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.
Add a new option to disable the listing of discarded sections
in map file output. The use case stems from a large application
built with -ffunction-sections --gc-sections where the list of
discarded sections blows up the map file output. The default
behaviour remains to print discarded sections, but the new option
allows us to disable it.
ld/
* NEWS: Mention new option --no-print-map-discarded.
* ld.h (ld_config_type) <print_map_discarded>: New field.
* ldlang.c (lang_map): Conditionally output discarded sections
in map files based on configuration option.
* ldlex.h (option_values) <OPTION_PRINT_MAP_DISCARDED,
OPTION_NO_PRINT_MAP_DISCARDED>: New.
* ldmain.c (main): Enabled print_map_discarded by default.
* lexsup.c (ld_options): Add new command-line options.
(parse_args) <OPTION_NO_PRINT_MAP_DISCARDED,
OPTION_PRINT_MAP_DISCARDED>: New cases.
* ld.texi: Document new options.
* testsuite/ld-gc/gc.exp: Add new test.
* testsuite/ld-gc/skip-map-discarded.s: New file.
* testsuite/ld-gc/skip-map-discarded.d: New file.
* testsuite/ld-gc/skip-map-discarded.map: New file.
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.
This is part of the patch series to add support for BTI and
PAC in AArch64 linker.
This patch implements the following:
1) This extends in the gnu property support in the linker for
AArch64 by defining backend hooks for elf_backend_setup_gnu_properties,
elf_backend_merge_gnu_properties and elf_backend_parse_gnu_properties.
2) It defines AArch64 specific GNU property
GNU_PROPERTY_AARCH64_FEATURE_1_AND and 2 bit for BTI and PAC in it.
3) It also adds support in readelf.c to read and print these new
GNU properties in AArch64.
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>
* elf-properties.c (_bfd_elf_link_setup_gnu_properties): Exclude
linker created inputs from merge.
* elfnn-aarch64.c (struct elf_aarch64_obj_tdata): Add field for
GNU_PROPERTY_AARCH64_FEATURE_1_AND properties.
(elfNN_aarch64_link_setup_gnu_properties): New.
(elfNN_aarch64_merge_gnu_properties): New.
(elf_backend_setup_gnu_properties): Define for AArch64.
(elf_backend_merge_gnu_properties): Likewise.
* elfxx-aarch64.c (_bfd_aarch64_elf_link_setup_gnu_properties): Define.
(_bfd_aarch64_elf_parse_gnu_properties): Define.
(_bfd_aarch64_elf_merge_gnu_properties): Define.
* elfxx-aarch64.h (_bfd_aarch64_elf_link_setup_gnu_properties): Declare.
(_bfd_aarch64_elf_parse_gnu_properties): Declare.
(_bfd_aarch64_elf_merge_gnu_properties): Declare.
(elf_backend_parse_gnu_properties): Define for AArch64.
*** binutils/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* readelf.c (decode_aarch64_feature_1_and): New.
(print_gnu_property_note): Add case for AArch64 gnu notes.
*** include/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* elf/common.h (GNU_PROPERTY_AARCH64_FEATURE_1_AND): New.
(GNU_PROPERTY_AARCH64_FEATURE_1_BTI): New.
(GNU_PROPERTY_AARCH64_FEATURE_1_PAC): New.
*** ld/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
* NEWS: Document GNU_PROPERTY_AARCH64_FEATURE_1_BTI and
GNU_PROPERTY_AARCH64_FEATURE_1_PAC.
* testsuite/ld-aarch64/aarch64-elf.exp: Add run commands for new tests.
* testsuite/ld-aarch64/property-bti-pac1.d: New test.
* testsuite/ld-aarch64/property-bti-pac1.s: New test.
* testsuite/ld-aarch64/property-bti-pac2.d: New test.
* testsuite/ld-aarch64/property-bti-pac2.s: New test.
* testsuite/ld-aarch64/property-bti-pac3.d: New test.
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.
Binutils documentation uses a mix of spelling for the compound word
"command-line X". According to [1]:
"Sometimes compound words are written separately (nail polish),
sometimes with a hyphen (short-sighted) and sometimes as one word
(eyelashes). Often new compounds are written as two separate words and,
as they become more familiar, they are either connected with a hyphen
(-) or made into one word."
I think command-line X is common enough in our industry that the two
workds command and line should be connected. Since command-line is more
common than commandline, I propose to update binutils documentation to
consistently use "command-line" when this is used as an adjective to a
noun (eg. command-line argument, command-line switch, command-line
option and command-line flag). I've left occurences of "the command
line" as is. I've also left gdb, sim and readline alone and have only
touched public documentation (texi and NEWS files).
[1]
http://dictionary.cambridge.org/grammar/british-grammar/word-formation/compounds
2018-07-02 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* doc/bfdint.texi: Use command-line consistently when used in a
compount word.
* doc/bfdsumm.texi: Likewise.
binutils/
* NEWS: Use command-line consistently when used in a compount word.
* doc/binutils.texi: Likewise and fix trailing whitespace on same
line.
gas/
* NEWS: Use command-line consistently when used in a compount word.
* doc/as.texi: Likewise.
* doc/c-aarch64.texi: Likewise.
* doc/c-alpha.texi: Likewise.
* doc/c-arc.texi: Likewise.
* doc/c-arm.texi: Likewise.
* doc/c-avr.texi: Likewise.
* doc/c-bfin.texi: Likewise.
* doc/c-cris.texi: Likewise.
* doc/c-epiphany.texi: Likewise.
* doc/c-i386.texi: Likewise.
* doc/c-ia64.texi: Likewise.
* doc/c-lm32.texi: Likewise.
* doc/c-m32r.texi: Likewise.
* doc/c-m68k.texi: Likewise.
* doc/c-mips.texi: Likewise.
* doc/c-mmix.texi: Likewise.
* doc/c-msp430.texi: Likewise.
* doc/c-mt.texi: Likewise.
* doc/c-nios2.texi: Likewise.
* doc/c-ppc.texi: Likewise.
* doc/c-pru.texi: Likewise.
* doc/c-rl78.texi: Likewise.
* doc/c-rx.texi: Likewise.
* doc/c-tic6x.texi: Likewise.
* doc/c-v850.texi: Likewise.
* doc/c-vax.texi: Likewise.
* doc/c-visium.texi: Likewise.
* doc/c-xstormy16.texi: Likewise.
* doc/c-xtensa.texi: Likewise.
* doc/c-z80.texi: Likewise.
* doc/c-z8k.texi: Likewise.
* doc/internals.texi: Likewise.
gprof/
* gprof.texi: Use command-line consistently when used in a compount
word.
ld/
* NEWS: Use command-line consistently when used in a compount word.
* ld.texinfo: Likewise.
* ldint.texinfo: Likewise.
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${EMULATION_NAME}_before_parse): Set
link_info.separate_code DEFAULT_LD_Z_SEPARATE_CODE.
Currently we have no obvious way to revert the action of the "-z defs"
command line option. The "--unresolved-symbols=ignore-in-object-files"
does pretty much what is needed, but it is non-obvious and it also
touches the setting for reporting unresolved symbol references from
shared libraries. So I am proposing adding a "-z undefs" option to be
the inverse of "-z defs". (I thought that "-z nodefs" might be
confusing since it implies banning all definitions, rather than
allowing them).
In addition the description of the "-z defs" option in the linker
documentation is misleading in one place, where it says:
'defs'
Disallows undefined symbols in object files. Undefined
symbols in shared libraries are still allowed.
whereas later on it gets it right:
'-z defs'
Report unresolved symbol references from regular object files.
This is done even if the linker is creating a non-symbolic shared
library. The switch '--[no-]allow-shlib-undefined' controls the
behaviour for reporting unresolved references found in shared
libraries being linked in.
* emultempl/elf32.em (_handle_option): Add support for "-z undefs"
as the opposite of "-z defs".
* ld.texinfo: Document the new option. Update the description of
the -z defs option to make it clear that it does generate an error
if an undefined symbol reference is found in an object file whilst
creating a shared library.
* NEWS: Document this new feature.
The new "-z separate-code" option will generate separate code LOAD
segment which must be in wholly disjoint pages from any other data.
include/
PR ld/22393
* bfdlink.h (bfd_link_info): Add separate_code.
ld/
PR ld/22393
* NEWS: Mention "-z separate-code".
* emultempl/elf32.em (gld${EMULATION_NAME}_get_script): Get
builtin linker scripts and return linker scripts from disk for
"-z separate-code".
(gld${EMULATION_NAME}_handle_option): Handle "-z separate-code"
and "-z noseparate-code".
* genscripts.sh: Generate linker scripts for "-z separate-code".
(LD_FLAG): Set to *textonly for "-z separate-code".
* ld.texinfo: Document "-z separate-code".
* lexsup.c (elf_shlib_list_options): Add linker help messsages
for "-z separate-code" and "-z noseparate-code".
* scripttempl/elf.sc (SEPARATE_TEXT): New
(TEXT_SEGMENT_ALIGN): Likewise.
Use ${TEXT_SEGMENT_ALIGN} to align and pad text segment to
${MAXPAGESIZE}.
* emultempl/elf32.em (handle_option): Accept the -z globalaudit
command line option.
* lexsup.c (elf_static_list_options): Add -z globalaudit.
* ld.texinfo: Document the support for the new command line
option.
* NEWS: Mention the new feature.
* testsuite/ld-elf/audit.exp: Add a test of the -z globalaudit
command line option.
* testsuite/ld-elf/globalaudit.rd: New file: Expected output from
readelf.
* ldgram.y (ldgram_had_keep): Make static.
(ldgram_vers_current_lang): Likewise.
(filename_spec): New rule.
(input_section_spec_no_keep): Use filename_spec.
(wildcard_maybe_exclude): New rule.
(wildcard_spec): Rename to...
(section_name_spec): ...this.
(section_NAME_list): Rename to...
(section_name_list): ...this.
(section_name_spec): Simplifiy and use wildcard_maybe_exclude.
* ldlang.c (placed_commons): Delete.
(lang_add_wild): No longer set placed_commons.
(print_wild_statement): Use full names for SORT specifiers.
* testsuite/ld-scripts/align.exp: Run new tests.
* testsuite/ld-scripts/align3.d: New file.
* testsuite/ld-scripts/align3.t: New file.
* testsuite/ld-scripts/align4.d: New file.
* testsuite/ld-scripts/align4.t: New file.
* testsuite/ld-scripts/align5.d: New file.
* testsuite/ld-scripts/align5.t: New file.
* testsuite/ld-scripts/exclude-file-5.d: New file.
* testsuite/ld-scripts/exclude-file-5.map: New file.
* testsuite/ld-scripts/exclude-file-5.t: New file.
* testsuite/ld-scripts/exclude-file-6.d: New file.
* testsuite/ld-scripts/exclude-file-6.map: New file.
* testsuite/ld-scripts/exclude-file-6.t: New file.
* NEWS: Mention the changes.
To support IBT in Intel Control-flow Enforcement Technology (CET)
instructions:
https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-enforcement-technology-preview.pdf
#define GNU_PROPERTY_X86_FEATURE_1_AND 0xc0000002
#define GNU_PROPERTY_X86_FEATURE_1_IBT (1U << 0)
are added to GNU program properties to indicate that all executable
sections are compatible with IBT when ENDBR instruction starts each
valid target where an indirect branch instruction can land.
GNU_PROPERTY_X86_FEATURE_1_IBT is set on output only if it is set on
all relocatable inputs.
The followings changes are made to the Procedure Linkage Table (PLT):
1. For 64-bit x86-64, PLT is changed to
PLT0: push GOT[1]
bnd jmp *GOT[2]
nop
...
PLTn: endbr64
push namen_reloc_index
bnd jmp PLT0
together with the second PLT section:
PLTn: endbr64
bnd jmp *GOT[namen_index]
nop
BND prefix is also added so that IBT-enabled PLT is compatible with MPX.
2. For 32-bit x86-64 (x32) and i386, PLT is changed to
PLT0: push GOT[1]
jmp *GOT[2]
nop
...
PLTn: endbr64 # endbr32 for i386.
push namen_reloc_index
jmp PLT0
together with the second PLT section:
PLTn: endbr64 # endbr32 for i386.
jmp *GOT[namen_index]
nop
BND prefix isn't used since MPX isn't supported on x32 and BND registers
aren't used in parameter passing on i386.
GOT is an array of addresses. Initially, GOT[namen_index] is filled
with the address of the ENDBR instruction of the corresponding entry
in the first PLT section. The function, namen, is called via the
ENDBR instruction in the second PLT entry. GOT[namen_index] is updated
to the actual address of the function, namen, at run-time.
2 linker command line options are added:
1. -z ibtplt: Generate IBT-enabled PLT.
2. -z ibt: Generate GNU_PROPERTY_X86_FEATURE_1_IBT in GNU program
properties as well as IBT-enabled PLT.
bfd/
* elf32-i386.c (elf_i386_lazy_ibt_plt0_entry): New.
(elf_i386_lazy_ibt_plt_entry): Likewise.
(elf_i386_pic_lazy_ibt_plt0_entry): Likewise.
(elf_i386_non_lazy_ibt_plt_entry): Likewise.
(elf_i386_pic_non_lazy_ibt_plt_entry): Likewise.
(elf_i386_eh_frame_lazy_ibt_plt): Likewise.
(elf_i386_lazy_plt_layout): Likewise.
(elf_i386_non_lazy_plt_layout): Likewise.
(elf_i386_link_hash_entry): Add plt_second.
(elf_i386_link_hash_table): Add plt_second and
plt_second_eh_frame.
(elf_i386_allocate_dynrelocs): Use the second PLT if needed.
(elf_i386_size_dynamic_sections): Use .plt.got unwind info for
the second PLT. Check the second PLT.
(elf_i386_relocate_section): Use the second PLT to resolve
PLT reference if needed.
(elf_i386_finish_dynamic_symbol): Fill and use the second PLT if
needed.
(elf_i386_finish_dynamic_sections): Set sh_entsize on the
second PLT. Generate unwind info for the second PLT.
(elf_i386_plt_type): Add plt_second.
(elf_i386_get_synthetic_symtab): Support the second PLT.
(elf_i386_parse_gnu_properties): Support
GNU_PROPERTY_X86_FEATURE_1_AND.
(elf_i386_merge_gnu_properties): Support
GNU_PROPERTY_X86_FEATURE_1_AND. If info->ibt is set, turn
on GNU_PROPERTY_X86_FEATURE_1_IBT
(elf_i386_link_setup_gnu_properties): If info->ibt is set,
turn on GNU_PROPERTY_X86_FEATURE_1_IBT. Use IBT-enabled PLT
for info->ibtplt, info->ibt or GNU_PROPERTY_X86_FEATURE_1_IBT
is set on all relocatable inputs.
* elf64-x86-64.c (elf_x86_64_lazy_ibt_plt_entry): New.
(elf_x32_lazy_ibt_plt_entry): Likewise.
(elf_x86_64_non_lazy_ibt_plt_entry): Likewise.
(elf_x32_non_lazy_ibt_plt_entry): Likewise.
(elf_x86_64_eh_frame_lazy_ibt_plt): Likewise.
(elf_x32_eh_frame_lazy_ibt_plt): Likewise.
(elf_x86_64_lazy_ibt_plt): Likewise.
(elf_x32_lazy_ibt_plt): Likewise.
(elf_x86_64_non_lazy_ibt_plt): Likewise.
(elf_x32_non_lazy_ibt_plt): Likewise.
(elf_x86_64_get_synthetic_symtab): Support the second PLT.
(elf_x86_64_parse_gnu_properties): Support
GNU_PROPERTY_X86_FEATURE_1_AND.
(elf_x86_64_merge_gnu_properties): Support
GNU_PROPERTY_X86_FEATURE_1_AND. If info->ibt is set, turn
on GNU_PROPERTY_X86_FEATURE_1_IBT
(elf_x86_64_link_setup_gnu_properties): If info->ibt is set,
turn on GNU_PROPERTY_X86_FEATURE_1_IBT. Use IBT-enabled PLT
for info->ibtplt, info->ibt or GNU_PROPERTY_X86_FEATURE_1_IBT
is set on all relocatable inputs.
binutils/
* readelf.c (decode_x86_feature): New.
(print_gnu_property_note): Call decode_x86_feature on
GNU_PROPERTY_X86_FEATURE_1_AND.
* testsuite/binutils-all/i386/empty.d: New file.
* testsuite/binutils-all/i386/empty.s: Likewise.
* testsuite/binutils-all/i386/ibt.d: Likewise.
* testsuite/binutils-all/i386/ibt.s: Likewise.
* testsuite/binutils-all/x86-64/empty-x32.d: Likewise.
* testsuite/binutils-all/x86-64/empty.d: Likewise.
* testsuite/binutils-all/x86-64/empty.s: Likewise.
* testsuite/binutils-all/x86-64/ibt-x32.d: Likewise.
* testsuite/binutils-all/x86-64/ibt.d: Likewise.
* testsuite/binutils-all/x86-64/ibt.s: Likewise.
include/
* bfdlink.h (bfd_link_info): Add ibtplt and ibt.
* elf/common.h (GNU_PROPERTY_X86_FEATURE_1_AND): New.
(GNU_PROPERTY_X86_FEATURE_1_IBT): Likewise.
ld/
* Makefile.am (ELF_X86_DEPS): Add $(srcdir)/emulparams/cet.sh.
* Makefile.in: Regenerated.
* NEWS: Mention GNU_PROPERTY_X86_FEATURE_1_IBT, -z ibtplt
and -z ibt.
* emulparams/cet.sh: New file.
* testsuite/ld-i386/ibt-plt-1.d: Likewise.
* testsuite/ld-i386/ibt-plt-1.s: Likewise.
* testsuite/ld-i386/ibt-plt-2.s: Likewise.
* testsuite/ld-i386/ibt-plt-2a.d: Likewise.
* testsuite/ld-i386/ibt-plt-2b.d: Likewise.
* testsuite/ld-i386/ibt-plt-2c.d: Likewise.
* testsuite/ld-i386/ibt-plt-2d.d: Likewise.
* testsuite/ld-i386/ibt-plt-3.s: Likewise.
* testsuite/ld-i386/ibt-plt-3a.d: Likewise.
* testsuite/ld-i386/ibt-plt-3b.d: Likewise.
* testsuite/ld-i386/ibt-plt-3c.d: Likewise.
* testsuite/ld-i386/ibt-plt-3d.d: Likewise.
* testsuite/ld-i386/plt-main-ibt.dd: Likewise.
* testsuite/ld-i386/plt-pie-ibt.dd: Likewise.
* testsuite/ld-i386/property-x86-empty.s: Likewise.
* testsuite/ld-i386/property-x86-ibt.s: Likewise.
* testsuite/ld-i386/property-x86-ibt1a.d: Likewise.
* testsuite/ld-i386/property-x86-ibt1b.d: Likewise.
* testsuite/ld-i386/property-x86-ibt2.d: Likewise.
* testsuite/ld-i386/property-x86-ibt3a.d: Likewise.
* testsuite/ld-i386/property-x86-ibt3b.d: Likewise.
* testsuite/ld-i386/property-x86-ibt4.d: Likewise.
* testsuite/ld-i386/property-x86-ibt5.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-1-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-1.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-1.s: Likewise.
* testsuite/ld-x86-64/ibt-plt-2.s: Likewise.
* testsuite/ld-x86-64/ibt-plt-2a-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2a.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2b-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2b.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2c-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2c.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2d-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-2d.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3.s: Likewise.
* testsuite/ld-x86-64/ibt-plt-3a-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3a.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3b-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3b.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3c-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3c.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3d-x32.d: Likewise.
* testsuite/ld-x86-64/ibt-plt-3d.d: Likewise.
* testsuite/ld-x86-64/plt-main-ibt-now.rd: Likewise.
* testsuite/ld-x86-64/plt-main-ibt-x32.dd: Likewise.
* testsuite/ld-x86-64/plt-main-ibt.dd: Likewise.
* testsuite/ld-x86-64/property-x86-empty.s: Likewise.
* testsuite/ld-x86-64/property-x86-ibt.s: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1a-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1a.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1b-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1b.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt2-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt2.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt3a-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt3a.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt3b-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt3b.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt4-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt4.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt5-x32.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt5.d: Likewise.
* emulparams/elf32_x86_64.sh: Source emulparams/cet.sh.
(TINY_READONLY_SECTION): Add .plt.sec.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_x86_64.sh: Source emulparams/cet.sh.
* ld.texinfo: Document -z ibtplt and -z ibt.
* testsuite/ld-i386/i386.exp: Run IBT and IBT PLT tests.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
* testsuite/ld-x86-64/pr21481b.S (check): Updated for x32.
This commit adds a new linker feature: the ability to resolve section
groups as part of a relocatable link.
Currently section groups are automatically resolved when performing a
final link, and are carried through when performing a relocatable link.
By carried through this means that one copy of each section group (from
all the copies that might be found in all the input files) is placed
into the output file. Sections that are part of a section group will
not match input section specifiers within a linker script and are
forcibly kept as separate sections.
There is a slight resemblance between section groups and common
section. Like section groups, common sections are carried through when
performing a relocatable link, and resolved (allocated actual space)
only at final link time.
However, with common sections there is an ability to force the linker to
allocate space for the common sections when performing a relocatable
link, there's currently no such ability for section groups.
This commit adds such a mechanism. This new facility can be accessed in
two ways, first there's a command line switch --force-group-allocation,
second, there's a new linker script command FORCE_GROUP_ALLOCATION. If
one of these is used when performing a relocatable link then the linker
will resolve the section groups as though it were performing a final
link, the section group will be deleted, and the members of the group
will be placed like normal input sections. If there are multiple copies
of the group (from multiple input files) then only one copy of the group
members will be placed, the duplicate copies will be discarded.
Unlike common sections that have the --no-define-common command line
flag, and INHIBIT_COMMON_ALLOCATION linker script command there is no
way to prevent group resolution during a final link, this is because the
ELF gABI specifically prohibits the presence of SHT_GROUP sections in a
fully linked executable. However, the code as written should make
adding such a feature trivial, setting the new resolve_section_groups
flag to false during a final link should work as you'd expect.
bfd/ChangeLog:
* elf.c (_bfd_elf_make_section_from_shdr): Don't initially mark
SEC_GROUP sections as SEC_EXCLUDE.
(bfd_elf_set_group_contents): Replace use of abort with an assert.
(assign_section_numbers): Use resolve_section_groups flag instead
of relocatable link type.
(_bfd_elf_init_private_section_data): Use resolve_section_groups
flag instead of checking the final_link flag for part of the
checks in here. Fix white space as a result.
* elflink.c (elf_link_input_bfd): Use resolve_section_groups flag
instead of relocatable link type.
(bfd_elf_final_link): Likewise.
include/ChangeLog:
* bfdlink.h (struct bfd_link_info): Add new resolve_section_groups
flag.
ld/ChangeLog:
* ld.h (struct args_type): Add force_group_allocation field.
* ldgram.y: Add support for FORCE_GROUP_ALLOCATION.
* ldlex.h: Likewise.
* ldlex.l: Likewise.
* lexsup.c: Likewise.
* ldlang.c (unique_section_p): Check resolve_section_groups flag
not the relaxable link flag.
(lang_add_section): Discard section groups when we're resolving
groups. Clear the SEC_LINK_ONCE flag if we're resolving section
groups.
* ldmain.c (main): Initialise resolve_section_groups flag in
link_info based on command line flags.
* testsuite/ld-elf/group11.d: New file.
* testsuite/ld-elf/group12.d: New file.
* testsuite/ld-elf/group12.ld: New file.
* NEWS: Mention new features.
* ld.texinfo (Options): Document --force-group-allocation.
(Miscellaneous Commands): Document FORCE_GROUP_ALLOCATION.
Mark an ALLOC section, which should be placed in special memory area,
with SHF_GNU_MBIND. Its sh_info field indicates the special memory
type. GNU_MBIND section names start with ".mbind" so that they are
placed as orphan sections by linker. All input GNU_MBIND sections
with the same sh_type, sh_flags and sh_info are placed in one output
GNU_MBIND section. In executable and shared object, create a
GNU_MBIND segment for each GNU_MBIND section and its segment type is
PT_GNU_MBIND_LO plus the sh_info value. Each GNU_MBIND segment is
aligned at page boundary.
The assembler syntax:
.section .mbind.foo,"adx",%progbits
^ 0: Special memory type.
|
'd' for SHF_GNU_MBIND.
.section .mbind.foo,"adx",%progbits,0x1
^ 1: Special memory type.
|
'd' for SHF_GNU_MBIND.
.section .mbind.bar,"adG",%progbits,.foo_group,comdat,0x2
^ 2: Special memory type.
|
'd' for SHF_GNU_MBIND.
bfd/
* elf.c (get_program_header_size): Add a GNU_MBIND segment for
each GNU_MBIND section and align GNU_MBIND section to page size.
(_bfd_elf_map_sections_to_segments): Create a GNU_MBIND
segment for each GNU_MBIND section.
(_bfd_elf_init_private_section_data): Copy sh_info from input
for GNU_MBIND section.
binutils/
* NEWS: Mention support for ELF SHF_GNU_MBIND and
PT_GNU_MBIND_XXX.
* readelf.c (get_segment_type): Handle PT_GNU_MBIND_XXX.
(get_elf_section_flags): Handle SHF_GNU_MBIND.
(process_section_headers): Likewise.
* testsuite/binutils-all/mbind1.s: New file.
* testsuite/binutils-all/objcopy.exp: Run readelf test on
mbind1.s.
gas/
* NEWS: Mention support for ELF SHF_GNU_MBIND.
* config/obj-elf.c (section_match): New.
(get_section): Match both sh_info and group name.
(obj_elf_change_section): Add argument for sh_info. Pass both
sh_info and group name to get_section. Issue an error for
SHF_GNU_MBIND section without SHF_ALLOC. Set sh_info.
(obj_elf_parse_section_letters): Set SHF_GNU_MBIND for 'd'.
(obj_elf_section): Support SHF_GNU_MBIND section info.
* config/obj-elf.h (obj_elf_change_section): Add argument for
sh_info.
* config/tc-arm.c (start_unwind_section): Pass 0 as sh_info to
obj_elf_change_section.
* config/tc-ia64.c (obj_elf_vms_common): Likewise.
* config/tc-microblaze.c (microblaze_s_data): Likewise.
(microblaze_s_sdata): Likewise.
(microblaze_s_rdata): Likewise.
(microblaze_s_bss): Likewise.
* config/tc-mips.c (s_change_section): Likewise.
* config/tc-msp430.c (msp430_profiler): Likewise.
* config/tc-rx.c (parse_rx_section): Likewise.
* config/tc-tic6x.c (tic6x_start_unwind_section): Likewise.
* doc/as.texinfo: Document 'd' for SHF_GNU_MBIND.
* testsuite/gas/elf/elf.exp: Run section12a, section12b and
section13.
* testsuite/gas/elf/section10.d: Updated.
* testsuite/gas/elf/section10.s: Likewise.
* testsuite/gas/elf/section12.s: New file.
* testsuite/gas/elf/section12a.d: Likewise.
* testsuite/gas/elf/section12b.d: Likewise.
* testsuite/gas/elf/section13.l: Likewise.
* testsuite/gas/elf/section13.d: Likewise.
* testsuite/gas/elf/section13.s: Likewise.
include/
* elf/common.h (PT_GNU_MBIND_NUM): New.
(PT_GNU_MBIND_LO): Likewise.
(PT_GNU_MBIND_HI): Likewise.
(SHF_GNU_MBIND): Likewise.
ld/
* NEWS: Mention support for ELF SHF_GNU_MBIND and
PT_GNU_MBIND_XXX.
* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Place
input GNU_MBIND sections with the same type, attributes and
sh_info field into a single output GNU_MBIND section.
* testsuite/ld-elf/elf.exp: Run mbind2a and mbind2b.
* testsuite/ld-elf/mbind1.s: New file.
* testsuite/ld-elf/mbind1a.d: Likewise.
* testsuite/ld-elf/mbind1b.d: Likewise.
* testsuite/ld-elf/mbind1c.d: Likewise.
* testsuite/ld-elf/mbind2a.s: Likewise.
* testsuite/ld-elf/mbind2b.c: Likewise.
Given a linker script fragment like this:
SECTIONS {
. = 0x1000;
.text : AT(0x100) { *(.text) }
.data : AT(0x200) { *(.data) }
.rodata : AT(0x300) { *(.rodata) }
}
and an input file containing sections, '.text', '.data.1', and
'.rodata', then we'd expect the linker to place '.text' and '.rodata' in
the obvious way, and the '.data.1' orphan section would be located after
the '.data' section (assuming similar section properties).
Further, I believe that the expectation would be that the LMA for the
orphan '.data.1' section would start from 0x200 (as there is no '.data'
content).
However, right now, the LMA for '.data.1' would be 0x101, following on
from the '.text' section, this is because the change in LMA for the
'.data' section is not noticed by the linker, if there's no content in
the '.data' section.
What can be even more confusing to a user (though the cause is obvious
once you understand what's going on) is that adding some content to
'.data' will cause the orphan '.data.1' to switch to an LMA based off of
0x200.
This commit changes the behaviour so that an empty section that is in
the default lma region, and sets its lma, will adjust the lma of the
default region, this change will then be reflected in following sections
within the default lma memory region.
There's a new test to cover this issue that passes on a range of
targets, however, some targets generate additional sections, or have
stricter memory region size requirements that make it harder to come
up with a generic pass pattern, that still tests the required
features. For now I've set the test to ignore these targets.
ld/ChangeLog:
* ldlang.c (lang_size_sections_1): Shortcut loop only after
tracking changes to the default regions LMA.
* testsuite/ld-elf/orphan-9.ld: Extend header comment.
* testsuite/ld-elf/orphan-10.d: New file.
* testsuite/ld-elf/orphan-10.s: New file.
* NEWS: Mention change in behaviour.
When picking an lma_region for an orphan section we currently create a
new lang_output_section_statement_type and then populate this with the
orphan section.
The problem is that the lang_output_section_statement_type has a prev
pointer that links back to the previous output section. For non-orphan
output sections, that are created in linker script order, the prev
pointer will point to the output section that appears previous in linker
script order, as you'd probably expect.
The problem is that orphan sections are placed after processing the
linker script, and so, in the case of an output section created for an
orphan input section, the prev pointer actually points to the last
output section created.
This causes some unexpected behaviour when the orphan section is not
placed after the last non-orphan section that was created.
For example, consider this linker script:
MEMORY {
TEXT : ORIGIN = 0x200, LENGTH = 0x10
RODATA : ORIGIN = 0x400, LENGTH = 0x10
}
SECTIONS {
.text : {*(.text) } AT>TEXT
.data : AT(0x300) { *(.data) }
.rodata : { *(.rodata) } AT>RODATA
}
If we are processing an orphan section '.data.1' and decide to place
this after '.data', then the output section created will have a prev
pointer that references the '.rodata' output section. The result of
this is that '.data.1' will actually be assigned to the RODATA lma
region, which is probably not the expected behaviour.
The reason why '.data.1' is placed into the lma region of the '.rodata'
section is that lma region propagation is done at the time we create the
output section, based on the previous output section pointer, which is
really just a last-output-section-created pointer at that point in time,
though the prev point is fixed up later to reflect the true order of the
output sections.
The solution I propose in this commit is to move the propagation of lma
regions into a separate pass of the linker, rather than performing this
as part of the enter/exit of output sections during linker script
parsing.
During this later phase we have all of the output sections to hand, and
the prev/next points have been fixed up by this point to reflect the
actual placement ordering.
There's a new test to cover this issue that passes on a range of
targets, however, some targets generate additional sections, or have
stricter memory region size requirements that make it harder to come
up with a generic pass pattern, that still tests the required
features. For now I've set the test to ignore these targets.
ld/ChangeLog:
* ldlang.c (lang_leave_output_section_statement): Move lma_region
logic to...
(lang_propagate_lma_regions): ...this new function.
(lang_process): Call new function.
* testsuite/ld-elf/orphan-9.d: New file.
* testsuite/ld-elf/orphan-9.ld: New file.
* testsuite/ld-elf/orphan-9.s: New file.
* NEWS: Mention change in behaviour.
If we are configuring for an arc/linux target, and --with-cpu=nps400 is
used at configure time then change the default linker emulation to the
nps specific version. All of the alternative linker emulations are
still available using the -mNAME option for ld.
ld/ChangeLog:
* configure.tgt (arc*-*-linux*): Change the default linker
emulation based on --with-cpu selection.
* NEWS: Mention new configuration option.
Currently the EXCLUDE_FILE linker script construct can only be used
within the input section list, and applied only to the section pattern
immediately following the EXCLUDE_FILE. For example:
*.o (EXCLUDE_FILE (a.o) .text .rodata)
In this case all sections matching '.text' are included from all files
matching '*.o' but not from the file 'a.o'. All sections matching
'.rodata' are also included from all files matching '*.o' (incluing from
'a.o').
If the user wants to restrict the inclusion of section '.rodata' so that
this too is not taken from the file 'a.o' then the above example must be
extended like this:
*.o (EXCLUDE_FILE (a.o) .text EXCLUDE_FILE (a.o) .rodata)
However, due to the internal grammar of the linker script language the
snippet 'EXCLUDE_FILE (a.o) .text' is parsed by a pattern called
'wildcard_spec'. The same 'wildcard_spec' pattern is also used to parse
the input file name snippet '*.o' in the above examples. As a result of
this pattern reuse within the linker script grammar then the following
is also a valid linker script construct:
EXCLUDE_FILE (a.o) *.o (.text .rodata)
However, though the linker accepts this without complaint the
EXCLUDE_FILE part is silently ignored and has no effect.
This commit takes this last example and makes it a useful, valid,
construct. The last example now means to include sections '.text' and
'.rodata' from all files matching '*.o' except for the file 'a.o'.
If the list of input sections is long, and the user knows that the file
exclusion applies across the list then the second form might be a
clearer alternative to replicating the EXCLUDE_FILE construct.
I've added a set of tests for EXCLUDE_FILE to the linker, including
tests for the new functionality.
ld/ChangeLog:
* ldlang.h (struct lang_wild_statement_struct): Add
exclude_name_list field.
* ldlang.c (walk_wild_file_in_exclude_list): New function.
(walk_wild_consider_section): Use new
walk_wild_file_in_exclude_list function.
(walk_wild_file): Add call to walk_wild_file_in_exclude_list.
(print_wild_statement): Print new exclude_name_list field.
(lang_add_wild): Initialise new exclude_name_list field.
* testsuite/ld-scripts/exclude-file-1.d: New file.
* testsuite/ld-scripts/exclude-file-1.map: New file.
* testsuite/ld-scripts/exclude-file-1.t: New file.
* testsuite/ld-scripts/exclude-file-2.d: New file.
* testsuite/ld-scripts/exclude-file-2.map: New file.
* testsuite/ld-scripts/exclude-file-2.t: New file.
* testsuite/ld-scripts/exclude-file-3.d: New file.
* testsuite/ld-scripts/exclude-file-3.map: New file.
* testsuite/ld-scripts/exclude-file-3.t: New file.
* testsuite/ld-scripts/exclude-file-4.d: New file.
* testsuite/ld-scripts/exclude-file-4.map: New file.
* testsuite/ld-scripts/exclude-file-4.t: New file.
* testsuite/ld-scripts/exclude-file-a.s: New file.
* testsuite/ld-scripts/exclude-file-b.s: New file.
* testsuite/ld-scripts/exclude-file.exp: New file.
* ld.texinfo (Input Section Basics): Update description of
EXCLUDE_FILE to cover the new features.
* NEWS: Mention new EXCLUDE_FILE usage.
PR ld/20537
* emultempl/elf32.em: More OPTION_xxx values into an enum. Add
OPTION_NO_EH_FRAME_HDR.
(_add_options): Add support for --no-eh-frame-hdr.
* ld.texinfo: Document new option.
* lexsup.c (elf_shlib_list_options): List new option.
* NEWS: Mention the new option.
2016-08-26 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* bfd-in.h (bfd_elf32_arm_set_target_relocs): Add a new parameter for
the input import library bfd.
* bfd-in2.h: Regenerate.
* elf32-arm.c (struct elf32_arm_link_hash_table): New in_implib_bfd
and new_cmse_stub_offset fields.
(stub_hash_newfunc): Initialize stub_offset and stub_template_size to
-1.
(elf32_arm_add_stub): Likewise for stub_offset.
(arm_new_stubs_start_offset_ptr): New function.
(arm_build_one_stub): Only allocate a stub_offset if it is -1. Allow
empty SG veneers to have zero relocations.
(arm_size_one_stub): Only initialize stub size and template
information for non empty veneers. Do not update veneer section size
if veneer already has an offset.
(elf32_arm_create_stub): Return the stub entry pointer or NULL instead
of a boolean indicating success or failure.
(cmse_scan): Change stub_changed parameter into an integer pointer
parameter cmse_stub_created to count the number of stub created and
adapt to change of return value in elf32_arm_create_stub.
(cmse_entry_fct_p): New function.
(arm_list_new_cmse_stub): Likewise.
(set_cmse_veneer_addr_from_implib): Likewise.
(elf32_arm_size_stubs): Define cmse_stub_created, pass its address to
cmse_scan instead of that of cmse_stub_changed to compute the number
of stub created and use it to initialize stub_changed. Call
set_cmse_veneer_addr_from_implib after all cmse_scan. Adapt to change
of return value in elf32_arm_create_stub. Use
arm_stub_section_start_offset () if not NULL to initialize size of
secure gateway veneers section. Initialize stub_offset of Cortex-A8
erratum fix to -1. Use ret to hold return value.
(elf32_arm_build_stubs): Use arm_stub_section_start_offset () if not
NULL to initialize size of secure gateway veneers section. Adapt
comment to stress the importance of zeroing veneer section content.
(bfd_elf32_arm_set_target_relocs): Add new in_implib_bfd parameter to
initialize eponymous field in struct elf32_arm_link_hash_table.
ld/
* emultempl/armelf.em (in_implib_filename): Declare and initialize new
variable.
(arm_elf_create_output_section_statements): Open import input library
file for writing and pass resulting in_implib_bfd to
bfd_elf32_arm_set_target_relocs.
(PARSE_AND_LIST_PROLOGUE): Define OPTION_IN_IMPLIB option.
(PARSE_AND_LIST_LONGOPTS): Define --in-implib option.
(PARSE_AND_LIST_OPTIONS): Add help message for --in-implib option.
(PARSE_AND_LIST_ARGS_CASES): Handle new OPTION_IN_IMPLIB case.
* ld.texinfo (--cmse-implib): Update to mention --in-implib.
(--in-implib): Document new option.
* NEWS: Likewise.
* testsuite/ld-arm/arm-elf.exp
(Secure gateway import library generation): add --defsym VER=1 to gas
CLI.
(Secure gateway import library generation: errors): Likewise.
(Input secure gateway import library): New test.
(Input secure gateway import library: no output import library):
Likewise.
(Input secure gateway import library: not an SG input import library):
Likewise.
(Input secure gateway import library: earlier stub section base):
Likewise.
(Input secure gateway import library: later stub section base):
Likewise.
(Input secure gateway import library: veneer comeback): Likewise.
(Input secure gateway import library: entry function change):
Likewise.
* testsuite/ld-arm/cmse-implib.s: Add input import library testing.
* testsuite/ld-arm/cmse-implib.rd: Update accordingly.
* testsuite/ld-arm/cmse-new-implib.out: New file.
* testsuite/ld-arm/cmse-new-implib.rd: Likewise.
* testsuite/ld-arm/cmse-new-implib-no-output.out: Likewise.
* testsuite/ld-arm/cmse-new-implib-not-sg-in-implib.out: Likewise.
* testsuite/ld-arm/cmse-new-earlier-later-implib.out: Likewise.
* testsuite/ld-arm/cmse-new-comeback-implib.rd: Likewise.
* testsuite/ld-arm/cmse-new-wrong-implib.out: Likewise.
Add a configure option --enable-relro to decide whether -z relro should
be enabled in ELF linker by default. Default to yes for all Linux
targets, except FRV, HPPA, IA64 and MIPS, since many relro tests fail
on these targets.
PR ld/20283
* NEWS: Mention --enable-relro.
* configure.ac: Add --enable-relro.
(DEFAULT_LD_Z_RELRO): New. Set by --enable-relro.
* configure.tgt (ac_default_ld_z_relro): Default it to 1 for
some Linux targets.
* config.in: Regenerated.
* configure: Likewise.
* emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set
link_info.relro to DEFAULT_LD_Z_RELRO.
* testsuite/config/default.exp (ld_elf_shared_opt): New.
* testsuite/lib/ld-lib.exp (run_dump_test): Pass
$ld_elf_shared_opt to ld for ELF targets with shared object
support.
(run_ld_link_tests): Likewise.
When handling absolute relocations for global symbols bind within the
shared object, AArch64 will generate one dynamic RELATIVE relocation,
but won't apply the value for this absolution relocations at static
linking stage. This is different from AArch64 gold linker and x86-64.
This is not a bug as AArch64 is RELA, there is only guarantee that
relocation addend is placed in the relocation entry. But some
system softwares originally writen for x86-64 might assume AArch64
bfd linker gets the same behavior as x86-64, then they could take
advantage of this buy skipping those RELATIVE dynamic relocations
if the load address is the same as the static linking address.
This patch makes AArch64 BFD linker applies absolution relocations at
static linking stage for scenario described above. Meanwhile old AArch64
android loader has a bug (PR19163) which relies on current linker behavior
as a workaround, so the same option --no-apply-dynamic-relocs added.
NOCROSSREFS_TO is similar to the existing NOCROSSREFS command but only
checks one direction of cross referencing.
ld/ChangeLog
* ld.texinfo: Document NOCROSSREFS_TO script command.
* ldlang.h (struct lang_nocrossrefs): Add onlyfirst field.
(lang_add_nocrossref_to): New prototype.
* ldcref.c (check_local_sym_xref): Use onlyfirst to only look for
symbols defined in the first section.
(check_nocrossref): Likewise.
* ldgram.y (NOCROSSREFS_TO): New script command.
* ldlang.c (lang_add_nocrossref): Set onlyfirst to FALSE.
(lang_add_nocrossref_to): New function.
* ldlex.l (NOCROSSREFS_TO): New token.
* NEWS: Mention NOCROSSREFS_TO.
* testsuite/ld-scripts/cross4.t: New file.
* testsuite/ld-scripts/cross5.t: Likewise.
* testsuite/ld-scripts/cross6.t: Likewise.
* testsuite/ld-scripts/cross7.t: Likewise.
* testsuite/ld-scripts/crossref.exp: Run 4 new NOCROSSREFS_TO
tests.
bfd * bfd-in2.h: Regenerate.
* bfd-in.h (bfd_arm_stm32l4xx_fix): New enum. Specify how
STM32L4XX instruction scanning should be done.
(bfd_elf32_arm_set_stm32l4xx_fix)
(bfd_elf32_arm_stm32l4xx_erratum_scan)
(bfd_elf32_arm_stm32l4xx_fix_veneer_locations): Add prototypes.
(bfd_elf32_arm_set_target_relocs): Add stm32l4xx fix type argument
to prototype.
* elf32-arm.c (STM32L4XX_ERRATUM_VENEER_SECTION_NAME)
(STM32L4XX_ERRATUM_VENEER_ENTRY_NAME): Define macros.
(elf32_stm32l4xx_erratum_type): New enum.
(elf32_stm32l4xx_erratum_list): New struct. List of veneers or
jumps to veneers.
(_arm_elf_section_data): Add stm32l4xx_erratumcount,
stm32l4xx_erratumlist.
(elf32_arm_link_hash_table): Add stm32l4xx_erratum_glue_size,
stm32l4xx_fix and num_stm32l4xx_fixes fields.
(ctz): New function.
(popcount): New function.
(elf32_arm_link_hash_table_create): Initialize stm32l4xx_fix.
(put_thumb2_insn): New function.
(STM32L4XX_ERRATUM_LDM_VENEER_SIZE): Define. Size of a veneer for
LDM instructions.
(STM32L4XX_ERRATUM_VLDM_VENEER_SIZE): Define. Size of a veneer for
VLDM instructions.
(bfd_elf32_arm_allocate_interworking_sections): Initialise erratum
glue section.
(record_stm32l4xx_erratum_veneer) : New function. Create a single
veneer, and its associated symbols.
(bfd_elf32_arm_add_glue_sections_to_bfd): Add STM32L4XX erratum glue.
(bfd_elf32_arm_set_stm32l4xx_fix): New function. Set the type of
erratum workaround required.
(bfd_elf32_arm_stm32l4xx_fix_veneer_locations): New function. Find
out where veneers and branches to veneers have been placed in
virtual memory after layout.
(is_thumb2_ldmia): New function.
(is_thumb2_ldmdb): Likewise.
(is_thumb2_vldm ): Likewise.
(stm32l4xx_need_create_replacing_stub): New function. Decide if a
veneer must be emitted.
(bfd_elf32_arm_stm32l4xx_erratum_scan): Scan the sections of an
input BFD for potential erratum-triggering insns. Record results.
(bfd_elf32_arm_set_target_relocs): Set stm32l4xx_fix field in
global hash table.
(elf32_arm_size_dynamic_sections): Collect glue information.
(create_instruction_branch_absolute): New function.
(create_instruction_ldmia): Likewise.
(create_instruction_ldmdb): Likewise.
(create_instruction_mov): Likewise.
(create_instruction_sub): Likewise.
(create_instruction_vldmia): Likewise.
(create_instruction_vldmdb): Likewise.
(create_instruction_udf_w): Likewise.
(create_instruction_udf): Likewise.
(push_thumb2_insn32): Likewise.
(push_thumb2_insn16): Likewise.
(stm32l4xx_fill_stub_udf): Likewise.
(stm32l4xx_create_replacing_stub_ldmia): New function. Expands the
replacing stub for ldmia instructions.
(stm32l4xx_create_replacing_stub_ldmdb): Likewise for ldmdb.
(stm32l4xx_create_replacing_stub_vldm): Likewise for vldm.
(stm32l4xx_create_replacing_stub): New function. Dispatches the
stub emission to the appropriate functions.
(elf32_arm_write_section): Output veneers, and branches to veneers.
ld * ld.texinfo: Description of the STM32L4xx erratum workaround.
* emultempl/armelf.em (stm32l4xx_fix): New.
(arm_elf_before_allocation): Choose the type of fix, scan for
erratum.
(gld${EMULATION_NAME}_finish): Fix veneer locations.
(arm_elf_create_output_section_statements): Propagate
stm32l4xx_fix value.
(PARSE_AND_LIST_PROLOGUE): Define OPTION_STM32L4XX_FIX.
(PARSE_AND_LIST_LONGOPTS): Add entry for handling
--fix-stm32l4xx-629360.
(PARSE_AND_LIST_OPTION): Add entry for helping on
--fix-stm32l4xx-629360.
(PARSE_AND_LIST_ARGS_CASES): Treat OPTION_STM32L4XX_FIX.
tests * ld-arm/arm-elf.exp (armelftests_common): Add STM32L4XX
tests.
* ld-arm/stm32l4xx-cannot-fix-far-ldm.d: New.
* ld-arm/stm32l4xx-cannot-fix-far-ldm.s: Likewise.
* ld-arm/stm32l4xx-cannot-fix-it-block.d: Likewise.
* ld-arm/stm32l4xx-cannot-fix-it-block.s: Likewise.
* ld-arm/stm32l4xx-fix-all.d: Likewise.
* ld-arm/stm32l4xx-fix-all.s: Likewise.
* ld-arm/stm32l4xx-fix-it-block.d: Likewise.
* ld-arm/stm32l4xx-fix-it-block.s: Likewise.
* ld-arm/stm32l4xx-fix-ldm.d: Likewise.
* ld-arm/stm32l4xx-fix-ldm.s: Likewise.
* ld-arm/stm32l4xx-fix-vldm.d: Likewise.
* ld-arm/stm32l4xx-fix-vldm.s: Likewise.