Add linker relaxation. The first relaxation added is converting
GOTPC32 to PCREL relocations. This relaxation doesn't change the size of
the binary.
bfd/
xxxx-xx-xx Claudiu Zissulescu <claziss@synopsys.com>
* elf32-arc.c (bfd_get_32_me): New function.
(bfd_put_32_me): Likewise.
(arc_elf_relax_section): Likewise.
(bfd_elf32_bfd_relax_section): Define.
ld/testsuite/
xxxx-xx-xx Claudiu Zissulescu <claziss@synopsys.com>
* ld-arc/relax-local-pic.d: New test.
* ld-arc/relax-local-pic.s: New file.
I missed some early exits from final_write_processing that mean
_bfd_elf_final_write_processing could be missed.
* elf-vxworks.c (elf_vxworks_final_write_processing): Don't return
early.
* elf32-arc.c (arc_elf_final_write_processing): Likewise.
* elf32-xtensa.c (elf_xtensa_final_write_processing): Likewise.
When SHF_GNU_MBIND was added in the SHF_LOOS to SHF_HIOS range, it
should have required ELFOSABI_GNU since these flags are already in use
by other OSes. HPUX SHF_HP_TLS in fact has the same value. That
means no place in binutils should test SHF_GNU_MBIND without first
checking OSABI, and SHF_GNU_MBIND should not be set without also
setting OSABI. At least, that's the ideal, but the patch accepts
SHF_GNU_MBIND on ELFOSABI_NONE object files since gas didn't always
set OSABI. However, to reinforce the fact that SHF_GNU_MBIND isn't
proper without a non-zero OSABI, readelf will display the flag as
LOOS+0 if OSABI isn't set.
The clash with SHF_HP_TLS means that hppa64-linux either has that flag
on .tbss sections or supports GNU_MBIND, not both. (hppa64-linux
users, if there are any, may have noticed that GNU ld since 2017
mysteriously aligned their .tbss sections to a 4k boundary. That was
one consequence of SHF_HP_TLS being blindly interpreted as
SHF_GNU_MBIND.) Since it seems that binutils, gdb, gcc, glibc, and
the linux kernel don't care about SHF_HP_TLS I took that flag out of
.tbss for hppa64-linux.
bfd/
* elf-bfd.h (enum elf_gnu_osabi): Add elf_gnu_osabi_mbind.
* elf.c (_bfd_elf_make_section_from_shdr): Set elf_gnu_osabi_mbind.
(get_program_header_size): Formatting. Only test SH_GNU_MBIND
when elf_gnu_osabi_mbind is set.
(_bfd_elf_map_sections_to_segments): Likewise.
(_bfd_elf_init_private_section_data): Likewise.
(_bfd_elf_final_write_processing): Update comment.
* elf64-hppa.c (elf64_hppa_special_sections): Move .tbss entry.
(elf_backend_special_sections): Define without .tbss for linux.
binutils/
* readelf.c (get_parisc_segment_type): Split off hpux entries..
(get_ia64_segment_type): ..and these..
(get_hpux_segment_type): ..to here.
(get_segment_type): Condition GNU_MBIND on osabi. Use
get_hpux_segment_type.
(get_symbol_binding): Do not print UNIQUE for ELFOSABI_NONE.
(get_symbol_type): Do not print IFUNC for ELFOSABI_NONE.
gas/
* config/obj-elf.c (obj_elf_change_section): Don't emit a fatal
error for non-SHF_ALLOC SHF_GNU_MBIND here.
(obj_elf_parse_section_letters): Return SHF_GNU_MBIND in new
gnu_attr param.
(obj_elf_section): Adjust obj_elf_parse_section_letters call.
Formatting. Set SHF_GNU_MBIND and elf_osabi from gnu_attr.
Emit normal error for non-SHF_ALLOC SHF_GNU_MBIND and wrong osabi.
(obj_elf_type): Set elf_osabi for ifunc.
* testsuite/gas/elf/section12a.d: xfail msp430 and hpux.
* testsuite/gas/elf/section12b.d: Likewise.
* testsuite/gas/elf/section13.d: Likewise.
* testsuite/gas/elf/section13.l: Adjust expected error.
ld/
* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Condition
SHF_GNU_MBIND on osabi. Set output elf_gnu_osabi_mbind.
This patch supports using pcrel instructions in TLS code sequences. A
number of new relocations are needed, gas operand modifiers to
generate those relocations, and new TLS optimisation. For
optimisation it turns out that the new pcrel GD and LD sequences can
be distinguished from the non-pcrel GD and LD sequences by there being
different relocations on the new sequence. The final "add ra,rb,13"
on IE sequences similarly needs a new relocation, or as I chose, a
modification of R_PPC64_TLS. On pcrel IE code, the R_PPC64_TLS points
one byte into the "add" instruction rather than being on the
instruction boundary.
GD:
pla 3,z@got@tlsgd@pcrel # R_PPC64_GOT_TLSGD34
bl __tls_get_addr@notoc(z@tlsgd) # R_PPC64_TLSGD and R_PPC64_REL24_NOTOC
edited to IE
pld 3,z@got@tprel@pcrel
add 3,3,13
edited to LE
paddi 3,13,z@tprel
nop
LD:
pla 3,z@got@tlsld@pcrel # R_PPC64_GOT_TLSLD34
bl __tls_get_addr@notoc(z@tlsld) # R_PPC64_TLSLD and R_PPC64_REL24_NOTOC
..
paddi 9,3,z2@dtprel
pld 10,z3@got@dtprel@pcrel
add 10,10,3
edited to LE
paddi 3,13,0x1000
nop
IE:
pld 9,z@got@tprel@pcrel # R_PPC64_GOT_TPREL34
add 3,9,z@tls@pcrel # R_PPC64_TLS at insn+1
ldx 4,9,z@tls@pcrel
lwax 5,9,z@tls@pcrel
stdx 5,9,z@tls@pcrel
edited to LE
paddi 9,13,z@tprel
nop
ld 4,0(9)
lwa 5,0(9)
std 5,0(9)
LE:
paddi 10,13,z@tprel
include/
* elf/ppc64.h (R_PPC64_TPREL34, R_PPC64_DTPREL34),
(R_PPC64_GOT_TLSGD34, R_PPC64_GOT_TLSLD34),
(R_PPC64_GOT_TPREL34, R_PPC64_GOT_DTPREL34): Define.
(IS_PPC64_TLS_RELOC): Include new tls relocs.
bfd/
* reloc.c (BFD_RELOC_PPC64_TPREL34, BFD_RELOC_PPC64_DTPREL34),
(BFD_RELOC_PPC64_GOT_TLSGD34, BFD_RELOC_PPC64_GOT_TLSLD34),
(BFD_RELOC_PPC64_GOT_TPREL34, BFD_RELOC_PPC64_GOT_DTPREL34),
(BFD_RELOC_PPC64_TLS_PCREL): New pcrel tls relocs.
* elf64-ppc.c (ppc64_elf_howto_raw): Add howtos for pcrel tls relocs.
(ppc64_elf_reloc_type_lookup): Translate pcrel tls relocs.
(must_be_dyn_reloc, dec_dynrel_count): Add R_PPC64_TPREL64.
(ppc64_elf_check_relocs): Support pcrel tls relocs.
(ppc64_elf_tls_optimize, ppc64_elf_relocate_section): Likewise.
* bfd-in2.h: Regenerate.
* libbfd.h: Regenerate.
gas/
* config/tc-ppc.c (ppc_elf_suffix): Map "tls@pcrel", "got@tlsgd@pcrel",
"got@tlsld@pcrel", "got@tprel@pcrel", and "got@dtprel@pcrel".
(fixup_size, md_assemble): Handle pcrel tls relocs.
(ppc_force_relocation, ppc_fix_adjustable): Likewise.
(md_apply_fix, tc_gen_reloc): Likewise.
ld/
* testsuite/ld-powerpc/tlsgd.d,
* testsuite/ld-powerpc/tlsgd.s,
* testsuite/ld-powerpc/tlsie.d,
* testsuite/ld-powerpc/tlsie.s,
* testsuite/ld-powerpc/tlsld.d,
* testsuite/ld-powerpc/tlsld.s: New tests.
* testsuite/ld-powerpc/powerpc.exp: Run them.
It's not correct to use non-STT_TLS symbols with TLS relocation, not
that it matters much when editing relocs, but this edited reloc can be
output by --emit-relocs. So don't use a symbol on the reloc.
* elf64-ppc.c (ppc64_elf_relocate_section): Don't bother selecting
a TLS section symbol for edited relocs. Tighten TLS symbol/reloc
match test.
This saves a bit in tls_mask, and fixes a bug that could be triggered
in the unlikely case that both @got (usual ELF style) and @toc
(PowerOpen style) code was used to set up args for __tls_get_addr.
* elf64-ppc.c (TLS_EXPLICIT): Define as 256.
(ppc64_elf_check_relocs): Don't store TLS_EXPLICIT even if char
is more than 8 bits.
(ppc64_elf_tls_optimize): Likewise. Make tls_set, tls_clear, and
tls_type vars unsigned int.
(ppc64_elf_relocate_section): Use r_type rather than TLS_EXPLICIT
to select r_type edit.
Choose a better name, that reflects why the flag is set (GD to IE
optimisation) rather than what the flag produces (TPREL64 reloc on
a single GOT entry replacing a tls_index pair).
* elf32-ppc.c (TLS_GDIE): Rename from TLS_TPRELGD throughout file.
Correct comment.
* elf64-ppc.c (TLS_GDIE): Likewise.
I don't expect anyone will have hit this bug. You'd need a TLS
segment of 2G before you'd notice.
* elf64-ppc.c (ppc64_elf_tls_optimize): Correct test for allowed
range of tp-relative offsets.
> Building LLVM 6.0 on FreeBSD/powerpc (devel/llvm60 port) the assertion
> in the subject trips (displays twice) when linking libLTO.so.1. The
> issue has been filed in FreeBSD's bugzilla, at
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237068 . It appears
> the 'llvm::hashing::detail::get_execution_seed()::seed@@JL_LLVM_6.0'
> symbol is being weakly aliased to an indirect symbol
> __bss_start@@JL_LLVM_6.0. Since __bss_start@@JL_LLVM_6.0 is an
> indirect symbol, it fails the assertion.
I haven't looked under a debugger at your testcase but I think I know
what is going on here. You have a shared library with a weakly
defined llvm::hashing::detail::get_execution_seed()::seed which
happens to be at the same location as __bss_start in that library. At
the time the linker loads symbols for that library, it sees they are
both versioned and thus introduces non-versioned indirect symbols for
them. The linker considers the symbols as possibly being aliases,
setting up h->u.alias and h->is_weakalias such that
__bss_start@@JL_LLVM_6.0 is the definition. No real problem so far,
the definition is bfd_link_hash_defined, except that the zero size, no
type __bss_start symbol possibly should not be considered an alias in
the first place.
Later, __bss_start as defined by the linker script is entered into the
linker symbol table. This is similar to __bss_start being defined by
a regular object file in that ELF symbol resolution rules say that the
value of __bss_start in the library is overridden by __bss_start in
the executable/library being produced. So to accomplish the override,
ld flips __bss_start from being an indirect symbol pointing at
__bss_start@@JL_LLVM_6.0 to __bss_start@@JL_LLVM_6.0 being an indirect
symbol pointing at __bss_start. That's how we get an unexpected
indirect symbol and hit the assert.
What should happen I think, is for the def->def_regular code above the
assert to run in this case. The symbols are no longer aliases.
* elflink.c (_bfd_elf_fix_symbol_flags): If the def for an
alias is no longer bfd_link_hash_defined, clear the alias.
It is possible to create shared libraries on PowerPC using
-ftls-model=inital-exec or -ftls-model=local-exec. The first is half
reasonable, getting you a shared library that can't be dlopen'd but
otherwise is reasonable. The second is quite bad. Not only do you
lose being able to dlopen, the library also has dynamic text
relocations. Worse, the TPREL16_LO, TPREL16_HA and other TPREL16
dynamic relocs emitted were wrong, resulting in wrong values being
applied by ld.so.
Using the first TLS section symbol in dynamic relocations for local
TLS symbols doesn't work. It's wrong because TLS symbols used by TLS
relocs have values relative to the TLS segment, whereas the TLS
section symbols are addresses. This patch instead uses a symbol index
of zero which is used elsewhere by PowerPC on dynamic TLS relocs.
It's not strictly ABI compliant to use a non-TLS symbol with TLS
relocs but symbol index zero can be interpreted as "no symbol". Not
using the first TLS section symbol means it doesn't need to be dynamic.
The patch also fixes a further problem with PowerPC32 dynamic TPREL16*
relocs, which shouldn't have the symbol value in the addend as we do
for non-TLS symbols.
bfd/
* elflink.c (_bfd_elf_omit_section_dynsym_default): Don't keep
tls_sec.
(_bfd_elf_init_1_index_section): Prefer not using TLS sections.
(_bfd_elf_init_2_index_sections): Likewise.
* elf64-ppc.c (ppc64_elf_relocate_section): When emitting dynamic
relocations for local TLS symbols, use STN_UNDEF as the relocation
symbol.
* elf32-ppc.c (ppc_elf_relocate_section): Likewise, and don't
leave TLS symbol value in the addend.
ld/
* testsuite/ld-powerpc/tlsso.r: Update.
* testsuite/ld-powerpc/tlsso32.g: Update.
* testsuite/ld-powerpc/tlsso32.r: Update.
* testsuite/ld-powerpc/tlstocso.r: Update.
* testsuite/ld-cris/tls-dso-dtpoffd2.d: Update.
* testsuite/ld-cris/tls-dso-dtpoffd4.d: Update.
* testsuite/ld-cris/tls-dso-tpoffgotcomm1.d: Update.
* testsuite/ld-cris/tls-gd-1.d: Update.
* testsuite/ld-cris/tls-gd-1h.d: Update.
* testsuite/ld-cris/tls-gd-2.d: Update.
* testsuite/ld-cris/tls-gd-2h.d: Update.
* testsuite/ld-cris/tls-ie-10.d: Update.
* testsuite/ld-cris/tls-ie-11.d: Update.
* testsuite/ld-cris/tls-ie-8.d: Update.
* testsuite/ld-cris/tls-ie-9.d: Update.
* testsuite/ld-cris/tls-js1.d: Update.
* testsuite/ld-cris/tls-ld-4.d: Update.
* testsuite/ld-cris/tls-ld-5.d: Update.
* testsuite/ld-cris/tls-ld-6.d: Update.
* testsuite/ld-cris/tls-ld-7.d: Update.
* testsuite/ld-cris/tls-ldgd-14.d: Update.
* testsuite/ld-cris/tls-ldgd-15.d: Update.
* testsuite/ld-cris/tls-ldgdx-14.d: Update.
* testsuite/ld-cris/tls-ldgdx-15.d: Update.
* testsuite/ld-cris/tls-local-54.d: Update.
* testsuite/ld-cris/tls-local-60.d: Update.
* testsuite/ld-cris/tls-local-61.d: Update.
* testsuite/ld-cris/tls-local-63.d: Update.
* testsuite/ld-cris/tls-local-64.d: Update.
* testsuite/ld-cris/tls-ok-30.d: Update.
* testsuite/ld-cris/tls-ok-32.d: Update.
* testsuite/ld-cris/tls-ok-34.d: Update.
* testsuite/ld-mips-elf/tls-multi-got-1.got: Update.
* testsuite/ld-mips-elf/tls-multi-got-1.r: Update.
* testsuite/ld-mips-elf/tlsdyn-pie-o32.d: Update.
* testsuite/ld-mips-elf/tlsdyn-pie-o32.got: Update.
* testsuite/ld-mips-elf/tlslib-o32-hidden.got: Update.
* testsuite/ld-mips-elf/tlslib-o32-ver.got: Update.
* testsuite/ld-mips-elf/tlslib-o32.got: Update.
* testsuite/ld-s390/tlspic.rd: Update.
* testsuite/ld-s390/tlspic_64.rd: Update.
* testsuite/ld-sparc/tlssunnopic32.rd: Update.
* testsuite/ld-sparc/tlssunnopic64.rd: Update.
* testsuite/ld-sparc/tlssunpic32.rd: Update.
* testsuite/ld-sparc/tlssunpic64.rd: Update.
PR 24717
* elf.c (is_debuginfo_file): New function.
(assign_file_positions_for_non_load_sections): Do not warn about
allocated sections outside of loadable segments if they are found
in a debuginfo file.
* elf-bfd.h (is_debuginfo_file): Prototype.
PR 24753
bfd * compress.c (bfd_get_full_section_contents): Do not complain
about linker created sections that are larger than the file size.
ld * emultempl/aarch64elf.em (_aarch64_add_stub_section): Include the
LINKER_CREATED section flag when creating the stub section.
As discussed in the PR, we do not support the case where CMSE stubs
are inserted too far from their destination. This would require an
intermediate long-branch stub, which is tricky in this context.
Instead of crashing, this patch emit an error message and exits.
2019-07-02 Christophe Lyon <christophe.lyon@linaro.org>
* bfd/elf32-arm.c (CMSE_STUB_NAME): New define.
(elf32_arm_get_stub_entry): Do not try to emit long-branch stubs
for CMSE stubs.
(arm_dedicated_stub_output_section_name): Use CMSE_STUB_NAME.
Change-Id: I6d4e1c0fdee6bb9f4b07e5e1b46700b5ba31c62e
Consider a file containing only Armv8-M secure entry functions.
This file is compiled and linked with "-march=armv8-m.main -mfloat-abi=hard
-mfpu=fpv5-sp-d16 -mcmse -static --specs=rdimon.specs
-Wl,--section-start,.gnu.sgstubs=0x190000 -ffunction-sections
-fdata-sections
-Wl,--gc-sections -g" options to generate an executable.
The executable generated does not contain any debug information of these
secure entry functions even though it contains secure entry functions in
the .text section. This patch fixes this problem.
PR 23839
bfd * elf32-arm.c (elf32_arm_update_relocs): Do not include the
section VMA in the offset used to update exidx relocs.
ld * testsuite/ld-arm/unwind-4.d: Adjust for corrected calculation of
exidx relocs.
PR 24708
* elf.c (_bfd_elf_slurp_version_tables): Check for an excessively
large version reference section.
* compress.c (bfd_get_full_section_contents): Check for an
uncompressed section whose size is larger than the file size.
This patch fixes failures with LTO on mingw32 targets. Since git
commit 7cf7fcc83c all possible targets (minus binary) are matched in
bfd_check_format_matches rather than lower priority targets being
excluded once a higher priority target matches. During linking that
results in the ld/plugin.c plugin_object_p function being called with
the input file xvec set to plugin_vec, which means
plugin_get_ir_dummy_bfd doesn't see the real format of the file
(pe-i386). It defaults to the output format instead, which happens to
be pei-i386, and this wrong choice persists for the dummy bfd.
pei-i386 isn't recognised as a valid linker input file.
So, omit recognizing a plugin object in bfd_check_format_matches when
some other object format matches, and make sure those other object
formats are checked first.
* format.c (bfd_check_format_matches): Don't match plugin target
if another target matches. Expand comment.
* targets.c (_bfd_target_vector): Move plugin_vec after all other
non-corefile targets, outside !SELECT_VECS.
* config.bfd: Don't handle targ=plugin here.
* configure.ac: Don't add plugin to enable_targets or handle in
target loop setting selvecs and other target vars.
* configure: Regenerate.
