Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 23 Jul 2014 19:44:55 -0400
From:      Shawn Webb <lattera@gmail.com>
To:        Pedro Giffuni <pfg@freebsd.org>
Cc:        PaX Team <pageexec@freemail.hu>, Oliver Pinter <oliver.pntr@gmail.com>, Robert Watson <rwatson@FreeBSD.org>, Bryan Drewery <bdrewery@FreeBSD.org>, freebsd-arch@freebsd.org
Subject:   Re: [RFC] ASLR Whitepaper and Candidate Final Patch
Message-ID:  <20140723234455.GP29618@pwnie.vrt.sourcefire.com>
In-Reply-To: <D7CEDB47-2818-461A-BB70-479BEBDCEEE9@freebsd.org>
References:  <96C72773-3239-427E-A90B-D05FF0F5B782@freebsd.org> <20140720201858.GB29618@pwnie.vrt.sourcefire.com> <alpine.BSF.2.11.1407230017490.88645@fledge.watson.org> <20140723004543.GH29618@pwnie.vrt.sourcefire.com> <D7CEDB47-2818-461A-BB70-479BEBDCEEE9@freebsd.org>

next in thread | previous in thread | raw e-mail | index | archive | help

--o41d8xLWOaLD8vYh
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Jul 23, 2014 06:37 PM -0500, Pedro Giffuni wrote:
> Hi;
>=20
> Il giorno 22/lug/2014, alle ore 19:45, Shawn Webb <lattera@gmail.com> ha =
scritto:
>=20
> >>> ...
> >>=20
> >> Hi Shawn:
> >>=20
> >> Great news that this work is coming to fruition -- ASLR is long overdu=
e.
> >>=20
> >> Are you having any luck with performance measurements?  Unixbench seem=
s like a=20
> >> good starting point, but I wonder if it would be useful to look, in=20
> >> particular, at memory-mapping intensive workloads that might be affect=
ed as a=20
> >> result of changes in kernel VM data-structure use, or greater fragment=
ation of=20
> >> the address space.  I'm not sure I have a specific application here in=
 mind --=20
> >> in the past I might have pointed out tools such as ElectricFence that =
tend to=20
> >> increase fragmentation themselves.
> >=20
> > The unixbench tests on that laptop have finished. However, I've been
> > fighting a pesky migraine these last couple days, so I haven't had the
> > opportunity to aggregate the results into a nice little spreadsheet. I'm
> > hoping to finish it up by the end of the week.
> >=20
> > I'll take a look at ElectricFence this weekend. Additionally, I have a
> > netbook somewhere. Once I find it and its power cord, I'll install
> > FreeBSD/x86 and re-run the same tests on that.
> >=20
>=20
> Somewhat related to ElectricFence? will ASLR have an adverse effect on de=
buggers?
>=20
> I googled around and got to this:
>=20
> http://www.outflux.net/blog/archives/2010/07/03/gdb-turns-off-aslr/

I've been doing all my ClamAV development on my FreeBSD box with ASLR
enabled. Development tools like gdb and valgrind work great, even with
corefiles. I have not, however, tried lldb.

>=20
> So I guess we may have to patch gdb (and lldb)?

=46rom my experience with ClamAV development, I don't think so. gdb uses
ptrace to get and set the registers, so ASLR doesn't matter.

>=20
> Pedro.
>=20

--o41d8xLWOaLD8vYh
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
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=JlWH
-----END PGP SIGNATURE-----

--o41d8xLWOaLD8vYh--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20140723234455.GP29618>