Date: Wed, 05 Nov 2014 07:59:21 -0500 From: Shawn Webb <lattera@gmail.com> To: Konstantin Belousov <kostikbel@gmail.com>, Baptiste Daroussin <bapt@FreeBSD.org> Cc: FreeBSD Arch <freebsd-arch@freebsd.org> Subject: Re: PIE/PIC support on base Message-ID: <FFED1081-4EE0-4037-BF5F-2F16C09282A2@gmail.com> In-Reply-To: <20141105122612.GC53947@kib.kiev.ua> References: <CAGSa5y2=bKpaeLO_S5W%2B1YGq02WMgCZn_5bbEMw%2Bx3j-MYDOoA@mail.gmail.com> <CADt0fhzg5G1cLEBNfHXSEi9iP7mCP=8sSwpXbFobig=pm=QsFQ@mail.gmail.com> <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>
next in thread | previous in thread | raw e-mail | index | archive | help
-----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: >> On Wed, Nov 05, 2014 at 11:26:14AM +0200, Konstantin Belousov wrote: >> > On Wed, Nov 05, 2014 at 10:02:15AM +0100, Baptiste Daroussin wrote: >> > > On amd64 WANTS_PIE will be useless as we can easily activate PIE >on every places >> > > For i386 we would propably prefer cherry picking the what we want >to see built >> > > with PIE. Don't know for other arches. >> > > >> > > So here is what I do propose: >> > > if MK_PIE=no: no PIE at all >> > > if MK_PIE=yes: >> > > - on amd64/(platforms without performance penalty): build >everything with PIE >> > > from libs to prog >> > See below. >> > >> > > - on i386/(platforms with performance penalty): build with PIE if >WANTS_PIE >> > > is defined. >> > > >> > > So the difference with the previous approach are: >> > > - No way to opt out PIE for a single binary either totally >disable or enable (I >> > > have encountered no binary so far in the base system which >fails with PIE >> > > enabled - again only tested on amd64) >> > > - Activate PIE for both binaries and libraries (no reason not to >include >> > > libraries) >> > What does it mean 'PIE for library' ? There is simply no such >thing. >> >> Sorry I badly explained, I was meaning PIC for libs PIE for binaries. >> > >> > 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? >> > >> > Also, what is the state of static binaries + PIE ? Do our binutils >> > support this at all ? The csu is definitely not ready for >'everything >> > PIE'. >> >> Only dynamic binaries will receive PIE support (and in case of using >an >> INTERNALLIB will link to the libbla_pic.a) static ones will remain >non PIE. > >And what about libX.a libraries, required by those static binaries ? >It is wrong to compile the .o files for those static libraries in >pic mode. > >More, take look at things which are done with -DPIC, e.g. in the >lib/libc/sys/stack_protector*.c. There, it is critical for >correctness. > > >_______________________________________________ >freebsd-arch@freebsd.org mailing list >http://lists.freebsd.org/mailman/listinfo/freebsd-arch >To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org" - -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -----BEGIN PGP SIGNATURE----- Version: APG v1.1.1 iQI8BAEBCgAmBQJUWh8pHxxTaGF3biBXZWJiIDxsYXR0ZXJhQGdtYWlsLmNvbT4A CgkQaoRlj1JFbu7dvA//UsGATM6oO3Wutl6AeD17GyAd3b8LcYnxeF2mRV7EWwn+ o0I2Riact18cjO8VvCKqb3PGDdiARJK9Qi7kcJz2zQeMg6CvNWKfXBZ+W3Fp5KeC 8dhFaw+vzxG/FaAE/ZfsyUJhjB2kDWPrMqqoui1HNWG3AG8P92r7XEphs3XMX5+s tS68r1P9C02q+jI/GgIyyNmReBlRKdAN7g05vW08TfGSPiI2SG5pd6q7zHn/iVXX eHiHZ06mS3ljpm6rTfrNZlUqX8sPH8/wGGGcR9zWlHhxT8fvdY+2jZ59R2ddCcHu pRZ4oZ3RTMFCh7vBCPPC1FjjzWmp6CNnRu51Ud+w2Yau0bt9AyAcplCCEhiO+jDI ZjWTgkLMnZRyarnHqaF7eHtKRifKL29k/D4Uc3eL5mK8UYHtbDIAAlNAYWdDecwt E8lYT4VUWnw7/slGRt6Zv+lbieEk0Q5iHyNaoE28BZnOLC6smLeNd1CAz7bOradb 8c2C5NH7oOWqV9ZarX2oSgBQdFLhRRTLAKUFBbDY22nRBpLdNKCF48MIzds5ZCo8 dlxSM6DjnJQF4dtIM9VL6zr3o9SqCLn1mGqkAABAYvnTo/zBMJ3u21ayzWYMYAs6 NWD9a/+Iu3dYP4uyi2139/Pvwy6C/Riuiag4iVk+/qc9m42FnNAPzsPgHIEtgRY= =HscB -----END PGP SIGNATURE-----
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?FFED1081-4EE0-4037-BF5F-2F16C09282A2>