Date: Fri, 17 Oct 2014 05:55:55 +0100 From: David Carlier <david.carlier@hardenedbsd.org> To: freebsd-arch@freebsd.org Subject: Fwd: PIE/PIC support on base Message-ID: <CAMe1fxaEd4w2P_=HAGyW9x8QKqCQ1QF-c_FRv4A0B%2BmhUcN=%2Bw@mail.gmail.com> In-Reply-To: <CAMe1fxYjHjJcyKCtuD5gEJ2urnyd6=suLL5nTWHJbGsn5fSUVg@mail.gmail.com> References: <CAMe1fxaYn%2BJaKzGXx%2Bywv8F0mKDo72g=W23KUWOKZzpm8wX4Tg@mail.gmail.com> <CAGSa5y3s9r0DRyinfqV=PJc_BT=Em-SLfwhD25nP0=6ki9pHWw@mail.gmail.com> <CAMe1fxaBEc5T77xjpRsMi_kkc5LXwPGooLWTO9C1FJcLSPnO8w@mail.gmail.com> <CAGSa5y2=bKpaeLO_S5W%2B1YGq02WMgCZn_5bbEMw%2Bx3j-MYDOoA@mail.gmail.com> <CADt0fhzg5G1cLEBNfHXSEi9iP7mCP=8sSwpXbFobig=pm=QsFQ@mail.gmail.com> <5440489F.3080602@FreeBSD.org> <CAMe1fxYjHjJcyKCtuD5gEJ2urnyd6=suLL5nTWHJbGsn5fSUVg@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
---------- Forwarded message ---------- From: David Carlier <david.carlier@hardenedbsd.org> Date: Fri, Oct 17, 2014 at 5:52 AM Subject: Re: PIE/PIC support on base To: Jeremie Le Hen <jlh@freebsd.org>, Baptiste Daroussin <bapt@freebsd.org>, Shawn Webb <shawn.webb@hardenedbsd.org> Except Baptiste, what do you all think about USE_PIE versus WITH_PIE ? On Thu, Oct 16, 2014 at 11:37 PM, Bryan Drewery <bdrewery@freebsd.org> wrote: > On 10/16/2014 5:15 PM, Shawn Webb wrote: > > > > > > On Thu, Oct 16, 2014 at 5:59 PM, Jeremie Le Hen <jlh@freebsd.org > > <mailto:jlh@freebsd.org>> wrote: > > > > On Thu, Oct 16, 2014 at 8:21 PM, David Carlier > > <david.carlier@hardenedbsd.org > > <mailto:david.carlier@hardenedbsd.org>> wrote: > > > > > > I chose the "atomic" approach, at the moment very few binaries are > > > concerned at the moment. So I applied INCLUDE_PIC_ARCHIVE in the > needed > > > libraries plus created WITH_PIE which add fPIE/fpie -pie flags > only if you > > > include <bsd.prog.pie.mk <http://bsd.prog.pie.mk>>; (which include > > <bsd.prog.mk <http://bsd.prog.mk>>...) otherwise other > > > binaries include <bsd.prog.mk <http://bsd.prog.mk>>; as usual > hence does not apply. Look > > > reasonable approach ? > > > > I think I understand what you mean. But I think PIE is commonplace > > nowadays and I don't understand what you win by not enabling it for > > the whole system. Is it a performance concern? Is it to preserve > > conservative minds from to much change? :) > > > > > > Looping in Kostik, Bryan Drewery, the PaX team, Hunger, and Sean Bruno. > > > > On i386, there is a performance cost due to not having an extra register > > available for the relocation work that has to happen. PIE doesn't carry > > much of a performance penalty on amd64, though it still does carry some > > on first resolution of functions (due to the extra relocation step the > > RTLD has to worry about). On amd64, after symbol resolution has taken > > place, there is no further performance penalty due to amd64 having an > > extra register to use for PIE/PIC. I'm unsure what, if any, performance > > penalty PIE carries on ARM, AArch64, and sparc64. > > > > I think if the performance impact can be well understood on all > architectures, and that it is not more than a few % points, other people > may be more willing to enable it on all. I can't speak for them, but if > the impact is not significant then it is safer and simpler to enable > everywhere and I would think that argument would win over anything else. > What do I know though? That approach failed already. > > > Certain folk would prefer to see PIE enabled only in certain > > applications. /bin/ls can't really make much use of PIE. But sshd can. I > > personally would like to see all of base's applications compiled as > > PIEs, but that's a long ways off. It took OpenBSD several years to > > accomplish that. Having certain high-visibility applications (like sshd, > > inetd, etc) is a great start. Providing a framework for application > > developers to opt their application into PIE is another great start. > > > > Those are my two cents. > > > > Thanks, > > > > Shawn > > > -- > Regards, > Bryan Drewery > >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAMe1fxaEd4w2P_=HAGyW9x8QKqCQ1QF-c_FRv4A0B%2BmhUcN=%2Bw>