Bug 221107 - -r322109 and -r322210 (so clang 5) TARGET_ARCH=powerpc agp.kld or agp.kld gets: R_PPC_PLTREL24 reloc against local symbol; could not read symbols: Bad value
Summary: -r322109 and -r322210 (so clang 5) TARGET_ARCH=powerpc agp.kld or agp.kld get...
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: powerpc Any
: --- Affects Only Me
Assignee: freebsd-bugs mailing list
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2017-07-30 19:58 UTC by Mark Millard
Modified: 2017-08-11 05:16 UTC (History)
0 users

See Also:


Attachments

Note You need to log in before you can comment on or make changes to this bug.
Description Mark Millard 2017-07-30 19:58:15 UTC
This happens to be via a amd64 -> powerpc
cross build. I experiment with system clang
targeting powerpc (and powerpc64). Until
recently I could buildkernel via clang (but
it had problems if tried to boot the build).

First I show the error reporting text then
the build context used.

--- all_subdir_aha ---
Building /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha.kld
. . .
--- all_subdir_aha ---
Building /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha.ko.full
. . .
--- aha.ko.full ---
ld: aha.kld(.text+0x2b94): R_PPC_PLTREL24 reloc against local symbol
aha.kld: could not read symbols: Bad value
. . .
--- all_subdir_aha ---
*** [aha.ko.full] Error code 1

make[4]: stopped in /usr/src/sys/modules/aha
.ERROR_TARGET='aha.ko.full'
.ERROR_META_FILE='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha.ko.full.meta'
.MAKE.LEVEL='4'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose'
_ERROR_CMD='ld -m elf32ppc_fbsd -Bshareable -znotext -d -warn-common  -o aha.ko.full aha.kld;'
.CURDIR='/usr/src/sys/modules/aha'
.MAKE='make'
.OBJDIR='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha'
.TARGETS='all'
DESTDIR=''
LD_LIBRARY_PATH=''
MACHINE='powerpc'
MACHINE_ARCH='powerpc'
MAKEOBJDIRPREFIX='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules'
MAKESYSPATH='/usr/src/share/mk'
MAKE_VERSION='20170720'
--- all_subdir_agp ---
Building /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp.ko.full
--- all_subdir_aha ---
PATH='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/bin:/sbin:/bin:/usr/sbin:/usr/bin'
SRCTOP='/usr/src'
OBJTOP='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src'
.MAKE.MAKEFILES='/usr/src/share/mk/sys.mk /usr/src/share/mk/local.sys.env.mk /usr/src/share/mk/src.sys.env.mk /root/src.configs/src.conf.powerpc-clang-bootstrap.amd64-host /usr/src/share/mk/bsd.mkopt.mk /usr/src/share/mk/bsd.suffixes.mk /root/src.configs/make.conf /usr/src/share/mk/local.sys.mk /usr/src/share/mk/src.sys.mk /dev/null /usr/src/sys/modules/aha/Makefile /usr/src/share/mk/bsd.kmod.mk /usr/src/sys/conf/kmod.mk /usr/src/share/mk/bsd.init.mk /usr/src/share/mk/bsd.opts.mk /usr/src/share/mk/bsd.cpu.mk /usr/src/share/mk/local.init.mk /usr/src/share/mk/src.init.mk /usr/src/sys/modules/aha/../Makefile.inc /usr/src/share/mk/bsd.own.mk /usr/src/share/mk/bsd.compiler.mk /usr/src/share/mk/bsd.linker.mk /usr/src/sys/conf/kern.opts.mk /usr/src/sys/conf/config.mk /usr/src/share/mk/bsd.links.mk /usr/src/share/mk/bsd.dep.mk /usr/src/share/mk/bsd.clang-analyze.mk /usr/src/share/mk/bsd.obj.mk /usr/src/share/mk/bsd.subdir.mk /usr/src/sys/conf/kern.mk'
.PATH='. /usr/src/sys/modules/aha /usr/src/sys/dev/aha /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG'
1 error

make[4]: stopped in /usr/src/sys/modules/aha
.ERROR_TARGET='aha.ko.full'
.ERROR_META_FILE='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha.ko.full.meta'
.MAKE.LEVEL='4'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose'
_ERROR_CMD='ld -m elf32ppc_fbsd -Bshareable -znotext -d -warn-common  -o aha.ko.full aha.kld;'
.CURDIR='/usr/src/sys/modules/aha'
.MAKE='make'
.OBJDIR='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha'
.TARGETS='all'
DESTDIR=''
LD_LIBRARY_PATH=''
MACHINE='powerpc'
MACHINE_ARCH='powerpc'
MAKEOBJDIRPREFIX='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules'
MAKESYSPATH='/usr/src/share/mk'
MAKE_VERSION='20170720'
PATH='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/bin:/sbin:/bin:/usr/sbin:/usr/bin'
SRCTOP='/usr/src'
OBJTOP='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src'
.MAKE.MAKEFILES='/usr/src/share/mk/sys.mk /usr/src/share/mk/local.sys.env.mk /usr/src/share/mk/src.sys.env.mk /root/src.configs/src.conf.powerpc-clang-bootstrap.amd64-host /usr/src/share/mk/bsd.mkopt.mk /usr/src/share/mk/bsd.suffixes.mk /root/src.configs/make.conf /usr/src/share/mk/local.sys.mk /usr/src/share/mk/src.sys.mk /dev/null /usr/src/sys/modules/aha/Makefile /usr/src/share/mk/bsd.kmod.mk /usr/src/sys/conf/kmod.mk /usr/src/share/mk/bsd.init.mk /usr/src/share/mk/bsd.opts.mk /usr/src/share/mk/bsd.cpu.mk /usr/src/share/mk/local.init.mk /usr/src/share/mk/src.init.mk /usr/src/sys/modules/aha/../Makefile.inc /usr/src/share/mk/bsd.own.mk /usr/src/share/mk/bsd.compiler.mk /usr/src/share/mk/bsd.linker.mk /usr/src/sys/conf/kern.opts.mk /usr/src/sys/conf/config.mk /usr/src/share/mk/bsd.links.mk /usr/src/share/mk/bsd.dep.mk /usr/src/share/mk/bsd.clang-analyze.mk /usr/src/share/mk/bsd.obj.mk /usr/src/share/mk/bsd.subdir.mk /usr/src/sys/conf/kern.mk'
.PATH='. /usr/src/sys/modules/aha /usr/src/sys/dev/aha /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG'
*** [all_subdir_aha] Error code 2


Build context:

~/sys_build_scripts.amd64-host/make_powerpcvtsc_nodebug_clang_bootstrap-amd64-host.sh -j8 buildworld buildkernel

# more ~/sys_build_scripts.amd64-host/make_powerpcvtsc_nodebug_clang_bootstrap-amd64-host.sh 
kldload -n filemon && \
script ~/sys_typescripts/typescript_make_powerpcvtsc_nodebug_clang_bootstrap-amd64-host-$(date +%Y-%m-%d:%H:%M:%S) \
env __MAKE_CONF="/root/src.configs/make.conf" SRCCONF="/dev/null" SRC_ENV_CONF="/root/src.configs/src.conf.powerpc-clang-bootstrap.amd64-host" \
WITH_META_MODE=yes \
MAKEOBJDIRPREFIX="/usr/obj/powerpcvtsc_clang" \
make $*

C# more /root/src.configs/make.conf
CFLAGS.gcc+= -v

# more /root/src.configs/src.conf.powerpc-clang-bootstrap.amd64-host
TO_TYPE=powerpc
#
KERNCONF=GENERICvtsc-NODBG
TARGET=${TO_TYPE}
.if ${.MAKE.LEVEL} == 0
TARGET_ARCH=${TO_TYPE}
.export TARGET_ARCH
.endif
#
WITH_CROSS_COMPILER=
WITHOUT_SYSTEM_COMPILER=
#
WITH_LIBCPLUSPLUS=
WITH_BINUTILS_BOOTSTRAP=
WITH_ELFTOOLCHAIN_BOOTSTRAP=
WITH_CLANG_BOOTSTRAP=
WITH_CLANG=
WITH_CLANG_IS_CC=
WITH_CLANG_FULL=
WITH_CLANG_EXTRAS=
WITHOUT_LLD=
# lldb requires missing atomic 8-byte operations for powerpc (non-64)
WITHOUT_LLDB=
#
WITH_BOOT=
WITHOUT_LIB32=
#
WITHOUT_GCC_BOOTSTRAP=
WITHOUT_GCC=
WITHOUT_GCC_IS_CC=
WITHOUT_GNUCXX=
#
NO_WERROR=
#
# Use WERROR to avoid stopping at the likes of:
# error: implicit conversion from 'int' to 'int8_t' (aka 'signed char') changes value from 128 to -128 [-Werror,-Wconstant-conversion]
WERROR=
MALLOC_PRODUCTION=
#
WITH_REPRODUCIBLE_BUILD=
WITH_DEBUG_FILES=
Comment 1 Mark Millard 2017-07-30 20:25:23 UTC
objdump reports that the .text+0x2b94 is in
aha_isa_probe and is a reference to aha_alloc:

(sorted objdump -x output:)
00002b78 R_PPC_PLTREL24    bus_alloc_resource
00002b88 R_PPC_PLTREL24    rman_get_start
00002b94 R_PPC_PLTREL24    aha_alloc
00002b96 R_PPC_ADDR32      .debug_str+0x0000266c
00002b9c R_PPC_PLTREL24    aha_probe
00002b9f R_PPC_ADDR32      .debug_str+0x00001904

(objdump -d --prefix-addresses output:)
00002aa4 <aha_isa_probe> mflr    r0
. . .
00002b7c <aha_isa_probe+0xd8> cmplwi  r3,0
00002b80 <aha_isa_probe+0xdc> stw     r3,188(r28)
00002b84 <aha_isa_probe+0xe0> beq     00002c1c <aha_isa_probe+0x178>
00002b88 <aha_isa_probe+0xe4> bl      00002b88 <aha_isa_probe+0xe4>
00002b8c <aha_isa_probe+0xe8> mr      r3,r28
00002b90 <aha_isa_probe+0xec> mr      r27,r4
00002b94 <aha_isa_probe+0xf0> bl      00002b94 <aha_isa_probe+0xf0>
00002b98 <aha_isa_probe+0xf4> mr      r3,r28
00002b9c <aha_isa_probe+0xf8> bl      00002b9c <aha_isa_probe+0xf8>
00002ba0 <aha_isa_probe+0xfc> cmplwi  r3,0
Comment 2 Mark Millard 2017-08-06 21:37:05 UTC
My -r322109 update got the same type of error in a different
place:

--- all_subdir_agp ---
Building /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp.ko.full
. . .
--- all_subdir_agp ---
--- agp.ko.full ---
ld: agp.kld(.text+0x2e08): R_PPC_PLTREL24 reloc against local symbol
agp.kld: could not read symbols: Bad value
*** [agp.ko.full] Error code 1

make[4]: stopped in /usr/src/sys/modules/agp
.ERROR_TARGET='agp.ko.full'
.ERROR_META_FILE='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp.ko.full.meta'
.MAKE.LEVEL='4'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose'
_ERROR_CMD='ld -m elf32ppc_fbsd -Bshareable -znotext -d -warn-common  -o agp.ko.full agp.kld;'
.CURDIR='/usr/src/sys/modules/agp'
.MAKE='make'
.OBJDIR='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp'
.TARGETS='all'
DESTDIR=''
LD_LIBRARY_PATH=''
MACHINE='powerpc'
MACHINE_ARCH='powerpc'
MAKEOBJDIRPREFIX='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules'
MAKESYSPATH='/usr/src/share/mk'
MAKE_VERSION='20170720'
PATH='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/bin:/sbin:/bin:/usr/sbin:/usr/bin'
SRCTOP='/usr/src'
OBJTOP='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src'
.MAKE.MAKEFILES='/usr/src/share/mk/sys.mk /usr/src/share/mk/local.sys.env.mk /usr/src/share/mk/src.sys.env.mk /root/src.configs/src.conf.powerpc-clang-bootstrap.amd64-host /usr/src/share/mk/bsd.mkopt.mk /usr/src/share/mk/bsd.suffixes.mk /root/src.configs/make.conf /usr/src/share/mk/local.sys.mk /usr/src/share/mk/src.sys.mk /dev/null /usr/src/sys/modules/agp/Makefile /usr/src/share/mk/bsd.kmod.mk /usr/src/sys/conf/kmod.mk /usr/src/share/mk/bsd.init.mk /usr/src/share/mk/bsd.opts.mk /usr/src/share/mk/bsd.cpu.mk /usr/src/share/mk/local.init.mk /usr/src/share/mk/src.init.mk /usr/src/sys/modules/agp/../Makefile.inc /usr/src/share/mk/bsd.own.mk /usr/src/share/mk/bsd.compiler.mk /usr/src/share/mk/bsd.linker.mk /usr/src/sys/conf/kern.opts.mk /usr/src/sys/conf/config.mk /usr/src/share/mk/bsd.links.mk /usr/src/share/mk/bsd.dep.mk /usr/src/share/mk/bsd.clang-analyze.mk /usr/src/share/mk/bsd.obj.mk /usr/src/share/mk/bsd.subdir.mk /usr/src/sys/conf/kern.mk'
.PATH='. /usr/src/sys/modules/agp /usr/src/sys/dev/agp /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG'
1 error
--- all_subdir_aha ---
A failure has been detected in another branch of the parallel make

make[4]: stopped in /usr/src/sys/modules/aha
.ERROR_TARGET=''
.ERROR_META_FILE=''
.MAKE.LEVEL='4'
MAKEFILE=''
.MAKE.MODE='meta missing-filemon=yes missing-meta=yes silent=yes verbose'
_ERROR_CMD='.PHONY'
.CURDIR='/usr/src/sys/modules/aha'
.MAKE='make'
.OBJDIR='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha'
.TARGETS='all'
DESTDIR=''
LD_LIBRARY_PATH=''
MACHINE='powerpc'
MACHINE_ARCH='powerpc'
MAKEOBJDIRPREFIX='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules'
MAKESYSPATH='/usr/src/share/mk'
MAKE_VERSION='20170720'
PATH='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/usr/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/legacy/bin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/sbin:/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/tmp/usr/bin:/sbin:/bin:/usr/sbin:/usr/bin'
SRCTOP='/usr/src'
OBJTOP='/usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src'
.MAKE.MAKEFILES='/usr/src/share/mk/sys.mk /usr/src/share/mk/local.sys.env.mk /usr/src/share/mk/src.sys.env.mk /root/src.configs/src.conf.powerpc-clang-bootstrap.amd64-host /usr/src/share/mk/bsd.mkopt.mk /usr/src/share/mk/bsd.suffixes.mk /root/src.configs/make.conf /usr/src/share/mk/local.sys.mk /usr/src/share/mk/src.sys.mk /dev/null /usr/src/sys/modules/aha/Makefile /usr/src/share/mk/bsd.kmod.mk /usr/src/sys/conf/kmod.mk /usr/src/share/mk/bsd.init.mk /usr/src/share/mk/bsd.opts.mk /usr/src/share/mk/bsd.cpu.mk /usr/src/share/mk/local.init.mk /usr/src/share/mk/src.init.mk /usr/src/sys/modules/aha/../Makefile.inc /usr/src/share/mk/bsd.own.mk /usr/src/share/mk/bsd.compiler.mk /usr/src/share/mk/bsd.linker.mk /usr/src/sys/conf/kern.opts.mk /usr/src/sys/conf/config.mk /usr/src/share/mk/bsd.links.mk /usr/src/share/mk/bsd.dep.mk /usr/src/share/mk/bsd.clang-analyze.mk /usr/src/share/mk/bsd.obj.mk /usr/src/share/mk/bsd.subdir.mk /usr/src/sys/conf/kern.mk'
.PATH='. /usr/src/sys/modules/aha /usr/src/sys/dev/aha /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG'
*** [all_subdir_aha] Error code 2
Comment 3 Mark Millard 2017-08-08 15:23:12 UTC
(In reply to Mark Millard from comment #2)

Building under/for -r322210 got the R_PPC_PLTREL24 report
for aha.kld instead of agp.aha :

--- aha.ko.full ---
ld: aha.kld(.text+0x2b8c): R_PPC_PLTREL24 reloc against local symbol
aha.kld: could not read symbols: Bad value
--- all_subdir_agp ---
Building /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp.ko.full
--- all_subdir_aha ---
*** [aha.ko.full] Error code 1

Looks like a race as two which occurs first but both
fail.
Comment 4 Mark Millard 2017-08-11 01:02:22 UTC
The "reloc against local symbol" text
is omitted by code from:

/usr/src/contrib/binutils/bfd/elf32-ppc.c

in its routine:

/* Look through the relocs for a section during the first phase, and
   allocate space in the global offset table or procedure linkage
   table.  */
          
static bfd_boolean
ppc_elf_check_relocs (bfd *abfd,
                      struct bfd_link_info *info,
                      asection *sec,
                      const Elf_Internal_Rela *relocs)

via:

      tls_type = 0;
      r_type = ELF32_R_TYPE (rel->r_info);
. . .              
      switch (r_type)
        {
. . .
        case R_PPC_PLT32:
        case R_PPC_PLTREL24:
        case R_PPC_PLTREL32:
        case R_PPC_PLT16_LO:
        case R_PPC_PLT16_HI:
        case R_PPC_PLT16_HA:
#ifdef DEBUG
          fprintf (stderr, "Reloc requires a PLT entry\n");
#endif
          /* This symbol requires a procedure linkage table entry.  We
             actually build the entry in finish_dynamic_symbol,
             because this might be a case of linking PIC code without
             linking in any dynamic objects, in which case we don't
             need to generate a procedure linkage table after all.  */
              
          if (h == NULL)
            {
              /* It does not make sense to have a procedure linkage
                 table entry for a local symbol.  */
              (*_bfd_error_handler) (_("%B(%A+0x%lx): %s reloc against "
                                       "local symbol"),
                                     abfd,
                                     sec,
                                     (long) rel->r_offset,
                                     ppc_elf_howto_table[r_type]->name);
              bfd_set_error (bfd_error_bad_value);
              return FALSE;
            }
          else
            {
              bfd_vma addend = 0;
        
              if (r_type == R_PPC_PLTREL24)
                {
                  ppc_elf_tdata (abfd)->makes_plt_call = 1;
                  addend = rel->r_addend;
                }
              h->needs_plt = 1;
              if (!update_plt_info (abfd, h, got2, addend))
                return FALSE;
            }
          break;

where the earlier code for finding the h value is:

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
        h = NULL;
      else  
        {
          h = sym_hashes[r_symndx - symtab_hdr->sh_info];
          while (h->root.type == bfd_link_hash_indirect
                 || h->root.type == bfd_link_hash_warning)
            h = (struct elf_link_hash_entry *) h->root.u.i.link;
        }
Comment 5 Mark Millard 2017-08-11 01:38:53 UTC
There is something consistent between the two example
failures. Even across builds of different versions
that have moved the .text offset of one of the routines
the same routines fail.

(I inserted some lines not matched by the shown grep.)

# readelf -a /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha.kld | grep aha_alloc
00002b8c 00003e12 R_PPC_PLTREL24      00000000 aha_alloc + 0
000031a8 00003e12 R_PPC_PLTREL24      00000000 aha_alloc + 0
Symbol table (.symtab) contains 180 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
    62: 0000000000000000    96 FUNC    LOCAL  DEFAULT    1 aha_alloc

(2b8c is different than reported before: newer head version used)

# readelf -a /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp.kld | grep agp_find_caps
00002e08 00004912 R_PPC_PLTREL24      00000000 agp_find_caps + 0
Symbol table (.symtab) contains 180 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
    73: 0000000000000000   172 FUNC    LOCAL  DEFAULT    1 agp_find_caps

The "Value" is zero for "FUNC LOCCAL DEFAULT" in the failing references.
Comment 6 Mark Millard 2017-08-11 02:13:19 UTC
Using the agp example:

Section Headers:
  [Nr] Name
       Type            Addr     Off    Size   ES   Lk Inf Al
       Flags
. . .
  [35] .symtab
       SYMTAB          00000000 025418 000b40 10  36 108  4
       [00000000]: 

is related to:

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
        h = NULL;
      else  

where for the agp example: r_symndx == 0x49
(73 decimal) for agp_find_caps. So
r_symndx < 108 (if 108 is the sh_info field
value).

Note that in agp.o :

    58: 0000000000000000   172 FUNC    GLOBAL DEFAULT    2 agp_find_caps

but in agp.kld :

    73: 0000000000000000   172 FUNC    LOCAL  DEFAULT    1 agp_find_caps



For the aha example:

  [34] .symtab
       SYMTAB          00000000 020a54 000930 10  35  70  4
       [00000000]: 

So 0x3e == 62 for aha_alloc and 62 < 70.

Note that in aha.o :

    44: 0000000000000000    96 FUNC    GLOBAL DEFAULT    2 aha_alloc

but in aha.kld :

    62: 0000000000000000    96 FUNC    LOCAL  DEFAULT    1 aha_alloc
Comment 7 Mark Millard 2017-08-11 03:13:43 UTC
For reference for how aha.kld and agp.kld are
produced:

# Meta data file /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha.kld.meta
CMD ld -m elf32ppc_fbsd -d -warn-common -r -d -o aha.kld aha.o aha_isa.o
CMD ctfmerge -L VERSION -g -o aha.kld aha.o aha_isa.o
CMD :> export_syms
CMD awk -f /usr/src/sys/conf/kmod_syms.awk aha.kld  export_syms | xargs -J% objcopy % aha.kld
CWD /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha
TARGET aha.kld

# Meta data file /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp.kld.meta
CMD ld -m elf32ppc_fbsd -d -warn-common -r -d -o agp.kld agp.o agp_if.o agp_apple.o
CMD ctfmerge -L VERSION -g -o agp.kld agp.o agp_if.o agp_apple.o
CMD echo agp_find_device                 agp_state               agp_acquire             agp_release             agp_enable              agp_alloc_memory        agp_free_memory                 agp_bin
d_memory                 agp_unbind_memory       agp_memory_info > export_syms
CMD awk -f /usr/src/sys/conf/kmod_syms.awk agp.kld  export_syms | xargs -J% objcopy % agp.kld
CWD /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp
TARGET agp.kld

It looks like (via kmod_syms.awk) objcopy is
explicitly turning various R_PPC_PLTREL24
examples into LOCAL symbols.

May be before clang 5 these were not
R_PPC_PLTREL24 ?

They are now and the conversion to LOCAL while
keeping R_PPC_PLTREL24 is rejected by:

ppc_elf_check_relocs

which in turn stops ld from producing the
matching .full files. And that in turn stops
the buildkernel .
Comment 8 Mark Millard 2017-08-11 05:16:19 UTC
clang 5 and gcc 4.2.1 do not match for what
goes in aha*.o and agp*.o files for the
problem symbols:

gcc 4.2.1 ( R_PPC_ADDR16_HA / R_PPC_ADDR16_LO ):

# readelf -at /usr/obj/powerpcvtsc_gcc421/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha*.o | grep aha_alloc
    50: 0000000000000514   112 FUNC    GLOBAL DEFAULT    1 aha_alloc
00000032 00003206 R_PPC_ADDR16_HA     00000000 aha_alloc + 0
0000003e 00003204 R_PPC_ADDR16_LO     00000000 aha_alloc + 0
0000052a 00003206 R_PPC_ADDR16_HA     00000000 aha_alloc + 0
0000052e 00003204 R_PPC_ADDR16_LO     00000000 aha_alloc + 0
    50: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND aha_alloc

# readelf -at /usr/obj/powerpcvtsc_gcc421/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp*.o | grep caps
0000204a 00003a06 R_PPC_ADDR16_HA     00000434 agp_find_caps + 0
0000204e 00003a04 R_PPC_ADDR16_LO     00000434 agp_find_caps + 0
00002312 00003a06 R_PPC_ADDR16_HA     00000434 agp_find_caps + 0
0000231a 00003a04 R_PPC_ADDR16_LO     00000434 agp_find_caps + 0
00000000 00003a01 R_PPC_ADDR32        00000434 agp_find_caps + 0
    58: 0000000000000434   192 FUNC    GLOBAL DEFAULT    1 agp_find_caps
000002be 00003906 R_PPC_ADDR16_HA     00000000 agp_find_caps + 0
000002c6 00003904 R_PPC_ADDR16_LO     00000000 agp_find_caps + 0
    57: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND agp_find_caps


clang 5 ( R_PPC_PLTREL24 ):

# readelf -at /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/aha/aha*.o | grep aha_alloc
    44: 0000000000000000    96 FUNC    GLOBAL DEFAULT    2 aha_alloc
000000f0 00002e12 R_PPC_PLTREL24      00000000 aha_alloc + 0
0000070c 00002e12 R_PPC_PLTREL24      00000000 aha_alloc + 0
    46: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND aha_alloc

# readelf -at /usr/obj/powerpcvtsc_clang/powerpc.powerpc/usr/src/sys/GENERICvtsc-NODBG/modules/usr/src/sys/modules/agp/agp*.o | grep caps
    58: 0000000000000000   172 FUNC    GLOBAL DEFAULT    2 agp_find_caps
00000138 00003512 R_PPC_PLTREL24      00000000 agp_find_caps + 0
    53: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND agp_find_caps