git commit 3e04d7655b introduced a bug by sizing output sections
earlier in ppc_before_allocation. That meant PLT (and GOT) sizes were
not included when calculating total executable section sizes.
* emultempl/ppc32elf.em (ppc_before_allocation): Force running
prelim_size_sections before deciding whether branch trampolines
might be needed.
"next" and "next_real_file" in lang_input_statement_type always point
to another lang_input_statement_type, so it makes sense for these to
not be the generic lang_statement_union_type. This patch also updates
a number of variables in ldlang.c for the same reason, and modifies
lang_statement_append to reduce the need for casts.
* ldlang.h (lang_input_statement_type): Make next
and next_real_file a lang_input_statement_type pointer.
(lang_statement_append): Delete prototype.
(LANG_FOR_EACH_INPUT_STATEMENT): Update for lang_input_statement_type
change.
* ldmain.c (add_archive_element): Likewise.
* ldlang.c: Likewise throughout.
(lang_statement_append): Make static. Make element and field
void pointers. Remove casts in calls.
(lang_check): Use a lang_input_statement_type pointer for "file".
(find_rescan_insertion): Similarly for "iter" and return value.
(lang_process): Similarly for "insert", "iter" and "temp".
* emultempl/spuelf.em (embedded_spu_file): Likewise.
* emultempl/aix.em (gld${EMULATION_NAME}_before_allocation): Expand
lang_statment_append call.
This patch is a reimplementation of [1] which was submitted in 2015 by
Neil Schellenberger. Copyright issue was sorted out [2] last year.
It proposed a new section (.gnu.xhash) and related dynamic tag
(DT_GNU_XHASH). The new section would be virtually identical to the
existing .gnu.hash except for the translation table (xlat) which would
contain correct MIPS .dynsym indexes corresponding to the hashvals in
chains. This is because MIPS ABI imposes a different ordering on the
dynsyms than the one expected by the .gnu.hash section. Another addition
would be a leading word (ngnusyms) which would contain the number of
entries in the translation table.
In this patch, the new section name and dynamic tag are changed to
reflect the fact that the section should be treated as MIPS-specific
(.MIPS.xhash and DT_MIPS_XHASH).
This patch addresses the alignment issue as reported in [3], which is
caused by the leading word added to the .MIPS.xhash section. Leading word
is removed in this patch, and the number of entries in the translation
table is now calculated using DT_MIPS_SYMTABNO dynamic tag (this is
addressed by the corresponding glibc patch).
Suggestions on coding style in [4] were taken into account. Existing
GNU hash testcase was covered, and another one was added in the MIPS
part of the testsuite.
The other major change is reserving MIPS ABI version 5 for .MIPS.xhash,
marking the need of support for .MIPS.xhash in the dynamic linker (again,
addressed in the corresponding glibc patch). This is something which I
am not sure of, especially after reading [5]. I am confused on whether
this ABI version is reserved for IFUNC, or it can be used for this
purpose.
Already mentioned glibc patch is submitted at:
https://sourceware.org/ml/libc-alpha/2019-06/msg00456.html
[1] https://sourceware.org/ml/binutils/2015-10/msg00057.html
[2] https://sourceware.org/ml/binutils/2018-03/msg00025.html
[3] https://sourceware.org/ml/binutils/2016-01/msg00006.html
[4] https://sourceware.org/ml/binutils/2016-02/msg00097.html
[5] https://sourceware.org/ml/libc-alpha/2016-12/msg00853.html
ld * emulparams/elf32bmip.sh: Add .MIPS.xhash section.
* emulparams/elf32bmipn32-defs.sh: Add .MIPS.xhash section.
* emulparams/elf64bmip-defs.sh: Add .MIPS.xhash section.
* emultempl/mipself.em: Remove mips_after_parse function.
* testsuite/ld-elf/hash.d: Update comment.
* testsuite/ld-mips-elf/hash1.d: New test.
* testsuite/ld-mips-elf/hash1.s: Ditto.
* testsuite/ld-mips-elf/hash1a.d: Remove.
* testsuite/ld-mips-elf/hash1b.d: Ditto.
* testsuite/ld-mips-elf/hash1c.d: Ditto
* testsuite/ld-mips-elf/hash2.d: New test.
* testsuite/ld-mips-elf/mips-elf.exp: New tests.
* testsuite/ld-mips-elf/start.s: New test.
bfd * elf-bfd.h (struct elf_backend_data): New members.
* elflink.c (_bfd_elf_link_create_dynamic_sections): Create
.gnu.hash section if necessary.
(struct collect_gnu_hash_codes): New member.
(elf_gnu_hash_process_symidx): New function name.
(elf_renumber_gnu_hash_syms): Ignore local and undefined
symbols. Record xlat location for every symbol which should have
a .MIPS.xhash entry.
(bfd_elf_size_dynamic_sections): Add DT_GNU_HASH dynamic tag to
dynamic section if necessary.
(GNU_HASH_SECTION_NAME): New define.
(bfd_elf_size_dynsym_hash_dynstr): Get .MIPS.xhash section.
Update the section size info.
* elfxx-mips.c (struct mips_elf_hash_sort_data): New members.
(struct mips_elf_link_hash_entry): New member.
(mips_elf_link_hash_newfunc): Initialize .MIPS.xhash translation
table location.
(mips_elf_sort_hash_table): Initialize the pointer to the
.MIPS.xhash section.
(mips_elf_sort_hash_table_f): Populate the .MIPS.xhash
translation table entry with the symbol dynindx.
(_bfd_mips_elf_section_from_shdr): Add SHT_MIPS_XHASH.
(_bfd_mips_elf_fake_sections): Initialize .MIPS.xhash section
info.
(_bfd_mips_elf_create_dynamic_sections): Create .MIPS.xhash
section.
(_bfd_mips_elf_size_dynamic_sections): Add DT_MIPS_XHASH tag to
dynamic section.
(_bfd_mips_elf_finish_synamic_sections): Add DT_MIPS_XHASH.
(_bfd_mips_elf_final_write_processing): Set .MIPS.xhash section
sh_link info.
(_bfd_mips_elf_get_target_dtag): Get DT_MIPS_XHASH tag.
(MIPS_LIBC_ABI_XHASH): New ABI version enum value.
(_bfd_mips_post_process_headers): Mark the ABI version as
MIPS_LIBC_ABI_XHASH if there exists a .MIPS.xhash section,
but not a .hash section.
(_bfd_mips_elf_record_xhash_symbol): New function. Record a
position in the translation table, associated with the hash
entry.
* elfxx-mips.h (literal_reloc_p): Define
elf_backend_record_xhash_symbol backend hook.
* elfxx-target.h: Initialize elf_backend_record_xhash_symbol
backend hook.
include * elf/mips.h (SHT_GNU_XHASH): New define.
(DT_GNU_XHASH): New define.
binutils * readelf.c (get_mips_dynamic_type): Return MIPS_XHASH dynamic type.
(get_mips_section_type_name): Return MI{S_XHASH name string.
(dynamic_section_mips_val): Initialize the .MIPS.xhash dynamic
info.
(process_symbol_table): Initialize the .MIPS.xhash section
pointer. Adjust the readelf output to support the new section.
(process_object): Set the .MIPS.xhash dynamic info to zero.
The idea is to make it a little easier to find uses of this list,
so searches don't hit occurrences of lang_output_section_statement_type
and lang_output_section_statement_enum.
* ldlang.h (lang_os_list): Rename from lang_output_section_statement.
* ldlang.c: Likewise throughout file.
* emultempl/alphaelf.em: Likewise.
* emultempl/elf32.em: Likewise.
* emultempl/mmo.em: Likewise.
* emultempl/pe.em: Likewise.
* emultempl/pep.em: Likewise.
* emultempl/ppc32elf.em: Likewise.
* emultempl/spuelf.em: 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.
When doing a relocatable link, members of input section group are
placed in their own output sections. We need to make sure that no
input sections are merged with member of output section group.
PR ld/24819
* emultempl/elf32.em (elf_orphan_compatible): Return FALSE for
member of output section group when doing a relocatable link.
* testsuite/ld-elf/pr24819.d: New file.
* testsuite/ld-elf/pr24819.s: Likewise.
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.
PR 24596
* emultempl/pe.em (gld_${EMULATION_NAME}_after_open): Check that
the output is coff before accessing coff tdata.
* emultempl/pep.em (gld_${EMULATION_NAME}_after_open): Likewise.
Even though the generic ELF target doesn't handle groups correctly,
this helps avoid a segfault in bfd_elf_set_group_contents seen on
d30v-elf, dlx-elf, pj-elf, and xgate-elf when linking the pr22836
testcase.
PR 24596
bfd/
* linker.c (_bfd_generic_link_output_symbols): Heed BSF_KEEP.
ld/
* emultempl/genelf.em (gld${EMULATION_NAME}_after_open): Set
BFS_KEEP on group signature symbol.
Add a new option to get the linker to emit PLTs that use compact
branches instead of delay slot branches.
bfd/
* elfxx-mips.c (LA25_BC): New macro.
(mips_elf_link_hash_table)<compact_branches>: New field.
(STUB_JALRC): New macro.
(mipsr6_o32_exec_plt0_entry_compact): New array.
(mipsr6_n32_exec_plt0_entry_compact): Likewise.
(mipsr6_n64_exec_plt0_entry_compact): Likewise.
(mipsr6_exec_plt_entry_compact): Likewise.
(mips_elf_create_la25_stub): Use BC instead of J for stubs
when compact_branches is true.
(_bfd_mips_elf_finish_dynamic_symbol): Choose the compact
PLT for MIPSR6 with compact_branches. Do not reorder the
compact branches PLT. Switch the lazy stub for MIPSR6
with compact_branches to use JALRC.
(mips_finish_exec_plt): Choose the compact PLT0 for MIPSR6
when compact_branches is true.
(_bfd_mips_elf_compact_branches): New function.
* elfxx-mips.h (_bfd_mips_elf_compact_branches): New prototype.
ld/
* emultempl/mipself.em (compact_branches): New static variable.
(mips_create_output_section_statements): Call
_bfd_mips_elf_compact_branches.
(PARSE_AND_LIST_PROLOGUE): Add OPTION_COMPACT_BRANCHES and
OPTION_NO_COMPACT_BRANCHES.
(PARSE_AND_LIST_LONGOPTS): Add compact-branches,
no-compact-branches.
(PARSE_AND_LIST_OPTIONS): Add --compact-branches,
--no-compact-branches.
(PARSE_AND_LIST_ARGS_CASES): Handle the above.
* ld.texinfo: Document --compact-branches, --no-compact-branches.
* testsuite/ld-mips-elf/pic-and-nonpic-1-r6.dd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1-r6.nd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.dd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.gd: New test.
* testsuite/ld-mips-elf/pic-and-nonpic-1a-r6.s: New test source.
* testsuite/ld-mips-elf/pic-and-nonpic-3a-r6.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
The Cortex-A53 erratum currently has two ways it can resolve the erratum when
using the flag --fix-cortex-a53-843419:
1) If the address is within the range of an ADR instruction it rewrites the ADRP
into an ADR, and those doesn't need the use of a veneer.
2) If the address is not within range, it adds a branch to a veneer which will
execute the final bit of the erratum workaround and branch back to the call
site.
When we do this we always generate the veneers and we always align the size of
the text section to 4KB. This is because we only know which workaround we can
use after all linking has finished and all addresses are known. This means even
though the veneers are not used, we still generate the section and we still
change the size of the input section.
This is problematic for small memory devices as this would require the user to
take about a ~4KB hit in memory even though it's not even used.
Since there's no real way to restart the linking process from the final write
phase this patch solves the issue by allowing the user more control over which
erratum workaround gets used.
Concretely this changes the option --fix-cortex-a53-843419 to take optional
arguments --fix-cortex-a53-843419[=full|adr|adrp]
- full (default): Use both ADRP and ADR workaround. This is equivalent to not
specifying any options and is the default behavior before this
patch.
- adr: Only use the ADR workaround, this will not cause any increase in binary
size but linking will fail if the referenced address is out of range of
an ADR instruction.
- adrp: Use only the ADRP workaround, this will never rewrite your ADRP.
In the cases where the user knows how big their binaries are the `adr` option
would prevent the unneeded overhead.
bfd/ChangeLog:
PR ld/24373
* bfd-in.h (enum erratum_84319_opts): New
(bfd_elf64_aarch64_set_options, bfd_elf32_aarch64_set_options): Change
int to enum erratum_84319_opts.
* bfd-in2.h: Regenerate.
* elfnn-aarch64.c (struct elf_aarch64_link_hash_table): Change
fix_erratum_843419 to use new enum, remove fix_erratum_843419_adr.
(_bfd_aarch64_add_stub_entry_after): Conditionally create erratum stub.
(aarch64_size_one_stub): Conditionally size erratum 843419 stubs.
(_bfd_aarch64_resize_stubs): Amend comment.
(elfNN_aarch64_size_stubs): Don't generate stubs when no workaround
requested.
(bfd_elfNN_aarch64_set_options): Use new fix_erratum_843419 enum.
(_bfd_aarch64_erratum_843419_branch_to_stub): Implement selection of
erratum workaround.
(clear_erratum_843419_entry): Update erratum conditional.
ld/ChangeLog:
PR ld/24373
* emultempl/aarch64elf.em (PARSE_AND_LIST_LONGOPTS): Add optional args
to flags.
* NEWS: Add changes to flag.
(PARSE_AND_LIST_OPTIONS): Update help descriptions.
(PARSE_AND_LIST_ARGS_CASES): Add new options to parser.
* testsuite/ld-aarch64/aarch64-elf.exp: Add new run_dump_tests.
* testsuite/ld-aarch64/erratum843419-adr.d: New test.
* testsuite/ld-aarch64/erratum843419-adrp.d: New test.
* testsuite/ld-aarch64/erratum843419-far-adr.d: New test.
* testsuite/ld-aarch64/erratum843419-far-full.d: New test.
* testsuite/ld-aarch64/erratum843419-far.s: New test.
* testsuite/ld-aarch64/erratum843419-full.d: New test.
* testsuite/ld-aarch64/erratum843419-near.s: New test.
* testsuite/ld-aarch64/erratum843419-no-args.d: New test.
ld * config/tc-msp430.c (msp430_make_init_symbols): Define __crt0_init_bss
symbol when .lower.bss or .either.bss sections exist.
Define __crt0_movedata when .lower.data or .either.data sections exist.
* testsuite/gas/msp430/either-data-bss-sym.d: New test.
* testsuite/gas/msp430/low-data-bss-sym.d: New test.
* testsuite/gas/msp430/either-data-bss-sym.s: New test source.
* testsuite/gas/msp430/low-data-bss-sym.s: New test source.
* testsuite/gas/msp430/msp430.exp: Run new tests.
Enable large code model when running -mdata-region={upper,either}
tests.
This fixes the csky-elf ld-elf/pr21884 and ld-unique/pr21529 failures,
by disabling branch stubs for binary (and other non-csky) output.
The csky-linux target gets branch stubs off by default because
presumably there are reasons why branch stubs were disabled, but
rather than killing the support completely it can be enabled by
--branch-stub.
* emultempl/cskyelf.em (csk_elf_before_parse): New function,
setting use_branch_stub false for linux.
(csky_elf_create_output_section_statements): Do emit this
function and all others in the file for linux, plus the branch
option control. Disable branch stubs when non-ELF.
This is part of the patch series to add support for BTI and
PAC in AArch64 linker.
1) This patch adds new definitions of PAC enabled PLTs
and both BTI and PAC enabled PLTs.
2) It also defines the new dynamic tag DT_AARCH64_PAC_PLT
for the PAC enabled PLTs.
3) This patch adds a new ld command line option: --pac-plt.
In the presence of this option, the linker uses the PAC
enabled PLTs and marks with DT_AARCH64_PAC_PLT.
4) In case both BTI and PAC are enabled the linker should
pick PLTs enabled with both and also use dynamic tags for both.
All these are made according to the new AArch64 ELF ABI
https://developer.arm.com/docs/ihi0056/latest/elf-for-the-arm-64-bit-architecture-aarch64-abi-2018q4
*** bfd/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* elfnn-aarch64.c (PLT_PAC_ENTRY_SIZE, PLT_PAC_SMALL_ENTRY_SIZE): New.
(PLT_BTI_PAC_ENTRY_SIZE, PLT_BTI_PAC_SMALL_ENTRY_SIZE): New.
(setup_plt_values): Account for PAC or PAC and BTI enabled PLTs.
(elfNN_aarch64_size_dynamic_sections): Add checks for PLT_BTI_PAC
and PLT_PAC_PLT.
(elfNN_aarch64_finish_dynamic_sections): Account for PLT_BTI_PAC.
(get_plt_type): Add case for DT_AARCH64_PAC_PLT.
(elfNN_aarch64_plt_sym_val): Add cases for PLT_BTI_PAC and PLT_PAC.
*** binutils/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* readelf.c (get_aarch64_dynamic_type): Add case for
DT_AARCH64_PAC_PLT.
(dynamic_section_aarch64_val): Likewise.
*** include/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* elf/aarch64.h (DT_AARCH64_PAC_PLT): New.
*** ld/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* NEWS: Document --pac-plt.
* emultempl/aarch64elf.em (OPTION_PAC_PLT): New.
(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS): Add pac-plt.
(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_PAC_PLT.
* testsuite/ld-aarch64/aarch64-elf.exp: Add the following tests.
* testsuite/ld-aarch64/bti-pac-plt-1.d: New test.
* testsuite/ld-aarch64/bti-pac-plt-2.d: New test.
* testsuite/ld-aarch64/pac-plt-1.d: New test.
* testsuite/ld-aarch64/pac-plt-2.d: New test.
* testsuite/ld-aarch64/bti-plt-1.s: Add .ifndef directive.
This is part of the patch series to add support for BTI and
PAC in AArch64 linker.
1) This patch adds a new ld command line option: --force-bti.
In the presence of this option, the linker enables BTI with the
GNU_PROPERTY_AARCH64_FEATURE_1_BTI feature. This gives out warning
in case of missing gnu notes for BTI in inputs.
2) It also defines a new set of BTI enabled PLTs. These are used either
when all the inputs are marked with GNU_PROPERTY_AARCH64_FEATURE_1_BTI
or when the new --force-bti option is used. This required adding new
fields in elf_aarch64_link_hash_table so that we could make the PLT
related information more generic.
3) It also defines a dynamic tag DT_AARCH64_BTI_PLT. The linker uses
this whenever it picks BTI enabled PLTs.
All these are made according to the new AArch64 ELF ABI
https://developer.arm.com/docs/ihi0056/latest/elf-for-the-arm-64-bit-architecture-aarch64-abi-2018q4
*** bfd/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* bfd-in.h (aarch64_plt_type, aarch64_enable_bti_type): New.
(aarch64_bti_pac_info): New.
(bfd_elf64_aarch64_set_options): Add aarch64_bti_pac_info argument.
(bfd_elf32_aarch64_set_options): Likewise.
* bfd-in2.h: Regenerate
* elfnn-aarch64.c (PLT_BTI_ENTRY_SIZE): New.
(PLT_BTI_SMALL_ENTRY_SIZE, PLT_BTI_TLSDESC_ENTRY_SIZE): New.
(elfNN_aarch64_small_plt0_bti_entry): New.
(elfNN_aarch64_small_plt_bti_entry): New.
(elfNN_aarch64_tlsdesc_small_plt_bti_entry): New.
(elf_aarch64_obj_tdata): Add no_bti_warn and plt_type fields.
(elf_aarch64_link_hash_table): Add plt0_entry, plt_entry and
tlsdesc_plt_entry_size fields.
(elfNN_aarch64_link_hash_table_create): Initialise the new fields.
(setup_plt_values): New helper function.
(bfd_elfNN_aarch64_set_options): Use new bp_info to set plt sizes and
bti enable type.
(elfNN_aarch64_allocate_dynrelocs): Use new size members instead of
fixed macros.
(elfNN_aarch64_size_dynamic_sections): Likewise and add checks.
(elfNN_aarch64_create_small_pltn_entry): Use new generic pointers
to plt stubs instead of fixed ones and update filling them according
to the need for bti.
(elfNN_aarch64_init_small_plt0_entry): Likewise.
(elfNN_aarch64_finish_dynamic_sections): Likewise.
(get_plt_type, elfNN_aarch64_get_synthetic_symtab): New.
(elfNN_aarch64_plt_sym_val): Update size accordingly.
(elfNN_aarch64_link_setup_gnu_properties): Set up plts if BTI GNU NOTE
is set.
(bfd_elfNN_get_synthetic_symtab): Define.
(elfNN_aarch64_merge_gnu_properties): Give out warning with --force-bti
and mising BTI NOTE SECTION.
*** binutils/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* readelf.c (get_aarch64_dynamic_type): New.
(get_dynamic_type): Use above for EM_AARCH64.
(dynamic_section_aarch64_val): New.
(process_dynamic_section): Use above for EM_AARCH64.
*** include/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* elf/aarch64.h (DT_AARCH64_BTI_PLT): New.
*** ld/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* NEWS: Document --force-bti.
* emultempl/aarch64elf.em (plt_type, bti_type, OPTION_FORCE_BTI): New.
(PARSE_AND_LIST_SHORTOPTS, PARSE_AND_LIST_OPTIONS): Add force-bti.
(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_FORCE_BTI.
* testsuite/ld-aarch64/aarch64-elf.exp: Add all the tests below.
* testsuite/ld-aarch64/bti-plt-1.d: New test.
* testsuite/ld-aarch64/bti-plt-1.s: New test.
* testsuite/ld-aarch64/bti-plt-2.s: New test.
* testsuite/ld-aarch64/bti-plt-2.d: New test.
* testsuite/ld-aarch64/bti-plt-3.d: New test.
* testsuite/ld-aarch64/bti-plt-4.d: New test.
* testsuite/ld-aarch64/bti-plt-5.d: New test.
* testsuite/ld-aarch64/bti-plt-6.d: New test.
* testsuite/ld-aarch64/bti-plt-7.d: New test.
* testsuite/ld-aarch64/bti-plt-so.s: New test.
* testsuite/ld-aarch64/bti-plt.ld: New test.
Recent gcc commit b4371b277f1e ("[ARC] Enable init_array support")
inhibits DT_"INIT,FINI} in favor of DT_{INIT,FINI}ARRAY.
Even prior to that, it seems ARC port is the only one with this
special DT_INIT/FINI handling in linker emulation. Removing it
doesn't seem to change any uClibc/glibc testsuite results,
so this can RIP anyways.
bfd/
2019-02-01 Vineet Gupta <vgupta@synopsys.com>
* elf32-arc.c: Delete init_str, fini_str
ld/
2019-02-01 Vineet Gupta <vgupta@synopsys.com>
* emultempl/arclinux.em : Delete special INIT/FINI handling.
place_orphan handled ELF SHT_REL/SHT_RELA specially, output_rel_find
didn't. This mismatch was a bug and also meant it was possible to
craft an object where ld accessed section->name out of bounds.
PR 24042
* emultempl/elf32.em (output_rel_find): Drop "sec" param. Add
"rela".
(gld${EMULATION_NAME}_place_orphan): Use sh_type to calculate
"rela" param of output_rel_find when ELF. Tidy uses of elfinput.
We have not only removed all unsupported and obsolete code, but also supported lost of new features,
including better link-time relaxations and TLS implementations. Besides, the files generated by the
newly assembler and linker usually get higher performance and more optimized code size.
ld * emultempl/nds32elf.em (hyper_relax): New variable.
(nds32_elf_create_output_section_statements):
the parameters of bfd_elf32_nds32_set_target_option
(PARSE_AND_LIST_PROLOGUE, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Add new option --mhyper-relax.
* emultempl/nds32elf.em (nds32_elf_after_open): Updated.
* emultempl/nds32elf.em (tls_desc_trampoline): New variable.
* (nds32_elf_create_output_section_statements): Updated.
* (nds32_elf_after_parse): Disable relaxations when PIC is enable.
* (PARSE_AND_LIST_PROLOGUE, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Add new option --m[no-]tlsdesc-trampoline.
include * elf/nds32.h: Remove the unused target features.
* dis-asm.h (disassemble_init_nds32): Declared.
* elf/nds32.h (E_NDS32_NULL): Removed.
(E_NDS32_HAS_DSP_INST, E_NDS32_HAS_ZOL): New.
* opcode/nds32.h: Ident.
(N32_SUB6, INSN_LW): New macros.
(enum n32_opcodes): Updated.
* elf/nds32.h: Doc fixes.
* elf/nds32.h: Add R_NDS32_LSI.
* elf/nds32.h: Add new relocations for TLS.
gas * config/tc-nds32.c: Remove the unused target features.
(nds32_relax_relocs, md_pseudo_table, nds32_elf_record_fixup_exp,
nds32_set_elf_flags_by_insn, nds32_insert_relax_entry,
nds32_apply_fix): Likewise.
(nds32_no_ex9_begin): Removed.
* config/tc-nds32.c (add_mapping_symbol_for_align,
make_mapping_symbol, add_mapping_symbol): New functions.
* config/tc-nds32.h (enum mstate): New.
(nds32_segment_info_type): Likewise.
* configure.ac (--enable-dsp-ext, --enable-zol-ext): New options.
* config.in: Regenerated.
* configure: Regenerated.
* config/tc-nds32.c (nds32_dx_regs):
Set the value according to the configuration.
(nds32_perf_ext, nds32_perf_ext2, nds32_string_ext, nds32_audio_ext):
Likewise.
(nds32_dsp_ext): New variable. Set the value according to the
configuration.
(nds32_zol_ext): Likewise.
(asm_desc, nds32_pseudo_opcode_table): Make them static.
(nds32_set_elf_flags_by_insn): Updated.
(nds32_check_insn_available): Updated.
(nds32_str_tolower): New function.
* config/tc-nds32.c (relax_table): Updated.
(md_begin): Updated.
(md_assemble): Use XNEW macro to allocate space for `insn.info',
and then remember to free it.
(md_section_align): Cast (-1) to ValueT.
(nds32_get_align): Cast (~0U) to addressT.
(nds32_relax_branch_instructions): Updated.
(md_convert_frag): Add new local variable `final_r_type'.
(invalid_prev_frag): Add new bfd_boolean parameter `relax'.
All callers changed.
* config/tc-nds32.c (struct nds32_relocs_pattern): Add `insn' field.
(struct nds32_hint_map): Add `option_list' field.
(struct suffix_name, suffix_table): Remove the unused `pic' field.
(do_pseudo_b, do_pseudo_bal): Remove the suffix checking.
(do_pseudo_la_internal, do_pseudo_pushpopm): Indent.
(relax_hint_bias, relax_hint_id_current): New static variables.
(reset_bias, relax_hint_begin): New variables.
(nds_itoa): New function.
(CLEAN_REG, GET_OPCODE): New macros.
(struct relax_hint_id): New.
(nds32_relax_hint): For .relax_hint directive, we can use `begin'
and `end' to mark the relax pattern without giving exactly id number.
(nds32_elf_append_relax_relocs): Handle the case that the .relax_hint
directives are attached to pseudo instruction.
(nds32_elf_save_pseudo_pattern): Change the second parameter from
instruction's opcode to byte code.
(nds32_elf_build_relax_relation): Add new bfd_boolean parameter
`pseudo_hint'.
(nds32_lookup_pseudo_opcode): Fix the overflow issue.
(enum nds32_insn_type): Add N32_RELAX_ALU1 and N32_RELAX_16BIT.
(nds32_elf_record_fixup_exp, relax_ls_table, hint_map,
nds32_find_reloc_table, nds32_match_hint_insn, nds32_parse_name):
Updated.
* config/tc-nds32.h (MAX_RELAX_NUM): Extend it to 6.
(enum nds32_relax_hint_type): Merge NDS32_RELAX_HINT_LA and
NDS32_RELAX_HINT_LS into NDS32_RELAX_HINT_LALS. Add
NDS32_RELAX_HINT_LA_PLT, NDS32_RELAX_HINT_LA_GOT and
NDS32_RELAX_HINT_LA_GOTOFF.
* config/tc-nds32.h (relax_ls_table): Add floating load/store
to gp relax pattern.
(hint_map, nds32_find_reloc_table): Likewise.
* configure.ac: Define NDS32_LINUX_TOOLCHAIN.
* configure: Regenerated.
* config.in: Regenerated.
* config/tc-nds32.h (enum nds32_ramp): Updated.
(enum nds32_relax_hint_type): Likewise.
* config/tc-nds32.c: Include "errno.h" and "limits.h".
(relax_ls_table): Add TLS relax patterns.
(nds32_elf_append_relax_relocs): Attach BFD_RELOC_NDS32_GROUP on
each instructions of TLS patterns.
(nds32_elf_record_fixup_exp): Updated.
(nds32_apply_fix): Likewise.
(suffix_table): Add TLSDESC suffix.
binutils* testsuite/binutils-all/objcopy.exp: Set the unsupported reloc number
from 215 to 255 for NDS32.
bfd * elf32-nds32.c (nds32_elf_relax_loadstore):
Remove the unused target features.
(bfd_elf32_nds32_set_target_option): Remove the unused parameters.
(nds32_elf_relax_piclo12, nds32_elf_relax_letlslo12,
nds32_elf_relax_letlsadd, nds32_elf_relax_letlsls,
nds32_elf_relax_pltgot_suff, nds32_elf_relax_got_suff
nds32_elf_relax_gotoff_suff, calculate_plt_memory_address,
calculate_plt_offset, calculate_got_memory_address,
nds32_elf_check_dup_relocs): Removed.
All callers changed.
* elf32-nds32.h: Remove the unused macros and defines.
(elf_nds32_link_hash_table): Remove the unused variable.
(bfd_elf32_nds32_set_target_option): Update prototype.
(nds32_elf_ex9_init): Removed.
* elf32-nds32.c (nds32_convert_32_to_16): Updated.
* elf32-nds32.c (HOWTO2, HOWTO3): Define new HOWTO macros
to initialize array nds32_elf_howto_table in any order
without lots of EMPTY_HOWTO.
(nds32_reloc_map): Updated.
* reloc.c: Add BFD_RELOC_NDS32_LSI.
* bfd-in2.h: Regenerated.
* bfd/libbfd.h: Regenerated.
* elf32-nds32.c (nds32_elf_relax_howto_table): Add R_NDS32_LSI.
(nds32_reloc_map): Likewise.
(nds32_elf_relax_flsi): New function.
(nds32_elf_relax_section): Support floating load/store relaxation.
* elf32-nds32.c (NDS32_GUARD_SEC_P, elf32_nds32_local_gp_offset):
New macro.
(struct elf_nds32_link_hash_entry): New `offset_to_gp' field.
(struct elf_nds32_obj_tdata): New `offset_to_gp' and `hdr_size' fields.
(elf32_nds32_allocate_local_sym_info, nds32_elf_relax_guard,
nds32_elf_is_target_special_symbol, nds32_elf_maybe_function_sym):
New functions.
(nds32_info_to_howto_rel): Add BFD_ASSERT.
(bfd_elf32_bfd_reloc_type_table_lookup, nds32_elf_link_hash_newfunc,
nds32_elf_link_hash_table_create, nds32_elf_relocate_section,
nds32_elf_relax_loadstore, nds32_elf_relax_lo12, nds32_relax_adjust_label,
bfd_elf32_nds32_set_target_option, nds32_fag_mark_relax): Updated.
(nds32_elf_final_sda_base): Improve it to find the better gp value.
(insert_nds32_elf_blank): Must consider `len' when inserting blanks.
* elf32-nds32.h (bfd_elf32_nds32_set_target_option): Update prototype.
(struct elf_nds32_link_hash_table): Add new variable `hyper_relax'.
* elf32-nds32.c (elf32_nds32_allocate_dynrelocs): New function.
(create_got_section): Likewise.
(allocate_dynrelocs, nds32_elf_size_dynamic_sections,
nds32_elf_relocate_section, nds32_elf_finish_dynamic_symbol): Updated.
(nds32_elf_check_relocs): Fix the issue that the shared library may
has TEXTREL entry in the dynamic section.
(nds32_elf_create_dynamic_sections): Enable to call readonly_dynrelocs
since the TEXTREL issue is fixed in the nds32_elf_check_relocs.
(nds32_elf_finish_dynamic_sections): Update and add DT_RELASZ
dynamic entry.
(calculate_offset): Remove the unused parameter `pic_ext_target' and
related codes.
All callers changed.
(elf_backend_dtrel_excludes_plt): Disable it temporarily since it
will cause some errors for our test cases.
* elf32-nds32.c (nds32_elf_merge_private_bfd_data): Allow to link the
generic object.
* reloc.c: Add TLS relocations.
* libbfd.h: Regenerated.
* bfd-in2.h: Regenerated.
* elf32-nds32.h (struct section_id_list_t): New.
(elf32_nds32_lookup_section_id, elf32_nds32_check_relax_group,
elf32_nds32_unify_relax_group, nds32_elf_unify_tls_model):
New prototypes.
(elf32_nds32_compute_jump_table_size, elf32_nds32_local_tlsdesc_gotent):
New macro.
(nds32_insertion_sort, bfd_elf32_nds32_set_target_option,
elf_nds32_link_hash_table): Updated.
* elf32-nds32.c (enum elf_nds32_tls_type): New.
(struct elf32_nds32_relax_group_t, struct relax_group_list_t): New.
(elf32_nds32_add_dynreloc, patch_tls_desc_to_ie, get_tls_type,
fls, ones32, list_insert, list_insert_sibling, dump_chain,
elf32_nds32_check_relax_group, elf32_nds32_lookup_section_id,
elf32_nds32_unify_relax_group, nds32_elf_unify_tls_model): New functions.
(elf_nds32_obj_tdata): Add new fields.
(elf32_nds32_relax_group_ptr, nds32_elf_local_tlsdesc_gotent): New macros.
(nds32_elf_howto_table): Add TLS relocations.
(nds32_reloc_map): Likewise.
(nds32_elf_copy_indirect_symbol, nds32_elf_size_dynamic_sections,
nds32_elf_finish_dynamic_symbol, elf32_nds32_allocate_local_sym_info,
nds32_elf_relocate_section, bfd_elf32_nds32_set_target_option,
nds32_elf_check_relocs, allocate_dynrelocs): Updated.
(nds32_elf_relax_section): Call nds32_elf_unify_tls_model.
(dtpoff_base): Rename it to `gottpof' and then update it.
opcodes * nds32-asm.c (operand_fields): Remove the unused fields.
(nds32_opcodes): Remove the unused instructions.
* nds32-dis.c (nds32_ex9_info): Removed.
(nds32_parse_opcode): Updated.
(print_insn_nds32): Likewise.
* nds32-asm.c (config.h, stdlib.h, string.h): New includes.
(LEX_SET_FIELD, LEX_GET_FIELD): Update defines.
(nds32_asm_init, build_operand_hash_table, build_keyword_hash_table,
build_opcode_hash_table): New functions.
(nds32_keyword_table, nds32_keyword_count_table, nds32_field_table,
nds32_opcode_table): New.
(hw_ktabs): Declare it to a pointer rather than an array.
(build_hash_table): Removed.
* nds32-asm.h (enum): Add SYN_INPUT, SYN_OUTPUT, SYN_LOPT,
SYN_ROPT and upadte HW_GPR and HW_INT.
* nds32-dis.c (keywords): Remove const.
(match_field): New function.
(nds32_parse_opcode): Updated.
* disassemble.c (disassemble_init_for_target):
Add disassemble_init_nds32.
* nds32-dis.c (eum map_type): New.
(nds32_private_data): Likewise.
(get_mapping_symbol_type, is_mapping_symbol, nds32_symbol_is_valid,
nds32_add_opcode_hash_table, disassemble_init_nds32): New functions.
(print_insn_nds32): Updated.
* nds32-asm.c (parse_aext_reg): Add new parameter.
(parse_re, parse_re2, parse_aext_reg): Only reduced registers
are allowed to use.
All callers changed.
* nds32-asm.c (keyword_usr, keyword_sr): Updated.
(operand_fields): Add new fields.
(nds32_opcodes): Add new instructions.
(keyword_aridxi_mx): New keyword.
* nds32-asm.h (enum): Add NASM_ATTR_DSP_ISAEXT, HW_AEXT_ARIDXI_MX
and NASM_ATTR_ZOL.
(ALU2_1, ALU2_2, ALU2_3): New macros.
* nds32-dis.c (nds32_filter_unknown_insn): Updated.
We have an issue in the MIPS backend, with the handling of undefined
hidden and internal weak symbols. References to such symbols are
supposed to resolve to 0 according to the ELF gABI[1]:
"Unresolved weak symbols have a zero value."
and the 64-bit MIPS psABI[2]:
"If a symbol with one of these [hidden or internal] attributes has no
definition within the executable/DSO being linked, then it must be
resolved to allocated space if common, resolved to zero if weak, or an
error reported otherwise."
however if a GOT relocation is used, then a local GOT entry is created
and used to satisfy the reference. Such an entry is then (in DSO and
PIE binaries) subject to the usual load-time relocation, which means a
non-zero value will be returned if the base address is non-zero. This
will defeat the usual run-time sequence like:
void a (void) __attribute__ ((visibility ("hidden"), weak));
void
x (void)
{
if (a)
a ();
}
This can be reproduced with this simple code:
$ cat libtest.c
extern int a __attribute__ ((visibility ("hidden"), weak));
int *
x (void)
{
return &a;
}
$ cat test.c
int *x (void);
int
main (void)
{
printf ("a: %p\n", x ());
return 0;
}
$ gcc -shared -fPIC -o libtest.so libtest.c
$ gcc -o test test.c -Wl,-rpath,$(pwd) libtest.so
$ ./test
a: 0x77184000
$
The usual approach targets take is making all the steps required to
assign a GOT entry for the symbol referred, and then leave its contents
at zero with no dynamic relocation attached, therefore ensuring that the
value does not change at load time. However this is not going to work
with the implicitly relocated GOT the MIPS psABI specifies[3]:
"The dynamic linker relocates the global offset table by first adding
the difference between the base where the shared object is loaded and
the value of the dynamic tag DT_MIPS_BASE_ADDRESS to all local global
offset table entries."
and we cannot therefore use the local GOT part.
And we cannot offhand use the global part either, as the symbol would
then have to be exported and possibly wrongly preempt symbols in other
modules involved in the dynamic load, because as per the ELF gABI[1] we
are not allowed to enter a hidden or internal symbol into the dynamic
symbol table (and then use its associated GOT entry):
"A hidden symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
and:
"An internal symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
So we have to choose something else.
Our choice is further limited by the need for the reference associated
with the GOT relocation to stay within the signed 16-bit limit from the
GOT pointer base register, while being compliant with the ELF gABI and
the MIPS psABI. However as Alan Modra has observed[4] one possibility
is to edit (relax) the code such that the GOT reference is removed
altogether.
Based on these observations then modify MIPS BFD linker backend code to:
1. Interpret code associated with GOT relocations and relax the usual LW
or LD instructions into a corresponding immediate load operation that
places the value of 0 in the intended register, while leaving the GOT
entry allocated and initialized as usually.
2. Leave any other instructions associated with GOT relocations in place
and instead redirect the reference to a global GOT entry associated
with a special `__gnu_absolute_zero' symbol created for this purpose,
whose value is 0, SHN_ABS section marks it absolute, binding is
global and export class protected, ensuring that the locally provided
value is always used at load time, and that the value is not
relocated by the dynamic loader.
3. Adjust any high-part GOT relocation used, typically associated with
a LUI instruction, accordingly, so that run-time consistency is
maintained, either by resolving to the original entry if the
instruction associated with the corresponding low-part GOT relocation
has been relaxed to an immediate load (in which case the value loaded
with LUI will be overwritten), or by also redirecting the reference
to `__gnu_absolute_zero' to complete the GOT access sequence if that
symbol has been used.
4. Add a target `elf_backend_hide_symbol' hook, for the three MIPS ABIs,
which prevents the `__gnu_absolute_zero' symbol from being forced
local, to ensure that the redirection works and the symbol remains
global/protected with existing linker scripts unchanged.
5. Observing the issue with handling SHN_ABS symbols in the GNU dynamic
loader, covered by glibc PR 19818, set the EI_ABIVERSION field in the
ELF file header produced to 4 (ABI_ABSOLUTE) if `__gnu_absolute_zero'
symbol has been produced and the target configured indicates the GNU
operating system, so that broken versions of the GNU dynamic loader
gracefully reject the file in loading rather than going astray. Keep
EI_ABIVERSION at the original value for other operating systems or if
no `__gnu_absolute_zero' symbol has been made.
The name of the special `__gnu_absolute_zero' has no meaning other than
how a human reader can interpret it, as it is ignored in dynamic loading
in the handling of the scenarios concerned. This is because the symbol
resolves locally, and it's only the symbol's attributes that matter so
that the associated GOT entry remains unchanged at load time.
Therefore the name is somewhat arbitrary, observing however the need to
use the name space reserved for the system so that it does not conflict
with a possible user symbol, and hence the leading underscore, and also
the `gnu' infix to denote a GNU feature. Other implementations wishing
to address the problem in a similar way may choose a different name and
have the solution still work, possibly with a mixture of modules used in
a dynamic having symbols of different names provided, which will however
not interact with each other due to the protected export class.
The symbol can be referred explicitly, however the name is an internal
implementation detail rather than a part of the ABI, and therefore no
specific semantics is guaranteed.
One limitation of this change is that if `__gnu_absolute_zero' has been
already defined, then we do not wipe the old definition and all kinds of
odd behavior can result. This is however like with other symbols we
internally define, such as `_GLOBAL_OFFSET_TABLE_' or `__rld_map', and
therefore left as a possible future enhancement.
As an optimization the relaxation of LW and LD instructions to a load of
immediate zero is always made, even SVR4 PIC code for code that will end
up in a regular (non-PIE) executable, because there is a cache advantage
with the avoidance of a load from the GOT, even if it is otherwise
guaranteed to remain zero. It does not reliably happen though, due to a
symbol exportation issue affecting executables, covered by PR ld/21805.
One existing test case needs to be updated, as it triggers relaxation
introduced with this change and consequently linker output does not
match expectations anymore. As we want to keep the original issue
covered with the test case modify it then to use the LWL instruction in
place of LW, and adjust the output expected accordingly.
References:
[1] "System V Application Binary Interface - DRAFT - 19 October 2010",
The SCO Group, Section "Symbol Table",
<http://www.sco.com/developers/gabi/2012-12-31/ch4.symtab.html>
[2] "64-bit ELF Object File Specification, Draft Version 2.5", MIPS
Technologies / Silicon Graphics Computer Systems, Order Number
007-4658-001, Section 2.5 "Symbol Table", p. 22,
<http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf>
[3] "SYSTEM V APPLICATION BINARY INTERFACE, MIPS RISC Processor
Supplement, 3rd Edition", Section "Global Offset Table", p. 5-10,
<http://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf>
[4] "Undo dynamic symbol state after regular object sym type mismatch",
<https://sourceware.org/ml/binutils/2017-07/msg00265.html>
bfd/
PR ld/21375
* elfxx-mips.h (_bfd_mips_elf_hide_symbol): New prototype.
(_bfd_mips_elf_linker_flags): Update prototype.
* elf32-mips.c (elf_backend_hide_symbol): New macro.
* elf64-mips.c (elf_backend_hide_symbol): Likewise.
* elfn32-mips.c (elf_backend_hide_symbol): Likewise.
* elfxx-mips.c (mips_elf_link_hash_table): Add
`use_absolute_zero' and `gnu_target' members.
(mips_elf_record_global_got_symbol): Call
`_bfd_mips_elf_hide_symbol' rather than
`_bfd_elf_link_hash_hide_symbol'.
(mips_use_local_got_p): Return FALSE if the symbol is absolute.
(mips_elf_obtain_contents): Reorder function.
(mips_elf_nullify_got_load): New function.
(mips_elf_calculate_relocation): Add `contents' parameter.
Nullify GOT loads or if it is not possible, then redirect GOT
relocations to the `__gnu_absolute_zero' symbol, for references
that are supposed to resolve to zero.
(mips_elf_define_absolute_zero): New function.
(_bfd_mips_elf_check_relocs): Prepare for arrangements made in
`mips_elf_calculate_relocation' for references made via the GOT
that are supposed to resolve to zero.
(_bfd_mips_elf_hide_symbol): New function.
(_bfd_mips_elf_linker_flags): Add the `gnu_target' parameter,
set the `gnu_target' member of the MIPS hash table.
(MIPS_LIBC_ABI_ABSOLUTE): New enumeration constant.
(_bfd_mips_post_process_headers): Use it.
ld/
PR ld/21375
* emultempl/mipself.em: Set `gnu_target' according to ${target}.
(mips_create_output_section_statements): Update call to
`_bfd_mips_elf_linker_flags'.
* testsuite/ld-mips-elf/pr21334.s: Use LWL rather than LW.
* testsuite/ld-mips-elf/pr21334.dd: Update accordingly.
git commit 702d16713 broke expressions using CONSTANT(COMMONPAGESIZE)
in ALIGN or SUBALIGN of output section statements, because these
optional fields were evaluated at script parse time and the patch in
question delayed setting of config.commonpagesize. The right thing to
do is keep the tree representation of those fields for later
evaluation.
PR 23571
* ldlang.h (section_alignment): Make it an expression tree.
(subsection_alignment): Likewise.
* ldlang.c (topower): Delete.
(output_section_statement_newfunc): Adjust initialization.
(init_os): Evaluate section_alignment.
(lang_size_sections_1): Likewise.
(size_input_section): Evaluate subsection_alignment.
(lang_enter_output_section_statement): Don't evaluate here.
(lang_new_phdr): Use exp_get_vma rather than exp_get_value_int.
* ldexp.h (exp_get_value_int): Delete.
(exp_get_power): Declare.
* ldexp.c (exp_get_value_int): Delete.
(exp_get_power): New function.
* emultempl/pe.em (place_orphan): Build expression for section
alignment.
* emultempl/pep.em (place_orphan): Likewise.
* testsuite/ld-scripts/pr23571.d,
* testsuite/ld-scripts/pr23571.t: New test.
* testsuite/ld-scripts/align.exp: Run it.
We force __ehdr_start to defined in before_allocation, then restore
the type and a union after dynamic symbols have been allocated.
The union contains a number of structs, all starting with a "next"
pointer, and various fields depending on the symbol type. The old
code restored the entire union, but it isn't necessary to restore the
"next" pointer, and in fact it could be wrong if __ehdr_start happened
to be last on the list and some symbols were added before restoring.
* emultempl/elf32.em (before_allocation): Don't restore
__ehdr_start u.*.next pointer.
This patch series is a new binutils port for C-SKY processors, including support for both the V1 and V2 processor variants. V1 is derived from the MCore architecture while V2 is substantially different, with mixed 16- and 32-bit instructions, a larger register set, a different (but overlapping) ABI, etc. There is support for bare-metal ELF targets and Linux with both glibc and uClibc.
This code is being contributed jointly by C-SKY Microsystems and Mentor Graphics. C-SKY is responsible for the technical content and has proposed Lifang Xia and Yunhai Shang as port maintainers. (Note that C-SKY does have a corporate copyright assignment on file with the FSF.) Mentor Graphics' role has been cleaning up the code, adding documentation and additional test cases, etc, to address issues we anticipated reviewers would complain about.
bfd * Makefile.am (ALL_MACHINES, ALL_MACHINES_CFILES): Add C-SKY.
(BFD32_BACKENDS, BFD_BACKENDS_CFILES): Likewise.
* Makefile.in: Regenerated.
* archures.c (enum bfd_architecture): Add bfd_arch_csky and
related bfd_mach defines.
(bfd_csky_arch): Declare.
(bfd_archures_list): Add C-SKY.
* bfd-in.h (elf32_csky_build_stubs): Declare.
(elf32_csky_size_stubs): Declare.
(elf32_csky_next_input_section: Declare.
(elf32_csky_setup_section_lists): Declare.
* bfd-in2.h: Regenerated.
* config.bfd: Add C-SKY.
* configure.ac: Likewise.
* configure: Regenerated.
* cpu-csky.c: New file.
* elf-bfd.h (enum elf_target_id): Add C-SKY.
* elf32-csky.c: New file.
* libbfd.h: Regenerated.
* reloc.c: Add C-SKY relocations.
* targets.c (csky_elf32_be_vec, csky_elf32_le_vec): Declare.
(_bfd_target_vector): Add C-SKY target vector entries.
binutils* readelf.c: Include elf/csky.h.
(guess_is_rela): Handle EM_CSKY.
(dump_relocations): Likewise.
(get_machine_name): Likewise.
(is_32bit_abs_reloc): Likewise.
include * dis-asm.h (csky_symbol_is_valid): Declare.
* opcode/csky.h: New file.
opcodes * Makefile.am (TARGET_LIBOPCODES_CFILES): Add csky-dis.c.
* Makefile.in: Regenerated.
* configure.ac: Add C-SKY.
* configure: Regenerated.
* csky-dis.c: New file.
* csky-opc.h: New file.
* disassemble.c (ARCH_csky): Define.
(disassembler, disassemble_init_for_target): Add case for ARCH_csky.
* disassemble.h (print_insn_csky, csky_get_disassembler): Declare.
gas * Makefile.am (TARGET_CPU_CFILES): Add entry for C-SKY.
(TARGET_CPU_HFILES, TARGET_ENV_HFILES): Likewise.
* Makefile.in: Regenerated.
* config/tc-csky.c: New file.
* config/tc-csky.h: New file.
* config/te-csky_abiv1.h: New file.
* config/te-csky_abiv1_linux.h: New file.
* config/te-csky_abiv2.h: New file.
* config/te-csky_abiv2_linux.h: New file.
* configure.tgt: Add C-SKY.
* doc/Makefile.am (CPU_DOCS): Add entry for C-SKY.
* doc/Makefile.in: Regenerated.
* doc/all.texi: Set CSKY feature.
* doc/as.texi (Overview): Add C-SKY options.
(Machine Dependencies): Likewise.
* doc/c-csky.texi: New file.
* testsuite/gas/csky/*: New test cases.
ld * Makefile.am (ALL_EMULATION_SOURCES): Add C-SKY emulations.
(ecskyelf.c, ecskyelf_linux.c): New rules.
* Makefile.in: Regenerated.
* configure.tgt: Add C-SKY.
* emulparams/cskyelf.sh: New file.
* emulparams/cskyelf_linux.sh: New file.
* emultempl/cskyelf.em: New file.
* gen-doc.texi: Add C-SKY.
* ld.texi: Likewise.
(Options specific to C-SKY targets): New section.
* testsuite/ld-csky/*: New tests.
With this patch dedicated linker scripts can be generated for partial
relro triggered by defining GENERATE_RELRO_SCRIPT in the target
specific scripts.
This is necessary for e.g. S/390 where usually the .got.plt comes
first and prevents the relro segment from being extended across the
non-plt GOT entries.
The patch started with the work from Marcin taken from the mwk user
branches. However, the patch needed substantial changes due to the
'separate code' feature which got committed in the meantime.
ld/ChangeLog:
2018-07-18 Andreas Krebbel <krebbel@linux.ibm.com>
Marcin Kościelnicki <koriakin@0x04.net>
* emultempl/elf32.em: Add code to pick dedicated linker scripts
for partial relro.
* genscripts.sh: Generate dedicated linker scripts for partial relro.
In case params.thumb_entry_symbol has its default NULL value, using it
to print a warning in gld${EMULATION_NAME}_finish results in a crash.
Use h->root.string instead which either points to
params.thumb_entry_symbol name or to entry_symbol name.
2018-07-09 Christophe Lyon <christophe.lyon@linaro.org>
* emultempl/armelf.em (gld${EMULATION_NAME}_finish): Use the right
symbol name in case of warning.
Change-Id: Iec61a833c0ad538b1440bf326ba67834c314dd63
This patch adds the analysis part of PLT call optimization, enabling
the code added with the previous patch that actually performs the
optimization.
Gold support is not available yet.
bfd/
* elf64-ppc.c (struct _ppc64_elf_section_data): Add has_pltcall field.
(struct ppc_link_hash_table): Add can_convert_all_inline_plt.
(ppc64_elf_check_relocs): Set has_pltcall.
(ppc64_elf_adjust_dynamic_symbol): Discard some PLT entries.
(ppc64_elf_inline_plt): New function.
(ppc64_elf_size_dynamic_sections): Discard some PLT entries for locals.
* elf64-ppc.h (ppc64_elf_inline_plt): Declare.
* elf32-ppc.c (has_pltcall): Define.
(struct ppc_elf_link_hash_table): Add can_convert_all_inline_plt.
(ppc_elf_check_relocs): Set has_pltcall.
(ppc_elf_inline_plt): New function.
(ppc_elf_adjust_dynamic_symbol): Discard some PLT entries.
(ppc_elf_size_dynamic_sections): Likewise.
* elf32-ppc.h (ppc_elf_inline_plt): Declare.
ld/
* emultempl/ppc64elf.em (no_inline_plt): New var.
(ppc_before_allocation): Call ppc64_elf_inline_plt.
(enum ppc64_opt): Add OPTION_NO_INLINE_OPT.
(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Handle --no-inline-optimize.
* emultemps/ppc32elf.em (no_inline_opt): New var.
(prelim_size_sections): New function, extracted from..
(ppc_before_allocation): ..here. Call ppc_elf_inline_plt.
(enum ppc32_opt): Add OPTION_NO_INLINE_OPT.
(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Handle --no-inline-optimize.
The current scheme where we output PLT relocs for global symbols in
finish_dynamic_symbol, and PLT relocs for local symbols when
outputting stubs does not work if PLT entries are to be used for
inline PLT sequences against non-dynamic globals or local symbols.
bfd/
* elf64-ppc.c (ppc_build_one_stub): Move output of PLT relocs
for local symbols to..
(write_plt_relocs_for_local_syms): ..here. New function.
(ppc64_elf_finish_dynamic_symbol): Move output of PLT relocs for
global symbols to..
(build_global_entry_stubs_and_plt): ..here. Rename from
build_global_entry_stubs.
(ppc64_elf_build_stubs): Always call build_global_entry_stubs_and_plt.
Call write_plt_relocs_for_local_syms.
* elf32-ppc.c (get_sym_h): New function.
(ppc_elf_relax_section): Use get_sym_h.
(ppc_elf_relocate_section): Move output of PLT relocs and glink
stubs for local symbols to..
(ppc_finish_symbols): ..here. New function.
(ppc_elf_finish_dynamic_symbol): Move output of PLT relocs for
global syms to..
(write_global_sym_plt): ..here. New function.
* elf32-ppc.h (ppc_elf_modify_segment_map): Delete attribute.
(ppc_finish_symbols): Declare.
ld/
* ppc32elf.em (ppc_finish): Call ppc_finish_symbols.
This patch deals with the auto-import feature. There are 2 versions
of this feature: the original one, which was piggybacked on the OS
loader with an optional help from the runtime (--enable-auto-import
--enable-runtime-pseudo-reloc-v1) and is still the one mostly
documented in the sources and manual; the enhanced one by Kai Tietz,
which is entirely piggybacked on the runtime (--enable-auto-import
--enable-runtime-pseudo-reloc-v2) and is the default for Mingw and
Cygwin nowadays.
The implementation is inefficient because of pe[p]_find_data_imports:
for every undefined symbol, the function walks the entire set of
relocations for all the input files and does a direct name comparison
for each of them.
This is easily fixable by using a hash-based map for v1 and a simple
hash table for v2. This patch leaves v1 alone and only changes v2.
It also factors out pe[p]_find_data_imports into a common function,
removes old cruft left and right, and attempts to better separate
the implementations of v1 and v2 in the code.
ld/
* emultempl/pe.em (U_SIZE): Delete.
(pe_data_import_dll): Likewise.
(make_import_fixup): Return void, take 4th parameter and pass it down
in call to pe_create_import_fixup.
(pe_find_data_imports): Move to...
(gld_${EMULATION_NAME}_after_open): Run the stdcall fixup pass after
the auto-import pass and add a guard before running the latter.
* emultempl/pep.em (U_SIZE): Delete.
(pep_data_import_dll): Likewise.
(make_import_fixup): Return void, take 4th parameter and pass it down
in call to pe_create_import_fixup.
(pep_find_data_imports): Move to...
(gld_${EMULATION_NAME}_after_open): Run the stdcall fixup pass after
the auto-import pass and add a guard before running the latter.
* pe-dll.c (runtime_pseudp_reloc_v2_init): Change type to bfd_boolean.
(pe_walk_relocs_of_symbol): Rename into...
(pe_walk_relocs): ...this. Add 2 more parameters,4th parameter to the
callback prototype and pass 4th parameter in calls to the callback.
If the import hash table is present, invoke the callback on the reloc
if the symbol name is in the table.
(pe_find_data_imports): ...here. Take 2 parameters. Build an import
hash table for the pseudo-relocation support version 2. When it is
built, walk the relocations only once at the end; when it is not, do
not build a fixup when the symbol isn't part of an import table.
Issue the associated warning only after a first fixup is built.
(tmp_seq2): Delete.
(make_singleton_name_imp): Likewise.
(make_import_fixup_mark): Return const char * and a stable string.
(make_import_fixup_entry): Do not deal with the pseudo-relocation
support version 2.
(make_runtime_pseudo_reloc): Factor out code and fix formatting.
(pe_create_import_fixup): Add 5th parameter. Clearly separate the
pseudo-relocation support version 2 from the rest. Fix formatting.
* pe-dll.h (pe_walk_relocs_of_symbol): Delete.
(pe_find_data_imports): Declare.
(pe_create_import_fixup): Add 5th parameter.
* pep-dll.c (pe_data_import_dll): Delete.
(pe_find_data_imports): Define.
(pe_walk_relocs_of_symbol): Delete.
* pep-dll.h (pep_walk_relocs_of_symbol): Delete.
(pep_find_data_imports): Declare.
(pep_create_import_fixup): Add 5th parameter.
* ld.texinfo (--enable-auto-import): Adjust to new implementation.
This patch adds --enable-separate-code to ld configure to turn on
-z separate-code by default and enables it by default for Linux/x86.
This avoids mixing code pages with data to improve cache performance
as well as security.
To reduce x86-64 executable and shared object sizes, the maximum page
size is reduced from 2MB to 4KB when -z separate-code is turned on by
default. Note: -z max-page-size= can be used to set the maximum page
size.
We compared SPEC CPU 2017 performance before and after this change on
Skylake server. There are no any significant performance changes.
Everything is mostly below +/-1%.
bfd/
* config.in: Regenerated.
* configure: Likewise.
* configure.ac: Add --enable-separate-code.
(DEFAULT_LD_Z_SEPARATE_CODE): New AC_DEFINE_UNQUOTED. Default
to 1 for Linux/x86 targets,
* elf64-x86-64.c (ELF_MAXPAGESIZE): Set to 0x1000 if
DEFAULT_LD_Z_SEPARATE_CODE is 1.
ld/
* NEWS: Mention --enable-separate-code.
* configure.ac: Add --enable-separate-code.
(DEFAULT_LD_Z_SEPARATE_CODE): New AC_DEFINE_UNQUOTED.
* configure.tgt: Default ac_default_ld_z_separate_code to 1 for
Linux/x86 targets.
* config.in: Regenerated.
* configure: Likewise.
* emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set
link_info.separate_code DEFAULT_LD_Z_SEPARATE_CODE.
This reverts most of commit 1be5d8d3bb.
Left in place are addition of --no-plt-align to some ppc32 ld tests
and the ld.texinfo --no-plt-thread-safe fix.
Since all ELF linkers call check_relocs after opening all inputs, we
can fold after_allocation into before_allocation so that local dynamic
symbols will be placed before global dynamic symbols in .dynsym section.
This fixed:
FAIL: Common symbol override test (auxiliary shared object build)
FAIL: ld-elf/pr19617a
FAIL: ld-elf/pr19698
for i386-solaris2.12 and x86_64-solaris2.12 targets.
PR ld/22728
* emultempl/solaris2.em (elf_solaris2_after_allocation): Fold
into ...
(elf_solaris2_before_allocation): This.
(LDEMUL_AFTER_ALLOCATION): Removed.
Asking for ppc32 plt call stubs to be aligned at 32 byte boundaries
didn't quite work. For ld.bfd they were spaced 32 bytes apart, but
only started on a 16 byte boundary. ld.gold also didn't get it right.
Finding that bug made me check over the ppc64 plt stub alignment,
where I found that negative values for alignment (meaning align to
minimize boundary crossing) were not accepted. Since no one has
complained about that, I guess I could have removed the feature from
ld.bfd documentation, but I've opted instead to correct the code.
I've also added an optional alignment paramenter for ppc32
--plt-align, for some consistency with gold and ppc64 ld.bfd.
bfd/
* elf32-ppc.c (ppc_elf_create_glink): Correct alignment of .glink.
* elf64-ppc.c (ppc64_elf_size_stubs): Handle negative plt_stub_align.
(ppc64_elf_build_stubs): Likewise.
gold/
* powerpc.cc (param_plt_align): New function supplying default
--plt-align values. Use it..
(Stub_table::plt_call_align): ..here, and..
(Output_data_glink::global_entry_align): ..here.
(Stub_table::stub_align): Correct 32-bit minimum alignment.
ld/
* emultempl/ppc32elf.em: Support optional --plt-align arg.
* emultempl/ppc64elf.em: Support negative --plt-align arg.
Alan Modra
Mihailo Stojanovic
H.J. Lu
Nick Clifton
Sudakshina Das
Matthew Fortune
Tamar Christina
Jozef Lawrynowicz
Claudiu Zissulescu
Maciej W. Rozycki
Andrew Jenner
Andreas Krebbel
Christophe Lyon
Eric Botcazou
Andreas Schwab
Kuan-Lin Chen
Jim Wilson