Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 08 Jun 2014 16:39:47 -0500
From:      Bryan Drewery <bdrewery@FreeBSD.org>
To:        Pedro Giffuni <pfg@FreeBSD.org>, Alfred Perlstein <bright@mu.org>, Konstantin Belousov <kostikbel@gmail.com>
Cc:        svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org
Subject:   Re: svn commit: r267233 - in head: . bin/rmail gnu/usr.bin/binutils/addr2line gnu/usr.bin/binutils/nm gnu/usr.bin/binutils/objcopy gnu/usr.bin/binutils/objdump gnu/usr.bin/binutils/readelf gnu/usr.bin/...
Message-ID:  <5394D823.60106@FreeBSD.org>
In-Reply-To: <5394C3D8.7040800@FreeBSD.org>
References:  <201406081729.s58HTWkc006213@svn.freebsd.org> <74512A27-DD5F-4D43-BFA1-0AC04E0D08B4@FreeBSD.org> <20140608182728.GX3991@kib.kiev.ua> <5394ABD2.5040009@mu.org> <20140608184451.GZ3991@kib.kiev.ua> <5394B607.1000109@mu.org> <5394C3D8.7040800@FreeBSD.org>

next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 4880 and 3156)
--XX6dQkPRTwcJmJ15NcOKnMWNuNTPWQ9nb
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: quoted-printable

On 6/8/2014 3:13 PM, Pedro Giffuni wrote:
> Hello;
>=20
> El 6/8/2014 2:14 PM, Alfred Perlstein escribi=F3:
>> On 6/8/14 11:44 AM, Konstantin Belousov wrote:
>>> On Sun, Jun 08, 2014 at 11:30:42AM -0700, Alfred Perlstein wrote:
>>>> On 6/8/14 11:27 AM, Konstantin Belousov wrote:
>>>>> On Sun, Jun 08, 2014 at 05:38:49PM +0000, Bjoern A. Zeeb wrote:
>>>>>> On 08 Jun 2014, at 17:29 , Bryan Drewery <bdrewery@FreeBSD.org>
>>>>>> wrote:
>>>>>>
>>>>>>> Author: bdrewery
>>>>>>> Date: Sun Jun  8 17:29:31 2014
>>>>>>> New Revision: 267233
>>>>>>> URL: http://svnweb.freebsd.org/changeset/base/267233
>>>>>>>
>>>>>>> Log:
>>>>>>>    In preparation for ASLR [1] support add WITH_PIE to support
>>>>>>> building with -fPIE.
>>>>>>>
>>>>>>>    This is currently an opt-in build flag. Once ASLR support is
>>>>>>> ready and stable
>>>>>>>    it should changed to opt-out and be enabled by default along
>>>>>>> with ASLR.
>>>>>>>
>>>>>>>    Each application Makefile uses opt-out to ensure that ASLR wil=
l
>>>>>>> be enabled by
>>>>>>>    default in new directories when the system is compiled with
>>>>>>> PIE/ASLR. [2]
>>>>>>>
>>>>>>>    Mark known build failures as NO_PIE for now.
>>>>>> No, no, no, no more NOs!
>>>>>>
>>>>>> I?ll leave it to others who understand the current build system in=

>>>>>> days when it?s not broken to fix this entire splattering across al=
l
>>>>>> these Makefiles;  we really need a better way for this.
>>>>> I have no words to express my dissatisfaction with this commit.
>>>>> If change to the build of _some_ usermode binaries require patching=

>>>>> of loader', csu and rtld Makefiles, obviously it is done wrong.
>>>>>
>>>>> Why almost half of the binaries require opt-out ?
>>>>>
>>>>> PLEASE REVERT THIS.
>>>> Wait.  Does this not serve as a useful stake in the ground for
>>>> people to
>>>> come in and update things?  Instead of asking to back out, shouldn't=
 we
>>>> be doing an announcement "ok folks, it's now time to fix this!" and
>>>> move
>>>> forward?  Otherwise we may never get any pie.
>>> Let me reformulate.
>>>
>>> Somebody commits broken change, despite it was pointed out by many
>>> before the commit. From the changes it is obvious that people which
>>> proposed it do not understand what they hack on. And then, somebody e=
lse
>>> must run and 'fix' previously non-broken code.
>>>
>>> Sure, you get the pie.
>> Sure, but hasn't the default stayed unchanged?
>>
>> It seems like you have to enable ASLR first before you see all the
>> breakage.  Right now it seems like goal was to document what even
>> compiles versus doesn't compile with ASLR.  Afaik there is not setting=

>> of ASLR on by default.
>>
>=20
> FWIW, and with huge respect to the people working on it, I have come to=

> the conclusion that ASLR is useless. The fact that MS and Apple enable
> it now by default is not really a point in favor of the technology as
> the workarounds became popular and finer randomization won't help[1].
>=20
> I am also worried about the performance: Redhat created PIE but
> backpedaled when they noticed the performance impact and AFAICT only us=
e
> PIE in a restricted set of binaries.
>=20
> I would like to see these as an option but I don't think it should ever=

> be made the default. Yes, I am aware these patches don't turn anything
> by default but I (and probably others) am suspecting such a switch may
> be thrown upon us without much discussion.
>=20
>=20
>> There has to be a way to call out what works and what doesn't work and=

>> form a transition from a world with no ASLR to one with some ASLR and
>> eventually one with almost entirely ASLR coverage.  I'm not sure it ca=
n
>> be done in one fell swoop.  Hooks like this in -current allow for this=

>> to be done as a group effort.
>>
>> It would be very unlikely that we retain the semantics all the way unt=
il
>> a -stable release.
>>
>=20
> I am not (yet) criticizing the patches to the build system as I want to=

> preserve my innocence ;) ... but perhaps if the semantics are not
> finalized this should be done in a branch. It is my opinion that in
> general we are not using SVN branches as much as we should.
>=20
> Pedro.
>=20
> For reference:
>=20
> [1] http://youtu.be/dkZ9zdSRQYM

Yes there are performance implications. No, the default of PIE and ASLR
won't be done without discussion.

--=20
Regards,
Bryan Drewery


--XX6dQkPRTwcJmJ15NcOKnMWNuNTPWQ9nb
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (MingW32)
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iQEcBAEBAgAGBQJTlNgjAAoJEDXXcbtuRpfPMf8IAKDs8yr/m+J2CzChPgve4pSX
TQMy57Vcd/7y8w4jTYZ6ANXqpg98ZlwDh0PFHZJYqfxnECCvV8iJie5uX7+ogUbs
a+wDt58+4MxY6EpYyE7prw6BYJLUTEmHp07yPQjWHRRPydxkkH+kk0uVcfFXefNz
sB7hxtg8mA8cIw/wrfuRXZS5rpxl6im5gIww1Yxgq15gyHM61vgVR763b3OugOG3
NSe7FhtbFttD8zBxlGGRC/mAJkUTDWXedTUCmDBbuaVYd6h5pm09ZWDmnRVdsrqs
jHSch/3YQWM9NbZiPbFTOHe8PazlpzCC0ohmxDYxYZY5GbemSpN9nAfT1/xJ2J4=
=QG+C
-----END PGP SIGNATURE-----

--XX6dQkPRTwcJmJ15NcOKnMWNuNTPWQ9nb--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?5394D823.60106>