Date: Wed, 5 Nov 2014 15:19:39 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Shawn Webb <lattera@gmail.com> Cc: Baptiste Daroussin <bapt@FreeBSD.org>, FreeBSD Arch <freebsd-arch@freebsd.org> Subject: Re: PIE/PIC support on base Message-ID: <20141105131939.GF53947@kib.kiev.ua> In-Reply-To: <FFED1081-4EE0-4037-BF5F-2F16C09282A2@gmail.com> References: <CAGSa5y1LBxkUNSgKkw=F9_uykXDeBV7_WL0a7Wt%2B%2BGgMTSULEQ@mail.gmail.com> <CADt0fhweiymn2D09%2Be7f44AreWe%2B8cmAtDVeec0NfmuWuOOhbg@mail.gmail.com> <315B4DC5-0E04-4F6B-BBB0-477D049025BF@bsdimp.com> <CADt0fhyCBa3PTnZ3dpc-hpysyC9V0MXR16s-e10V0ioAfaWHuw@mail.gmail.com> <C7C48B02-E65C-4F90-A503-1FDDCB590B7D@bsdimp.com> <20141105090215.GF10388@ivaldir.etoilebsd.net> <20141105092614.GB53947@kib.kiev.ua> <20141105114855.GH10388@ivaldir.etoilebsd.net> <20141105122612.GC53947@kib.kiev.ua> <FFED1081-4EE0-4037-BF5F-2F16C09282A2@gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Nov 05, 2014 at 07:59:21AM -0500, Shawn Webb wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > > > On November 5, 2014 7:26:12 AM EST, Konstantin Belousov <kostikbel@gmail.com> wrote: > >On Wed, Nov 05, 2014 at 12:48:55PM +0100, Baptiste Daroussin wrote: > >> > Also, I strongly oppose compiling everything with PIC, even on > >amd64. > >> > I described somewhere else that using PIC code changes symbol > >lookup > >> > rules for binaries. So despite not having performance impact, the > >> > thing does impact runtime behaviour in subtle ways. The most > >affected > >> > programs are those which support dynamic modules. > >Please do not ignore this ^^^^^^ issue. > > > > Can you go into detail what those changes are? PIE binary resolves its symbols through GOT/PLT. In particular, it is possible to interpose the symbols.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20141105131939.GF53947>