When you try to access the contents of a specific memory address, the only thing that can happen is a segmentation fault.
I experimented with this:
#!/usr/bin/perl
BEGIN {
$| = 1;
$^W = 1;
}
use strict;
use autodie;
use warnings FATAL => 'syntax';
use Data::Dumper::Concise;
use POSIX;
use POSIX::RT::Signal qw/sigwaitinfo sigqueue/;
use threads;
use Scalar::Util qw/refaddr/;
use Devel::Pointer::PP;
POSIX::sigprocmask( POSIX::SIG_BLOCK, POSIX::SigSet->new(&POSIX::SIGRT
+MIN) );
my $thr = threads->create( \&_thread );
sub _thread {
my $sigset = POSIX::SigSet->new(&POSIX::SIGRTMIN);
my $info = sigwaitinfo($sigset);
}
my $address = 5;
refaddr( \$address );
my $new_address = \$address;
$$new_address = $$new_address * 4;
sigqueue( $$, &POSIX::SIGRTMIN, $address );
$thr->join();
print Dumper($address);
my $smash = unsmash_sv( 0 + $address );
print Dumper($smash);
exit(0);