Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Debugger corrupts symbol table munging #9145

Closed
p5pRT opened this issue Dec 7, 2007 · 10 comments
Closed

Debugger corrupts symbol table munging #9145

p5pRT opened this issue Dec 7, 2007 · 10 comments

Comments

@p5pRT
Copy link

@p5pRT p5pRT commented Dec 7, 2007

Migrated from rt.perl.org#48332 (status was 'resolved')

Searchable as RT48332$

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Dec 7, 2007

From mjcarman@mchsi.com

Created by mjcarman@mchsi.com

This is a bug report for perl from mjcarman@​mchsi.com,
generated with the help of perlbug 1.35 running under perl v5.8.8.

-----------------------------------------------------------------

Given the following script​:

  use strict;
  use warnings;
 
  sub foo { print "1\n" }
 
  {
  no warnings 'redefine';
  *old_foo = \&foo;
  *foo = sub { print "2\n" }
  }
 
  old_foo();
  foo();
 
  __END__

Run normally, this works as expected. (i.e. it prints 1, 2) When run under the debugger,
*old_foo incorrectly points to the new foo(). (i.e. it prints 2, 2)

In the particular case where I noticed this bug the new foo() was a wrapper which called
old_foo(). This created an infinite recursion which the debugger eventually bailed out
of with the message "100 levels deep in subroutine calls!"

Perl Info

Flags:
    category=utilities
    severity=low

Site configuration information for perl v5.8.8:

Configured by SYSTEM at Tue Jul 31 19:34:29 2007.

Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
  Platform:
    osname=MSWin32, osvers=5.00, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    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 ='-DNDEBUG -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED -DUSE_SITECUSTOMIZE -DPRIVLIB_LAST_IN_INC -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX -DHASATTRIBUTE -fno-strict-aliasing',
    optimize='-O2',
    cppflags='-DWIN32'
    ccversion='', gccversion='3.4.2 (mingw-special)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=8
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='g++', ldflags ='-L"C:\Perl\lib\CORE"'
    libpth=\lib
    libs=-lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32 -lmsvcrt
    perllibs=-lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32 -lmsvcrt
    libc=msvcrt.lib, so=dll, useshrplib=true, libperl=perl58.lib
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-mdll -L"C:\Perl\lib\CORE"'

Locally applied patches:
    ACTIVEPERL_LOCAL_PATCHES_ENTRY
    Iin_load_module moved for compatibility with build 806
    Avoid signal flag SA_RESTART for older versions of HP-UX
    PerlEx support in CGI::Carp
    Less verbose ExtUtils::Install and Pod::Find
    Patch for CAN-2005-0448 from Debian with modifications
    Rearrange @INC so that 'site' is searched before 'perl'
    Partly reverted 24733 to preserve binary compatibility
    MAINT31223 plus additional changes
    31490 Problem bootstraping Win32CORE
    31324 Fix DynaLoader::dl_findfile() to locate .so files again
    31214 Win32::GetLastError fails when first called
    31211 Restore Windows NT support
    31188 Problem killing a pseudo-forked child on Win32
    29732 ANSIfy the PATH environment variable on Windows
    27527,29868 win32_async_check() can loop indefinitely
    26970 Make Passive mode the default for Net::FTP
    26379 Fix alarm() for Windows 2003
    24699 ICMP_UNREACHABLE handling in Net::Ping


@INC for perl v5.8.8:
    C:/Perl/site/lib
    C:/Perl/lib
    .


Environment for perl v5.8.8:
    HOME (unset)
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=C:\Program Files\Microsoft IntelliType Pro\;C:\Perl\bin;C:\WINDOWS;C:\WINDOWS\System32;C:\WINDOWS\System32\wbem;C:\Lotus\Notes\Data;C:\Lotus\Notes;C:\Program Files\Rational\ClearCase\bin;C:\Program Files\Rational\common;C:\Program Files\QuickTime\QTSystem\;C:\PROGRA~1\ATT\Graphviz\bin;C:\Tools;C:\Perl\site\bin;C:\MinGW\bin;Z:\FlexIO\Tools
    PERL_BADLANG (unset)
    SHELL (unset)

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jan 5, 2010

From @iabyn

I can't reproduce this in 5.8.8, but its present in 5.9.4, 5.10.0 and bleed​:

[davem@​pigeon bleed]$ ./perl -d /tmp/p

Loading DB routines from perl5db.pl version 1.33
Editor support available.

Enter h or `h h' for help, or `man perldebug' for more help.

main​::(/tmp/p​:9)​: no warnings 'redefine';
  DB<1> c
2
2
Debugged program terminated. Use q to quit or R to restart,
  use o inhibit_exit to avoid stopping after program termination,
  h q, h R or h o to get additional info.
  DB<1>

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jan 5, 2010

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

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Oct 1, 2010

From @cpansprout

Fixed by be1cc45.

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Oct 1, 2010

@cpansprout - Status changed from 'open' to 'resolved'

Loading

@p5pRT p5pRT closed this Oct 1, 2010
@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jul 6, 2011

From @salva

Created by @salva

If some function &A​::foo is exported to package B becomming &B​::foo, then, assigning a new CODE ref to *A​::foo also unexpectedly changes B​::foo.

The funny thing is that getting a reference to B​::foo returns a reference to the former function!

Debugger session follows​:

  DB<1> sub foo { print "former foo\n" }

  DB<2> *M​::foo = \&foo;

  DB<3> *foo = sub { print "reformed foo\n" }

  DB<4> x M​::foo
reformed foo
0  1
  DB<5> x (\&M​::foo)->()
former foo
0  1

Perl Info

Flags:
    category=core
    severity=high

Site configuration information for perl 5.12.3:

Configured by Debian Project at Thu May  5 10:00:04 UTC 2011.

Summary of my perl5 (revision 5 version 12 subversion 3) configuration:
   
  Platform:
    osname=linux, osvers=2.6.24-28-server, archname=x86_64-linux-gnu-thread-multi
    uname='linux allspice 2.6.24-28-server #1 smp wed aug 18 21:17:51 utc 2010 x86_64 x86_64 x86_64 gnulinux '
    config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.12 -Darchlib=/usr/lib/perl/5.12 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.12.3 -Dsitearch=/usr/local/lib/perl/5.12.3 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Duse64bitint -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -Ui_libutil -DDEBUGGING=-g -Doptimize=-O2 -Dplibpth=/lib/x86_64-linux-gnu /usr/lib/x86_64-linux-gnu -Duseshrplib -Dlibperl=libperl.so.5.12.3 -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 -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2 -g',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.6.1 20110503 (prerelease)', 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 =' -fstack-protector -L/usr/local/lib'
    libpth=/usr/local/lib /lib/x86_64-linux-gnu /usr/lib/x86_64-linux-gnu /lib /usr/lib /lib64 /usr/lib64
    libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
    perllibs=-ldl -lm -lpthread -lc -lcrypt
    libc=, so=so, useshrplib=true, libperl=libperl.so.5.12.3
    gnulibc_version='2.13'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -g -L/usr/local/lib -fstack-protector'

Locally applied patches:
    DEBPKG:debian/arm_thread_stress_timeout - http://bugs.debian.org/501970 Raise the timeout of ext/threads/shared/t/stress.t to accommodate slower build hosts
    DEBPKG:debian/cpan_config_path - Set location of CPAN::Config to /etc/perl as /usr may not be writable.
    DEBPKG:debian/cpan_definstalldirs - Provide a sensible INSTALLDIRS default for modules installed from CPAN.
    DEBPKG:debian/db_file_ver - http://bugs.debian.org/340047 Remove overly restrictive DB_File version check.
    DEBPKG:debian/doc_info - Replace generic man(1) instructions with Debian-specific information.
    DEBPKG:debian/enc2xs_inc - http://bugs.debian.org/290336 Tweak enc2xs to follow symlinks and ignore missing @INC directories.
    DEBPKG:debian/errno_ver - http://bugs.debian.org/343351 Remove Errno version check due to upgrade problems with long-running processes.
    DEBPKG:debian/extutils_hacks - Various debian-specific ExtUtils changes
    DEBPKG:debian/fakeroot - Postpone LD_LIBRARY_PATH evaluation to the binary targets.
    DEBPKG:debian/instmodsh_doc - Debian policy doesn't install .packlist files for core or vendor.
    DEBPKG:debian/ld_run_path - Remove standard libs from LD_RUN_PATH as per Debian policy.
    DEBPKG:debian/libnet_config_path - Set location of libnet.cfg to /etc/perl/Net as /usr may not be writable.
    DEBPKG:debian/m68k_thread_stress - http://bugs.debian.org/495826 Disable some threads tests on m68k for now due to missing TLS.
    DEBPKG:debian/mod_paths - Tweak @INC ordering for Debian
    DEBPKG:debian/module_build_man_extensions - http://bugs.debian.org/479460 Adjust Module::Build manual page extensions for the Debian Perl policy
    DEBPKG:debian/prune_libs - http://bugs.debian.org/128355 Prune the list of libraries wanted to what we actually need.
    DEBPKG:fixes/net_smtp_docs - http://bugs.debian.org/100195 [rt.cpan.org #36038] Document the Net::SMTP 'Port' option
    DEBPKG:fixes/processPL - http://bugs.debian.org/357264 [rt.cpan.org #17224] Always use PERLRUNINST when building perl modules.
    DEBPKG:debian/perlivp - http://bugs.debian.org/510895 Make perlivp skip include directories in /usr/local
    DEBPKG:debian/disable-zlib-bundling - Disable zlib bundling in Compress::Raw::Zlib
    DEBPKG:debian/cpanplus_definstalldirs - http://bugs.debian.org/533707 Configure CPANPLUS to use the site directories by default.
    DEBPKG:debian/cpanplus_config_path - Save local versions of CPANPLUS::Config::System into /etc/perl.
    DEBPKG:fixes/autodie-flock - http://bugs.debian.org/543731 Allow for flock returning EAGAIN instead of EWOULDBLOCK on linux/parisc
    DEBPKG:debian/devel-ppport-ia64-optim - http://bugs.debian.org/548943 Work around an ICE on ia64
    DEBPKG:fixes/cpanplus-without-home - http://bugs.debian.org/577011 [rt.cpan.org #52988] Fix CPANPLUS test failures when HOME doesn't exist
    DEBPKG:debian/arm_optim - http://bugs.debian.org/580334 Downgrade the optimization of sv.c on arm due to a gcc-4.4 bug
    DEBPKG:debian/deprecate-with-apt - http://bugs.debian.org/580034 Point users to Debian packages of deprecated core modules
    DEBPKG:fixes/hurd-ccflags - http://bugs.debian.org/587901 Make hints/gnu.sh append to $ccflags rather than overriding them
    DEBPKG:debian/squelch-locale-warnings - http://bugs.debian.org/508764 Squelch locale warnings in Debian package maintainer scripts
    DEBPKG:fixes/lc-numeric-docs - http://bugs.debian.org/379329 [perl #78452] [903eb63] LC_NUMERIC documentation fixes
    DEBPKG:fixes/lc-numeric-sprintf - http://bugs.debian.org/601549 [perl #78632] [b3fd614] Fix sprintf not to ignore LC_NUMERIC with constants
    DEBPKG:fixes/concat-stack-corruption - http://bugs.debian.org/596105 [perl #78674] [e3393f5] Fix stack pointer corruption in pp_concat() with 'use encoding'
    DEBPKG:fixes/h2ph-gcc-4.5 - http://bugs.debian.org/599933 [8d66b3f] h2ph fix for gcc 4.5
    DEBPKG:fixes/casing-taint-cve-2011-1487 - http://bugs.debian.org/622817 [perl #87336] fix unwanted taint laundering in lc(), uc() et al.
    DEBPKG:fixes/correct-module-corelist-version - [a0a0e54] Correct the version of Module::CoreList that was released with v5.12.3
    DEBPKG:patchlevel - http://bugs.debian.org/567489 List packaged patches for 5.12.3-6 in patchlevel.h


@INC for perl 5.12.3:
    /etc/perl
    /usr/local/lib/perl/5.12.3
    /usr/local/share/perl/5.12.3
    /usr/lib/perl5
    /usr/share/perl5
    /usr/lib/perl/5.12
    /usr/share/perl/5.12
    /usr/local/lib/site_perl
    .


Environment for perl 5.12.3:
    HOME=/home/salva
    LANG=en_US.UTF-8
    LANGUAGE=en_US:en
    LC_MESSAGES=en_US.UTF-8
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin
    PERL_BADLANG (unset)
    SHELL=/bin/bash

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jul 6, 2011

From @cpansprout

On Wed Jul 06 06​:27​:52 2011, salva wrote​:

If some function &A​::foo is exported to package B becomming &B​::foo,
then, assigning a new CODE ref to *A​::foo also unexpectedly changes
B​::foo.

The funny thing is that getting a reference to B​::foo returns a
reference to the former function!

Debugger session follows​:

� DB<1> sub foo { print "former foo\n" }

� DB<2> *M​::foo = \&foo;

� DB<3> *foo = sub { print "reformed foo\n" }

� DB<4> x M​::foo
reformed foo
0� 1
� DB<5> x (\&M​::foo)->()
former foo
0� 1

This is the same bug as #48332, which was fixed in 5.14.0.

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jul 6, 2011

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

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jul 6, 2011

@cpansprout - Status changed from 'open' to 'resolved'

Loading

@p5pRT
Copy link
Author

@p5pRT p5pRT commented Jul 12, 2011

From @iabyn

On Wed, Jul 06, 2011 at 06​:27​:53AM -0700, Salvador Fandiño wrote​:

If some function &A​::foo is exported to package B becomming &B​::foo, then, assigning a new CODE ref to *A​::foo also unexpectedly changes B​::foo.

The funny thing is that getting a reference to B​::foo returns a reference to the former function!

Debugger session follows​:

  DB<1> sub foo { print "former foo\n" }

  DB<2> *M​::foo = \&foo;

  DB<3> *foo = sub { print "reformed foo\n" }

  DB<4> x M​::foo
reformed foo
0  1
  DB<5> x (\&M​::foo)->()
former foo
0  1

This appears to have been fixed somewhere between 5.13.4 and 5.13.6

--
"You're so sadly neglected, and often ignored.
A poor second to Belgium, When going abroad."
  -- Monty Python, "Finland"

Loading

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Linked pull requests

Successfully merging a pull request may close this issue.

None yet
1 participant