Date: Fri, 24 Jul 2009 13:56:49 +0200 From: Ed Schouten <ed@80386.nl> To: Jeremie Le Hen <jeremie@le-hen.org> Cc: Kostik Belousov <kostikbel@gmail.com>, FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: concurrent sysctl implementation Message-ID: <20090724115649.GV68469@hoeg.nl> In-Reply-To: <20090724115404.GI54986@felucia.tataz.chchile.org> References: <a0806f900905050107u4cbf0624oc83aafa54ae651f0@mail.gmail.com> <d9f479c10905050239u5d6d8304y1f63e41eabee8624@mail.gmail.com> <20090508214117.GY58540@hoeg.nl> <20090509113459.GD56667@e.0x20.net> <20090509121313.GA58540@hoeg.nl> <20090724073451.GH54986@felucia.tataz.chchile.org> <20090724081842.GF55190@deviant.kiev.zoral.com.ua> <20090724115404.GI54986@felucia.tataz.chchile.org>
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--mjrw6G9AoRBv8oQK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable * Jeremie Le Hen <jeremie@le-hen.org> wrote: > On Fri, Jul 24, 2009 at 11:18:42AM +0300, Kostik Belousov wrote: > > On Fri, Jul 24, 2009 at 09:34:51AM +0200, Jeremie Le Hen wrote: > > > Hi Ed, > > >=20 > > > Sorry for the late reply. > > >=20 > > > On Sat, May 09, 2009 at 02:13:13PM +0200, Ed Schouten wrote: > > > > We probably could. I think I discussed this with Robert Watson some= time > > > > ago and we could use things like ELF hints. But still, that doesn't > > > > prevent us from reaching this limitation later on. > > >=20 > > > Can you elaborate a little? Are you talking about elf-hints.h? > > > I don't see where we can get randomness from it. > >=20 > > The thing is called ELF auxillary information vector. It is used to > > supply some useful information for interpreter from the kernel, > > see include/machine/elf.h for AT_* entries. >=20 > Ah ok, so the idea is to generate a new hint, for instance AT_RANDOM, > generated at link time, that will be used to fill the canary at exec(2) > time? Very short answer: yes! --=20 Ed Schouten <ed@80386.nl> WWW: http://80386.nl/ --mjrw6G9AoRBv8oQK Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkppoYAACgkQ52SDGA2eCwUlPgCeNqfd4voKNAzZinFJr/RimYM9 RaQAniUhizfxuQIcFg+w5MwPiWRqGhFF =564e -----END PGP SIGNATURE----- --mjrw6G9AoRBv8oQK--
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