Bug#508432: minimum testcase

[Martín Ferrari]

Hi, after working on this bug for a while, I was able to distill a
minimum code that triggers the segfault. The callback routine invoked
from pcap_loop needs to set a signal handler that it's used during the
callback.

In the fwknopd code, this happens when calling iptables, which triggers
a SIGCHLD on exit, but can happen with any signal.

The following backtrace makes me doubt if this is a Net::Pcap or a perl
problem. Maybe somebody in the list can shed some light? (Hello Niko :))

#0  0xb7e726c9 in free () from /lib/libc.so.6
#1  0x080c5b70 in Perl_sv_clear ()
#2  0x080c5d2a in Perl_sv_free2 ()
#3  0x080e0a10 in Perl_leave_scope ()
#4  0x080e137c in Perl_pop_scope ()
#5  0x080b463d in Perl_pp_leavesub ()
#6  0x080b1879 in Perl_runops_standard ()
#7  0x080aba15 in Perl_call_sv ()
#8  0xb7daf538 in callback_wrapper ()
from /usr/lib/perl5/auto/Net/Pcap/Pcap.so
#9  0xb7d75d45 in ?? () from /usr/lib/libpcap.so.0.8
#10 0x08ae4558 in ?? ()
#11 0xbf8a9e28 in ?? ()
#12 0x08afb54a in ?? ()
#13 0x00000020 in ?? ()
#14 0xbf8a9e14 in ?? ()
#15 0xbf8a9e38 in ?? ()
#16 0xbf8a9e48 in ?? ()
#17 0x080c4067 in Perl_sv_setsv_flags ()
#18 0xb7d76bab in pcap_loop () from /usr/lib/libpcap.so.0.8
#19 0xb7da9cf3 in XS_Net__Pcap_loop ()
   from /usr/lib/perl5/auto/Net/Pcap/Pcap.so
#20 0x080b32d2 in Perl_pp_entersub ()
#21 0x080b1879 in Perl_runops_standard ()
#22 0x080ac6a0 in perl_run ()
#23 0x08063ddd in main ()

-------------- next part --------------
A non-text attachment was scrubbed...
Name: testpcap
Type: application/x-perl
Size: 353 bytes
Desc: not available
Url : http://lists.alioth.debian.org/pipermail/pkg-perl-maintainers/attachments/20090214/2efd0a77/attachment.bin 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 197 bytes
Desc: This is a digitally signed message part
Url : http://lists.alioth.debian.org/pipermail/pkg-perl-maintainers/attachments/20090214/2efd0a77/attachment.pgp