrind-3.3.1-Debian, a dynamic binary instrumentation framework.
==17052== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al.
==17052== For more details, rerun with​: -v
==17052==
==17052== Invalid read of size 8
==17052== at 0x668308A​: PerlIOEncode_getarg (in /home/nick/Perl/perl/lib/auto/PerlIO/encoding/encoding.so)
==17052== by 0x4E7767​: PerlIOBase_dup (in /home/nick/Perl/perl/perl)
==17052== by 0x66815EF​: PerlIOEncode_dup (in /home/nick/Perl/perl/lib/auto/PerlIO/encoding/encoding.so)
==17052== by 0x48D03C​: Perl_fp_dup (in /home/nick/Perl/perl/perl)
==17052== by 0x4E8CBC​: PerlIO_clone (in /home/nick/Perl/perl/perl)
==17052== by 0x49A892​: perl_clone (in /home/nick/Perl/perl/perl)
==17052== by 0x6274C33​: XS_threads_create (in /home/nick/Perl/perl/lib/auto/threads/threads.so)
==17052== by 0x485B8E​: Perl_pp_entersub (in /home/nick/Perl/perl/perl)
==17052== by 0x484419​: Perl_runops_standard (in /home/nick/Perl/perl/perl)
==17052== by 0x42F534​: perl_run (in /home/nick/Perl/perl/perl)
==17052== by 0x41C978​: main (in /home/nick/Perl/perl/perl)
==17052== Address 0x18 is not stack'd, malloc'd or (recently) free'd
==17052==
==17052== Process terminating with default action of signal 11 (SIGSEGV)
==17052== Access not within mapped region at address 0x18
==17052== at 0x668308A​: PerlIOEncode_getarg (in /home/nick/Perl/perl/lib/auto/PerlIO/encoding/encoding.so)
==17052== by 0x4E7767​: PerlIOBase_dup (in /home/nick/Perl/perl/perl)
==17052== by 0x66815EF​: PerlIOEncode_dup (in /home/nick/Perl/perl/lib/auto/PerlIO/encoding/encoding.so)
==17052== by 0x48D03C​: Perl_fp_dup (in /home/nick/Perl/perl/perl)
==17052== by 0x4E8CBC​: PerlIO_clone (in /home/nick/Perl/perl/perl)
==17052== by 0x49A892​: perl_clone (in /home/nick/Perl/perl/perl)
==17052== by 0x6274C33​: XS_threads_create (in /home/nick/Perl/perl/lib/auto/threads/threads.so)
==17052== by 0x485B8E​: Perl_pp_entersub (in /home/nick/Perl/perl/perl)
==17052== by 0x484419​: Perl_runops_standard (in /home/nick/Perl/perl/perl)
==17052== by 0x42F534​: perl_run (in /home/nick/Perl/perl/perl)
==17052== by 0x41C978​: main (in /home/nick/Perl/perl/perl)
==17052==
==17052== ERROR SUMMARY​: 1 errors from 1 contexts (suppressed​: 38 from 2)
==17052== malloc/free​: in use at exit​: 1,206,133 bytes in 14,483 blocks.
==17052== malloc/free​: 27,110 allocs, 12,627 frees, 2,160,854 bytes allocated.
==17052== For counts of detected errors, rerun with​: -v
==17052== searching for pointers to 14,483 not-freed blocks.
==17052== checked 1,407,560 bytes.
==17052==
==17052== LEAK SUMMARY​:
==17052== definitely lost​: 2,420 bytes in 36 blocks.
==17052== possibly lost​: 0 bytes in 0 blocks.
==17052== still reachable​: 1,203,713 bytes in 14,447 blocks.
==17052== suppressed​: 0 bytes in 0 blocks.
==17052== Rerun with --leak-check=full to see details of leaked memory.
Segmentation fault

Obviously it shouldn't do that.

Nicholas Clark

Perl Info

Flags:
    category=core
    severity=low

Site configuration information for perl 5.13.10:

Configured by nick at Sun Mar 20 10:09:17 GMT 2011.

Summary of my perl5 (revision 5 version 13 subversion 10) configuration:
  Commit id: 75da9d4c616bae3e6791af93d2ced52dc8080f06
  Platform:
    osname=linux, osvers=2.6.35.4, archname=x86_64-linux-thread-multi
    uname='linux eris 2.6.35.4 #4 smp tue sep 21 09:54:22 bst 2010 x86_64 gnulinux '
    config_args='-Dusedevel=y -Dcc=ccache gcc -Dld=gcc -Ubincompat5005 -Uinstallusrbinperl -Dcf_email=nick@ccl4.org -Dperladmin=nick@ccl4.org -Dinc_version_list=  -Dinc_version_list_init=0 -Doptimize=-Os -Dusethreads -Uuselongdouble -Uuse64bitall -Uusemymalloc -Duseperlio -Dprefix=~/Sandpit/snap5.9.x-v5.13.10-526-g88ecb8a -Uusevendorprefix -Uvendorprefix=~/Sandpit/snap5.9.x-v5.13.10-526-g88ecb8a -Dinstallman1dir=none -Dinstallman3dir=none -Uuserelocatableinc -Umad -de'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='ccache gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-Os',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.3.2', gccosandvers=''
    intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=16
    ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib /lib64 /usr/lib64
    libs=-lnsl -ldb -ldl -lm -lcrypt -lutil -lpthread -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=/lib/libc-2.7.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.7'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -Os -L/usr/local/lib -fstack-protector'

Locally applied patches:
    


@INC for perl 5.13.10:
    lib
    /home/nick/Sandpit/snap5.9.x-v5.13.10-526-g88ecb8a/lib/perl5/site_perl/5.13.10/x86_64-linux-thread-multi
    /home/nick/Sandpit/snap5.9.x-v5.13.10-526-g88ecb8a/lib/perl5/site_perl/5.13.10
    /home/nick/Sandpit/snap5.9.x-v5.13.10-526-g88ecb8a/lib/perl5/5.13.10/x86_64-linux-thread-multi
    /home/nick/Sandpit/snap5.9.x-v5.13.10-526-g88ecb8a/lib/perl5/5.13.10
    .


Environment for perl 5.13.10:
    HOME=/home/nick
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/home/nick/bin:/usr/local/bin:/usr/bin:/bin:/usr/games:/usr/local/sbin:/sbin:/usr/sbin
    PERL_BADLANG (unset)
    SHELL=/bin/bash

[p5pRT]

From @nwc10

On Sun Mar 20 04​:04​:25 2011, nicholas wrote​:

$ valgrind ./perl -Ilib -Mthreads -e '{use encoding "latin1"} threads-

new(sub {})->join()'
Obviously it shouldn't do that.

The crash happens when trying to swap stacks here​:

  if (e->enc) {
  dSP;
  /* Not 100% sure stack swap is right thing to do during dup ... */
  PUSHSTACKi(PERLSI_MAGIC);

[that code is called both during dup, and at normal times]

That line was added in 2002 in 24f59af
The testcase crashes at that revision. It crashes at the next statement
(SPAGAIN;) in the parent revision. This bug is old. The fix isn't going
to be as simple as removing the stack swapping code.

Nicholas Clark

[p5pRT]

@nwc10 - Status changed from 'new' to 'open'