/ 
FreeBSD-i386-Ptrace-0.01
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/ FreeBSD::i386::Ptrace

NAME

FreeBSD::i386::Ptrace - Ptrace for FreeBSD-i386

VERSION

$Id: Ptrace.pm,v 0.1 2009/03/14 12:45:27 dankogai Exp dankogai $

SYNOPSIS

  # simple strace in perl
  use strict;
  use warnings;
  use FreeBSD::i386::Ptrace;
  use FreeBSD::i386::Ptrace::Syscall;
  die "$0 prog args ..." unless @ARGV;
  my $pid = fork();
  die "fork failed:$!" if !defined($pid);
  if ($pid == 0){ # son
    pt_trace_me;
    exec @ARGV;
  }else{  mom
    wait; # for exec;
    my $count = 0; # odd on enter, even on leave
    my ($call, $retval);  
    while(pt_syscall($pid) == 0){
	last if wait == -1;
	if (++$count & 1){
	    $call = pt_getcall($pid);
	}else{
	    $retval = pt_getcall($pid);
	    my $name = $SYS{$call} || 'unknown';
	    warn "$name -> $retval";

        }
    }
    warn $count/2," system calls issued";
  }

EXPORT

ptrace, pt_trace_me, pt_attach, pt_detach, pt_syscall pt_getcall pt_kill and PT_* constants.

for %SYS, use <FreeBSD::i386::Ptrace::Syscall>.

FUNCTIONS

ptrace($request, $pid, $addr, $data)

A thin wrapper to "2" in ptrace.

#include <sys/types.h>
#include <sys/ptrace.h>
int
ptrace(int request, pid_t pid, caddr_t addr, int data);

All arguments are integer from perl.

pt_trace_me()

Shortand for ptrace(PT_TRACE_ME, 0, 0, 0).

pt_attach($pid)

Shortand for ptrace(PT_ATTACH, pid, 0, 0).

pt_detach($pid)

Shortand for ptrace(PT_DETACH, pid, 0, 0).

pt_syscall($pid)

Shortand for ptrace(PT_SYSCALL, pid, 1, 0). Unlike Linux the 3rd argument must be 1 or it loops infinitely.

Note PT_SYSCALL is invoked both on entry to and return from the system call. See "SYNOPSIS" to see how to switch between them.

pt_getcall($pid)

Returns the value of EAX register which holds the system call NUMBER on entry and the return value on return.

To get the name of system call you can import FreeBSD::i386::Ptrace::Syscall and use %SYS.

my $call = pt_getcall(pid);
my $name = %SYS{$call};
pt_kill($pid)

Shortand for ptrace(PT_KILL, $pid, 0, 0; ptrace, pt_trace_me, pt_attach, pt_detach, pt_syscall pt_getcall pt_kill and PT_* constants.

AUTHOR

Dan Kogai, <dankogai at dan.co.jp>

BUGS

Please report any bugs or feature requests to bug-freebsd-i386-ptrace at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=FreeBSD-i386-Ptrace. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc FreeBSD::i386::Ptrace

You can also look for information at:

ACKNOWLEDGEMENTS

Sys::Ptrace

COPYRIGHT & LICENSE

Copyright 2009 Dan Kogai, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.