The AArch64 linker option to turn on BTI (--force-bti) warns in case there are
input objects which have a missing GNU NOTE section for BTI. This patch is trying
to improve the warnings that come out.
In order to do so, I propose adding a new argument to elf_merge_gnu_properties
and the backend function merge_gnu_properties. This new argument makes sure
that we now pass both the objects along with the properties to which they
belong to. The x86 backend function has also been updated to match this
change.
*** bfd/ChangeLog ***
2019-03-21 Sudakshina Das <sudi.das@arm.com>
* elf-bfd.h (struct elf_backend_data): Add argument to
merge_gnu_properties.
* elf-properties.c (elf_merge_gnu_properties): Add argument to
itself and while calling bed->merge_gnu_properties.
(elf_merge_gnu_property_list): Update the calls for
elf_merge_gnu_properties.
* elfnn-aarch64.c (elfNN_aarch64_merge_gnu_properties): Update handling
of --force-bti warning and add argument.
* elfxx-aarch64.c (_bfd_aarch64_elf_link_setup_gnu_properties): Add
warning.
* elfxx-x86.c (_bfd_x86_elf_merge_gnu_properties): Add argument.
* elfxx-x86.h (_bfd_x86_elf_merge_gnu_properties): Likewise in
declaration.
*** ld/ChangeLog ***
2019-03-21 Sudakshina Das <sudi.das@arm.com>
* testsuite/ld-aarch64/aarch64-elf.exp: Add new test.
* testsuite/ld-aarch64/bti-plt-1.s: Add .ifdef for PAC note section.
* testsuite/ld-aarch64/bti-plt-6.d: Update warning.
* testsuite/ld-aarch64/bti-plt-7.d: Likewise.
* testsuite/ld-aarch64/bti-warn.d: New test.
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.
The fix for PR ld/22263 causes TLS relocations using ADRP to be relaxed
into MOVZ, however this causes issues for the erratum code.
The erratum code scans the input sections looking for ADRP instructions
and notes their location in the stream.
It then later tries to find them again in order to generate the linker
stubs. Due to the relaxation it instead finds a MOVZ and hard aborts.
Since this relaxation is a valid one, and in which case the erratum no
longer applies, it shouldn't abort but instead just continue.
This changes the TLS relaxation code such that when it finds an ADRP and
it relaxes it, it removes the erratum entry from the work list by changing
the stub type into none so the stub is ignored.
The entry is not actually removed as removal is a more expensive operation
and we have already allocated the memory anyway.
The clearing is done for IE->LE and GD->LE relaxations, and a testcase is
added for the IE case. The GD case I believe to be impossible to get together
with the erratum sequence due to the required BL which would break the sequence.
However to cover all basis I have added the guard there as well.
build on native hardware and regtested on
aarch64-none-elf, aarch64-none-elf (32 bit host),
aarch64-none-linux-gnu, aarch64-none-linux-gnu (32 bit host)
Cross-compiled and regtested on
aarch64-none-linux-gnu, aarch64_be-none-linux-gnu
Testcase in PR23940 tested and works as expected now and benchmarks ran on A53
showing no regressions and no issues.
bfd/ChangeLog:
PR ld/23904
* elfnn-aarch64.c (_bfd_aarch64_adrp_p): Use existing constants.
(_bfd_aarch64_erratum_843419_branch_to_stub): Use _bfd_aarch64_adrp_p.
(struct erratum_835769_branch_to_stub_clear_data): New.
(_bfd_aarch64_erratum_843419_clear_stub): New.
(clear_erratum_843419_entry): New.
(elfNN_aarch64_tls_relax): Use it.
(elfNN_aarch64_relocate_section): Pass input_section.
(aarch64_map_one_stub): Handle branch type none as valid.
ld/ChangeLog:
PR ld/23904
* testsuite/ld-aarch64/aarch64-elf.exp: Add erratum843419_tls_ie.
* testsuite/ld-aarch64/erratum843419_tls_ie.d: New test.
* testsuite/ld-aarch64/erratum843419_tls_ie.s: New test.
For Local Exec TLS model, the offset of the variable from the thread pointer
can be computed at static link time. This doesn't require GOT indirection.
The initial change is a bad fix for a problem during TLS GD -> LE relaxation.
The proper fix is to check whether _GLOBAL_OFFSET_TABLE_ is referenced,
create got section if yes. And the fix is already in the repository.
bfd/
2018-10-31 Renlin Li <renlin.li@arm.com>
* elfnn-aarch64.c (elfNN_aarch64_check_relocs): Don't create got
section for Local Exec TLS model.
Use `bfd_is_abs_symbol' to determine whether a symbol is absolute,
avoiding a problem with ordinary symbols defined in a linker script
outside an output section definition. Such symbols have its owning
section set to the absolute section up to the final link phase. A flag
has been added to the link hash to identify such symbols. Rather than
checking the flag by hand, use the macro that does it uniformly for all
users.
bfd/
* elf32-nds32.c (nds32_elf_relax_loadstore): Use
`bfd_is_abs_symbol' rather than `bfd_is_abs_section' in checking
whether the symbol is absolute.
(nds32_elf_relax_lo12): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Likewise.
(elfNN_aarch64_check_relocs): Likewise.
* xcofflink.c (xcoff_need_ldrel_p): Likewise.
(bfd_xcoff_import_symbol): Likewise.
(xcoff_write_global_symbol): Likewise.
This patch adds the following relocation support into binutils bfd linker.
BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12_NC,
BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12_NC,
BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12_NC,
BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12_NC.
Those relocations includes both ip64 and ilp32 variant.
This patch adds the following relocation support into binutils gas.
BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12_NC,
BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12_NC,
BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12_NC,
BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12,
BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12_NC.
Those relocations includes both ip64 and ilp32 variant.
Following on from PR 22929, I have found the same problem exists with
other ifunc supporting targets too. Plus see this link for the bug
being reported against the s390x binutils for Fedora rawhide:
https://bugzilla.redhat.com/show_bug.cgi?id=1553705
So I am going to check in the patch below which applies the same
change that H.J. made for the x86_64 target to the other affected
targets. (Specifically: S390, AArch64 and Sparc). Plus it adds a new
test to the linker testsuite to make sure that this problem stays
fixed.
bfd * elf64-s390.c (elf_s390_relocate_section): Move check for
relocations against non-allocated sections to before the code that
handles ifunc relocations.
* elf32-s390.c (elf_s390_relocate_section): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Treat
relocs against IFUNC symbols in non-allocated sections as relocs
against FUNC symbols.
* elfxx-sparc.c (_bfd_sparc_elf_relocate_section): Likewise.
ld * testsuite/ld-ifunc/ifuncmod5.s: New test. Checks that targets
that support IFUNC symbols can handle relocations against those
symbols in NOTE sections.
* testsuite/ld-ifunc/ifuncmod5.d: New file: Driver for the new
test.
* testsuite/ld-ifunc/ifunc.exp: Run the new test.
For absolute symbols which are forced local or not dynamic, the ABS relocation
should be resolved at static linking time.
Originally, an RELATIVE/ABS relocation will be generated even for absolution
symbols for the dynamic linker to resolve.
bfd/
2018-03-07 Renlin Li <renlin.li@arm.com>
PR ld/20402
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Check absolute symbol,
and don't emit relocation in specific case.
ld/
2018-03-07 Renlin Li <renlin.li@arm.com>
PR ld/20402
* testsuite/ld-aarch64/aarch64-elf.exp: Run new test.
* testsuite/ld-aarch64/pr20402.s: New.
* testsuite/ld-aarch64/pr20402.d: New.
More standarization of error/warning messages. The ARM backend has
some multi-line error messages, which don't fit particularly well with
the GNU coding standard insistence that error messages shouldn't be
capitalized or have a full-stop. I've replaced the line breaks with
semicolons.
So for instance the following
system/path/to/ld: myobject.o: invalid special symbol `foo'.
system/path/to/ld: It must be a global or weak function symbol.
becomes
system/path/to/ld: myobject.o: invalid special symbol `foo'; it must be a global or weak function symbol
bfd/
* elf32-arm.c, * elfnn-aarch64.c: Standardize error/warning messages.
ld/
* testsuite/ld-aarch64/reloc-overflow-bad.d,
* testsuite/ld-arm/attr-merge-9.out,
* testsuite/ld-arm/attr-merge-arch-2.d,
* testsuite/ld-arm/attr-merge-unknown-1.d,
* testsuite/ld-arm/attr-merge-unknown-2.d,
* testsuite/ld-arm/attr-merge-unknown-2r.d,
* testsuite/ld-arm/attr-merge-unknown-3.d,
* testsuite/ld-arm/cmse-implib-errors.out,
* testsuite/ld-arm/cmse-new-earlier-later-implib.out,
* testsuite/ld-arm/cmse-new-implib-no-output.out,
* testsuite/ld-arm/cmse-new-implib-not-sg-in-implib.out,
* testsuite/ld-arm/cmse-new-implib.out,
* testsuite/ld-arm/cmse-new-wrong-implib.out,
* testsuite/ld-arm/cmse-veneers-no-gnu_sgstubs.out,
* testsuite/ld-arm/cmse-veneers-wrong-entryfct.out,
* testsuite/ld-arm/group-relocs-alu-bad-2.d,
* testsuite/ld-arm/group-relocs-alu-bad.d,
* testsuite/ld-arm/group-relocs-ldc-bad-2.d,
* testsuite/ld-arm/group-relocs-ldc-bad.d,
* testsuite/ld-arm/group-relocs-ldr-bad-2.d,
* testsuite/ld-arm/group-relocs-ldr-bad.d,
* testsuite/ld-arm/group-relocs-ldrs-bad-2.d,
* testsuite/ld-arm/group-relocs-ldrs-bad.d,
* testsuite/ld-arm/stm32l4xx-cannot-fix-far-ldm.d: Update.
The assumption that R_AARCH64_ABS16 and R_AARCH64_ABS32 relocation in LP64 abi
will be used to generate an address does not hold for absolute symbol.
In this case, it is a value fixed at static linking time.
The condition to check the relocations is relax to allow absolute symbol and
undefined symbol case.
bfd/
2018-02-05 Renlin Li <renlin.li@arm.com>
PR ld/22764
* elfnn-aarch64.c (elfNN_aarch64_check_relocs): Relax the
R_AARCH64_ABS32 and R_AARCH64_ABS16 for absolute symbol. Apply the
check for writeable section as well.
ld/
2018-02-05 Renlin Li <renlin.li@arm.com>
PR ld/22764
* testsuite/ld-aarch64/emit-relocs-258.s: Define symbol as an address.
* testsuite/ld-aarch64/emit-relocs-259.s: Likewise.
* testsuite/ld-aarch64/aarch64-elf.exp: Run new test.
* testsuite/ld-aarch64/pr22764.s: New.
* testsuite/ld-aarch64/pr22764.d: New.
R_AARCH64_ABS64, R_AARCH64_ABS32 and R_AARCH64_ABS16 are data relocations
supported in AArch64 elf ABI.
R_AARCH64_ABS64 under LP64 is allowed in shared object and a dynamic relocation entry
will be generated. This allows the dynamic linker to do further symbol resolution.
R_AARCH64_ABS32 likewise is allowed in shared object, however under ILP32 abi.
The original behavior for R_AARCH64_ABS32 under LP64 is that, it's allowed
in shared object and silently resolved at static linking time.
No dynamic relocation entry is generate for it.
R_AARCH64_ABS16 is allowed in shared object under both L64 and ILP32.
It's resolved at static linking time as well.
Under LP64, the address should be 64-bit. R_AARCH64_ABS32 relocation indicates
an address that is only sized 32 bits which is meaningless in LP64 shared object.
It's useful to error out.
I have checked glibc dynamic linker code, R_AARCH64_ABS16 is not supported at all. So
R_AARCH64_ABS16 should be reject in shared object completely.
In this patch, R_AARCH64_ABS32 is rejected under LP64 in constant section of shared object.
R_AARCH64_ABS16 is rejected in constant section of shared object in both ABI.
This will sometimes provide useful information for buggy code.
Past tense is wrong for a comment before some action.
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Comment tidy.
* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_adjust_dynamic_symbol): Likewise.
In early October, HJ Lu added support for a number of targets to "Dump
dynamic relocation in read-only section with minfo". This extends
that support to more targets, displays the symbol involved, and splits
the existing function that sets TEXTREL into a "readonly_dynrelocs"
and "maybe_set_textrel" function. I'll need "readonly_dynrelocs" if I
ever get around to fixing "pr22374 function pointer initialization"
fails.
am33_2.0, arc, bfin, hppa64, mn10300, and nios2 fail to mark a binary
needing text relocations with DT_TEXTREL. That's not good. xtensa also
fails to do so but complains about "dangerous relocation: dynamic
relocation in read-only section" so I reckon that is fine and have
marked the test as an xfail. The other targets need maintainer
attention.
Curiously, the map file dump wasn't added for x86, so the map test
currently fail on x86. It also fails on alpha, am33_2.0, arc, bfin,
hppa64, ia64, m68k, mips, mn10300, nios2, score and vax. cris
complains with "tmpdir/textrel.o, section .rodata: relocation
R_CRIS_32 should not be used in a shared object; recompile with -fPIC"
so I've marked it as an xfail.
bfd/
* elf32-hppa.c (maybe_set_textrel): Print symbol for map file output.
* elf32-ppc.c (maybe_set_textrel): Likewise.
* elf64-ppc.c (maybe_set_textrel): Likewise.
* elf32-arm.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing..
(elf32_arm_readonly_dynrelocs): ..this.
* elf32-lm32.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-m32r.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-metag.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-nds32.c: Delete unnecessary forward declarations.
(readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-or1k.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-s390.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-sh.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf32-tic6x.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing..
(elf32_tic6x_readonly_dynrelocs): ..this.
* elf32-tilepro.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elf64-s390.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elfnn-aarch64.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing..
(aarch64_readonly_readonly_dynrelocs): ..this.
* elfnn-riscv.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elfxx-sparc.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
* elfxx-tilegx.c (readonly_dynrelocs): New function.
(maybe_set_textrel): New function, replacing old version of..
(readonly_dynrelocs): ..this.
ld/
* testsuite/ld-elf/shared.exp: Run new textrel tests.
* testsuite/ld-elf/textrel.map: New file.
* testsuite/ld-elf/textrel.rd: New file.
* testsuite/ld-elf/textrel.s: New file.
* testsuite/ld-elf/textrel.warn: New file.
No dynamic relocs are needed for TLS defined in an executable, the
TP relative offset is known at link time.
Fixes
FAIL: Build pr22263-1
bfd/
PR ld/22263
* elfnn-aarch64.c (elfNN_aarch64_relocate_section): Use
bfd_link_executable instead of bfd_link_pic for TLS.
(elfNN_aarch64_allocate_dynrelocs): Likewise.
(aarch64_can_relax_tls): Likewise.
With static pie linking undefined weak symbols are forced to resolve locally
to 0, so no GOT setup is needed in elfNN_aarch64_finish_dynamic_symbol,
which previously failed for these symbols.
The failure caused the unhelpful error message:
"ld: final link failed: Nonrepresentable section on output"
bfd/
PR ld/22269
* elfnn-aarch64.c (elfNN_aarch64_finish_dynamic_symbol): Use
UNDEFWEAK_NO_DYNAMIC_RELOC to avoid dynamic GOT relocs.
(elfNN_aarch64_allocate_dynrelocs): Likewise.
This makes the elf_link_hash_entry weakdef field, currently used to
point from a weak symbol to a strong alias, a circular list so that
all aliases can be found from any of them. A new flag, is_weakalias,
distinguishes the weak symbol from a strong alias, and is used in all
places where we currently test u.weakdef != NULL.
With the original u.weakdef handling it was possible to have two or
more weak symbols pointing via u.weakdef to a strong definition.
Obviously that situation can't map to a circular list; One or more of
the weak symbols must point at another weak alias rather than the
strong definition. To handle that, I've added an accessor function to
return the strong definition.
* elf-bfd.h (struct elf_link_hash_entry): Add is_weakalias.
Rename u.weakdef to u.alias and update comment.
(weakdef): New static inline function.
* elflink.c (bfd_elf_record_link_assignment) Test is_weakalias
rather than u.weakdef != NULL, and use weakdef function.
(_bfd_elf_adjust_dynamic_symbol): Likewise.
(_bfd_elf_fix_symbol_flags): Likewise. Clear is_weakalias on
all aliases if def has been overridden in a regular object, not
u.weakdef.
(elf_link_add_object_symbols): Delete new_weakdef flag. Test
is_weakalias and use weakdef. Set is_weakalias and circular
u.alias. Update comments.
(_bfd_elf_gc_mark_rsec): Test is_weakalias rather than
u.weakdef != NULL and use weakdef function.
* elf-m10300.c (_bfd_mn10300_elf_adjust_dynamic_symbol): Test
is_weakalias rather than u.weakdef != NULL and use weakdef
function. Assert that def is strong defined.
* elf32-arc.c (elf_arc_adjust_dynamic_symbol): Likewise.
* elf32-arm.c (elf32_arm_adjust_dynamic_symbol): Likewise.
* elf32-bfin.c (elf32_bfinfdpic_adjust_dynamic_symbol): Likewise.
(bfin_adjust_dynamic_symbol): Likewise.
* elf32-cr16.c (_bfd_cr16_elf_adjust_dynamic_symbol): Likewise.
* elf32-cris.c (elf_cris_adjust_dynamic_symbol): Likewise.
* elf32-frv.c (elf32_frvfdpic_adjust_dynamic_symbol): Likewise.
* elf32-hppa.c (elf32_hppa_adjust_dynamic_symbol): Likewise.
* elf32-i370.c (i370_elf_adjust_dynamic_symbol): Likewise.
* elf32-lm32.c (lm32_elf_adjust_dynamic_symbol): Likewise.
* elf32-m32r.c (m32r_elf_adjust_dynamic_symbol): Likewise.
* elf32-m68k.c (elf_m68k_adjust_dynamic_symbol): Likewise.
* elf32-metag.c (elf_metag_adjust_dynamic_symbol): Likewise.
* elf32-microblaze.c (microblaze_elf_adjust_dynamic_symbol): Likewise.
* elf32-nds32.c (nds32_elf_adjust_dynamic_symbol): Likewise.
* elf32-nios2.c (nios2_elf32_adjust_dynamic_symbol): Likewise.
* elf32-or1k.c (or1k_elf_adjust_dynamic_symbol): Likewise.
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Likewise.
* elf32-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
* elf32-score.c (s3_bfd_score_elf_adjust_dynamic_symbol): Likewise.
* elf32-score7.c (s7_bfd_score_elf_adjust_dynamic_symbol): Likewise.
* elf32-sh.c (sh_elf_adjust_dynamic_symbol): Likewise.
* elf32-tic6x.c (elf32_tic6x_adjust_dynamic_symbol): Likewise.
* elf32-tilepro.c (tilepro_elf_gc_mark_hook): Likewise.
(tilepro_elf_adjust_dynamic_symbol): Likewise.
* elf32-vax.c (elf_vax_adjust_dynamic_symbol): Likewise.
* elf32-xtensa.c (elf_xtensa_adjust_dynamic_symbol): Likewise.
* elf64-alpha.c (elf64_alpha_adjust_dynamic_symbol): Likewise.
* elf64-hppa.c (elf64_hppa_adjust_dynamic_symbol): Likewise.
* elf64-ia64-vms.c (elf64_ia64_adjust_dynamic_symbol): Likewise.
* elf64-ppc.c (ppc64_elf_gc_mark_hook): Likewise.
(ppc64_elf_adjust_dynamic_symbol): Likewise.
* elf64-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
* elf64-sh64.c (sh64_elf64_adjust_dynamic_symbol): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_adjust_dynamic_symbol): Likewise.
* elfnn-ia64.c (elfNN_ia64_adjust_dynamic_symbol): Likewise.
* elfnn-riscv.c (riscv_elf_adjust_dynamic_symbol): Likewise.
* elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol): Likewise.
* elfxx-sparc.c (_bfd_sparc_elf_gc_mark_hook): Likewise.
(_bfd_sparc_elf_adjust_dynamic_symbol): Likewise.
* elfxx-tilegx.c (tilegx_elf_gc_mark_hook): Likewise.
(tilegx_elf_adjust_dynamic_symbol): Likewise.
* elfxx-x86.c (_bfd_x86_elf_adjust_dynamic_symbol): Likewise.
Don't generate dynamic relocation against weak undefined symbol if it
is resolved to zero. FIXME: UNDEFWEAK_NO_DYNAMIC_RELOC may need to be
checked in more places.
PR ld/22269
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Don't
generate dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is
true.
(elfNN_aarch64_allocate_dynrelocs): Discard dynamic relocations
if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
* reloc.c (enum bfd_reloc_status): Start values at 2.
* bfd-in2.h: Regenerate.
* elfnn-aarch64.c (aarch64_relocate): Invert sense of function, so
that a TRUE return indicates success. Compare the result of
calling _bfd_aarch64_elf_put_addend against bfd_reloc_ok.
(build_one_stub): Change sense of tests against aarch64_relocate
return value.
(elfNN_aarch64_tls_relax): Return bfd_reloc_notsupported, rather
than FALSE, when an error is detected.
(elfNN_aarch64_final_link_relocate): Likewise.
* testsuite/ld-aarch64/pcrel_pic_defined.d: Expect errors not
warnings. Expect errors about unsupported relocations.
* testsuite/ld-aarch64/pcrel_pic_undefined.d: Likewise.
Skip IFUNC relocations in debug sections ignored by ld.so.
Fixes the following ld test failures on aarch64:
FAIL: Build libpr18808.so
FAIL: Build libpr18808.so_2
FAIL: Run pr18808
aborting at bfd/elfnn-aarch64.c:4986 in elf64_aarch64_final_link_relocate.
bfd/
PR ld/18808
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Skip IFUNC
relocations in debug sections, change abort to _bfd_error_handler.
In order to get the ifunc relocs properly sorted the correct class
needs to be returned. The code mimics what has been done for x86.
Fixes
FAIL: Run pr18841 with libpr18841c.so
bfd/
PR ld/18841
* elfnn-aarch64.c (elfNN_aarch64_reloc_type_class): Return
reloc_class_ifunc for ifunc symbols.
The outer caller elf_link_output_extsym in elflink.c is a traverse function on
all external symbol, and it will only call *finish_dynamic_symbol if some
conditions is meet. It is executed conditionally.
If the condition to trigger that assertion is satisified, it then won't satify
the outer check in finish_dynamic_symbol, so *finish_dynamic_symbol won't be
called that the assertion is expected to be dead code.
If elf_link_output_extsym is a traverse function that unconditionally called
on external symbols decided to be exported, then an assertion to make sure these
symbols are in sane status might make sense.
bfd/
* elfnn-aarch64.c (elfNN_aarch64_finish_dynamic_symbol): Remove the
sanity check at the head of this function.
This fix is an adaption of the x86-64 PR ld/21402 fix to AArch64.
After the generic code deciding one symbol is not dynamic, AArch64 backend
only overrides the decision on undefined weak symbols.
bfd/
PR ld/21402
* elfnn-aarch64.c (elfNN_aarch64_allocate_dynrelocs): Only make
undefined weak symbols into dynamic.
(elfNN_aarch64_final_link_relocate): Generate runtime RELATIVE
relocation for non-dynamic symbols.
(elfNN_aarch64_finish_dynamic_symbol): Add sanity check.
There are quite a few duplicated code supporting several GP based
relocation types. They are:
BFD_RELOC_AARCH64_LD64_GOTOFF_LO15
BFD_RELOC_AARCH64_MOVW_GOTOFF_G0_NC
BFD_RELOC_AARCH64_MOVW_GOTOFF_G1
These relocation types are supposed to be used for large memory model PIC/pic
mode under which we will have an initialized GP register points to the base of
GOT table, then these relocations are supposed to put the distance between GOT
entry and GOT table base address into the related instructions.
So, the parameters required to calculate the relocation should be the same as
BFD_RELOC_AARCH64_LD64_GOTPAGE_LO15 etc, all of them are require the GOT entry
address and GOT table base address to perform the relocation.
This patch has removed those duplicated code when handling above listed
relocation types, grouped them with others as relocation types that are
require GOT table base address during performing relocation, reused the
existed GOT handling code.
The relocation calculation for these types before and after this patch should be
identical.
bfd/
* elfnn-aarch64.c (aarch64_relocation_aginst_gp_p): New function.
(elfNN_aarch64_final_link_relocate): Delete duplicated code for
BFD_RELOC_AARCH64_LD64_GOTOFF_LO15, BFD_RELOC_AARCH64_MOVW_GOTOFF_G0_NC,
BFD_RELOC_AARCH64_MOVW_GOTOFF_G1.
* elfxx-aarch64.c (_bfd_aarch64_elf_resolve_relocation): Optimize the
support for them.
For some pc-relative relocations we want to allow them under PIC mode while
a normal global symbol defined in the same dynamic object can still bind
externally through copy relocation. So, we should not allow pc-relative
relocation against such symbol.
SYMBOL_REFERENCES_LOCAL should be used and is more accurate than the original
individual checks.
bfd/
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Use
SYMBOL_REFERENCES_LOCAL.
ld/
* testsuite/ld-aarch64/aarch64-elf.exp: Update test name
* testsuite/ld-aarch64/pcrel.s: Add new testcases.
* testsuite/ld-aarch64/pcrel_pic_undefined.d: Update the expected
warnings.
* testsuite/ld-aarch64/pcrel_pic_defined_local.d: Rename ...
* testsuite/ld-aarch64/pcrel_pic_defined.d: ... to this.
Update expected warnings.
As discussed at the PR, this patch tries to avoid COPY relocation generation
and propagate the original relocation into runtime if it was relocating on
writable section. The ELIMINATE_COPY_RELOCS has been set to true and it's
underlying infrastructure has been improved so that the COPY reloc elimination
at least working on absoluate relocations (ABS64) on AArch64.
BFD linker copy relocation elimination framwork requires the backend to always
allocate dynrelocs for all those relocation types that are possible to introduce
copy relocations. This is for adjust_dynamic_symbol hook to be able to get all
symbol reference information. Should one symbol is referenced by more than one
relocations, if there is any of them needs copy relocation then linker should
generate it.
bfd/
PR ld/21532
* elfnn-aarch64.c (ELIMINATE_COPY_RELOCS): Set to 1.
(elfNN_aarch64_final_link_relocate): Also propagate relocations to
runtime for if there needs copy relocation elimination.
(need_copy_relocation_p): New function. Return true for symbol with
pc-relative references and if it's against read-only sections.
(elfNN_aarch64_adjust_dynamic_symbol): Use need_copy_relocation_p.
(elfNN_aarch64_check_relocs): Allocate dynrelocs for relocation types
that are related with accessing external objects.
(elfNN_aarch64_gc_sweep_hook): Sync the relocation types with the change
in elfNN_aarch64_check_relocs.
ld/
* testsuite/ld-aarch64/copy-reloc-exe-2.s: New test source file.
* testsuite/ld-aarch64/copy-reloc-2.d: New test.
* testsuite/ld-aarch64/copy-reloc-exe-eliminate.s: New test source file.
* testsuite/ld-aarch64/copy-reloc-eliminate.d: New test.
* testsuite/ld-aarch64/copy-reloc-so.s: Define new global objects.
* testsuite/ld-aarch64/aarch64-elf.exp: Run new tests.
This reverts commit bc327528fd.
This patch can only be committed after PC-relative relocation types
support on copy relocation elimination is also completed.
As discussed at the PR, this patch tries to avoid COPY relocation generation
and propagate the original relocation into runtime if it was relocating on
writable section. The ELIMINATE_COPY_RELOCS has been set to true and it's
underlying infrastructure has been improved so that the COPY reloc elimination
at least working on absoluate relocations (ABS64) after this patch.
bfd/
PR ld/21532
* elfnn-aarch64.c (ELIMINATE_COPY_RELOCS): Set to 1.
(elfNN_aarch64_final_link_relocate): Also propagate relocations to
runtime for copy relocation elimination cases.
(alias_readonly_dynrelocs): New function.
(elfNN_aarch64_adjust_dynamic_symbol): Keep the dynamic relocs instead
of generating copy relocation if it is not against read-only sections.
(elfNN_aarch64_check_relocs): Likewise.
ld/
* testsuite/ld-aarch64/copy-reloc-eliminate.d: New test.
* testsuite/ld-aarch64/copy-reloc-exe-eliminate.s: New test source file.
* testsuite/ld-aarch64/aarch64-elf.exp: Run new testcase.
Sudakshina Das
Alan Modra
Tamar Christina
Renlin Li
Rafeal Auler
Maciej W. Rozycki
Nick Clifton
Jim Wilson
H.J. Lu
Szabolcs Nagy
Yuri Chornovian
Jiong Wang