This is part of the patch series to add support for BTI and
PAC in AArch64 linker.
1) This patch adds a new ld command line option: --force-bti.
In the presence of this option, the linker enables BTI with the
GNU_PROPERTY_AARCH64_FEATURE_1_BTI feature. This gives out warning
in case of missing gnu notes for BTI in inputs.
2) It also defines a new set of BTI enabled PLTs. These are used either
when all the inputs are marked with GNU_PROPERTY_AARCH64_FEATURE_1_BTI
or when the new --force-bti option is used. This required adding new
fields in elf_aarch64_link_hash_table so that we could make the PLT
related information more generic.
3) It also defines a dynamic tag DT_AARCH64_BTI_PLT. The linker uses
this whenever it picks BTI enabled PLTs.
All these are made according to the new AArch64 ELF ABI
https://developer.arm.com/docs/ihi0056/latest/elf-for-the-arm-64-bit-architecture-aarch64-abi-2018q4
*** bfd/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* bfd-in.h (aarch64_plt_type, aarch64_enable_bti_type): New.
(aarch64_bti_pac_info): New.
(bfd_elf64_aarch64_set_options): Add aarch64_bti_pac_info argument.
(bfd_elf32_aarch64_set_options): Likewise.
* bfd-in2.h: Regenerate
* elfnn-aarch64.c (PLT_BTI_ENTRY_SIZE): New.
(PLT_BTI_SMALL_ENTRY_SIZE, PLT_BTI_TLSDESC_ENTRY_SIZE): New.
(elfNN_aarch64_small_plt0_bti_entry): New.
(elfNN_aarch64_small_plt_bti_entry): New.
(elfNN_aarch64_tlsdesc_small_plt_bti_entry): New.
(elf_aarch64_obj_tdata): Add no_bti_warn and plt_type fields.
(elf_aarch64_link_hash_table): Add plt0_entry, plt_entry and
tlsdesc_plt_entry_size fields.
(elfNN_aarch64_link_hash_table_create): Initialise the new fields.
(setup_plt_values): New helper function.
(bfd_elfNN_aarch64_set_options): Use new bp_info to set plt sizes and
bti enable type.
(elfNN_aarch64_allocate_dynrelocs): Use new size members instead of
fixed macros.
(elfNN_aarch64_size_dynamic_sections): Likewise and add checks.
(elfNN_aarch64_create_small_pltn_entry): Use new generic pointers
to plt stubs instead of fixed ones and update filling them according
to the need for bti.
(elfNN_aarch64_init_small_plt0_entry): Likewise.
(elfNN_aarch64_finish_dynamic_sections): Likewise.
(get_plt_type, elfNN_aarch64_get_synthetic_symtab): New.
(elfNN_aarch64_plt_sym_val): Update size accordingly.
(elfNN_aarch64_link_setup_gnu_properties): Set up plts if BTI GNU NOTE
is set.
(bfd_elfNN_get_synthetic_symtab): Define.
(elfNN_aarch64_merge_gnu_properties): Give out warning with --force-bti
and mising BTI NOTE SECTION.
*** binutils/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* readelf.c (get_aarch64_dynamic_type): New.
(get_dynamic_type): Use above for EM_AARCH64.
(dynamic_section_aarch64_val): New.
(process_dynamic_section): Use above for EM_AARCH64.
*** include/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* elf/aarch64.h (DT_AARCH64_BTI_PLT): New.
*** ld/ChangeLog ***
2019-03-13 Sudakshina Das <sudi.das@arm.com>
Szabolcs Nagy <szabolcs.nagy@arm.com>
* NEWS: Document --force-bti.
* emultempl/aarch64elf.em (plt_type, bti_type, OPTION_FORCE_BTI): New.
(PARSE_AND_LIST_SHORTOPTS, PARSE_AND_LIST_OPTIONS): Add force-bti.
(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_FORCE_BTI.
* testsuite/ld-aarch64/aarch64-elf.exp: Add all the tests below.
* testsuite/ld-aarch64/bti-plt-1.d: New test.
* testsuite/ld-aarch64/bti-plt-1.s: New test.
* testsuite/ld-aarch64/bti-plt-2.s: New test.
* testsuite/ld-aarch64/bti-plt-2.d: New test.
* testsuite/ld-aarch64/bti-plt-3.d: New test.
* testsuite/ld-aarch64/bti-plt-4.d: New test.
* testsuite/ld-aarch64/bti-plt-5.d: New test.
* testsuite/ld-aarch64/bti-plt-6.d: New test.
* testsuite/ld-aarch64/bti-plt-7.d: New test.
* testsuite/ld-aarch64/bti-plt-so.s: New test.
* testsuite/ld-aarch64/bti-plt.ld: New test.
Recent gcc commit b4371b277f1e ("[ARC] Enable init_array support")
inhibits DT_"INIT,FINI} in favor of DT_{INIT,FINI}ARRAY.
Even prior to that, it seems ARC port is the only one with this
special DT_INIT/FINI handling in linker emulation. Removing it
doesn't seem to change any uClibc/glibc testsuite results,
so this can RIP anyways.
bfd/
2019-02-01 Vineet Gupta <vgupta@synopsys.com>
* elf32-arc.c: Delete init_str, fini_str
ld/
2019-02-01 Vineet Gupta <vgupta@synopsys.com>
* emultempl/arclinux.em : Delete special INIT/FINI handling.
place_orphan handled ELF SHT_REL/SHT_RELA specially, output_rel_find
didn't. This mismatch was a bug and also meant it was possible to
craft an object where ld accessed section->name out of bounds.
PR 24042
* emultempl/elf32.em (output_rel_find): Drop "sec" param. Add
"rela".
(gld${EMULATION_NAME}_place_orphan): Use sh_type to calculate
"rela" param of output_rel_find when ELF. Tidy uses of elfinput.
We have not only removed all unsupported and obsolete code, but also supported lost of new features,
including better link-time relaxations and TLS implementations. Besides, the files generated by the
newly assembler and linker usually get higher performance and more optimized code size.
ld * emultempl/nds32elf.em (hyper_relax): New variable.
(nds32_elf_create_output_section_statements):
the parameters of bfd_elf32_nds32_set_target_option
(PARSE_AND_LIST_PROLOGUE, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Add new option --mhyper-relax.
* emultempl/nds32elf.em (nds32_elf_after_open): Updated.
* emultempl/nds32elf.em (tls_desc_trampoline): New variable.
* (nds32_elf_create_output_section_statements): Updated.
* (nds32_elf_after_parse): Disable relaxations when PIC is enable.
* (PARSE_AND_LIST_PROLOGUE, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Add new option --m[no-]tlsdesc-trampoline.
include * elf/nds32.h: Remove the unused target features.
* dis-asm.h (disassemble_init_nds32): Declared.
* elf/nds32.h (E_NDS32_NULL): Removed.
(E_NDS32_HAS_DSP_INST, E_NDS32_HAS_ZOL): New.
* opcode/nds32.h: Ident.
(N32_SUB6, INSN_LW): New macros.
(enum n32_opcodes): Updated.
* elf/nds32.h: Doc fixes.
* elf/nds32.h: Add R_NDS32_LSI.
* elf/nds32.h: Add new relocations for TLS.
gas * config/tc-nds32.c: Remove the unused target features.
(nds32_relax_relocs, md_pseudo_table, nds32_elf_record_fixup_exp,
nds32_set_elf_flags_by_insn, nds32_insert_relax_entry,
nds32_apply_fix): Likewise.
(nds32_no_ex9_begin): Removed.
* config/tc-nds32.c (add_mapping_symbol_for_align,
make_mapping_symbol, add_mapping_symbol): New functions.
* config/tc-nds32.h (enum mstate): New.
(nds32_segment_info_type): Likewise.
* configure.ac (--enable-dsp-ext, --enable-zol-ext): New options.
* config.in: Regenerated.
* configure: Regenerated.
* config/tc-nds32.c (nds32_dx_regs):
Set the value according to the configuration.
(nds32_perf_ext, nds32_perf_ext2, nds32_string_ext, nds32_audio_ext):
Likewise.
(nds32_dsp_ext): New variable. Set the value according to the
configuration.
(nds32_zol_ext): Likewise.
(asm_desc, nds32_pseudo_opcode_table): Make them static.
(nds32_set_elf_flags_by_insn): Updated.
(nds32_check_insn_available): Updated.
(nds32_str_tolower): New function.
* config/tc-nds32.c (relax_table): Updated.
(md_begin): Updated.
(md_assemble): Use XNEW macro to allocate space for `insn.info',
and then remember to free it.
(md_section_align): Cast (-1) to ValueT.
(nds32_get_align): Cast (~0U) to addressT.
(nds32_relax_branch_instructions): Updated.
(md_convert_frag): Add new local variable `final_r_type'.
(invalid_prev_frag): Add new bfd_boolean parameter `relax'.
All callers changed.
* config/tc-nds32.c (struct nds32_relocs_pattern): Add `insn' field.
(struct nds32_hint_map): Add `option_list' field.
(struct suffix_name, suffix_table): Remove the unused `pic' field.
(do_pseudo_b, do_pseudo_bal): Remove the suffix checking.
(do_pseudo_la_internal, do_pseudo_pushpopm): Indent.
(relax_hint_bias, relax_hint_id_current): New static variables.
(reset_bias, relax_hint_begin): New variables.
(nds_itoa): New function.
(CLEAN_REG, GET_OPCODE): New macros.
(struct relax_hint_id): New.
(nds32_relax_hint): For .relax_hint directive, we can use `begin'
and `end' to mark the relax pattern without giving exactly id number.
(nds32_elf_append_relax_relocs): Handle the case that the .relax_hint
directives are attached to pseudo instruction.
(nds32_elf_save_pseudo_pattern): Change the second parameter from
instruction's opcode to byte code.
(nds32_elf_build_relax_relation): Add new bfd_boolean parameter
`pseudo_hint'.
(nds32_lookup_pseudo_opcode): Fix the overflow issue.
(enum nds32_insn_type): Add N32_RELAX_ALU1 and N32_RELAX_16BIT.
(nds32_elf_record_fixup_exp, relax_ls_table, hint_map,
nds32_find_reloc_table, nds32_match_hint_insn, nds32_parse_name):
Updated.
* config/tc-nds32.h (MAX_RELAX_NUM): Extend it to 6.
(enum nds32_relax_hint_type): Merge NDS32_RELAX_HINT_LA and
NDS32_RELAX_HINT_LS into NDS32_RELAX_HINT_LALS. Add
NDS32_RELAX_HINT_LA_PLT, NDS32_RELAX_HINT_LA_GOT and
NDS32_RELAX_HINT_LA_GOTOFF.
* config/tc-nds32.h (relax_ls_table): Add floating load/store
to gp relax pattern.
(hint_map, nds32_find_reloc_table): Likewise.
* configure.ac: Define NDS32_LINUX_TOOLCHAIN.
* configure: Regenerated.
* config.in: Regenerated.
* config/tc-nds32.h (enum nds32_ramp): Updated.
(enum nds32_relax_hint_type): Likewise.
* config/tc-nds32.c: Include "errno.h" and "limits.h".
(relax_ls_table): Add TLS relax patterns.
(nds32_elf_append_relax_relocs): Attach BFD_RELOC_NDS32_GROUP on
each instructions of TLS patterns.
(nds32_elf_record_fixup_exp): Updated.
(nds32_apply_fix): Likewise.
(suffix_table): Add TLSDESC suffix.
binutils* testsuite/binutils-all/objcopy.exp: Set the unsupported reloc number
from 215 to 255 for NDS32.
bfd * elf32-nds32.c (nds32_elf_relax_loadstore):
Remove the unused target features.
(bfd_elf32_nds32_set_target_option): Remove the unused parameters.
(nds32_elf_relax_piclo12, nds32_elf_relax_letlslo12,
nds32_elf_relax_letlsadd, nds32_elf_relax_letlsls,
nds32_elf_relax_pltgot_suff, nds32_elf_relax_got_suff
nds32_elf_relax_gotoff_suff, calculate_plt_memory_address,
calculate_plt_offset, calculate_got_memory_address,
nds32_elf_check_dup_relocs): Removed.
All callers changed.
* elf32-nds32.h: Remove the unused macros and defines.
(elf_nds32_link_hash_table): Remove the unused variable.
(bfd_elf32_nds32_set_target_option): Update prototype.
(nds32_elf_ex9_init): Removed.
* elf32-nds32.c (nds32_convert_32_to_16): Updated.
* elf32-nds32.c (HOWTO2, HOWTO3): Define new HOWTO macros
to initialize array nds32_elf_howto_table in any order
without lots of EMPTY_HOWTO.
(nds32_reloc_map): Updated.
* reloc.c: Add BFD_RELOC_NDS32_LSI.
* bfd-in2.h: Regenerated.
* bfd/libbfd.h: Regenerated.
* elf32-nds32.c (nds32_elf_relax_howto_table): Add R_NDS32_LSI.
(nds32_reloc_map): Likewise.
(nds32_elf_relax_flsi): New function.
(nds32_elf_relax_section): Support floating load/store relaxation.
* elf32-nds32.c (NDS32_GUARD_SEC_P, elf32_nds32_local_gp_offset):
New macro.
(struct elf_nds32_link_hash_entry): New `offset_to_gp' field.
(struct elf_nds32_obj_tdata): New `offset_to_gp' and `hdr_size' fields.
(elf32_nds32_allocate_local_sym_info, nds32_elf_relax_guard,
nds32_elf_is_target_special_symbol, nds32_elf_maybe_function_sym):
New functions.
(nds32_info_to_howto_rel): Add BFD_ASSERT.
(bfd_elf32_bfd_reloc_type_table_lookup, nds32_elf_link_hash_newfunc,
nds32_elf_link_hash_table_create, nds32_elf_relocate_section,
nds32_elf_relax_loadstore, nds32_elf_relax_lo12, nds32_relax_adjust_label,
bfd_elf32_nds32_set_target_option, nds32_fag_mark_relax): Updated.
(nds32_elf_final_sda_base): Improve it to find the better gp value.
(insert_nds32_elf_blank): Must consider `len' when inserting blanks.
* elf32-nds32.h (bfd_elf32_nds32_set_target_option): Update prototype.
(struct elf_nds32_link_hash_table): Add new variable `hyper_relax'.
* elf32-nds32.c (elf32_nds32_allocate_dynrelocs): New function.
(create_got_section): Likewise.
(allocate_dynrelocs, nds32_elf_size_dynamic_sections,
nds32_elf_relocate_section, nds32_elf_finish_dynamic_symbol): Updated.
(nds32_elf_check_relocs): Fix the issue that the shared library may
has TEXTREL entry in the dynamic section.
(nds32_elf_create_dynamic_sections): Enable to call readonly_dynrelocs
since the TEXTREL issue is fixed in the nds32_elf_check_relocs.
(nds32_elf_finish_dynamic_sections): Update and add DT_RELASZ
dynamic entry.
(calculate_offset): Remove the unused parameter `pic_ext_target' and
related codes.
All callers changed.
(elf_backend_dtrel_excludes_plt): Disable it temporarily since it
will cause some errors for our test cases.
* elf32-nds32.c (nds32_elf_merge_private_bfd_data): Allow to link the
generic object.
* reloc.c: Add TLS relocations.
* libbfd.h: Regenerated.
* bfd-in2.h: Regenerated.
* elf32-nds32.h (struct section_id_list_t): New.
(elf32_nds32_lookup_section_id, elf32_nds32_check_relax_group,
elf32_nds32_unify_relax_group, nds32_elf_unify_tls_model):
New prototypes.
(elf32_nds32_compute_jump_table_size, elf32_nds32_local_tlsdesc_gotent):
New macro.
(nds32_insertion_sort, bfd_elf32_nds32_set_target_option,
elf_nds32_link_hash_table): Updated.
* elf32-nds32.c (enum elf_nds32_tls_type): New.
(struct elf32_nds32_relax_group_t, struct relax_group_list_t): New.
(elf32_nds32_add_dynreloc, patch_tls_desc_to_ie, get_tls_type,
fls, ones32, list_insert, list_insert_sibling, dump_chain,
elf32_nds32_check_relax_group, elf32_nds32_lookup_section_id,
elf32_nds32_unify_relax_group, nds32_elf_unify_tls_model): New functions.
(elf_nds32_obj_tdata): Add new fields.
(elf32_nds32_relax_group_ptr, nds32_elf_local_tlsdesc_gotent): New macros.
(nds32_elf_howto_table): Add TLS relocations.
(nds32_reloc_map): Likewise.
(nds32_elf_copy_indirect_symbol, nds32_elf_size_dynamic_sections,
nds32_elf_finish_dynamic_symbol, elf32_nds32_allocate_local_sym_info,
nds32_elf_relocate_section, bfd_elf32_nds32_set_target_option,
nds32_elf_check_relocs, allocate_dynrelocs): Updated.
(nds32_elf_relax_section): Call nds32_elf_unify_tls_model.
(dtpoff_base): Rename it to `gottpof' and then update it.
opcodes * nds32-asm.c (operand_fields): Remove the unused fields.
(nds32_opcodes): Remove the unused instructions.
* nds32-dis.c (nds32_ex9_info): Removed.
(nds32_parse_opcode): Updated.
(print_insn_nds32): Likewise.
* nds32-asm.c (config.h, stdlib.h, string.h): New includes.
(LEX_SET_FIELD, LEX_GET_FIELD): Update defines.
(nds32_asm_init, build_operand_hash_table, build_keyword_hash_table,
build_opcode_hash_table): New functions.
(nds32_keyword_table, nds32_keyword_count_table, nds32_field_table,
nds32_opcode_table): New.
(hw_ktabs): Declare it to a pointer rather than an array.
(build_hash_table): Removed.
* nds32-asm.h (enum): Add SYN_INPUT, SYN_OUTPUT, SYN_LOPT,
SYN_ROPT and upadte HW_GPR and HW_INT.
* nds32-dis.c (keywords): Remove const.
(match_field): New function.
(nds32_parse_opcode): Updated.
* disassemble.c (disassemble_init_for_target):
Add disassemble_init_nds32.
* nds32-dis.c (eum map_type): New.
(nds32_private_data): Likewise.
(get_mapping_symbol_type, is_mapping_symbol, nds32_symbol_is_valid,
nds32_add_opcode_hash_table, disassemble_init_nds32): New functions.
(print_insn_nds32): Updated.
* nds32-asm.c (parse_aext_reg): Add new parameter.
(parse_re, parse_re2, parse_aext_reg): Only reduced registers
are allowed to use.
All callers changed.
* nds32-asm.c (keyword_usr, keyword_sr): Updated.
(operand_fields): Add new fields.
(nds32_opcodes): Add new instructions.
(keyword_aridxi_mx): New keyword.
* nds32-asm.h (enum): Add NASM_ATTR_DSP_ISAEXT, HW_AEXT_ARIDXI_MX
and NASM_ATTR_ZOL.
(ALU2_1, ALU2_2, ALU2_3): New macros.
* nds32-dis.c (nds32_filter_unknown_insn): Updated.
We have an issue in the MIPS backend, with the handling of undefined
hidden and internal weak symbols. References to such symbols are
supposed to resolve to 0 according to the ELF gABI[1]:
"Unresolved weak symbols have a zero value."
and the 64-bit MIPS psABI[2]:
"If a symbol with one of these [hidden or internal] attributes has no
definition within the executable/DSO being linked, then it must be
resolved to allocated space if common, resolved to zero if weak, or an
error reported otherwise."
however if a GOT relocation is used, then a local GOT entry is created
and used to satisfy the reference. Such an entry is then (in DSO and
PIE binaries) subject to the usual load-time relocation, which means a
non-zero value will be returned if the base address is non-zero. This
will defeat the usual run-time sequence like:
void a (void) __attribute__ ((visibility ("hidden"), weak));
void
x (void)
{
if (a)
a ();
}
This can be reproduced with this simple code:
$ cat libtest.c
extern int a __attribute__ ((visibility ("hidden"), weak));
int *
x (void)
{
return &a;
}
$ cat test.c
int *x (void);
int
main (void)
{
printf ("a: %p\n", x ());
return 0;
}
$ gcc -shared -fPIC -o libtest.so libtest.c
$ gcc -o test test.c -Wl,-rpath,$(pwd) libtest.so
$ ./test
a: 0x77184000
$
The usual approach targets take is making all the steps required to
assign a GOT entry for the symbol referred, and then leave its contents
at zero with no dynamic relocation attached, therefore ensuring that the
value does not change at load time. However this is not going to work
with the implicitly relocated GOT the MIPS psABI specifies[3]:
"The dynamic linker relocates the global offset table by first adding
the difference between the base where the shared object is loaded and
the value of the dynamic tag DT_MIPS_BASE_ADDRESS to all local global
offset table entries."
and we cannot therefore use the local GOT part.
And we cannot offhand use the global part either, as the symbol would
then have to be exported and possibly wrongly preempt symbols in other
modules involved in the dynamic load, because as per the ELF gABI[1] we
are not allowed to enter a hidden or internal symbol into the dynamic
symbol table (and then use its associated GOT entry):
"A hidden symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
and:
"An internal symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
So we have to choose something else.
Our choice is further limited by the need for the reference associated
with the GOT relocation to stay within the signed 16-bit limit from the
GOT pointer base register, while being compliant with the ELF gABI and
the MIPS psABI. However as Alan Modra has observed[4] one possibility
is to edit (relax) the code such that the GOT reference is removed
altogether.
Based on these observations then modify MIPS BFD linker backend code to:
1. Interpret code associated with GOT relocations and relax the usual LW
or LD instructions into a corresponding immediate load operation that
places the value of 0 in the intended register, while leaving the GOT
entry allocated and initialized as usually.
2. Leave any other instructions associated with GOT relocations in place
and instead redirect the reference to a global GOT entry associated
with a special `__gnu_absolute_zero' symbol created for this purpose,
whose value is 0, SHN_ABS section marks it absolute, binding is
global and export class protected, ensuring that the locally provided
value is always used at load time, and that the value is not
relocated by the dynamic loader.
3. Adjust any high-part GOT relocation used, typically associated with
a LUI instruction, accordingly, so that run-time consistency is
maintained, either by resolving to the original entry if the
instruction associated with the corresponding low-part GOT relocation
has been relaxed to an immediate load (in which case the value loaded
with LUI will be overwritten), or by also redirecting the reference
to `__gnu_absolute_zero' to complete the GOT access sequence if that
symbol has been used.
4. Add a target `elf_backend_hide_symbol' hook, for the three MIPS ABIs,
which prevents the `__gnu_absolute_zero' symbol from being forced
local, to ensure that the redirection works and the symbol remains
global/protected with existing linker scripts unchanged.
5. Observing the issue with handling SHN_ABS symbols in the GNU dynamic
loader, covered by glibc PR 19818, set the EI_ABIVERSION field in the
ELF file header produced to 4 (ABI_ABSOLUTE) if `__gnu_absolute_zero'
symbol has been produced and the target configured indicates the GNU
operating system, so that broken versions of the GNU dynamic loader
gracefully reject the file in loading rather than going astray. Keep
EI_ABIVERSION at the original value for other operating systems or if
no `__gnu_absolute_zero' symbol has been made.
The name of the special `__gnu_absolute_zero' has no meaning other than
how a human reader can interpret it, as it is ignored in dynamic loading
in the handling of the scenarios concerned. This is because the symbol
resolves locally, and it's only the symbol's attributes that matter so
that the associated GOT entry remains unchanged at load time.
Therefore the name is somewhat arbitrary, observing however the need to
use the name space reserved for the system so that it does not conflict
with a possible user symbol, and hence the leading underscore, and also
the `gnu' infix to denote a GNU feature. Other implementations wishing
to address the problem in a similar way may choose a different name and
have the solution still work, possibly with a mixture of modules used in
a dynamic having symbols of different names provided, which will however
not interact with each other due to the protected export class.
The symbol can be referred explicitly, however the name is an internal
implementation detail rather than a part of the ABI, and therefore no
specific semantics is guaranteed.
One limitation of this change is that if `__gnu_absolute_zero' has been
already defined, then we do not wipe the old definition and all kinds of
odd behavior can result. This is however like with other symbols we
internally define, such as `_GLOBAL_OFFSET_TABLE_' or `__rld_map', and
therefore left as a possible future enhancement.
As an optimization the relaxation of LW and LD instructions to a load of
immediate zero is always made, even SVR4 PIC code for code that will end
up in a regular (non-PIE) executable, because there is a cache advantage
with the avoidance of a load from the GOT, even if it is otherwise
guaranteed to remain zero. It does not reliably happen though, due to a
symbol exportation issue affecting executables, covered by PR ld/21805.
One existing test case needs to be updated, as it triggers relaxation
introduced with this change and consequently linker output does not
match expectations anymore. As we want to keep the original issue
covered with the test case modify it then to use the LWL instruction in
place of LW, and adjust the output expected accordingly.
References:
[1] "System V Application Binary Interface - DRAFT - 19 October 2010",
The SCO Group, Section "Symbol Table",
<http://www.sco.com/developers/gabi/2012-12-31/ch4.symtab.html>
[2] "64-bit ELF Object File Specification, Draft Version 2.5", MIPS
Technologies / Silicon Graphics Computer Systems, Order Number
007-4658-001, Section 2.5 "Symbol Table", p. 22,
<http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf>
[3] "SYSTEM V APPLICATION BINARY INTERFACE, MIPS RISC Processor
Supplement, 3rd Edition", Section "Global Offset Table", p. 5-10,
<http://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf>
[4] "Undo dynamic symbol state after regular object sym type mismatch",
<https://sourceware.org/ml/binutils/2017-07/msg00265.html>
bfd/
PR ld/21375
* elfxx-mips.h (_bfd_mips_elf_hide_symbol): New prototype.
(_bfd_mips_elf_linker_flags): Update prototype.
* elf32-mips.c (elf_backend_hide_symbol): New macro.
* elf64-mips.c (elf_backend_hide_symbol): Likewise.
* elfn32-mips.c (elf_backend_hide_symbol): Likewise.
* elfxx-mips.c (mips_elf_link_hash_table): Add
`use_absolute_zero' and `gnu_target' members.
(mips_elf_record_global_got_symbol): Call
`_bfd_mips_elf_hide_symbol' rather than
`_bfd_elf_link_hash_hide_symbol'.
(mips_use_local_got_p): Return FALSE if the symbol is absolute.
(mips_elf_obtain_contents): Reorder function.
(mips_elf_nullify_got_load): New function.
(mips_elf_calculate_relocation): Add `contents' parameter.
Nullify GOT loads or if it is not possible, then redirect GOT
relocations to the `__gnu_absolute_zero' symbol, for references
that are supposed to resolve to zero.
(mips_elf_define_absolute_zero): New function.
(_bfd_mips_elf_check_relocs): Prepare for arrangements made in
`mips_elf_calculate_relocation' for references made via the GOT
that are supposed to resolve to zero.
(_bfd_mips_elf_hide_symbol): New function.
(_bfd_mips_elf_linker_flags): Add the `gnu_target' parameter,
set the `gnu_target' member of the MIPS hash table.
(MIPS_LIBC_ABI_ABSOLUTE): New enumeration constant.
(_bfd_mips_post_process_headers): Use it.
ld/
PR ld/21375
* emultempl/mipself.em: Set `gnu_target' according to ${target}.
(mips_create_output_section_statements): Update call to
`_bfd_mips_elf_linker_flags'.
* testsuite/ld-mips-elf/pr21334.s: Use LWL rather than LW.
* testsuite/ld-mips-elf/pr21334.dd: Update accordingly.
git commit 702d16713 broke expressions using CONSTANT(COMMONPAGESIZE)
in ALIGN or SUBALIGN of output section statements, because these
optional fields were evaluated at script parse time and the patch in
question delayed setting of config.commonpagesize. The right thing to
do is keep the tree representation of those fields for later
evaluation.
PR 23571
* ldlang.h (section_alignment): Make it an expression tree.
(subsection_alignment): Likewise.
* ldlang.c (topower): Delete.
(output_section_statement_newfunc): Adjust initialization.
(init_os): Evaluate section_alignment.
(lang_size_sections_1): Likewise.
(size_input_section): Evaluate subsection_alignment.
(lang_enter_output_section_statement): Don't evaluate here.
(lang_new_phdr): Use exp_get_vma rather than exp_get_value_int.
* ldexp.h (exp_get_value_int): Delete.
(exp_get_power): Declare.
* ldexp.c (exp_get_value_int): Delete.
(exp_get_power): New function.
* emultempl/pe.em (place_orphan): Build expression for section
alignment.
* emultempl/pep.em (place_orphan): Likewise.
* testsuite/ld-scripts/pr23571.d,
* testsuite/ld-scripts/pr23571.t: New test.
* testsuite/ld-scripts/align.exp: Run it.
We force __ehdr_start to defined in before_allocation, then restore
the type and a union after dynamic symbols have been allocated.
The union contains a number of structs, all starting with a "next"
pointer, and various fields depending on the symbol type. The old
code restored the entire union, but it isn't necessary to restore the
"next" pointer, and in fact it could be wrong if __ehdr_start happened
to be last on the list and some symbols were added before restoring.
* emultempl/elf32.em (before_allocation): Don't restore
__ehdr_start u.*.next pointer.
This patch series is a new binutils port for C-SKY processors, including support for both the V1 and V2 processor variants. V1 is derived from the MCore architecture while V2 is substantially different, with mixed 16- and 32-bit instructions, a larger register set, a different (but overlapping) ABI, etc. There is support for bare-metal ELF targets and Linux with both glibc and uClibc.
This code is being contributed jointly by C-SKY Microsystems and Mentor Graphics. C-SKY is responsible for the technical content and has proposed Lifang Xia and Yunhai Shang as port maintainers. (Note that C-SKY does have a corporate copyright assignment on file with the FSF.) Mentor Graphics' role has been cleaning up the code, adding documentation and additional test cases, etc, to address issues we anticipated reviewers would complain about.
bfd * Makefile.am (ALL_MACHINES, ALL_MACHINES_CFILES): Add C-SKY.
(BFD32_BACKENDS, BFD_BACKENDS_CFILES): Likewise.
* Makefile.in: Regenerated.
* archures.c (enum bfd_architecture): Add bfd_arch_csky and
related bfd_mach defines.
(bfd_csky_arch): Declare.
(bfd_archures_list): Add C-SKY.
* bfd-in.h (elf32_csky_build_stubs): Declare.
(elf32_csky_size_stubs): Declare.
(elf32_csky_next_input_section: Declare.
(elf32_csky_setup_section_lists): Declare.
* bfd-in2.h: Regenerated.
* config.bfd: Add C-SKY.
* configure.ac: Likewise.
* configure: Regenerated.
* cpu-csky.c: New file.
* elf-bfd.h (enum elf_target_id): Add C-SKY.
* elf32-csky.c: New file.
* libbfd.h: Regenerated.
* reloc.c: Add C-SKY relocations.
* targets.c (csky_elf32_be_vec, csky_elf32_le_vec): Declare.
(_bfd_target_vector): Add C-SKY target vector entries.
binutils* readelf.c: Include elf/csky.h.
(guess_is_rela): Handle EM_CSKY.
(dump_relocations): Likewise.
(get_machine_name): Likewise.
(is_32bit_abs_reloc): Likewise.
include * dis-asm.h (csky_symbol_is_valid): Declare.
* opcode/csky.h: New file.
opcodes * Makefile.am (TARGET_LIBOPCODES_CFILES): Add csky-dis.c.
* Makefile.in: Regenerated.
* configure.ac: Add C-SKY.
* configure: Regenerated.
* csky-dis.c: New file.
* csky-opc.h: New file.
* disassemble.c (ARCH_csky): Define.
(disassembler, disassemble_init_for_target): Add case for ARCH_csky.
* disassemble.h (print_insn_csky, csky_get_disassembler): Declare.
gas * Makefile.am (TARGET_CPU_CFILES): Add entry for C-SKY.
(TARGET_CPU_HFILES, TARGET_ENV_HFILES): Likewise.
* Makefile.in: Regenerated.
* config/tc-csky.c: New file.
* config/tc-csky.h: New file.
* config/te-csky_abiv1.h: New file.
* config/te-csky_abiv1_linux.h: New file.
* config/te-csky_abiv2.h: New file.
* config/te-csky_abiv2_linux.h: New file.
* configure.tgt: Add C-SKY.
* doc/Makefile.am (CPU_DOCS): Add entry for C-SKY.
* doc/Makefile.in: Regenerated.
* doc/all.texi: Set CSKY feature.
* doc/as.texi (Overview): Add C-SKY options.
(Machine Dependencies): Likewise.
* doc/c-csky.texi: New file.
* testsuite/gas/csky/*: New test cases.
ld * Makefile.am (ALL_EMULATION_SOURCES): Add C-SKY emulations.
(ecskyelf.c, ecskyelf_linux.c): New rules.
* Makefile.in: Regenerated.
* configure.tgt: Add C-SKY.
* emulparams/cskyelf.sh: New file.
* emulparams/cskyelf_linux.sh: New file.
* emultempl/cskyelf.em: New file.
* gen-doc.texi: Add C-SKY.
* ld.texi: Likewise.
(Options specific to C-SKY targets): New section.
* testsuite/ld-csky/*: New tests.
With this patch dedicated linker scripts can be generated for partial
relro triggered by defining GENERATE_RELRO_SCRIPT in the target
specific scripts.
This is necessary for e.g. S/390 where usually the .got.plt comes
first and prevents the relro segment from being extended across the
non-plt GOT entries.
The patch started with the work from Marcin taken from the mwk user
branches. However, the patch needed substantial changes due to the
'separate code' feature which got committed in the meantime.
ld/ChangeLog:
2018-07-18 Andreas Krebbel <krebbel@linux.ibm.com>
Marcin Kościelnicki <koriakin@0x04.net>
* emultempl/elf32.em: Add code to pick dedicated linker scripts
for partial relro.
* genscripts.sh: Generate dedicated linker scripts for partial relro.
In case params.thumb_entry_symbol has its default NULL value, using it
to print a warning in gld${EMULATION_NAME}_finish results in a crash.
Use h->root.string instead which either points to
params.thumb_entry_symbol name or to entry_symbol name.
2018-07-09 Christophe Lyon <christophe.lyon@linaro.org>
* emultempl/armelf.em (gld${EMULATION_NAME}_finish): Use the right
symbol name in case of warning.
Change-Id: Iec61a833c0ad538b1440bf326ba67834c314dd63
This patch adds the analysis part of PLT call optimization, enabling
the code added with the previous patch that actually performs the
optimization.
Gold support is not available yet.
bfd/
* elf64-ppc.c (struct _ppc64_elf_section_data): Add has_pltcall field.
(struct ppc_link_hash_table): Add can_convert_all_inline_plt.
(ppc64_elf_check_relocs): Set has_pltcall.
(ppc64_elf_adjust_dynamic_symbol): Discard some PLT entries.
(ppc64_elf_inline_plt): New function.
(ppc64_elf_size_dynamic_sections): Discard some PLT entries for locals.
* elf64-ppc.h (ppc64_elf_inline_plt): Declare.
* elf32-ppc.c (has_pltcall): Define.
(struct ppc_elf_link_hash_table): Add can_convert_all_inline_plt.
(ppc_elf_check_relocs): Set has_pltcall.
(ppc_elf_inline_plt): New function.
(ppc_elf_adjust_dynamic_symbol): Discard some PLT entries.
(ppc_elf_size_dynamic_sections): Likewise.
* elf32-ppc.h (ppc_elf_inline_plt): Declare.
ld/
* emultempl/ppc64elf.em (no_inline_plt): New var.
(ppc_before_allocation): Call ppc64_elf_inline_plt.
(enum ppc64_opt): Add OPTION_NO_INLINE_OPT.
(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Handle --no-inline-optimize.
* emultemps/ppc32elf.em (no_inline_opt): New var.
(prelim_size_sections): New function, extracted from..
(ppc_before_allocation): ..here. Call ppc_elf_inline_plt.
(enum ppc32_opt): Add OPTION_NO_INLINE_OPT.
(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS,
PARSE_AND_LIST_ARGS_CASES): Handle --no-inline-optimize.
The current scheme where we output PLT relocs for global symbols in
finish_dynamic_symbol, and PLT relocs for local symbols when
outputting stubs does not work if PLT entries are to be used for
inline PLT sequences against non-dynamic globals or local symbols.
bfd/
* elf64-ppc.c (ppc_build_one_stub): Move output of PLT relocs
for local symbols to..
(write_plt_relocs_for_local_syms): ..here. New function.
(ppc64_elf_finish_dynamic_symbol): Move output of PLT relocs for
global symbols to..
(build_global_entry_stubs_and_plt): ..here. Rename from
build_global_entry_stubs.
(ppc64_elf_build_stubs): Always call build_global_entry_stubs_and_plt.
Call write_plt_relocs_for_local_syms.
* elf32-ppc.c (get_sym_h): New function.
(ppc_elf_relax_section): Use get_sym_h.
(ppc_elf_relocate_section): Move output of PLT relocs and glink
stubs for local symbols to..
(ppc_finish_symbols): ..here. New function.
(ppc_elf_finish_dynamic_symbol): Move output of PLT relocs for
global syms to..
(write_global_sym_plt): ..here. New function.
* elf32-ppc.h (ppc_elf_modify_segment_map): Delete attribute.
(ppc_finish_symbols): Declare.
ld/
* ppc32elf.em (ppc_finish): Call ppc_finish_symbols.
This patch deals with the auto-import feature. There are 2 versions
of this feature: the original one, which was piggybacked on the OS
loader with an optional help from the runtime (--enable-auto-import
--enable-runtime-pseudo-reloc-v1) and is still the one mostly
documented in the sources and manual; the enhanced one by Kai Tietz,
which is entirely piggybacked on the runtime (--enable-auto-import
--enable-runtime-pseudo-reloc-v2) and is the default for Mingw and
Cygwin nowadays.
The implementation is inefficient because of pe[p]_find_data_imports:
for every undefined symbol, the function walks the entire set of
relocations for all the input files and does a direct name comparison
for each of them.
This is easily fixable by using a hash-based map for v1 and a simple
hash table for v2. This patch leaves v1 alone and only changes v2.
It also factors out pe[p]_find_data_imports into a common function,
removes old cruft left and right, and attempts to better separate
the implementations of v1 and v2 in the code.
ld/
* emultempl/pe.em (U_SIZE): Delete.
(pe_data_import_dll): Likewise.
(make_import_fixup): Return void, take 4th parameter and pass it down
in call to pe_create_import_fixup.
(pe_find_data_imports): Move to...
(gld_${EMULATION_NAME}_after_open): Run the stdcall fixup pass after
the auto-import pass and add a guard before running the latter.
* emultempl/pep.em (U_SIZE): Delete.
(pep_data_import_dll): Likewise.
(make_import_fixup): Return void, take 4th parameter and pass it down
in call to pe_create_import_fixup.
(pep_find_data_imports): Move to...
(gld_${EMULATION_NAME}_after_open): Run the stdcall fixup pass after
the auto-import pass and add a guard before running the latter.
* pe-dll.c (runtime_pseudp_reloc_v2_init): Change type to bfd_boolean.
(pe_walk_relocs_of_symbol): Rename into...
(pe_walk_relocs): ...this. Add 2 more parameters,4th parameter to the
callback prototype and pass 4th parameter in calls to the callback.
If the import hash table is present, invoke the callback on the reloc
if the symbol name is in the table.
(pe_find_data_imports): ...here. Take 2 parameters. Build an import
hash table for the pseudo-relocation support version 2. When it is
built, walk the relocations only once at the end; when it is not, do
not build a fixup when the symbol isn't part of an import table.
Issue the associated warning only after a first fixup is built.
(tmp_seq2): Delete.
(make_singleton_name_imp): Likewise.
(make_import_fixup_mark): Return const char * and a stable string.
(make_import_fixup_entry): Do not deal with the pseudo-relocation
support version 2.
(make_runtime_pseudo_reloc): Factor out code and fix formatting.
(pe_create_import_fixup): Add 5th parameter. Clearly separate the
pseudo-relocation support version 2 from the rest. Fix formatting.
* pe-dll.h (pe_walk_relocs_of_symbol): Delete.
(pe_find_data_imports): Declare.
(pe_create_import_fixup): Add 5th parameter.
* pep-dll.c (pe_data_import_dll): Delete.
(pe_find_data_imports): Define.
(pe_walk_relocs_of_symbol): Delete.
* pep-dll.h (pep_walk_relocs_of_symbol): Delete.
(pep_find_data_imports): Declare.
(pep_create_import_fixup): Add 5th parameter.
* ld.texinfo (--enable-auto-import): Adjust to new implementation.
This patch adds --enable-separate-code to ld configure to turn on
-z separate-code by default and enables it by default for Linux/x86.
This avoids mixing code pages with data to improve cache performance
as well as security.
To reduce x86-64 executable and shared object sizes, the maximum page
size is reduced from 2MB to 4KB when -z separate-code is turned on by
default. Note: -z max-page-size= can be used to set the maximum page
size.
We compared SPEC CPU 2017 performance before and after this change on
Skylake server. There are no any significant performance changes.
Everything is mostly below +/-1%.
bfd/
* config.in: Regenerated.
* configure: Likewise.
* configure.ac: Add --enable-separate-code.
(DEFAULT_LD_Z_SEPARATE_CODE): New AC_DEFINE_UNQUOTED. Default
to 1 for Linux/x86 targets,
* elf64-x86-64.c (ELF_MAXPAGESIZE): Set to 0x1000 if
DEFAULT_LD_Z_SEPARATE_CODE is 1.
ld/
* NEWS: Mention --enable-separate-code.
* configure.ac: Add --enable-separate-code.
(DEFAULT_LD_Z_SEPARATE_CODE): New AC_DEFINE_UNQUOTED.
* configure.tgt: Default ac_default_ld_z_separate_code to 1 for
Linux/x86 targets.
* config.in: Regenerated.
* configure: Likewise.
* emultempl/elf32.em (gld${EMULATION_NAME}_before_parse): Set
link_info.separate_code DEFAULT_LD_Z_SEPARATE_CODE.
This reverts most of commit 1be5d8d3bb.
Left in place are addition of --no-plt-align to some ppc32 ld tests
and the ld.texinfo --no-plt-thread-safe fix.
Since all ELF linkers call check_relocs after opening all inputs, we
can fold after_allocation into before_allocation so that local dynamic
symbols will be placed before global dynamic symbols in .dynsym section.
This fixed:
FAIL: Common symbol override test (auxiliary shared object build)
FAIL: ld-elf/pr19617a
FAIL: ld-elf/pr19698
for i386-solaris2.12 and x86_64-solaris2.12 targets.
PR ld/22728
* emultempl/solaris2.em (elf_solaris2_after_allocation): Fold
into ...
(elf_solaris2_before_allocation): This.
(LDEMUL_AFTER_ALLOCATION): Removed.
Asking for ppc32 plt call stubs to be aligned at 32 byte boundaries
didn't quite work. For ld.bfd they were spaced 32 bytes apart, but
only started on a 16 byte boundary. ld.gold also didn't get it right.
Finding that bug made me check over the ppc64 plt stub alignment,
where I found that negative values for alignment (meaning align to
minimize boundary crossing) were not accepted. Since no one has
complained about that, I guess I could have removed the feature from
ld.bfd documentation, but I've opted instead to correct the code.
I've also added an optional alignment paramenter for ppc32
--plt-align, for some consistency with gold and ppc64 ld.bfd.
bfd/
* elf32-ppc.c (ppc_elf_create_glink): Correct alignment of .glink.
* elf64-ppc.c (ppc64_elf_size_stubs): Handle negative plt_stub_align.
(ppc64_elf_build_stubs): Likewise.
gold/
* powerpc.cc (param_plt_align): New function supplying default
--plt-align values. Use it..
(Stub_table::plt_call_align): ..here, and..
(Output_data_glink::global_entry_align): ..here.
(Stub_table::stub_align): Correct 32-bit minimum alignment.
ld/
* emultempl/ppc32elf.em: Support optional --plt-align arg.
* emultempl/ppc64elf.em: Support negative --plt-align arg.
This is in preparation for the next patch adding Spectre variant 2
mitigation for PowerPC and PowerPC64. Besides tidying code involved
in stub output (to reduce the number of places where bctr is output),
the patch adds some user visible features:
1) PowerPC64 ELFv2 global entry stubs now are aligned under the
control of --plt-align, with a default alignment of 32 bytes.
2) PowerPC64 __glink_PLTresolve is no longer padded out with nops.
3) PowerPC32 PLT stubs are aligned under the control of --plt-align,
with the default alignment being 16 bytes as before.
4) The PowerPC32 branch/nop table emitted before __glink_PLTresolve
is now smaller in many cases. It was sized incorrectly when the
__tls_get_addr_opt stub was used, and unnecessarily included space
for local ifuncs.
bfd/
* elf32-ppc.c (GLINK_ENTRY_SIZE): Add parameters, handle
__tls_get_addr_opt, and alignment sizing.
(TLS_GET_ADDR_GLINK_SIZE): Delete.
(is_nonpic_glink_stub): Don't use GLINK_ENTRY_SIZE.
(ppc_elf_get_synthetic_symtab): Recognize stubs spaced at 4, 6,
or 8 insns.
(ppc_elf_link_hash_table_create): Init new ppc_elf_params field.
(allocate_dynrelocs): Use new GLINK_ENTRY_SIZE.
(ppc_elf_size_dynamic_sections): Likewise. Size branch table
by PLT reloc count.
(write_glink_stub): Handle __tls_get_addr_opt stub.
Pad out to size given by GLINK_ENTRY_SIZE.
(ppc_elf_relocate_section): Adjust write_glink_stub call.
(ppc_elf_finish_dynamic_symbol): Likewise.
(ppc_elf_finish_dynamic_sections): Write PLTresolve without using
insn array since so many need rewriting.
* elf32-ppc.h (struct ppc_elf_params): Add plt_stub_align.
* elf64-ppc.c (GLINK_PLTRESOLVE_SIZE): Rename from
GLINK_CALL_STUB_SIZE. Add htab param and evaluate to size without
nops. Adjust all uses.
(ppc64_elf_get_synthetic_symtab): Don't use GLINK_CALL_STUB_SIZE
in glink_vma calculation.
(struct ppc_link_hash_table): Add global_entry section pointer.
(create_linkage_sections): Create separate section for global
entry stubs.
(PPC_LO, PPC_HI, PPC_HA): Move earlier.
(size_global_entry_stubs): Handle sizing for aligned stubs.
(ppc64_elf_size_dynamic_sections): Handle global_entry alloc,
and don't stash end of glink branch table in rawsize.
(ppc_build_one_stub): Rewrite stub size calculations.
(build_global_entry_stubs): Use new section.
(ppc64_elf_build_stubs): Don't pad __glink_PLTresolve with nops.
Build lazy link stubs out to end of section. Build global entry
stubs in new section.
gold/
* options.h (plt_align): Support for PowerPC32 too.
* powerpc.cc (Stub_table::stub_align): Heed --plt-align for 32-bit.
(Stub_table::plt_call_size, branch_stub_size): Tidy.
(Stub_table::plt_call_align): Implement using stub_align.
(Output_data_glink::global_entry_align): New function.
(Output_data_glink::global_entry_off): New function.
(Output_data_glink::global_entry_address): Use global_entry_off.
(Output_data_glink::pltresolve_size): New function, replacing
pltresolve_size_ constant. Update all uses.
(Output_data_glink::add_global_entry): Align offset.
(Output_data_glink::set_final_data_size): Use global_entry_align.
(Stub_table::do_write): Don't pad __glink_PLTrelsolve with nops.
Tidy stub output. Use global_entry_off.
ld/
* emultempl/ppc32elf.em (params): Init new field.
(enum ppc32_opt): New enum to define OPTION_* values. Add
OPTION_PLT_ALIGN and OPTION_NO_PLT_ALIGN.
(PARSE_AND_LIST_LONGOPTS): Handle new options.
(PARSE_AND_LIST_ARGS_CASES): Likewise.
(PARSE_AND_LIST_OPTIONS): Likewise. Break up help output.
* emultempl/ppc64elf.em (ppc_add_stub_section): Init alignment
correctly for negative --plt-stub-align.
* testsuite/ld-powerpc/elfv2exe.d,
* testsuite/ld-powerpc/elfv2so.d,
* testsuite/ld-powerpc/relbrlt.d,
* testsuite/ld-powerpc/relbrlt.s,
* testsuite/ld-powerpc/tlsexe.d,
* testsuite/ld-powerpc/tlsexe.r,
* testsuite/ld-powerpc/tlsexe32.d,
* testsuite/ld-powerpc/tlsexe32.g,
* testsuite/ld-powerpc/tlsexe32.r,
* testsuite/ld-powerpc/tlsexetoc.d,
* testsuite/ld-powerpc/tlsexetoc.r,
* testsuite/ld-powerpc/tlsopt5_32.d,
* testsuite/ld-powerpc/tlsso.d,
* testsuite/ld-powerpc/tlstocso.d: Update for changed stub order.
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}.
PR 22419
* emultempl/v850elf.em (v850_create_output_section_statements):
New function. Generate an error if attempting to convert the
format of the output file.
* testsuite/ld-unique/pr21529.d: Skip for the V850.
* testsuite/ld-elf/pr21884.d: Skip for the V850.
We currently delete bytes by shifting an entire BFD backwards to
overwrite the bytes we no longer need. The result is that relaxing a
BFD is quadratic time.
This patch adds an additional relocation that specifies a byte range
that will be deleted from the final object file, and adds a relaxation
pass (between the existing passes that delete bytes and the alignment
pass) that actually deletes the bytes. Note that deletion is still
quadratic time, and nothing uses R_RISCV_DELETE yet.
I've been meaning to go convert all the other relaxations to use
R_RISCV_DELETE and then make it faster, but this patch has been sitting
around for months so it looks like that won't happen for a bit. The
PCREL->GPREL relaxation that comes next uses this, and since we've been
using these two patches out of tree since I wrote them months ago I
figure it's better to just get them in now. I (or someone else :)) can
convert all the relocations later...
R_RISCV_DELETE will never be emitted into ELF objects, so therefor isn't
exposed to the rest of binutils. As such, we're not considering this as
part of the ABI.
bfd/ChangeLog
2017-10-19 Palmer Dabbelt <palmer@dabbelt.com>
* elfnn-riscv (R_RISCV_DELETE): New define.
(_bfd_riscv_relax_delete): New function.
(perform_relocation): Handle R_RISCV_DELETE.
(_bfd_riscv_relax_section): Likewise.
ld/ChangeLog
2017-10-19 Palmer Dabbelt <palmer@dabbelt.com>
* emultempl/riscvelf.em (riscv_elf_before_allocation): Add a
third relaxation pass.
I believe we should be warning if ld is given both --no-dynamic-linker
and -z dynamic-undefined-weak. The two options are contradictory, the
first says an executable has no dynamic interpreter to resolve dynamic
symbols, while the second is asking for dynamic symbols to be emitted.
(And even if a static PIE's relocation code, which is needed to
process R_*_RELATIVE relocs, could process symbols, there are no
DT_NEEDED dynamic objects to define such symbols.)
I also think that dynamic_undefined_weak is the right flag to control
whether undefined weaks are made dynamic, whether in static PIEs or
anywhere else. So force it to 0 for static PIEs, fixing PR 22269 for
powerpc and any other target where the backend usually defaults to
undefined weaks being made dynamic.
This patch introduces regressions. I'd normally not do that, but
these are all in very recently added test cases, or expose bugs in the
x86 backend. The test cases were added after I'd made it known that
this patch or one like it was imminent.
PR 22269
* emultempl/elf32.em (after_parse): Warn on --no-dynamic-linker
-z dynamic-undefined-weak combination. Set dynamic_undefined_weak
to zero when nointerp.
This function shouldn't be called directly, except from backend code.
bfd/
* elflink.c (_bfd_elf_adjust_dynamic_symbol): Call
elf_backend_hide_symbol, not _bfd_elf_link_hash_hide_symbol.
(bfd_elf_define_start_stop): Likewise.
ld/
* emultempl/elf32.em (before_allocation): Call
elf_backend_hide_symbol, not _bfd_elf_link_hash_hide_symbol.
Formatting.
This changes the PowerPC64 --plt-align option to perform the usual
alignment of code as suggested by its name, as well as the previous
behaviour of padding so as to reduce boundary crossing. The old
behaviour is had by using a negative parameter.
The default is also changed to align plt stub code by default to 32
byte boundaries, the point being to get better bctr branch prediction
on power8 and power9 hardware.
bfd/
* elf64-ppp.c (plt_stub_pad): Handle positive and negative
plt_stub_align.
ld/
* ld.texinfo (--plt-align): Describe new behaviour of option.
* emultempl/ppc64elf.em (params): Default plt_stub_align to 5.
* testsuite/ld-powerpc/powerpc.exp: Pass --no-plt-align for
selected tests.
* testsuite/ld-powerpc/relbrlt.d: Pass --no-plt-align.
* testsuite/ld-powerpc/elfv2so.d: Adjust expected output.
* 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.
PR ld/21884
* testsuite/ld-elf/pr21884.d: Add AVR, HPPA, IA64, M68HC1x and
SCORE to list of targets not supporting file format changes during
linking.
* testsuite/ld-unique/pr21529.d: Likewise.
* emultempl/avrelf.em (_before_allocation): Skip for non-ELF
output formats.
(avr_elf_create_output_section_statements): Fail if the output
format is not ELF.
(avr_finish): Do not access the ELF header in non-ELF format
output bfds.
* emultempl/m68hc1xelf.em (_before_allocation): Skip for non-ELF
output formats.
(m68hc11elf_create_output_section_statements): Fail if the putput
format is not ELF.
(m68hc11elf_after_allocation): Skip for non-ELF output formats.
The loop checking for previous orphan placement should run even when
the output is non-ELF.
PR ld/21884
* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Revert
last change. Rename iself to elfinput. Expand comments. Condition
ELF checks on having both input and output ELF files. Extract..
(elf_orphan_compatible): ..this new function.
Fix a commit 861fb55ab5 ("Defer allocation of R_MIPS_REL32 GOT
slots"), <https://sourceware.org/ml/binutils/2008-08/msg00096.html>,
regression and a more recent:
FAIL: ld-unique/pr21529
new LD test case failure, observed with all the relevant MIPS targets
whenever the linker is invoked with one or more ELF inputs and the
output format set to `binary'.
The culprit is a segmentation fault caused in `mips_before_allocation'
by a null pointer dereference, where an attempt is made to access the
ELF file header's `e_flags' member, for the purpose of determining
whether to produce a PLT and copy relocations, without first checking
that the output BFD is ELF. The `e_flags' member is stored in BFD's
private data pointed to by `tdep', which in the case of the `binary' BFD
is null, causing the segmentation fault. With other non-ELF BFDs such
as SREC `tdep' is not null and consequently no crash may happen and in
that case random data will be interpreted as it was `e_flags'.
Disable the access to `e_flags' then and all the associated checks and
consequently never produce a PLT and copy relocations if output is not a
MIPS ELF BFD, matching `_bfd_mips_elf_merge_private_bfd_data' that does
not process `e_flags' in that case either and therefore does not let us
decide here anyway if all the input objects included in the link are
suitable for use with a PLT and copy relocations.
ld/
* emultempl/mipself.em (mips_before_allocation): Avoid ELF
processing if not MIPS ELF.
* testsuite/ld-mips-elf/binary.d: New test.
* testsuite/ld-mips-elf/binary.ld: New test linker script.
* testsuite/ld-mips-elf/binary.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
All sections on a --just-syms bfd are discarded from the output, so
attaching linker created sections to such a bfd results in errors.
In other cases, like the .note.GNU-stack check, it's wrong to have a
--just-syms object potentially affect the output.
bfd/
* elflink.c (_bfd_elf_link_create_dynstrtab): Don't make dynobj
a --just-syms bfd.
(_bfd_elf_size_group_sections): Skip --just-syms bfds.
(bfd_elf_size_dynamic_sections): Ignore .note.GNU-stack and
.preinit_array on --just-syms bfds.
(_bfd_elf_gc_mark_extra_sections): Skip --just-syms bfds.
(elf_gc_sweep, bfd_elf_parse_eh_frame_entries): Likewise.
(bfd_elf_gc_sections, bfd_elf_discard_info): Likewise.
ld/
* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Skip
--just-syms bfds when looking for a place to attach .note.gnu.build-id
and .eh_frame_hdr sections. Delete dead code.
This patch adds a new S/390 specific segment type: PT_S390_PGSTE. For
binaries marked with that segment the kernel will allocate 4k page
tables. The only user so far will be qemu.
ld/ChangeLog:
2017-06-23 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* Makefile.in: Add s390.em as build dependency.
* emulparams/elf64_s390.sh (EXTRA_EM_FILE): Add s390.em.
* emultempl/s390.em: New file.
* gen-doc.texi: Add documentation for --s390-pgste option.
* ld.texinfo: Likewise.
include/ChangeLog:
2017-06-23 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* elf/s390.h (PT_S390_PGSTE): Define macro.
binutils/ChangeLog:
2017-06-23 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* readelf.c (get_s390_segment_type): Add support for the new
segment type PT_S390_PGSTE.
(get_segment_type): Call get_s390_segment_type.
elfcpp/ChangeLog:
2017-06-23 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* elfcpp.h (enum PT): Add PT_S390_PGSTE to enum.
bfd/ChangeLog:
2017-06-23 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* elf-s390.h: New file.
* elf64-s390.c (struct elf_s390_link_hash_table): Add params
field.
(elf_s390_additional_program_headers): New function.
(elf_s390_modify_segment_map): New function.
(bfd_elf_s390_set_options): New function.
(elf_backend_additional_program_headers)
(elf_backend_modify_segment_map): Add macro definitions.
Currently, linker will define __start_SECNAME and __stop_SECNAME symbols
only for orphaned sections.
However, during garbage collection, ELF linker marks all sections with
references to __start_SECNAME and __stop_SECNAME symbols as used even
when section SECNAME isn't an orphaned section and linker won't define
__start_SECNAME nor __stop_SECNAME. And ELF linker stores the first
input section whose name matches __start_SECNAME or __stop_SECNAME in
u.undef.section for garbage collection. If these symbols are provided
in linker script, u.undef.section is set to the section where they will
defined by linker script, which leads to the incorrect output.
This patch changes linker to always define referenced __start_SECNAME and
__stop_SECNAME if the input section name is the same as the output section
name, which is always true for orphaned sections, and SECNAME is a C
identifier. Also __start_SECNAME and __stop_SECNAME symbols are marked
as hidden by ELF linker so that __start_SECNAME and __stop_SECNAME symbols
for section SECNAME in different modules are unique. For garbage
collection, ELF linker stores the first matched input section in the
unused vtable field.
bfd/
PR ld/20022
PR ld/21557
PR ld/21562
PR ld/21571
* elf-bfd.h (elf_link_hash_entry): Add start_stop. Change the
vtable field to a union.
(_bfd_elf_is_start_stop): Removed.
* elf32-i386.c (elf_i386_convert_load_reloc): Also check for
__start_SECNAME and __stop_SECNAME symbols.
* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Likewise.
* elflink.c (_bfd_elf_is_start_stop): Removed.
(_bfd_elf_gc_mark_rsec): Check start_stop instead of calling
_bfd_elf_is_start_stop.
(elf_gc_propagate_vtable_entries_used): Skip __start_SECNAME and
__stop_SECNAME symbols. Updated.
(elf_gc_smash_unused_vtentry_relocs): Likewise.
(bfd_elf_gc_record_vtinherit): Likewise.
(bfd_elf_gc_record_vtentry): Likewise.
ld/
PR ld/20022
PR ld/21557
PR ld/21562
PR ld/21571
* ld.texinfo: Update __start_SECNAME/__stop_SECNAME symbols.
* ldlang.c (lang_insert_orphan): Move handling of __start_SECNAME
and __stop_SECNAME symbols to ...
(lang_set_startof): Here. Also define __start_SECNAME and
__stop_SECNAME for -Ur.
* emultempl/elf32.em (gld${EMULATION_NAME}_after_open): Mark
referenced __start_SECNAME and __stop_SECNAME symbols as hidden
and set start_stop for garbage collection.
* testsuite/ld-elf/pr21562a.d: New file.
* testsuite/ld-elf/pr21562a.s: Likewise.
* testsuite/ld-elf/pr21562a.t: Likewise.
* testsuite/ld-elf/pr21562b.d: Likewise.
* testsuite/ld-elf/pr21562b.s: Likewise.
* testsuite/ld-elf/pr21562b.t: Likewise.
* testsuite/ld-elf/pr21562c.d: Likewise.
* testsuite/ld-elf/pr21562c.t: Likewise.
* testsuite/ld-elf/pr21562d.d: Likewise.
* testsuite/ld-elf/pr21562d.t: Likewise.
* testsuite/ld-elf/pr21562e.d: Likewise.
* testsuite/ld-elf/pr21562f.d: Likewise.
* testsuite/ld-elf/pr21562g.d: Likewise.
* testsuite/ld-elf/pr21562h.d: Likewise.
* testsuite/ld-elf/pr21562i.d: Likewise.
* testsuite/ld-elf/pr21562j.d: Likewise.
* testsuite/ld-elf/pr21562k.d: Likewise.
* testsuite/ld-elf/pr21562l.d: Likewise.
* testsuite/ld-elf/pr21562m.d: Likewise.
* testsuite/ld-elf/pr21562n.d: Likewise.
* testsuite/ld-gc/pr20022.d: Likewise.
* testsuite/ld-gc/pr20022a.s: Likewise.
* testsuite/ld-gc/pr20022b.s: Likewise.
* testsuite/ld-gc/gc.exp: Run PR ld/20022 tests.
* testsuite/ld-gc/pr19161.d: Also accept local __start_SECNAME
symbol.
* testsuite/ld-gc/start.d: Likewise.
* testsuite/ld-x86-64/lea1a.d: Updated.
* testsuite/ld-x86-64/lea1b.d: Updated.
* testsuite/ld-x86-64/lea1d.d: Updated.
* testsuite/ld-x86-64/lea1e.d: Likewise.
ELFv2 functions with localentry:0 are those with a single entry point,
ie. global entry == local entry, and that have no requirement on r2 or
r12, and guarantee r2 is unchanged on return. Such an external
function can be called via the PLT without saving r2 or restoring it
on return, avoiding a common load-hit-store for small functions. The
optimization is attractive. The TOC pointer load-hit-store is a major
reason why calls to small functions that need no register saves, or
with shrink-wrap, no register saves on a fast path, are slow on
powerpc64le.
To be safe, this optimization needs ld.so support to check that the
run-time matches link-time function implementation. If a function
in a shared library with st_other localentry non-zero is called
without saving and restoring r2, r2 will be trashed on return, leading
to segfaults. For that reason the optimization does not happen for
weak functions since a weak definition is a fairly solid hint that the
function will likely be overridden. I'm also not enabling the
optimization by default unless glibc-2.26 is detected, which should
have the ld.so checks implemented.
bfd/
* elf64-ppc.c (struct ppc_link_hash_table): Add has_plt_localentry0.
(ppc64_elf_merge_symbol_attribute): Merge localentry bits from
dynamic objects.
(is_elfv2_localentry0): New function.
(ppc64_elf_tls_setup): Default params->plt_localentry0.
(plt_stub_size): Adjust size for tls_get_addr_opt stub.
(build_tls_get_addr_stub): Use a simpler stub when r2 is not saved.
(ppc64_elf_size_stubs): Leave stub_type as ppc_stub_plt_call for
optimized localentry:0 stubs.
(ppc64_elf_build_stubs): Save r2 in ELFv2 __glink_PLTresolve.
(ppc64_elf_relocate_section): Leave nop unchanged for optimized
localentry:0 stubs.
(ppc64_elf_finish_dynamic_sections): Set PPC64_OPT_LOCALENTRY in
DT_PPC64_OPT.
* elf64-ppc.h (struct ppc64_elf_params): Add plt_localentry0.
include/
* elf/ppc64.h (PPC64_OPT_LOCALENTRY): Define.
ld/
* emultempl/ppc64elf.em (params): Init plt_localentry0 field.
(enum ppc64_opt): New, replacing OPTION_* defines. Add
OPTION_PLT_LOCALENTRY, and OPTION_NO_PLT_LOCALENTRY.
(PARSE_AND_LIST_*): Support --plt-localentry and --no-plt-localentry.
* testsuite/ld-powerpc/elfv2so.d: Update.
* testsuite/ld-powerpc/powerpc.exp (TLS opt 5): Use --no-plt-localentry.
* testsuite/ld-powerpc/tlsopt5.d: Update.
Don't use fixed size buffers for symbol names.
PR 21274
PR 18466
* emultempl/pe.em (pe_find_data_imports): Don't use fixed size
symbol buffer. Instead, xmalloc max size needed with space for
prefix. Wrap overlong lines. Formatting. Pass symbol buffer
copy of name to pe_walk_relocs_of_symbol.
(make_inport_fixup): Add "name" param, pass to pe_create_import_fixup.
* emultempl/pe.em (pep_find_data_imports): As for pe_find_data_imports.
(make_import_fixup): Add "name" param, pass to pep_create_import_fixup.
Use bfd_get_signed_* and remove unnecessary casts. Formatting.
* pe-dll.c (pe_walk_relocs_of_symbol): Add "name" param. Pass to
callback.
(make_import_fixup_mark): Add "name" param. Make use of prefix
space rather than xmalloc here.
(pe_create_import_fixup): Likewise.
* pe-dll.h (pe_walk_relocs_of_symbol): Update prototype.
(pe_create_import_fixup): Likewise.
* pep-dll.h (pep_walk_relocs_of_symbol): Likewise.
(pep_create_import_fixup): Likewise.
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${EMULATION_NAME}_place_orphan): Place
input GNU_MBIND sections with the same type, attributes and
sh_info field into a single output GNU_MBIND section.
* testsuite/ld-elf/elf.exp: Run mbind2a and mbind2b.
* testsuite/ld-elf/mbind1.s: New file.
* testsuite/ld-elf/mbind1a.d: Likewise.
* testsuite/ld-elf/mbind1b.d: Likewise.
* testsuite/ld-elf/mbind1c.d: Likewise.
* testsuite/ld-elf/mbind2a.s: Likewise.
* testsuite/ld-elf/mbind2b.c: Likewise.
Relative paths shouldn't have the sysroot prefix added. The patch
also makes some attempt at supporting DOS paths, and tidies code using
the new add_sysroot.
* emultempl/elf32.em (gld${EMULATION_NAME}_add_sysroot): Rewrite.
Only prefix absolute paths with sysroot. Handle DOS paths.
(gld${EMULATION_NAME}_check_ld_elf_hints): Constify variable.
(gld${EMULATION_NAME}_check_ld_so_conf): Likewise.
(gld${EMULATION_NAME}_after_open): Short-circuit NULL path
searches. Rename variable. Simplify get_runpath search.
Complement commit 9d862524f6 ("MIPS: Verify the ISA mode and alignment
of branch and jump targets") and add GAS and LD options to control the
checks for invalid branches between ISA modes introduced there, to help
with some handwritten code lacking `.insn' annotation for labels used as
branch targets and code produced by older versions of GCC which suffers
from the issue with branches to code that has been optimized away,
addressed with GCC commit 242424 ("MIPS/GCC: Mark trailing labels with
`.insn'"), <https://gcc.gnu.org/ml/gcc-patches/2016-11/msg01061.html>.
bfd/
* elfxx-mips.h (_bfd_mips_elf_insn32): Rename prototype to...
(_bfd_mips_elf_linker_flags): ... this. Add another parameter.
* elfxx-mips.c (mips_elf_link_hash_table): Add
`ignore_branch_isa' member.
(mips_elf_perform_relocation): Do not treat an ISA mode mismatch
in branch relocation calculation as an error if
`ignore_branch_isa' has been set.
(_bfd_mips_elf_insn32): Rename to...
(_bfd_mips_elf_linker_flags): ... this. Rename the `on'
parameter to `insn32' and add an `ignore_branch_isa' parameter.
Handle the new parameter.
gas/
* config/tc-mips.c (mips_ignore_branch_isa): New variable.
(options): Add OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA enum values.
(md_longopts): Add "mignore-branch-isa" and
"mno-ignore-branch-isa" options.
(md_parse_option): Handle OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA.
(fix_bad_cross_mode_branch_p): Return FALSE if
`mips_ignore_branch_isa' has been set.
(md_show_usage): Add `-mignore-branch-isa' and
`-mno-ignore-branch-isa'.
* doc/as.texinfo (Target MIPS options): Add
`-mignore-branch-isa' and `-mno-ignore-branch-isa' options.
(-mignore-branch-isa, -mno-ignore-branch-isa): New options.
* doc/c-mips.texi (MIPS Options): Add `-mignore-branch-isa' and
`-mno-ignore-branch-isa' options.
* testsuite/gas/mips/branch-local-ignore-2.d: New test.
* testsuite/gas/mips/branch-local-ignore-3.d: New test.
* testsuite/gas/mips/branch-local-ignore-n32-2.d: New test.
* testsuite/gas/mips/branch-local-ignore-n32-3.d: New test.
* testsuite/gas/mips/branch-local-ignore-n64-2.d: New test.
* testsuite/gas/mips/branch-local-ignore-n64-3.d: New test.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* emultempl/mipself.em (ignore_branch_isa): New variable.
(mips_create_output_section_statements): Rename
`_bfd_mips_elf_insn32' called to `_bfd_mips_elf_linker_flags',
add `ignore_branch_isa' argument.
(PARSE_AND_LIST_PROLOGUE): Add OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA enum values.
(PARSE_AND_LIST_LONGOPTS): Add "ignore-branch-isa" and
"no-ignore-branch-isa" options.
(PARSE_AND_LIST_OPTIONS): Add `--ignore-branch-isa' and
`--no-ignore-branch-isa'.
(PARSE_AND_LIST_ARGS_CASES): Handle OPTION_IGNORE_BRANCH_ISA and
OPTION_NO_IGNORE_BRANCH_ISA.
* ld.texinfo (Options specific to MIPS targets): Add
`--ignore-branch-isa' and `--no-ignore-branch-isa' options.
(ld and the MIPS family): Likewise.
* testsuite/ld-mips-elf/bal-jalx-pic-ignore.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic-ignore-n32.d: New test.
* testsuite/ld-mips-elf/bal-jalx-pic-ignore-n64.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-2.d: New test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-r6-1: New test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-mips16: New
test.
* testsuite/ld-mips-elf/unaligned-branch-ignore-micromips: New
test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Correct a bug in Solaris 2 linker emulation code triggered by a test
introduced with commit 81ff47b3a5 ("PR ld/20828: Fix linker script
symbols wrongly forced local with section GC") and only create implicit
version nodes if versioning is actually introduced with a version script
(or VERSION command) rather than only global vs local symbol visibility
selected, fixing an:
ld: anonymous version tag cannot be combined with other version tags
linker error produced whenever a version script (or VERSION command) is
used that does not assign symbol versions, such as:
{ global: foo; bar; local: *; };
and consequently removing a:
FAIL: PR ld/20828 dynamic symbols with section GC (version script)
test suite failure with the `x86_64-solaris2' target.
ld/
* emultempl/solaris2.em (elf_solaris2_before_allocation): Do not
add implicit version nodes if an anonymous version tag is being
used.
Lots of fixes for the compatibility code that handles linking of
-mcall-aixdesc code (or that generated by 12 year old gcc) with
current ELFv1 ABI code.
1) A reference to a dot-symbol in an object file wasn't satisfied by a
function descriptor in later object files.
2) The as-needed code had bit-rotted; Shared libs now need a strong
reference to be counted as needed.
3) --gc-sections involving dot-symbols was broken, needing
func_desc_adjust to be run early and lots of other fixes.
bfd/
* elf64-ppc.c (struct ppc_link_hash_entry): Delete "was_undefined".
(struct ppc_link_hash_table): Delete "twiddled_syms". Add
"need_func_desc_adj".
(lookup_fdh): Link direct fdh sym via oh field and set flags.
(make_fdh): Make strong and weak undefined function descriptor
symbols.
(ppc64_elf_merge_symbol): New function.
(elf_backend_merge_symbol): Define.
(ppc64_elf_archive_symbol_lookup): Don't test undefweak for fake
function descriptors.
(add_symbol_adjust): Don't twiddle symbols to undefweak.
Propagate more ref flags to function descriptor symbol. Make
some function descriptor symbols dynamic.
(ppc64_elf_before_check_relocs): Only run add_symbol_adjust for
ELFv1. Set need_func_desc_adj. Don't fix undefs list.
(ppc64_elf_check_relocs): Set non_ir_ref for descriptors.
Don't call lookup_fdh here.
(ppc64_elf_gc_sections): New function.
(bfd_elf64_bfd_gc_sections): Define.
(ppc64_elf_gc_mark_hook): Mark descriptor.
(func_desc_adjust): Don't make fake function descriptor syms strong
here. Exit earlier on non-dotsyms. Take note of elf.dynamic
flag when deciding whether a dynamic function descriptor might
be needed. Transfer elf.dynamic and set elf.needs_plt. Move
plt regardless of visibility. Make descriptor dynamic if
entry sym is dynamic, not for other cases.
(ppc64_elf_func_desc_adjust): Don't run func_desc_adjust if
already done.
(ppc64_elf_edit_opd): Use oh field rather than lookup_fdh.
(ppc64_elf_size_stubs): Likewise.
(ppc_build_one_stub): Don't clear was_undefined. Only set sym
undefweak if stub symbol is defined.
(undo_symbol_twiddle, ppc64_elf_restore_symbols): Delete.
* elf64-ppc.h (ppc64_elf_restore_symbols): Don't declare.
ld/
* emultempl/ppc64elf.em (gld${EMULATION_NAME}_finish): Don't call
ppc64_elf_restore_symbols.
* testsuite/ld-powerpc/dotsym1.d: New.
* testsuite/ld-powerpc/dotsym2.d: New.
* testsuite/ld-powerpc/dotsym3.d: New.
* testsuite/ld-powerpc/dotsym4.d: New.
* testsuite/ld-powerpc/dotsymref.s: New.
* testsuite/ld-powerpc/nodotsym.s: New.
* testsuite/ld-powerpc/powerpc.exp: Run new tests.
PR ld/20784
* emultempl/elf32.em (search_needed): Fix infinite loop when
unable to process a token. Add support for curly braced enclosed
tokens.
* ld.texinfo (--rpath-link): Document supprot for $ORIGIN and
$LIB.
* emultempl/elf32.em (search_needed): Remove use of getauxval and
inclusion of <sys/auxv.h>. Replace support for $PLATFORM with a
warning message.
* configure.ac (AC_CHECK_FUNCS): Remove getauxval.
* configure: Regenerate.
* config.in: Regenerate.
SEC_EXCLUDE is ignored when doing a relocatable link. But we can't
merge 2 input sections with the same name when only one of them has
SHF_EXCLUDE.
PR ld/20528
* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Don't
merge 2 sections with different SHF_EXCLUDE.
* testsuite/ld-elf/pr20528a.d: New file.
* testsuite/ld-elf/pr20528a.s: Likewise.
* testsuite/ld-elf/pr20528b.d: Likewise.
* testsuite/ld-elf/pr20528b.s: Likewise.
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 (struct elf32_arm_params): Define.
(bfd_elf32_arm_set_target_relocs): Rename into ...
(bfd_elf32_arm_set_target_params): This. Use a struct
elf32_arm_params to pass all parameters but the bfd and bfd_link_info.
* bfd-in2.h: Regenerate.
* elf32-arm.c (bfd_elf32_arm_set_target_relocs): Rename into ...
(bfd_elf32_arm_set_target_params): This. Pass all values via a struct
elf32_arm_params rather than as individual parameters.
ld/
* emultempl/armelf.em (params): New static variable.
(thumb_entry_symbol, byteswap_code, target1_is_rel, target2_type,
fix_v4bx, use_blx, vfp11_denorm_fix, stm32l4xx_fix, fix_cortex_a8,
no_enum_size_warning, no_wchar_size_warning, pic_veneer,
merge_exidx_entries, fix_arm1176, cmse_implib): move as part of the
above new structure.
(arm_elf_before_allocation): Access static variable from the params
structure.
(gld${EMULATION_NAME}_finish): Likewise.
(arm_elf_create_output_section_statements): Likewise and pass the
address of that structure to bfd_elf32_arm_set_target_relocs instead
of the static variables.
(PARSE_AND_LIST_ARGS_CASES): Access static variable from the params
structure.
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.
2016-05-23 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* bfd-in.h (bfd_elf32_arm_keep_private_stub_output_sections): Declare
bfd hook.
* bfd-in2.h: Regenerate.
* elf32-arm.c (arm_dedicated_stub_output_section_required): New
function.
(arm_dedicated_stub_output_section_required_alignment): Likewise.
(arm_dedicated_stub_output_section_name): Likewise.
(arm_dedicated_stub_input_section_ptr): Likewise.
(elf32_arm_create_or_find_stub_sec): Add stub type parameter and
function description comment. Add support for dedicated output stub
section to given stub types.
(elf32_arm_add_stub): Add a stub type parameter and pass it down to
elf32_arm_create_or_find_stub_sec.
(elf32_arm_create_stub): Pass stub type down to elf32_arm_add_stub.
(elf32_arm_size_stubs): Pass stub type when calling
elf32_arm_create_or_find_stub_sec for Cortex-A8 erratum veneers.
(bfd_elf32_arm_keep_private_stub_output_sections): New function.
ld/
* emultempl/armelf.em (arm_elf_before_allocation): Call
bfd_elf32_arm_keep_private_stub_output_sections before generic
before_allocation function.
2016-05-10 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* elf32-arm.c (elf32_arm_size_stubs): Use new macros
ARM_GET_SYM_BRANCH_TYPE and ARM_SET_SYM_BRANCH_TYPE to respectively get
and set branch type of a symbol.
(bfd_elf32_arm_process_before_allocation): Likewise.
(elf32_arm_relocate_section): Likewise and fix identation along the
way.
(allocate_dynrelocs_for_symbol): Likewise.
(elf32_arm_finish_dynamic_symbol): Likewise.
(elf32_arm_swap_symbol_in): Likewise.
(elf32_arm_swap_symbol_out): Likewise.
gas/
* config/tc-arm.c (arm_adjust_symtab): Use ARM_SET_SYM_BRANCH_TYPE to
set branch type of a symbol.
gdb/
* arm-tdep.c (arm_elf_make_msymbol_special): Use
ARM_GET_SYM_BRANCH_TYPE to get branch type of a symbol.
include/
* arm.h (enum arm_st_branch_type): Add new ST_BRANCH_ENUM_SIZE
enumerator.
(NUM_ENUM_ARM_ST_BRANCH_TYPE_BITS): New macro.
(ENUM_ARM_ST_BRANCH_TYPE_BITMASK): Likewise.
(ARM_SYM_BRANCH_TYPE): Replace by ...
(ARM_GET_SYM_BRANCH_TYPE): This and ...
(ARM_SET_SYM_BRANCH_TYPE): This in two versions depending on whether
BFD_ASSERT is defined or not.
ld/
* emultempl/armelf.em (gld${EMULATION_NAME}_finish): Use
ARM_GET_SYM_BRANCH_TYPE to get branch type of a symbol.
opcodes/
* arm-dis.c (get_sym_code_type): Use ARM_GET_SYM_BRANCH_TYPE to get
branch type of a symbol.
(print_insn): Likewise.
2016-05-10 Thomas Preud'homme <thomas.preudhomme@arm.com>
bfd/
* bfd-in.h (elf32_arm_size_stubs): Add an output section parameter.
* bfd-in2.h: Regenerated.
* elf32-arm.c (struct elf32_arm_link_hash_table): Add an output section
parameter to add_stub_section callback.
(elf32_arm_create_or_find_stub_sec): Get output section from link_sec
and pass it down to add_stub_section.
(elf32_arm_add_stub): Set section to stub_sec if NULL before using it
for error message.
(elf32_arm_size_stubs): Add output section parameter to
add_stub_section function pointer parameter.
ld/
* emultempl/armelf.em (elf32_arm_add_stub_section): Add output_section
parameter and rename input_section parameter to after_input_section.
Append input stub section to the output section if after_input_section
is NULL.
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.
Sudakshina Das
Claudiu Zissulescu
Alan Modra
Nick Clifton
Maciej W. Rozycki
Andrew Jenner
Andreas Krebbel
Christophe Lyon
Eric Botcazou
Andreas Schwab
Kuan-Lin Chen
Jim Wilson
H.J. Lu
Palmer Dabbelt
Jozef Lawrynowicz
Max Filippov
Maciej W. Rozycki
Dimitar Dimitrov
Ambrogino Modigliani
Thomas Preud'homme
Jiong Wang