Hey Peter, Here you go! https://hardenedbsd.org/~shawn/2018-11-28_reproduce-01.tar Thanks, -- Shawn Webb Cofounder and Security Engineer HardenedBSD Tor-ified Signal: +1 443-546-8752 Tor+XMPP+OTR: lattera at is.a.hacker.sx GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE On Wed, Nov 28, 2018 at 05:30:57PM -0800, Peter Collingbourne wrote:> Hi Shawn, > > Can you please create a reproducer tarball (using ld.lld --reproduce) so > that we don't need to install HardenedBSD in order to reproduce? > > Peter > > On Wed, Nov 28, 2018 at 5:16 PM Shawn Webb via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > > Hey LLVM folks, > > > > I've run into an interesting assertion. In one of HardenedBSD's > > feature branches, we're working on integration llvm's Cross-DSO CFI > > implementation. Using Cross-DSO CFI requires building libs with LTO, > > which causes clang to emit LLVM IR intermediate object files rather > > than ELF intermediate object files. > > > > I've found that with lld, attempting to link LLVM IR intermediate > > object files hits an assert in lld. I've created a reproduction test > > case in this tiny little repo: https://github.com/lattera/ifunc_repro > > > > The assertion I hit is detailed in the commit message of the initial > > commit: > > > > https://github.com/lattera/ifunc_repro/commit/0be98f9e81a1c91e80b135da6bb8d073d7a0c6f7 > > > > HardenedBSD's Cross-DSO CFI feature branch uses clang/llvm/lld 7.0.1. > > I'm more than happy to test out patches to help address this issue. > > > > Please let me know if you have any questions, comments, or concerns. > > > > Thanks, > > > > -- > > Shawn Webb > > Cofounder and Security Engineer > > HardenedBSD > > > > Tor-ified Signal: +1 443-546-8752 > > Tor+XMPP+OTR: lattera at is.a.hacker.sx > > GPG Key ID: 0x6A84658F52456EEE > > GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE > > _______________________________________________ > > LLVM Developers mailing list > > llvm-dev at lists.llvm.org > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > > > > > -- > -- > Peter-------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20181128/360c0359/attachment.sig>
https://reviews.llvm.org/D55046 fixes your reproducer here. Let me know if that works for you. Note that I had to rebuild one of your bitcode files to be a regular object file, this is because LTO doesn't want the .eh_frame terminator to live in a bitcode file. $ mv ./usr/lib/crtendS.o ./usr/lib/crtendS.o.bak $ ~/l4/ra/bin/llc -o ./usr/lib/crtendS.o ./usr/lib/crtendS.o.bak -filetype=obj -relocation-model=pic Peter On Wed, Nov 28, 2018 at 5:35 PM Shawn Webb <shawn.webb at hardenedbsd.org> wrote:> Hey Peter, > > Here you go! > > https://hardenedbsd.org/~shawn/2018-11-28_reproduce-01.tar > > Thanks, > > -- > Shawn Webb > Cofounder and Security Engineer > HardenedBSD > > Tor-ified Signal: +1 443-546-8752 > Tor+XMPP+OTR: lattera at is.a.hacker.sx > GPG Key ID: 0x6A84658F52456EEE > GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE > > On Wed, Nov 28, 2018 at 05:30:57PM -0800, Peter Collingbourne wrote: > > Hi Shawn, > > > > Can you please create a reproducer tarball (using ld.lld --reproduce) so > > that we don't need to install HardenedBSD in order to reproduce? > > > > Peter > > > > On Wed, Nov 28, 2018 at 5:16 PM Shawn Webb via llvm-dev < > > llvm-dev at lists.llvm.org> wrote: > > > > > Hey LLVM folks, > > > > > > I've run into an interesting assertion. In one of HardenedBSD's > > > feature branches, we're working on integration llvm's Cross-DSO CFI > > > implementation. Using Cross-DSO CFI requires building libs with LTO, > > > which causes clang to emit LLVM IR intermediate object files rather > > > than ELF intermediate object files. > > > > > > I've found that with lld, attempting to link LLVM IR intermediate > > > object files hits an assert in lld. I've created a reproduction test > > > case in this tiny little repo: https://github.com/lattera/ifunc_repro > > > > > > The assertion I hit is detailed in the commit message of the initial > > > commit: > > > > > > > https://github.com/lattera/ifunc_repro/commit/0be98f9e81a1c91e80b135da6bb8d073d7a0c6f7 > > > > > > HardenedBSD's Cross-DSO CFI feature branch uses clang/llvm/lld 7.0.1. > > > I'm more than happy to test out patches to help address this issue. > > > > > > Please let me know if you have any questions, comments, or concerns. > > > > > > Thanks, > > > > > > -- > > > Shawn Webb > > > Cofounder and Security Engineer > > > HardenedBSD > > > > > > Tor-ified Signal: +1 443-546-8752 > > > Tor+XMPP+OTR: lattera at is.a.hacker.sx > > > GPG Key ID: 0x6A84658F52456EEE > > > GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE > > > _______________________________________________ > > > LLVM Developers mailing list > > > llvm-dev at lists.llvm.org > > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > > > > > > > > > -- > > -- > > Peter >-- -- Peter -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20181128/743b19fe/attachment.html>
Thanks for providing the patch! I got around to testing it this morning and it appears it fixes compilation, but produces a non-working system. I know that's kinda vague and I'll have more details soon, including sample binaries. I at least wanted to give a status update so you didn't think you were being ignored. Thanks, -- Shawn Webb Cofounder and Security Engineer HardenedBSD Tor-ified Signal: +1 443-546-8752 Tor+XMPP+OTR: lattera at is.a.hacker.sx GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE On Wed, Nov 28, 2018 at 09:16:24PM -0800, Peter Collingbourne wrote:> https://reviews.llvm.org/D55046 fixes your reproducer here. Let me know if > that works for you. > > Note that I had to rebuild one of your bitcode files to be a regular object > file, this is because LTO doesn't want the .eh_frame terminator to live in > a bitcode file. > > $ mv ./usr/lib/crtendS.o ./usr/lib/crtendS.o.bak > $ ~/l4/ra/bin/llc -o ./usr/lib/crtendS.o ./usr/lib/crtendS.o.bak > -filetype=obj -relocation-model=pic > > Peter > > On Wed, Nov 28, 2018 at 5:35 PM Shawn Webb <shawn.webb at hardenedbsd.org> > wrote: > > > Hey Peter, > > > > Here you go! > > > > https://hardenedbsd.org/~shawn/2018-11-28_reproduce-01.tar > > > > Thanks, > > > > -- > > Shawn Webb > > Cofounder and Security Engineer > > HardenedBSD > > > > Tor-ified Signal: +1 443-546-8752 > > Tor+XMPP+OTR: lattera at is.a.hacker.sx > > GPG Key ID: 0x6A84658F52456EEE > > GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE > > > > On Wed, Nov 28, 2018 at 05:30:57PM -0800, Peter Collingbourne wrote: > > > Hi Shawn, > > > > > > Can you please create a reproducer tarball (using ld.lld --reproduce) so > > > that we don't need to install HardenedBSD in order to reproduce? > > > > > > Peter > > > > > > On Wed, Nov 28, 2018 at 5:16 PM Shawn Webb via llvm-dev < > > > llvm-dev at lists.llvm.org> wrote: > > > > > > > Hey LLVM folks, > > > > > > > > I've run into an interesting assertion. In one of HardenedBSD's > > > > feature branches, we're working on integration llvm's Cross-DSO CFI > > > > implementation. Using Cross-DSO CFI requires building libs with LTO, > > > > which causes clang to emit LLVM IR intermediate object files rather > > > > than ELF intermediate object files. > > > > > > > > I've found that with lld, attempting to link LLVM IR intermediate > > > > object files hits an assert in lld. I've created a reproduction test > > > > case in this tiny little repo: https://github.com/lattera/ifunc_repro > > > > > > > > The assertion I hit is detailed in the commit message of the initial > > > > commit: > > > > > > > > > > https://github.com/lattera/ifunc_repro/commit/0be98f9e81a1c91e80b135da6bb8d073d7a0c6f7 > > > > > > > > HardenedBSD's Cross-DSO CFI feature branch uses clang/llvm/lld 7.0.1. > > > > I'm more than happy to test out patches to help address this issue. > > > > > > > > Please let me know if you have any questions, comments, or concerns. > > > > > > > > Thanks, > > > > > > > > -- > > > > Shawn Webb > > > > Cofounder and Security Engineer > > > > HardenedBSD > > > > > > > > Tor-ified Signal: +1 443-546-8752 > > > > Tor+XMPP+OTR: lattera at is.a.hacker.sx > > > > GPG Key ID: 0x6A84658F52456EEE > > > > GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE > > > > _______________________________________________ > > > > LLVM Developers mailing list > > > > llvm-dev at lists.llvm.org > > > > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev > > > > > > > > > > > > > -- > > > -- > > > Peter > > > > > -- > -- > Peter-------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20181201/bb6e3df4/attachment.sig>