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Posted to modperl@perl.apache.org by Stephane Chazelas <st...@artesyncp.com> on 2007/03/28 12:46:15 UTC

mod_perl closes apache's stdin and/or stdout

1. Problem Description:

  Hiya,

  After querying a mod_perl run CGI, the corresponding apache2
  process ends up having its fd 0 and/or fd 1 closed. This then
  causes some other CGIs (for instance mod_python's viewvc) to
  fail because they are not robust enough to cope with a closed
  fd 0.

  Stracing the apache2 process, here is what I observe:
[...]
4760  dup(0)                            = 17
4760  ioctl(17, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
4760  _llseek(17, 0, [0], SEEK_CUR)     = 0
4760  fstat64(17, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
4760  fcntl64(17, F_SETFD, FD_CLOEXEC)  = 0
4760  close(0)                          = 0
4760  dup(1)                            = 0
4760  ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
4760  _llseek(0, 0, [0], SEEK_CUR)      = 0
4760  fstat64(0, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
4760  fcntl64(0, F_SETFD, 0)            = 0
4760  ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94918) = -1 ENOTTY (Inappropriate ioctl for device)
4760  _llseek(0, 0, [0], SEEK_CUR)      = 0
4760  close(1)                          = 0
[...]

And in the end:

[...]
4760  close(18)                         = 0
4760  close(1)                          = 0
4760  chdir("/etc/apache2")             = 0
4760  dup(17)                           = 1
4760  ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
4760  _llseek(1, 0, [0], SEEK_CUR)      = 0
4760  fstat64(1, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
4760  fcntl64(1, F_SETFD, 0)            = 0
4760  close(17)                         = 0
4760  dup(0)                            = 17
4760  ioctl(17, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
4760  _llseek(17, 0, [0], SEEK_CUR)     = 0
4760  fstat64(17, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
4760  fcntl64(17, F_SETFD, FD_CLOEXEC)  = 0
4760  ioctl(17, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94918) = -1 ENOTTY (Inappropriate ioctl for device)
4760  _llseek(17, 0, [0], SEEK_CUR)     = 0
4760  close(0)                          = 0
4760  writev(16, [{"10\r\n", 4}, {"\n</body>\n</html>", 16}, {"\r\n", 2}, {"0\r\n\r\n", 5}], 4) = 27
4760  read(16, 0x84a69c0, 8000)         = -1 EAGAIN (Resource temporarily unavailable)
4760  write(9, "10.95.129.198 - - [28/Mar/2007:1"..., 2220) = 2220
4760  poll( <unfinished ...>

As you can see mod_perl saves the fd 0 with a dup, and then
closes it. It does the same for fd 1 but as 0 is now an
available fd, fd 1 ends up being dupped to fd 0. Things are then
messed up when mod_perl restores the fds in the end.

This is using debian's unstable apache 2.2.3, using the prefork
MPM.

I get the same behavior with either of the debian mod_perl
package (2.0.2) or 2.0.3 or a checkout (a few minutes ago) from
the svn repository.


2. Used Components and their Configuration:

*** mod_perl version 2.000004

*** using /usr/local/lib/perl/5.8.8/Apache2/BuildConfig.pm

*** Makefile.PL options:
  MP_APR_LIB     => aprext
  MP_APXS        => /usr/bin/apxs
  MP_COMPAT_1X   => 1
  MP_GENERATE_XS => 1
  MP_LIBNAME     => mod_perl
  MP_USE_DSO     => 1


*** The httpd binary was not found

$ apache2ctl -V
Server version: Apache/2.2.3
Server built:   Feb  5 2007 02:13:07
Server's Module Magic Number: 20051115:3
Server loaded:  APR 1.2.7, APR-Util 1.2.7
Compiled using: APR 1.2.7, APR-Util 1.2.7
Architecture:   32-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT=""
 -D SUEXEC_BIN="/usr/lib/apache2/suexec"
 -D DEFAULT_PIDLOG="/var/run/apache2.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="/var/run/apache2/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="/etc/apache2/mime.types"
 -D SERVER_CONFIG_FILE="/etc/apache2/apache2.conf"


*** (apr|apu)-config linking info

 -L/usr/lib -laprutil-1  
 -L/usr/lib -lapr-1 -luuid -lrt -lcrypt  -lpthread -ldl 



*** /usr/bin/perl -V
Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=linux, osvers=2.6.18.3, archname=i486-linux-gnu-thread-multi
    uname='linux saens 2.6.18.3 #1 smp sat nov 25 13:39:52 est 2006 i686 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8 -Darchlib=/usr/lib/perl/5.8 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.8 -Dsitearch=/usr/local/lib/perl/5.8.8 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.8 -Dd_dosuid -des'
    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='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include'
    ccversion='', gccversion='4.1.2 20061115 (prerelease) (Debian 4.1.1-20)', 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='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=/lib/libc-2.3.6.so, so=so, useshrplib=true, libperl=libperl.so.5.8.8
    gnulibc_version='2.3.6'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'


Characteristics of this binary (from libperl): 
  Compile-time options: MULTIPLICITY PERL_IMPLICIT_CONTEXT
                        PERL_MALLOC_WRAP THREADS_HAVE_PIDS USE_ITHREADS
                        USE_LARGE_FILES USE_PERLIO USE_REENTRANT_API
  Built under linux
  Compiled at Dec  6 2006 23:05:53
  %ENV:
    PERL5LIB="/home/stephane/lib/perl"
    PERL_LWP_USE_HTTP_10="1"
  @INC:
    /home/stephane/lib/perl
    /etc/perl
    /usr/local/lib/perl/5.8.8
    /usr/local/share/perl/5.8.8
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.8
    /usr/share/perl/5.8
    /usr/local/lib/site_perl
    .

*** Packages of interest status:

Apache2            : -
Apache2::Request   : -
CGI                : 3.15
ExtUtils::MakeMaker: 6.30_01
LWP                : 5.805
mod_perl           : -
mod_perl2          : 2.000004

$ svn info
Path: .
URL: https://svn.apache.org/repos/asf/perl/modperl/trunk
Repository Root: https://svn.apache.org/repos/asf
Repository UUID: 13f79535-47bb-0310-9956-ffa450edef68
Revision: 523256
Node Kind: directory
Schedule: normal
Last Changed Author: geoff
Last Changed Rev: 522508
Last Changed Date: 2007-03-26 14:04:00 +0100 (Mon, 26 Mar 2007)


Best regards,
Stephane

Re: mod_perl closes apache's stdin and/or stdout

Posted by Stephane Chazelas <st...@artesyncp.com>.
On Thu, Mar 29, 2007 at 11:01:57PM +0100, Stephane Chazelas wrote:
[...]
> COMMAND   PID     USER   FD   TYPE   DEVICE    SIZE     NODE NAME
> [...]
> sh      19113 www-data    0r   CHR      1,3             1673 /dev/null
> sh      19113 www-data    1w   CHR      1,3             1673 /dev/null
> sh      19113 www-data    2w   REG      8,9 2041426   244362 /var/log/apache2/error.log
> [...]
> sh      19113 www-data   16u  IPv4 14009527              TCP ant.artesyncp.com:www->ant.artesyncp.com:43127 (ESTABLISHED)
> 
> fds 0 and 1 are /dev/null as they should be if apache was not running modperl
> because modperl does
> 
> 
> dup(0);
> close(0);
> dup(1);
> close(1);
> 
> so that the second dup assigns stdin as a copy of stdout!
[...]

Well, actually, I get that when I run the script twice with the
same apache process.

On the first time, I rather get instead:


sh      14044 www-data    0w   CHR      1,3             1673 /dev/null
sh      14044 www-data    2w   REG      8,9 2047900   244362 /var/log/apache2/error.log
[...]
sh      14044 www-data   16u  IPv4 14051633              TCP ant.astec.com:www->ant.astec.com:39533 (ESTABLISHED)

which does tie up with

dup(0);
close(0);
dup(1);
close(1);

Sorry about the confusion,
Stephane

Re: mod_perl closes apache's stdin and/or stdout

Posted by Stephane Chazelas <st...@artesyncp.com>.
On Thu, Mar 29, 2007 at 09:06:20PM +0100, Stephane Chazelas wrote:
[...]
> print STDOUT "...";
> actually did a write(16, "..."), so STDOUT was affected another
> fd that 1. Tomorrow, I'll try doing a system() within perl, but
> I suspect for instance system("echo foo") will no output
> anything to the socket.
[...]

I can confirm. This script:

print "Content-Type: text/plain\r\n\r\n";
print "test\n";
system 'lsof -p $$';
print "test\n";

outputs 

test
test

while

print "Content-Type: text/plain\r\n\r\n";
print "test\n";
system 'lsof -p $$ >&16';
print "test\n";

outputs

COMMAND   PID     USER   FD   TYPE   DEVICE    SIZE     NODE NAME
[...]
sh      19113 www-data    0r   CHR      1,3             1673 /dev/null
sh      19113 www-data    1w   CHR      1,3             1673 /dev/null
sh      19113 www-data    2w   REG      8,9 2041426   244362 /var/log/apache2/error.log
[...]
sh      19113 www-data   16u  IPv4 14009527              TCP ant.artesyncp.com:www->ant.artesyncp.com:43127 (ESTABLISHED)

fds 0 and 1 are /dev/null as they should be if apache was not running modperl
because modperl does


dup(0);
close(0);
dup(1);
close(1);

so that the second dup assigns stdin as a copy of stdout!


Cheers,
Stephane

Re: mod_perl closes apache's stdin and/or stdout

Posted by Stephane Chazelas <st...@artesyncp.com>.
On Thu, Mar 29, 2007 at 02:49:36PM -0500, Frank Wiles wrote:
> On Thu, 29 Mar 2007 10:12:00 +0100
> Stephane Chazelas <st...@artesyncp.com> wrote:
> 
> > On Wed, Mar 28, 2007 at 11:46:15AM +0100, Stephane Chazelas wrote:
> > > 1. Problem Description:
> > > 
> > >   Hiya,
> > > 
> > >   After querying a mod_perl run CGI, the corresponding apache2
> > >   process ends up having its fd 0 and/or fd 1 closed. This then
> > >   causes some other CGIs (for instance mod_python's viewvc) to
> > >   fail because they are not robust enough to cope with a closed
> > >   fd 0.
> > 
> > I should add that this is how mod_perl is told to run the CGI
> > script:
> > 
> > <IfModule mod_perl.c>
> >   <Location /cgi-bin/gnatsweb.pl>
> >     SetHandler perl-script
> >     PerlResponseHandler ModPerl::PerlRunPrefork
> >     PerlOptions +ParseHeaders
> >   </Location>
> > </IfModule>
> > 
> > I disabled mod_perl for now. But could anyone please indicate
> > whether I'm not using it properly or whether it is indeed a bug
> > or whether that version of Apache is not supported?
> 
>    Hi Stephane, 
> 
>    This isn't a bug, but a normal aspect of mod_perl.  You can however
>    re-tie them.  I think this page gives you all the info you need: 
> 
>    http://perl.apache.org/docs/1.0/guide/porting.html#STDIN__STDOUT_and_STDERR_streams
[...]

Hi Frank,

the problem I'm talking about is not that the CGI's STDIN/STDOUT
is reaffected. IT's normal for a normal CGI operation, it's that
the fds 0 and 1 are not restored when modperl returns, so that
other handlers run afterwards by the same Apache process (here
my problem was with mod_python) get messed up. 

And if you look carefully at the traces, even for the CGI, maybe
perl's STDIN/STDOUT /handles/ were reaffected, but they were not
affected fds 0 and 1, it was not a dup, the CGI's

print STDOUT "...";
actually did a write(16, "..."), so STDOUT was affected another
fd that 1. Tomorrow, I'll try doing a system() within perl, but
I suspect for instance system("echo foo") will no output
anything to the socket.

Cheers,
Stephane

Re: mod_perl closes apache's stdin and/or stdout

Posted by Frank Wiles <fr...@wiles.org>.
On Thu, 29 Mar 2007 10:12:00 +0100
Stephane Chazelas <st...@artesyncp.com> wrote:

> On Wed, Mar 28, 2007 at 11:46:15AM +0100, Stephane Chazelas wrote:
> > 1. Problem Description:
> > 
> >   Hiya,
> > 
> >   After querying a mod_perl run CGI, the corresponding apache2
> >   process ends up having its fd 0 and/or fd 1 closed. This then
> >   causes some other CGIs (for instance mod_python's viewvc) to
> >   fail because they are not robust enough to cope with a closed
> >   fd 0.
> 
> I should add that this is how mod_perl is told to run the CGI
> script:
> 
> <IfModule mod_perl.c>
>   <Location /cgi-bin/gnatsweb.pl>
>     SetHandler perl-script
>     PerlResponseHandler ModPerl::PerlRunPrefork
>     PerlOptions +ParseHeaders
>   </Location>
> </IfModule>
> 
> I disabled mod_perl for now. But could anyone please indicate
> whether I'm not using it properly or whether it is indeed a bug
> or whether that version of Apache is not supported?

   Hi Stephane, 

   This isn't a bug, but a normal aspect of mod_perl.  You can however
   re-tie them.  I think this page gives you all the info you need: 

   http://perl.apache.org/docs/1.0/guide/porting.html#STDIN__STDOUT_and_STDERR_streams

 ---------------------------------
   Frank Wiles <fr...@wiles.org>
   http://www.wiles.org
 ---------------------------------


Re: mod_perl closes apache's stdin and/or stdout

Posted by Stephane Chazelas <st...@artesyncp.com>.
On Wed, Mar 28, 2007 at 11:46:15AM +0100, Stephane Chazelas wrote:
> 1. Problem Description:
> 
>   Hiya,
> 
>   After querying a mod_perl run CGI, the corresponding apache2
>   process ends up having its fd 0 and/or fd 1 closed. This then
>   causes some other CGIs (for instance mod_python's viewvc) to
>   fail because they are not robust enough to cope with a closed
>   fd 0.

I should add that this is how mod_perl is told to run the CGI
script:

<IfModule mod_perl.c>
  <Location /cgi-bin/gnatsweb.pl>
    SetHandler perl-script
    PerlResponseHandler ModPerl::PerlRunPrefork
    PerlOptions +ParseHeaders
  </Location>
</IfModule>

I disabled mod_perl for now. But could anyone please indicate
whether I'm not using it properly or whether it is indeed a bug
or whether that version of Apache is not supported?

Thanks,
Stephane

> 
>   Stracing the apache2 process, here is what I observe:
> [...]
> 4760  dup(0)                            = 17
> 4760  ioctl(17, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
> 4760  _llseek(17, 0, [0], SEEK_CUR)     = 0
> 4760  fstat64(17, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
> 4760  fcntl64(17, F_SETFD, FD_CLOEXEC)  = 0
> 4760  close(0)                          = 0
> 4760  dup(1)                            = 0
> 4760  ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
> 4760  _llseek(0, 0, [0], SEEK_CUR)      = 0
> 4760  fstat64(0, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
> 4760  fcntl64(0, F_SETFD, 0)            = 0
> 4760  ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94918) = -1 ENOTTY (Inappropriate ioctl for device)
> 4760  _llseek(0, 0, [0], SEEK_CUR)      = 0
> 4760  close(1)                          = 0
> [...]
> 
> And in the end:
> 
> [...]
> 4760  close(18)                         = 0
> 4760  close(1)                          = 0
> 4760  chdir("/etc/apache2")             = 0
> 4760  dup(17)                           = 1
> 4760  ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
> 4760  _llseek(1, 0, [0], SEEK_CUR)      = 0
> 4760  fstat64(1, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
> 4760  fcntl64(1, F_SETFD, 0)            = 0
> 4760  close(17)                         = 0
> 4760  dup(0)                            = 17
> 4760  ioctl(17, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94938) = -1 ENOTTY (Inappropriate ioctl for device)
> 4760  _llseek(17, 0, [0], SEEK_CUR)     = 0
> 4760  fstat64(17, {st_dev=makedev(0, 14), st_ino=1673, st_mode=S_IFCHR|0666, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=0, st_rdev=makedev(1, 3), st_atime=2007/02/20-09:50:23, st_mtime=2007/02/20-09:50:23, st_ctime=2007/02/20-09:50:23}) = 0
> 4760  fcntl64(17, F_SETFD, FD_CLOEXEC)  = 0
> 4760  ioctl(17, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbfa94918) = -1 ENOTTY (Inappropriate ioctl for device)
> 4760  _llseek(17, 0, [0], SEEK_CUR)     = 0
> 4760  close(0)                          = 0
> 4760  writev(16, [{"10\r\n", 4}, {"\n</body>\n</html>", 16}, {"\r\n", 2}, {"0\r\n\r\n", 5}], 4) = 27
> 4760  read(16, 0x84a69c0, 8000)         = -1 EAGAIN (Resource temporarily unavailable)
> 4760  write(9, "10.95.129.198 - - [28/Mar/2007:1"..., 2220) = 2220
> 4760  poll( <unfinished ...>
> 
> As you can see mod_perl saves the fd 0 with a dup, and then
> closes it. It does the same for fd 1 but as 0 is now an
> available fd, fd 1 ends up being dupped to fd 0. Things are then
> messed up when mod_perl restores the fds in the end.
> 
> This is using debian's unstable apache 2.2.3, using the prefork
> MPM.
> 
> I get the same behavior with either of the debian mod_perl
> package (2.0.2) or 2.0.3 or a checkout (a few minutes ago) from
> the svn repository.
> 
> 
> 2. Used Components and their Configuration:
> 
> *** mod_perl version 2.000004
> 
> *** using /usr/local/lib/perl/5.8.8/Apache2/BuildConfig.pm
> 
> *** Makefile.PL options:
>   MP_APR_LIB     => aprext
>   MP_APXS        => /usr/bin/apxs
>   MP_COMPAT_1X   => 1
>   MP_GENERATE_XS => 1
>   MP_LIBNAME     => mod_perl
>   MP_USE_DSO     => 1
> 
> 
> *** The httpd binary was not found
> 
> $ apache2ctl -V
> Server version: Apache/2.2.3
> Server built:   Feb  5 2007 02:13:07
> Server's Module Magic Number: 20051115:3
> Server loaded:  APR 1.2.7, APR-Util 1.2.7
> Compiled using: APR 1.2.7, APR-Util 1.2.7
> Architecture:   32-bit
> Server MPM:     Prefork
>   threaded:     no
>     forked:     yes (variable process count)
> Server compiled with....
>  -D APACHE_MPM_DIR="server/mpm/prefork"
>  -D APR_HAS_SENDFILE
>  -D APR_HAS_MMAP
>  -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
>  -D APR_USE_SYSVSEM_SERIALIZE
>  -D APR_USE_PTHREAD_SERIALIZE
>  -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
>  -D APR_HAS_OTHER_CHILD
>  -D AP_HAVE_RELIABLE_PIPED_LOGS
>  -D DYNAMIC_MODULE_LIMIT=128
>  -D HTTPD_ROOT=""
>  -D SUEXEC_BIN="/usr/lib/apache2/suexec"
>  -D DEFAULT_PIDLOG="/var/run/apache2.pid"
>  -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
>  -D DEFAULT_LOCKFILE="/var/run/apache2/accept.lock"
>  -D DEFAULT_ERRORLOG="logs/error_log"
>  -D AP_TYPES_CONFIG_FILE="/etc/apache2/mime.types"
>  -D SERVER_CONFIG_FILE="/etc/apache2/apache2.conf"
> 
> 
> *** (apr|apu)-config linking info
> 
>  -L/usr/lib -laprutil-1  
>  -L/usr/lib -lapr-1 -luuid -lrt -lcrypt  -lpthread -ldl 
> 
> 
> 
> *** /usr/bin/perl -V
> Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
>   Platform:
>     osname=linux, osvers=2.6.18.3, archname=i486-linux-gnu-thread-multi
>     uname='linux saens 2.6.18.3 #1 smp sat nov 25 13:39:52 est 2006 i686 gnulinux '
>     config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i486-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.8 -Darchlib=/usr/lib/perl/5.8 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.8.8 -Dsitearch=/usr/local/lib/perl/5.8.8 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Uusenm -Duseshrplib -Dlibperl=libperl.so.5.8.8 -Dd_dosuid -des'
>     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='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
>     optimize='-O2',
>     cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include'
>     ccversion='', gccversion='4.1.2 20061115 (prerelease) (Debian 4.1.1-20)', 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='cc', ldflags =' -L/usr/local/lib'
>     libpth=/usr/local/lib /lib /usr/lib
>     libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
>     perllibs=-ldl -lm -lpthread -lc -lcrypt
>     libc=/lib/libc-2.3.6.so, so=so, useshrplib=true, libperl=libperl.so.5.8.8
>     gnulibc_version='2.3.6'
>   Dynamic Linking:
>     dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
>     cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'
> 
> 
> Characteristics of this binary (from libperl): 
>   Compile-time options: MULTIPLICITY PERL_IMPLICIT_CONTEXT
>                         PERL_MALLOC_WRAP THREADS_HAVE_PIDS USE_ITHREADS
>                         USE_LARGE_FILES USE_PERLIO USE_REENTRANT_API
>   Built under linux
>   Compiled at Dec  6 2006 23:05:53
>   %ENV:
>     PERL5LIB="/home/stephane/lib/perl"
>     PERL_LWP_USE_HTTP_10="1"
>   @INC:
>     /home/stephane/lib/perl
>     /etc/perl
>     /usr/local/lib/perl/5.8.8
>     /usr/local/share/perl/5.8.8
>     /usr/lib/perl5
>     /usr/share/perl5
>     /usr/lib/perl/5.8
>     /usr/share/perl/5.8
>     /usr/local/lib/site_perl
>     .
> 
> *** Packages of interest status:
> 
> Apache2            : -
> Apache2::Request   : -
> CGI                : 3.15
> ExtUtils::MakeMaker: 6.30_01
> LWP                : 5.805
> mod_perl           : -
> mod_perl2          : 2.000004
> 
> $ svn info
> Path: .
> URL: https://svn.apache.org/repos/asf/perl/modperl/trunk
> Repository Root: https://svn.apache.org/repos/asf
> Repository UUID: 13f79535-47bb-0310-9956-ffa450edef68
> Revision: 523256
> Node Kind: directory
> Schedule: normal
> Last Changed Author: geoff
> Last Changed Rev: 522508
> Last Changed Date: 2007-03-26 14:04:00 +0100 (Mon, 26 Mar 2007)