Bug#538757: panic:restartop and segfault in perl interpreter

[Andrew Suffield]

Package: perl
Version: 5.10.0-24

asuffield at cyclone:~/work/perl-bug$ cat One.pm
package One;
use Moose;
use overload '""' => 'stringify';
use Two;
asuffield at cyclone:~/work/perl-bug$ cat Two.pm
package Two;
One->new();
asuffield at cyclone:~/work/perl-bug$ perl -MOne
panic: restartop
Segmentation fault (core dumped)
asuffield at cyclone:~/work/perl-bug$ perl --version

This is perl, v5.10.0 built for x86_64-linux-gnu-thread-multi


Inspection with valgrind indicates that the segfault is a
read-after-free error, which suggests bad reference counting somewhere
- but that comes *after* the panic, so it may simply be a double
fault. Alas, my perl-fu is too rusty to track down problems this deep
in the interpreter, it's changed a lot since I last looked in there.

Of course, there's no guarantee that this is an actual perl bug. It
could be one of the data structures getting mangled by any of these:

0x00007f66c75547d0  0x00007f66c7559088  Yes         /usr/lib/perl/5.10/auto/List/Util/Util.so
0x00007f66c7350000  0x00007f66c7350bd8  Yes         /usr/lib/perl5/auto/Sub/Name/Name.so
0x00007f66c714dd70  0x00007f66c714e508  Yes         /usr/lib/perl5/auto/Devel/GlobalDestruction/GlobalDestruction.so
0x00007f66c6f497d0  0x00007f66c6f4c248  Yes         /usr/lib/perl5/auto/Params/Util/Util.so
0x00007f66c6d43250  0x00007f66c6d46e28  Yes         /usr/lib/perl5/auto/Class/MOP/MOP.so
0x00007f66c6b2ee20  0x00007f66c6b3fac8  Yes         /usr/lib/perl5/auto/List/MoreUtils/MoreUtils.so

Unfortunately there's no good way to determine which (or if it is in
fact a perl bug) without heavy-duty triage.