[perl #123878] Infinite recursion (+segfault) on die() after goto-ing out of __DIE__ handler

[[e-mail] (via RT)]

# New Ticket Created by ***@fbriere.net
# Please include the string: [perl #123878]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=123878 >



This is a bug report for perl from ***@fbriere.net,
generated with the help of perlbug 1.40 running under perl 5.20.1.


-----------------------------------------------------------------
[Please describe your issue here]

A full description would probably be longer than this code snippet:

$ perl -w
sub foo { die }
sub bar { goto &foo }

$SIG{__DIE__} = \&bar;
die;
Deep recursion on subroutine "main::foo" at - line 2.
Segmentation fault


Segfault aside, I did not expect the die() in foo() to trigger the __DIE__
handler; according to perlvar(1), the handler "is explicitly disabled *during*
the call", from which we haven't returned yet (even though we have technically
left the subroutine).


[Please do not change anything below this line]
-----------------------------------------------------------------
---
Flags:
category=core
severity=low
---
Site configuration information for perl 5.20.1:

Configured by Debian Project at Sun Jan 25 20:36:53 UTC 2015.

Summary of my perl5 (revision 5 version 20 subversion 1) configuration:

Platform:
osname=linux, osvers=3.2.0-4-amd64, archname=i586-linux-gnu-thread-multi-64int
uname='linux brahms 3.2.0-4-amd64 #1 smp debian 3.2.65-1+deb7u1 i686 gnulinux '
config_args='-Dusethreads -Duselargefiles -Dccflags=-DDEBIAN -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Dldflags= -Wl,-z,relro -Dlddlflags=-shared -Wl,-z,relro -Dcccdlflags=-fPIC -Darchname=i586-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.20 -Darchlib=/usr/lib/i386-linux-gnu/perl/5.20 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/i386-linux-gnu/perl5/5.20 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.20.1 -Dsitearch=/usr/local/lib/i386-linux-gnu/perl/5.20.1 -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 -Uversiononly -DDEBUGGING=-g -Doptimize=-O2 -Duseshrplib -Dlibperl=libperl.so.5.20.1 -des'
hint=recommended, useposix=true, d_sigaction=define
useithreads=define, usemultiplicity=define
use64bitint=define, use64bitall=undef, uselongdouble=undef
usemymalloc=n, bincompat5005=undef
Compiler:
cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
optimize='-O2 -g',
cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include'
ccversion='', gccversion='4.9.2', 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=4, prototype=define
Linker and Libraries:
ld='cc', ldflags =' -fstack-protector -L/usr/local/lib'
libpth=/usr/local/lib /usr/lib/gcc/i586-linux-gnu/4.9/include-fixed /usr/include/i386-linux-gnu /usr/lib /lib/i386-linux-gnu /lib/../lib /usr/lib/i386-linux-gnu /usr/lib/../lib /lib
libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt
perllibs=-ldl -lm -lpthread -lc -lcrypt
libc=libc-2.19.so, so=so, useshrplib=true, libperl=libperl.so.5.20
gnulibc_version='2.19'
Dynamic Linking:
dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib -fstack-protector'

Locally applied patches:
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/libperl_embed_doc - http://bugs.debian.org/186778 Note that libperl-dev package is required for embedded linking
DEBPKG:fixes/respect_umask - Respect umask during installation
DEBPKG:debian/writable_site_dirs - Set umask approproately for site install directories
DEBPKG:debian/extutils_set_libperl_path - EU:MM: set location of libperl.a under /usr/lib
DEBPKG:debian/no_packlist_perllocal - Don't install .packlist or perllocal.pod for perl or vendor
DEBPKG:debian/prefix_changes - Fiddle with *PREFIX and variables written to the makefile
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/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 - [rt.cpan.org #36038] http://bugs.debian.org/100195 Document the Net::SMTP 'Port' option
DEBPKG:debian/perlivp - http://bugs.debian.org/510895 Make perlivp skip include directories in /usr/local
DEBPKG:debian/deprecate-with-apt - http://bugs.debian.org/747628 Point users to Debian packages of deprecated core modules
DEBPKG:debian/squelch-locale-warnings - http://bugs.debian.org/508764 Squelch locale warnings in Debian package maintainer scripts
DEBPKG:debian/skip-upstream-git-tests - Skip tests specific to the upstream Git repository
DEBPKG:debian/patchlevel - http://bugs.debian.org/567489 List packaged patches for 5.20.1-5 in patchlevel.h
DEBPKG:debian/skip-kfreebsd-crash - http://bugs.debian.org/628493 [perl #96272] Skip a crashing test case in t/op/threads.t on GNU/kFreeBSD
DEBPKG:fixes/document_makemaker_ccflags - http://bugs.debian.org/628522 [rt.cpan.org #68613] Document that CCFLAGS should include $Config{ccflags}
DEBPKG:debian/find_html2text - http://bugs.debian.org/640479 Configure CPAN::Distribution with correct name of html2text
DEBPKG:debian/perl5db-x-terminal-emulator.patch - http://bugs.debian.org/668490 Invoke x-terminal-emulator rather than xterm in perl5db.pl
DEBPKG:debian/cpan-missing-site-dirs - http://bugs.debian.org/688842 Fix CPAN::FirstTime defaults with nonexisting site dirs if a parent is writable
DEBPKG:fixes/memoize_storable_nstore - [rt.cpan.org #77790] http://bugs.debian.org/587650 Memoize::Storable: respect 'nstore' option not respected
DEBPKG:debian/regen-skip - Skip a regeneration check in unrelated git repositories
DEBPKG:fixes/regcomp-mips-optim - [perl #122817] http://bugs.debian.org/754054 Downgrade the optimization of regcomp.c on mips and mipsel due to a gcc-4.9 bug
DEBPKG:debian/makemaker-pasthru - http://bugs.debian.org/758471 Pass LD settings through to subdirectories
DEBPKG:fixes/perldoc-less-R - [rt.cpan.org #98636] http://bugs.debian.org/758689 Tell the 'less' pager to allow terminal escape sequences
DEBPKG:fixes/pod_man_reproducible_date - http://bugs.debian.org/759405 Support POD_MAN_DATE in Pod::Man for the left-hand footer
DEBPKG:fixes/data_dump_infinite_recurse - [19be3be] don't recurse infinitely in Data::Dumper
DEBPKG:fixes/io_uncompress_gunzip_inmemory - http://bugs.debian.org/747363 [rt.cpan.org #95494] Fix gunzip to in-memory file handle
DEBPKG:fixes/socket_test_recv_fix - http://bugs.debian.org/758718 [perl #122657] Compare recv return value to peername in socket test
DEBPKG:fixes/hurd_socket_recv_todo - http://bugs.debian.org/758718 [perl #122657] TODO checking the result of recv() on hurd

---
@INC for perl 5.20.1:
/etc/perl
/usr/local/lib/i386-linux-gnu/perl/5.20.1
/usr/local/share/perl/5.20.1
/usr/lib/i386-linux-gnu/perl5/5.20
/usr/share/perl5
/usr/lib/i386-linux-gnu/perl/5.20
/usr/share/perl/5.20
/usr/local/lib/site_perl
.

---
Environment for perl 5.20.1:
HOME=/home/fbriere
LANG=en_CA.UTF-8
LANGUAGE (unset)
LD_LIBRARY_PATH (unset)
LOGDIR (unset)
PATH=/home/fbriere/bin:/home/fbriere/humble/bin:/usr/lib/ccache:/usr/local/bin:/usr/bin:/bin:/usr/games
PERL_BADLANG (unset)
SHELL=/bin/bash

[Reini Urban via RT]

This SEGV with a nested die handler doesn't seem severity low to me.
It seems to be similar to Lukas Mai's fix for 'don't fatalize warnings during unwinding (#123398)',
which is not even applied yet.

[Dagfinn Ilmari Mannsåker]

Post by Reini Urban via RT
This SEGV with a nested die handler doesn't seem severity low to me.
It seems to be similar to Lukas Mai's fix for 'don't fatalize warnings
during unwinding (#123398)', which is not even applied yet.

You appear to be looking at an outdated copy of the perl source, it was
applied by TonyC on 2015-07-08:

http://perl5.git.perl.org/perl.git/commitdiff/46b27d2f2c37f40dde845f9b4743975c69f2cc27

If you think it should be backported to maint-5.22, feel free to suggest
it.

[Reini Urban via RT]

Die handler testcases added in the attached patch. do not apply, fix it first.
or I'll do I'm faster