On 12/19/20 8:27 PM, Ryan Libby wrote: > On Sat, Dec 19, 2020 at 7:23 PM John Baldwin <j...@freebsd.org> wrote: >> >> On 12/19/20 12:38 AM, Ryan Libby wrote: >>> Author: rlibby >>> Date: Sat Dec 19 08:38:31 2020 >>> New Revision: 368789 >>> URL: https://svnweb.freebsd.org/changeset/base/368789 >>> >>> Log: >>> rtld-elf: link udivmoddi4 from compiler_rt >>> >>> This fixes the gcc9 build of rtld-elf32 on amd64, which needed an >>> implementation of udivmoddi4. >>> >>> rtld-elf uses certain functions normally found in libc, and so it >>> includes certain files from libc in its own build. It has two >>> mechanisms to include files from libc: one that rebuilds source files in >>> the rtld-elf environment, and one that extracts object files from a >>> purpose-built no-SSP PIC archive. >>> >>> In addition to libc functions, rtld-elf may need to link functions >>> normally found in libcompiler_rt (formerly libgcc). Now, add an ability >>> to rebuild libcompiler_rt source files in the rtld-elf environment. We >>> don't yet have a need for an object file extraction mechanism. >>> >>> libcompiler_rt could also supply udivdi3 and umoddi3, but leave them >>> alone for now. >>> >>> Reviewed by: arichardson, kib >>> Sponsored by: Dell EMC Isilon >>> Differential Revision: https://reviews.freebsd.org/D27665 >> >> Hmm, I had just linked against libcompiler_rt directly as we do on arm: >> >> https://reviews.freebsd.org/D26199 >> >> It was stuck waiting for review feedback. >> >> Given libcompiler_rt is a static archive, we could probably safely link >> against it directly unlike libc where we have to pick specific object >> files. >> >> -- >> John Baldwin > > Sorry, I wasn't aware of your review. Do you want this backed out?
No. I do have other patches you can see in that review stack that might be relevant for GCC 9. Some of them I should push as they've been reviewed, but not all of them are ok'd I think. > I did see the arm path. I think it is not quite right, because > libcompiler_rt is compiled with -fstack-protector-strong, which is not > compatible with rtld. However, it will work in practice if stack > protection doesn't actually get used on any linked function. Hmm, ok. I think it's fine to use the current approach then, and perhaps fix arm to match it and keep SSP out of rtld. -- John Baldwin _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
