Important update: the problem is nothing to do with Apache or mod_perl. The easiest demonstration:
> perl -le 'use PerlIO::via::QuotedPrint; binmode(\*STDERR, ":via(PerlIO::via::QuotedPrint):utf8"); open (ERROR, ">&STDERR");'
zsh: segmentation fault perl -le
In fact binmode
is performed by my code and open (ERROR, ">&STDERR");
by Parse::RecDescent.
Original question:
I have a problem with Spreadsheet::WriteExcel under mod_perl 2.0.5
Apache dies with segmentation fault, and I found out that it occurs on require Parse::RecDescent
statement within Spreadsheet::WriteExcel
package.
strace shows that last things that happens is dup'ing STDERR:
[pid 31253] dup(2) = 8
[pid 31253] ioctl(8, SNDCTL_TMR_TIMEBASE or TCGETS, 0x7fffcf66a328) = -1 ENOTTY (Inappropriate ioctl for device)
[pid 31253] lseek(8, 0, SEEK_CUR) = 0
[pid 31253] --- SIGSEGV (Segmentation fault) @ 0 (0) ---
I read through the code of Parse::RecDescent
and noticed statements like open (ERROR, ">&STDERR");
Well, after some additional experiments I have this minimalistic Plack app to reproduce the segfault:
use strict;
use warnings;
# DANGEROUS
use PerlIO::via::QuotedPrint;
binmode(\*STDERR, ":via(PerlIO::via::QuotedPrint):utf8");
my $app = sub {
my $env = shift;
open (ERROR, ">&STDERR"); # segmenatation fault
return [
'200',
[ 'Content-Type' => 'text/plain' ],
[ "hello world" ],
];
};
$app;
(In fact I use binmode layer other than PerlIO::via::QuotedPrint
, but effect is the same)
If I don't perform binmode(\*STDERR, ":via(PerlIO...
, apache doesn't segfault.
If I don't duplicate STDERR
, apache doesn't segfault.
If I do the both, it segfaults.
As a workaround I can avoid using binmode
on STDERR, but it's not good.
Any suggestions on where and how should be fixed this?
Thanks.
My environment:
perl -v |grep version
This is perl 5, version 14, subversion 2 (v5.14.2) built for x86_64-linux-gnu-thread-multi
uname -a
Linux thinkpad 3.2.0-32-generic #51-Ubuntu SMP Wed Sep 26 21:33:09 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
lsb_release -c
Codename: precise
dpkg -l |grep mod-perl
ii libapache2-mod-perl2 2.0.5-5ubuntu1 Integration of perl with the Apache2 web server
Upd: the same code works well under outdated Ubuntu 8.04 + perl 5.8.8 + mod_perl2 2.0.3
Upd2: FreeBSD 9.1 + perl 5.14 + mod_perl 2.0.8 -- segfault repeats
uname -a
FreeBSD liruoko.ru 9.1-RELEASE-p5 FreeBSD 9.1-RELEASE-p5 #7 r253740: Sun Jul 28 16:53:08 MSK 2013 [email protected]:/usr/obj/usr/src/sys/MINI amd64
pkg info |grep apache
apache22-itk-mpm-2.2.25 Version 2.2.x of Apache web server with itk MPM.
pkg info |grep mod_perl
ap22-mod_perl2-2.0.8,3 Embeds a Perl interpreter in the Apache2 server
perl -v |grep version
This is perl 5, version 14, subversion 4 (v5.14.4) built for amd64-freebsd
Inappropriate ioctl for device
makes me think of permissions on a socket or file somewhere. Perhaps your kernel,apache
,mod_perl
orperl IO::
layers have changed the way they handle these. Areapache
andmod_perl
compiled from source? – Culdesacopen()
in Perl and seems to be "normal". – Criminalperl
bug. Congratulations! In case you want to file this bug yourself (seeperldoc perlbug
), I will wait awhile before filing it. If I file the bug I will link to this question. Good detective work! – Culdesac