segmentation fault in string

[tokuhirom]

perl5i -e 'my $x; my $y; "@{[ $x->$y ]}"'

makes core.

(gdb) run
Starting program: /home/disk-firstaid/app/perl-5.12.1/bin/perl5i -e my\ \$x\;\ my\ \$y\;\ \"@\{\[\ \$x-\>\$y\ \]\}\"
process 21181 is executing new program: /home/disk-firstaid/app/perl-5.12.1/bin/perl

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff46d08b8 in indirect_ck_method () from /usr/local/app/perl-5.12.1/lib/site_perl/5.12.1/x86_64-linux/auto/indirect/indirect.so
(gdb) bt
#0  0x00007ffff46d08b8 in indirect_ck_method () from /usr/local/app/perl-5.12.1/lib/site_perl/5.12.1/x86_64-linux/auto/indirect/indirect.so
#1  0x0000000000426f6c in Perl_newUNOP ()
#2  0x000000000045a527 in Perl_yyparse ()
#3  0x0000000000433f4d in S_parse_body ()
#4  0x0000000000435c5d in perl_parse ()
#5  0x000000000041ff33 in main ()

[schwern]

I cannot replicate. Can you give your perl -V please?

Its likely a problem in indirect. Can you check if this has the same problem?

perl -we 'use indirect; my $x; my $y; "@{[ $x->$y ]}"'

[tokuhirom]

% perl -we 'use indirect; my $x; my $y; "@{[ $x->$y ]}"'
Useless use of string in void context at -e line 1.
Use of uninitialized value $y in method lookup at -e line 1.
Can't call method "" on an undefined value at -e line 1.

Summary of my perl5 (revision 5 version 12 subversion 1) configuration:

  Platform:
    osname=linux, osvers=2.6.32-22-server, archname=x86_64-linux
    uname='linux gpath 2.6.32-22-server #33-ubuntu smp wed apr 28 14:34:48 utc 2010 x86_64 gnulinux '
    config_args='-des -Duse64bitint -Dprefix=/usr/local/app/perl-5.12.1/'
    hint=recommended, useposix=true, d_sigaction=define
    useithreads=undef, usemultiplicity=undef
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=define, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include'
    ccversion='', gccversion='4.4.3', 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 /usr/lib /lib64 /usr/lib64
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lc -lgdbm_compat
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.11.1.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.11.1'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fPIC', lddlflags='-shared -O2 -L/usr/local/lib -fstack-protector'

Characteristics of this binary (from libperl):
  Compile-time options: PERL_DONT_CREATE_GVSV PERL_MALLOC_WRAP USE_64_BIT_ALL
                        USE_64_BIT_INT USE_LARGE_FILES USE_PERLIO
                        USE_PERL_ATOF
  Built under linux
  Compiled at May 18 2010 00:52:15
  %ENV:
    PERL_AUTOINSTALL="--defaultdeps"
    PERL_BADLANG="0"
  @INC:
    /usr/local/app/perl-5.12.1/lib/site_perl/5.12.1/x86_64-linux
    /usr/local/app/perl-5.12.1/lib/site_perl/5.12.1
    /usr/local/app/perl-5.12.1/lib/5.12.1/x86_64-linux
    /usr/local/app/perl-5.12.1/lib/5.12.1
    .

[tokuhirom]

% perl -e 'use indirect; BEGIN  { indirect::unimport(__PACKAGE__, ":fatal")  }; my $x; my $y; "@{[ $x->$y ]}"

cause segmentation fault on my machine, too.

[tokuhirom]

It is completely indirect.pm's issue. I'll create RT ticket to indirect.pm :)

[tokuhirom]

ref. https://rt.cpan.org/Ticket/Display.html?id=60378&results=cc5682744d75680675c79cd07bd637d4

[schwern]

Thanks! Let us know when its fixed and we'll bump the dependency on indirect.

[tokuhirom]

This issue was fixed at 0.22! http://cpansearch.perl.org/src/VPIT/indirect-0.22/Changes

[schwern]

I've bumped the requirement on indirect and written a test to make sure the segfault doesn't happen again. Would you please try out http://github.com/schwern/perl5i/tree/github164 and check that it catches the segfault when using indirect 0.20? And if not, patch it up? I can't reproduce the problem here so I'm flying blind.

[tokuhirom]

Passed all tests in github164 branch with indirect 0.22! thanks.

[schwern]

Thank you, but I need to know that it fails with 0.20.

[tokuhirom]

Oops. sorry.

With indrect 0.20, it fails.

% perl -Ilib t/github164.t
zsh: segmentation fault  perl -Ilib t/github164.t

[schwern]

Fixed by cd7b3248f6d0b1bcceadcf7946f83c0e852b35a4