LLD has dropped the option -Ttext-segment for specifying image base
addresses, instead forcing the use of the --image-base option for both
ELF and PE targets. As it stands, GNU LD and LLVM LLD are incompatible,
having two different options for the same functionality.
This patch enables the use of --image-base on ELF targets, advancing
consistency and compatibility.
See: https://reviews.llvm.org/D70468https://maskray.me/blog/2020-11-15-explain-gnu-linker-options#address-relatedhttps://sourceware.org/bugzilla/show_bug.cgi?id=25207
Moreover, a new test has been added to ensure -z separate-code behaviour
when used with -Ttext-segment stays the same. When this combination is
used, -Ttext-segment sets the address of the first segment (R), not the
text segment (RX), and like with -z noseparate-code, no segments lesser
than the specified address are created. If this behaviour was to change,
the first (R) segment of the ELF file would begin in a lesser address
than the specified text (RX) segment, breaking traditional use of this
option for specifying image base address.
The is patch adds a new ld build-id computation mode, "xx", using
xxhash in its 128-bit mode. The patch prereqs the xxhash-devel
headers being installed, and uses the "all-inlined" model, so no
run-time or link-time library dependence exists.
The xxhash mode performs well, saving roughly 20% of total userspace
run time from an ld job over a 800MB shared library relative to sha1.
128 bits of good hash should be collision-resistant to a number of
distinct binaries that numbers in the 2**32 - 2**64 range, even if not
"crypto" level hash. Confirmations of this are in progress.
ld/configury: add --with-xxhash mode, different from gdb case
because only using it in inline mode
ld/ldbuildid.c: add "xx" mode, #if WITH_XXHASH
ld/NEWS, ld.texi: mention new option
ld/lexsup.c: add enumeration of --build-id STYLES to --help
ld/testsuite/ld-elf/build-id.exp: add test case for 0xHEX case
and conditional for xx case;
also, simply tcl list syntax
https://inbox.sourceware.org/binutils/20240917201509.GB26396@redhat.com/
Signed-off-by: Frank Ch. Eigler <fche@redhat.com>
Say why we even mention shared libraries here (ET_DYN), and clarify
symbol resolution. There are of course many other ways that PIEs
resemble PDEs more closely than shared libraries.
PR 19871
* ld.texi (-pie): Clarify.
Add -plugin-save-temps to store plugin intermediate files permanently.
It can be used to exam the final input object files generated from IR
inputs.
* NEWS: Mention -plugin-save-temps.
* ld.h (ld_config_type): Add plugin_save_temps.
* ld.texi: Document -plugin-save-temps.
* ldlex.h (option_values): Add OPTION_PLUGIN_SAVE_TEMPS.
* lexsup.c (ld_options): Add -plugin-save-temps.
(parse_args): Handle OPTION_PLUGIN_SAVE_TEMPS.
* plugin.c (plugin_call_cleanup): Don't call plugin
cleanup_handler for -plugin-save-temps.
Adds two new external authors to etc/update-copyright.py to cover
bfd/ax_tls.m4, and adds gprofng to dirs handled automatically, then
updates copyright messages as follows:
1) Update cgen/utils.scm emitted copyrights.
2) Run "etc/update-copyright.py --this-year" with an extra external
author I haven't committed, 'Kalray SA.', to cover gas testsuite
files (which should have their copyright message removed).
3) Build with --enable-maintainer-mode --enable-cgen-maint=yes.
4) Check out */po/*.pot which we don't update frequently.
PR 31067
* linker.c (_bfd_generic_link_add_one_symbol): When issuing a warning message, also display a message about the warning not being affected by garbage colleciton.
* ld.texi (Special Sections): New entry in the linker manual. Describes how the .gnu.warning and .gnu.warning.SYM sections behave.
In a safety context, it could interesting to track the trampolines being
generated, ensuring there are expected or not.
bfd/ChangeLog:
* elf32-ppc.c (ppc_elf_relax_section): Log branch fixups.
ld/ChangeLog:
* ld.texi (--print-map): Add new item about fixups.
PR 30865
* ld.texi: Update description of the FILL command.
* testsuite/ld-scripts/fill2.d: New test.
* testsuite/ld-scripts/fill2.t: New test source.
* testsuite/ld-scripts/data.exp: Run the new test.
PR 27565
* ldlex.l: Add REVERSE.
* ldgram.y: Allow REVERSE to be used wherever a sorting command can be used.
* ld.h (struct wildcard_spec): Add 'reversed' field.
* ldlang.h (lang_wild_statement_struct): Add 'filenames_reversed' field.
* ldlang.c (compare_sections): Add reversed parameter. (wild_sort): Reverse the comparison if requested. (print_wild_statement): Handle the reversed field.
* ld.texi: Document the new feature.
* NEWS: Mention the new feature.
* testsuite/ld-scripts/sort-file-reversed-1.d: New test driver.
* testsuite/ld-scripts/sort-file-reversed-1.t: New test source.
* testsuite/ld-scripts/sort-file-reversed-2.t: New test source.
* testsuite/ld-scripts/sort-file-reversed-2.d: New test driver.
* testsuite/ld-scripts/sort-sections-reversed-1.d: New test driver.
* testsuite/ld-scripts/sort-sections-reversed-1.t: New test source.
* testsuite/ld-scripts/sort-sections-reversed-2.t: New test source.
* testsuite/ld-scripts/sort-sections-reversed-2.d: New test driver.
* testsuite/ld-scripts/sort-sections-reversed-3.d: New test driver.
* testsuite/ld-scripts/sort-sections-reversed-3.t: New test source.
The PLT entry in executables and shared libraries contains an indirect
branch, like
jmp *foo@GOTPCREL(%rip)
push $index_foo
jmp .PLT0
or
endbr64
jmp *foo@GOTPCREL(%rip)
NOP padding
which is used to branch to the function, foo, defined in another object.
Each R_X86_64_JUMP_SLOT relocation has a corresponding PLT entry.
The dynamic tags have been added to the x86-64 psABI to mark such PLT
entries:
6d824a52a4
Add an x86-64 linker option, -z mark-plt, to mark PLT entries with
#define DT_X86_64_PLT (DT_LOPROC + 0)
#define DT_X86_64_PLTSZ (DT_LOPROC + 1)
#define DT_X86_64_PLTENT (DT_LOPROC + 3)
1. DT_X86_64_PLT: The address of the procedure linkage table.
2. DT_X86_64_PLTSZ: The total size, in bytes, of the procedure linkage
table.
3. DT_X86_64_PLTENT: The size, in bytes, of a procedure linkage table
entry.
and set the r_addend field of the R_X86_64_JUMP_SLOT relocation to the
memory offset of the indirect branch instruction. The dynamic linker
can use these tags to update the PLT section to direct branch.
bfd/
* elf-linker-x86.h (elf_linker_x86_params): Add mark_plt.
* elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Set the
r_addend of R_X86_64_JUMP_SLOT to the indirect branch offset
in PLT entry for -z mark-plt.
* elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Add
DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT for
-z mark-plt.
(_bfd_x86_elf_finish_dynamic_sections): Set DT_X86_64_PLT,
DT_X86_64_PLTSZ and DT_X86_64_PLTENT.
(_bfd_x86_elf_get_synthetic_symtab): Ignore addend for
JUMP_SLOT relocation.
(_bfd_x86_elf_link_setup_gnu_properties): Set
plt_indirect_branch_offset.
* elfxx-x86.h (elf_x86_plt_layout): Add plt_indirect_branch_offset.
binutils/
* readelf.c (get_x86_64_dynamic_type): New function.
(get_dynamic_type): Call get_x86_64_dynamic_type.
include/
* elf/x86-64.h (DT_X86_64_PLT): New.
(DT_X86_64_PLTSZ): Likewise.
(DT_X86_64_PLTENT): Likewise.
ld/
* ld.texi: Document -z mark-plt and -z nomark-plt.
* emulparams/elf32_x86_64.sh: Source x86-64-plt.sh.
* emulparams/elf_x86_64.sh: Likewise.
* emulparams/x86-64-plt.sh: New file.
* testsuite/ld-x86-64/mark-plt-1.s: Likewise.
* testsuite/ld-x86-64/mark-plt-1a-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1a.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1b-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1b.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1c-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1c.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1d-x32.d: Likewise.
* testsuite/ld-x86-64/mark-plt-1d.d: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run -z mark-plt tests.
bfd
* peXXigen.c (_bfd_XXi_only_swap_filehdr_out): If inserting a timestamp, use the value held in the SOURCE_DATE_EPOCH environment variable, if it is defined.
binutils
* doc/binutils.texi (objcopy): Document change in behaviour of objcopy's --preserve-dates command line option.
ld
* pe-dll.c (fill_edata): If inserting a timestamp, use the value held in the SOURCE_DATE_EPOCH environment variable, if it is defined.
* ld.texi (--insert-timestamp): Document change in behaviour.
This patch is aimed at making __bss_start properly aligned with the
first of any bss-style sections following. Most of the work here
involves keeping track of the last output section seen when processing
the linker script.
You can almost align __bss_start properly by using
${RELOCATING+. = ALIGN(${DATA_SDATA-${NO_SMALL_DATA-ALIGNOF(.${SBSS_NAME}) != 0 ? ALIGNOF(.${SBSS_NAME}) : }}${BSS_PLT+ALIGNOF(.plt) != 0 ? ALIGNOF(.plt) : }ALIGNOF(.${BSS_NAME}));}
and changing every place that defines NO_SMALL_DATA to use " ", but
having two .plt sections (marked SPECIAL) on some backends foils that
idea. The problem is that you only want to pick up the following
.plt, not the one preceeding __bss_start in the data segment if the
backend decides that is the proper .plt section.
Perhaps that could be fixed too, but I decided instead to extend the
linker script a little. THIS_SECTION and PREV_SECTION could easily be
added too.
* ld.texi (ALIGNOF, SIZEOF): Update and mention NEXT_SECTION.
* ldexp.c (output_section_find): New function.
(fold_name <ALIGNOF, SIZEOF>): Use output_section_find.
(exp_fold_tree): Add os parameter. Adjust all calls.
(exp_fold_tree_no_dot, exp_get_vma, exp_get_power): Likewise.
* ldexp.h (struct ldexp_control): Add last_os.
(exp_fold_tree, exp_fold_tree_no_dot): Update prototypes.
(exp_get_vma, exp_get_power): Likewise.
* ldlang.c: Pass last output section to expression folder
calls throughout file.
(open_input_bfds): Add os parameter to track last os seen.
(lang_size_sections_1): Rename output_section_statement param
to current_os. Track last os.
(lang_do_assignments_1): Track last os.
* scripttempl/arclinux.sc: Align to ALIGNOF NEXT_SECTION
before defining __bss_start.
* scripttempl/elf.sc: Likewise.
* scripttempl/elf64bpf.sc: Likewise.
* scripttempl/elf64hppa.sc: Likewise.
* scripttempl/elf_chaos.sc: Likewise.
* scripttempl/elfarc.sc: Likewise.
* scripttempl/elfd10v.sc: Likewise.
* scripttempl/elfxtensa.sc: Likewise.
* scripttempl/epiphany_4x4.sc: Likewise.
* scripttempl/iq2000.sc: Likewise.
* scripttempl/mep.sc: Likewise.
* scripttempl/nds32elf.sc: Likewise.
* scripttempl/xstormy16.sc: Likewise.
* testsuite/ld-x86-64/pe-x86-64-5.od: Update expected __bss_start.
* testsuite/ld-x86-64/pe-x86-64-5.rd: Likewise.
PR 30374
* ldfile.c (struct input_remap): New structure. (ldfile_add_remap): New function. (ldfile_remap_input_free): New function. (ldfile_add_remap_file): New function. (ldfile_possibly_remap_input): New function. (ldfile_print_input_remaps): New function. * ldfile.h: Add prototypes for new functions.
* ldlang.c (new_afile): Call ldfile_possibly_remap_input. (lang_finish): Call ldfile_remap_input_free. (lang_map): Call ldfile_print_input_remaps.
* ldlex.h (OPTION_REMAP_INPUTS, OPTION_REMAP_INPUTS_FILE): Define.
* lexsup.c (ld_options): Add --remap-inputs-file and --remap-inputs. (parse_args): Handle new options.
* NEWS: Mention the new feature.
* ld.texi: Document the new options.
* testsuite/ld-misc/input-remap.exp: New test driver.
* testsuite/ld-misc/remaps.r: New file: Expected linker output.
* testsuite/ld-misc/remaps.txt: New file. Input remaps file.
The answer to PR28902 may be deduced from the existing INSERT
documentation that says the default script is parsed after the -T
INSERT script, if you assume (correctly) that nothing special is done
when inserting into -T scripts overriding the default script. In both
cases INSERT handling looks for the specified output section later on
the internal list of parsed script commands. This isn't obvious
though, so make the ordering explicit, and mention that section
assignments are the same too.
PR 28902
* ld.texi (INSERT): Specify ordering when -T is used both to
override the default script and to augment.
PR 16566
* ldlang.c (ld_is_local_symbol): New function. (print_input_section): Add code to display local symbols in the section.
* ldlex.h (enum option_values): Add OPTION_PRINT_MAP_LOCALS and OPTION_PRINT_MAP_LOCALS.
* lexsup.c (ld_options[]): Add entries for --print-map-locals and --no-print-map-locals.
* NEWS: Mention the new feature.
* ld.h (struct ld_config_type): Add print_map_locals field.
* ld.texi: Document the new command line option.
* testsuite/ld-scripts/sizeof.s: Add a local symbol.
* testsuite/ld-scripts/map-locals.d: New test control file.
* testsuite/ld-scripts/map-address.exp: Run the new test.
Revert "Prevent the ASCII linker script directive from generating huge amounts of padding if the size expression is not a constant."
This reverts commit adbe951fc9.
Revert "ld test asciz and ascii fails"
This reverts the ascii.d part of commit 5f497256be.
Revert "Add support for the ASCII directive inside linker scripts."
This mostly reverts commit 9fe129a410
leaving the asciz.d and asciz.t changes in place.
This is a hopefully temporary reversion of new ld features for
embedded processors by Ulf Samuelsson, plus some followup patches.
Squashed together from the following:
Revert "lddigest 32-bit support and gcc-4 compile errors"
This reverts commit d7ee19be87110a8f5342cec6e323d83d01c641d1.
Revert "ld: Use correct types for crc64 calculations"
This reverts commit 9a534b9f8e.
Revert "Re: DIGEST: testsuite"
This reverts commit c8e85484d8.
Revert "Regen potfiles"
This reverts commit 4d98c966f8.
Revert "DIGEST: Makefile.*"
This reverts commit 78ef6ab03f.
Revert "DIGEST: calculation"
This reverts commit 5243990191.
Revert "DIGEST: ldlang.*: add timestamp"
This reverts commit bd9466d4aa.
Revert "DIGEST: ldmain.c"
This reverts commit c8f8653fa7.
Revert "DIGEST: ldgram.y"
This reverts commit d73c01be26.
Revert "DIGEST: ldlex.l"
This reverts commit 48b5163a9d.
Revert "DIGEST: testsuite"
This reverts commit a4135d1a48.
Revert "DIGEST: Documentation"
This reverts commit 3ec28966c3.
Revert "DIGEST: NEWS"
This reverts commit 099bf2927d.
Revert "DIGEST: LICENSING"
This reverts commit 5c8a0c6654.
