Bug#753444: perl-base - Segfaults in libperl.so.5.18

[Niko Tyni]

On Wed, Jul 02, 2014 at 12:26:57AM +0200, Bastian Blank wrote:
> Package: perl-base
> Version: 5.18.2-4+b1
> Severity: grave
> 
> On s390x perl fails to run debconf and segfaults later on:

> | $ gdb --args perl /usr/share/debconf/frontend
[...]
> | debconf: DbDriver "passwords" warning: could not open /var/cache/debconf/passwords.dat: Permission denied
> | Use of uninitialized value $ARGV[0] in string eq at /usr/share/debconf/frontend line 17.
> | Use of uninitialized value $ARGV[0] in pattern match (m//) at /usr/share/debconf/frontend line 24.
> | Use of uninitialized value $ARGV[0] in concatenation (.) or string at /usr/share/debconf/frontend line 60.
> | Use of uninitialized value $ARGV[0] in pattern match (m//) at /usr/share/debconf/frontend line 61.
> | Use of uninitialized value $ARGV[0] in pattern match (m//) at /usr/share/debconf/frontend line 62.
> | Use of uninitialized value $ARGV[0] in pattern match (m//) at /usr/share/debconf/frontend line 72.
> | Use of uninitialized value $r in <HANDLE> at /usr/share/perl5/Debconf/ConfModule.pm line 72.
> | readline() on unopened filehandle at /usr/share/perl5/Debconf/ConfModule.pm line 72.

FWIW these messages seem to be "normal" when running
/usr/share/debconf/frontend by hand. I see them on amd64 too.

> | Program received signal SIGSEGV, Segmentation fault.
> | 0x000003fffded8838 in ?? () from /usr/lib/libperl.so.5.18
> | (gdb) bt
> | #0  0x000003fffded8838 in ?? () from /usr/lib/libperl.so.5.18
> | #1  0x000003fffdeceba0 in ?? () from /usr/lib/libperl.so.5.18
> | #2  0x000003fffded8f60 in Perl_sv_clean_objs () from /usr/lib/libperl.so.5.18
> | #3  0x000003fffde45634 in perl_destruct () from /usr/lib/libperl.so.5.18
> | #4  0x0000000080000f30 in main ()
> | (gdb) 

Unfortunately I can't reproduce the segfault on zelenka, in a sid or
jessie s390x chroot.  To make matters worse, even gdb doesn't seem to
work there:

(gdb) run
Starting program: /usr/bin/perl /usr/share/debconf/frontend
Couldn't write registers: Invalid argument.

Is it possible to arrange access on a box where it happens?

> This breaks installation of glibc binary packages like tzdata.  As there
> are no debugging infos available, no further information can be shown.

Do you get a better backtrace after installing perl-debug?
(Not that I expect that to help much.)

I see 5.18.2-4+b1 is a rebuild against libc6 2.19, built with 2.19-1 on
zani three weeks ago. Do you know the rebuild was necessary?

Two builds failed on zemlinsky with libc6 2.19-1 and

  t/comp/parser FAILED--non-zero wait status: 11

which might be the same segfault issue. I guess it could be HW or kernel
related...

The zelenka chroot has libc6 2.19-4 installed. Which version do you have?

If you download the perl_5.18.2-4 source and run
 perl t/comp/parser.t
in the source directory, do you see a segfault too?

#604128 / #679811 (tagged as unreproducible) might be the same issue.
-- 
Niko Tyni   ntyni at debian.org