On Fri, 16 Jun 2017 17:15:44 -0700 Jason Evans <jas...@canonware.com> wrote: > On Fri, 16 Jun 2017 18:45:17 -0400 > Shawn Webb <shawn.w...@hardenedbsd.org> wrote: > > On Thu, Jun 15, 2017 at 07:15:06AM +0000, Jason Evans wrote: > > > Author: jasone > > > Date: Thu Jun 15 07:15:05 2017 > > > New Revision: 319971 > > > URL: https://svnweb.freebsd.org/changeset/base/319971 > > > > > > Log: > > > Update jemalloc to 5.0.0. > > > > This breaks buildworld for arm64: > > > > /usr/obj/arm64.aarch64/scratch/fbsd/tmp/usr/bin/ld: error: > > sigsetjmp.pico:(function sigsetjmp): relocation R_AARCH64_CONDBR19 out of > > range > > /usr/obj/arm64.aarch64/scratch/fbsd/tmp/usr/bin/ld: error: > > sigsetjmp.pico:(function siglongjmp): relocation R_AARCH64_CONDBR19 out of > > range > > cc: error: linker command failed with exit code 1 (use -v to see invocation) > > --- libc.so.7.full --- > > *** [libc.so.7.full] Error code 1 > > > > make[4]: stopped in /scratch/fbsd/lib/libc > > Indeed, this happens for me too with TARGET=arm64 TARGET_ARCH=aarch64. I > haven't found anything specifically about this error message, but it looks > vaguely like the amd64-specific messages that happen when trying to link > non-PIC object files into a shared library. In > src/lib/libc/aarch64/gen/sigsetjmp.S, we have two conditional jumps > > b.eq C_LABEL(_setjmp) > [...] > b.eq C_LABEL(_longjmp) > > Maybe there's a simple macro change that can make these relocatable jumps. > Alternatively, we could probably simplify the code by merging setjmp.S and > sigsetjmp.S, so that PC-relative jumps could be used.
Given how arm handles similar branches, it seems like the correct fix would be to change these (and probably other branches) from e.g. b.eq _C_LABEL(_setjmp) to b.eq PIC_SYM(_C_LABEL(_setjmp), PLT) However, doing so triggers a clang crash. PIC_SYM is explicitly defined for aarch64, but is otherwise unused. It appears that we don't actually generate relocations, at least during initial linking. As a side effect, we have an implicit dependency on all of libc's dependent symbols serendipitously being within some limited range of each other. When using conditional branches, that range is +-1 MiB; for unconditional branches it is +-128 MiB. The jemalloc update changed libc's layout, and the conditional branches exceeded the +-1 MiB range. This latent bug is worked around in r320136, though it seems likely we have broader problems with how we build PIC libraries for arm64. Jason _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"