Example from ~ia64 (build failure on sys-devel/gcc-6.3.0) Build fails as: make[3]: Leaving directory '/var/tmp/portage/sys-devel/gcc-6.3.0/work/build' Comparing stages 2 and 3 warning: gcc/cc1-checksum.o differs warning: gcc/cc1plus-checksum.o differs strip(14295): unaligned access to 0x600000000002c5d2, ip=0x20000000001405f0 strip(14297): unaligned access to 0x600000000002c5d2, ip=0x20000000001405f0 Bootstrap comparison failure! gcc/sel-sched-ir.o differs gcc/c/c-decl.o differs gcc/c-family/c-common.o differs gcc/fortran/trans-decl.o differs gcc/tree-ssa-loop-ivopts.o differs gcc/ipa-cp.o differs gcc/tree-ssa-pre.o differs gcc/fold-const.o differs gcc/cp/tree.o differs gcc/cp/name-lookup.o differs gcc/cp/decl.o differs gcc/cp/pt.o differs gcc/cp/class.o differs gcc/cp/semantics.o differs gcc/haifa-sched.o differs gcc/emit-rtl.o differs gcc/omp-low.o differs gcc/dwarf2out.o differs It looks like new strip does not handle debugging info cleanly. I'll try to look at what exactly compare stage does.
And compare-debug fails because 'strip' SIGSEGVs on both stage2 and stage3 binaries: guppy build # bash -x /var/tmp/portage/sys-devel/gcc-6.3.0/work/gcc-6.3.0/contrib/compare-debug stage2-gcc/dwarf2out.o stage3-gcc/dwarf2out.o + rm='rm -f' + case $1 in + test 2 '!=' 2 + test '!' -f stage2-gcc/dwarf2out.o + test '!' -f stage3-gcc/dwarf2out.o + suf1=stripped + test -f stage2-gcc/dwarf2out.o.stripped + suf2=stripped + test -f stage3-gcc/dwarf2out.o.stripped + trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15 + case `uname -s` in ++ uname -s + cp stage2-gcc/dwarf2out.o stage2-gcc/dwarf2out.o.stripped + strip stage2-gcc/dwarf2out.o.stripped strip: stage2-gcc/sthBJTp4: Failed to find link section for section 13 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 19 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 22 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 25 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 29 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 32 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 35 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 38 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 41 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 44 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 49 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 52 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 56 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 59 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 62 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 65 strip: stage2-gcc/sthBJTp4: Failed to find link section for section 68 /var/tmp/portage/sys-devel/gcc-6.3.0/work/gcc-6.3.0/contrib/compare-debug: line 60: 7022 Segmentation fault strip "$1.$suf1"
Reproducible on cross-ia64 toolchain as well. Here is the exact object file generated by gcc: http://dev.gentoo.org/~slyfox/bugs/622500-ia64-strip/dwarf2out.o Here is the backtrace: $ gdb -q --args ia64-unknown-linux-gnu-strip dwarf2out.o Reading symbols from ia64-unknown-linux-gnu-strip...Reading symbols from /usr/lib64/debug//usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/inutils-bin/2.28/strip.debug...done. done. (gdb) run Starting program: /usr/bin/ia64-unknown-linux-gnu-strip dwarf2out.o /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 13 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 19 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 22 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 25 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 29 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 32 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 35 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 38 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 41 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 44 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 49 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 52 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 56 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 59 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 62 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 65 /usr/bin/ia64-unknown-linux-gnu-strip: stIrODgt: Failed to find link section for section 68 Program received signal SIGSEGV, Segmentation fault. 0x00007f2606fd701d in section_match (b=0x555555794370, a=0x84000804c0420080) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1258 1258 && a->sh_entsize == b->sh_entsize (gdb) bt #0 0x00007f2606fd701d in section_match (b=0x555555794370, a=0x84000804c0420080) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1258 #1 find_link (iheader=0x555555794370, hint=<optimized out>, obfd=<optimized out>) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1278 #2 0x00007f2606fd71a6 in copy_special_section_fields (ibfd=ibfd@entry=0x55555578dc70, obfd=obfd@entry=0x5555557cb780, iheader=0x555555794460, oheader=oheader@entry=0x5555557db170, secnum=secnum@entry=71) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1359 #3 0x00007f2606fd8f22 in _bfd_elf_copy_private_bfd_data (ibfd=0x55555578dc70, obfd=0x5555557cb780) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1481 #4 0x000055555555fb7c in copy_object (ibfd=<optimized out>, obfd=<optimized out>, input_arch=<optimized out>) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/binutils/objcopy.c:2517 #5 0x0000555555560e46 in copy_file (input_filename=0x7fffffffd6b6 "dwarf2out.o", output_filename=0x55555578cf00 "stIrODgt", input_target=<optimized out>, output_target=<optimized out>, input_arch=0x0) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/binutils/objcopy.c:2879 #6 0x000055555555b926 in strip_main (argv=<optimized out>, argc=<optimized out>) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/binutils/objcopy.c:3791 #7 main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/binutils/objcopy.c:4891 (gdb) bt full #0 0x00007f2606fd701d in section_match (b=0x555555794370, a=0x84000804c0420080) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1258 No locals. #1 find_link (iheader=0x555555794370, hint=<optimized out>, obfd=<optimized out>) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1278 oheaders = 0x55555581cb20 i = <optimized out> #2 0x00007f2606fd71a6 in copy_special_section_fields (ibfd=ibfd@entry=0x55555578dc70, obfd=obfd@entry=0x5555557cb780, iheader=0x555555794460, oheader=oheader@entry=0x5555557db170, secnum=secnum@entry=71) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1359 bed = <optimized out> iheaders = <optimized out> changed = 0 sh_link = <optimized out> #3 0x00007f2606fd8f22 in _bfd_elf_copy_private_bfd_data (ibfd=0x55555578dc70, obfd=0x5555557cb780) at /usr/src/debug/cross-ia64-unknown-linux-gnu/binutils-2.28-r2/binutils-2.28/bfd/elf.c:1481 iheader = <optimized out> j = 164 oheader = 0x5555557db170 iheaders = <optimized out> oheaders = <optimized out> bed = <optimized out> i = 71
Created attachment 477738 [details, diff] binutils-2.28-bfd-elf.c-fix-out-of-bounds-access-in-find_link.patch And we have a workaround! Looks like binutils has a 'hint' optimisation to resolve section type to section number in output file in 'find_link()' function. somehow 'strip' breaks that hint. My guess is that when sections are discarded array of output sections shrinks (instead of leaving discarded elements to cintain NULL pinters). binutils-2.28-bfd-elf.c-fix-out-of-bounds-access-in-find_link.patch adds a workaround to check for hint array size before dereferencing it out-of-bounds. The fix allowed to build gcc-6.3.0 on ~ia64. Will poke at binutils a bit more for a proper fix and will try to propose it upstream.
Reported upstream as https://sourceware.org/bugzilla/show_bug.cgi?id=21669
Patch made it's way upstream as https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=5cc4ca837deac7dc962d8a3741aa120c50ab41da
toolchain@, can we get this fix into this release or cut a next ~arch release so we could fast-track it for ia64@ at least?
Patch applied in 2.28.1 commit cf5003fe2fc3b45f366d0a3c6fdf834ed9d54321 Author: Matthias Maier <tamiko@gentoo.org> Date: Tue Aug 1 19:05:14 2017 -0500 sys-devel/binutils: version bump to 2.28.1, patchset 1.0 Includes fixes for bugs #622036 #622500 #622886 #624524 #624702 Package-Manager: Portage-2.3.6, Repoman-2.3.3
binutils-2.28.1 is stable on ia64 and can build gcc without issues.
