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.
Since the only information which SYMBOL_REFERENCES_LOCAL_P doesn't check
is relocations, UNDEFINED_WEAK_RESOLVED_TO_ZERO only needs to check for
relocations with SYMBOL_REFERENCES_LOCAL_P.
* elf32-i386.c (elf_i386_relocate_section): Update usage of
UNDEFINED_WEAK_RESOLVED_TO_ZERO.
(elf_i386_finish_dynamic_symbol): Likewise.
* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
(elf_x86_64_finish_dynamic_symbol): Likewise.
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Likewise.
(_bfd_x86_elf_fixup_symbol): Likewise.
_bfd_x86_elf_link_symbol_references_local should depend only on symbol
references, not relocations, to work in check_relocs.
* elfxx-x86.c (_bfd_x86_elf_link_symbol_references_local): Don't
check has_non_got_reloc.
After _bfd_i386_elf_convert_load and _bfd_x86_64_elf_convert_load are
removed, elf_i386_convert_load_reloc and elf_x86_64_convert_load_reloc
see __ehdr_start as an undefined symbol when they are called from
check_relocs to convert GOT relocations against local symbols. But
__ehdr_start will be defined as a hidden symbol by linker at the later
stage if it is referenced. This patch marks __ehdr_start as a defined
local symbol at the start of check_relocs if it is referenced and not
defined.
bfd/
PR ld/22115
* elf32-i386.c (elf_i386_convert_load_reloc): Check linker_def.
Don't use UNDEFINED_WEAK_RESOLVED_TO_ZERO.
* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Check
linker_def. Don't use UNDEFINED_WEAK_RESOLVED_TO_ZERO.
* elfxx-x86.c (_bfd_x86_elf_link_check_relocs): Set local_ref
and linker_def on __ehdr_start if it is referenced and not
defined.
(_bfd_x86_elf_link_symbol_references_local): Also set local_ref
and return TRUE when building executable, if a symbol has
non-GOT/non-PLT relocations in text section or there is no
dynamic linker.
* elfxx-x86.h (elf_x86_link_hash_entry): Add linker_def.
ld/
PR ld/22115
* ld-i386/i386.exp: Run PR ld/22115 tests,
* ld/testsuite/ld-x86-64/x86-64.exp: Likewise.
* testsuite/ld-i386/pr22115-1.s: New file.
* testsuite/ld-i386/pr22115-1a.d: Likewise.
* testsuite/ld-i386/pr22115-1b.d: Likewise.
* testsuite/ld-i386/pr22115-1c.d: Likewise.
* testsuite/ld-i386/pr22115-1d.d: Likewise.
* testsuite/ld-x86-64/pr22115-1.s: Likewise.
* testsuite/ld-x86-64/pr22115-1a-x32.d: Likewise.
* testsuite/ld-x86-64/pr22115-1a.d: Likewise.
* testsuite/ld-x86-64/pr22115-1b-x32.d: Likewise.
* testsuite/ld-x86-64/pr22115-1b.d: Likewise.
* testsuite/ld-x86-64/pr22115-1c-x32.d: Likewise.
* testsuite/ld-x86-64/pr22115-1c.d: Likewise.
* testsuite/ld-x86-64/pr22115-1d-x32.d: Likewise.
* testsuite/ld-x86-64/pr22115-1d.d: Likewise.
Don't set r_info and r_sym fields in _bfd_x86_elf_link_hash_table_create.
Instead, set them in _bfd_x86_elf_link_setup_gnu_properties. We can
avoid adding elf64-x86-64.lo and elf64.lo together with elfxx-x86.lo to
bfd_backends.
* configure.ac (bfd_backends): Don't add elf64-x86-64.lo nor
elf64.lo together with elfxx-x86.lo for 64-bit BFD.
* configure: Regenerated.
* elf32-i386.c (elf_i386_link_setup_gnu_properties): Set r_info
and r_sym fields of plt_layout.
* elf64-x86-64.c (elf_x86_64_link_setup_gnu_properties):
Likewise.
* elfxx-x86.c (elf_x86_64_is_reloc_section): Remove BFD64 check.
(_bfd_x86_elf_link_hash_table_create): Likewise. Don't set
r_info nor r_sym fields.
(_bfd_x86_elf_link_setup_gnu_properties): Set r_info and r_sym
fields of htab.
* elfxx-x86.h (elf_x86_plt_layout_table): Add r_info and r_sym.
This used to just print "can't relax section: Success", which is a silly
error message.
bfd/ChangeLog
2017-09-07 Palmer Dabbelt <palmer@dabbelt.com>
* elfnn-riscv.c (_bfd_riscv_relax_align): Call bfd_set_error and
print an error message when unable to relax a .align directive.
I recently modified our Linux port's base address such the absolute
address 0 is no longer addressable as a 32-bit PC-relative offset.
Since Linux links a weak undefined symbol in an intermediate binary, it
needs to be able to reference absolute address 0.
This patch changes R_RISCV_PCREL_* relocations to absolute relocations
while resolving them in order to allow these symbols to be referenced in
PC-relative programs linked at high addresses. Note that this doesn't
apply to PIC, which also uses PC-relative relocations, just to
position-dependent objects, which we use to allow programs to be linked
at high addresses.
In case some of our embedded users are using R_RISCV_PCREL_* as a hacked
up method of getting position-independent binaries (which can work if
you have very simple programs), we only convert the relocations when the
PC-relative version would overflow.
bfd/ChangeLog:
2017-09-07 Palmer Dabbelt <palmer@dabbelt.com>
* elfnn-riscv.c (riscv_zero_pcrel_hi_reloc): New function.
(riscv_record_pcrel_hi_reloc): Add absolute argument.
(riscv_elf_relocate_section): Call riscv_zero_pcrel_hi_reloc for
R_RISCV_PCREL_HI20 relocs, and pass the result to
riscv_record_pcrel_hi_reloc.
Instead of converting GOT relocations when sizing dynamic sections, we
convert GOT relocations during relocation check. Add a field, local_ref,
to elf_x86_link_hash_entry to indicate if symbol references are always
local with a new function to check if symbol references are always local,
which works in check_relocs.
* elf32-i386.c (elf_i386_convert_load_reloc): Add an argument,
r_type_p. Remove the converted argument. Replace
SYMBOL_REFERENCES_LOCAL with SYMBOL_REFERENCES_LOCAL_P. Return
the new relocation type via r_type_p.
(elf_i386_relocate_section): Likewise.
(elf_i386_finish_dynamic_symbol): Likewise.
(need_convert_load): Removed.
(check_relocs_failed): Updated.
(elf_i386_check_relocs): Call elf_i386_convert_load_reloc,
instead of setting need_convert_load.
(_bfd_i386_elf_convert_load): Removed.
* elf64-x86-64.c (need_convert_load): Removed.
(check_relocs_failed): Updated.
(elf_x86_64_convert_load_reloc): Add an argument, r_type_p.
Replace SYMBOL_REFERENCES_LOCAL with SYMBOL_REFERENCES_LOCAL_P.
Return the new relocation type via r_type_p.
(elf_x86_64_check_relocs): Call elf_x86_64_convert_load_reloc,
instead of setting need_convert_load.
(elf_x86_64_check_relocs): Don't check PIC if relocation has
been converted.
(_bfd_x86_64_elf_convert_load): Removed.
(elf_x86_64_relocate_section): Replace SYMBOL_REFERENCES_LOCAL
with SYMBOL_REFERENCES_LOCAL_P.
(elf_x86_64_finish_dynamic_symbol): Likewise.
* elfxx-x86.c (_bfd_x86_elf_link_hash_table_create): Don't
set convert_load.
(_bfd_x86_elf_size_dynamic_sections): Don't call convert_load.
(_bfd_x86_elf_link_symbol_references_local): New function.
* elfxx-x86.h (SYMBOL_REFERENCES_LOCAL_P): New.
(UNDEFINED_WEAK_RESOLVED_TO_ZERO): Replace elf.forced_local with
SYMBOL_REFERENCES_LOCAL_P.
(elf_x86_link_hash_entry): Add local_ref.
(elf_x86_link_hash_table): Remove convert_load.
(_bfd_i386_elf_convert_load): Removed.
(_bfd_x86_64_elf_convert_load): Likewise.
(_bfd_x86_elf_link_symbol_references_local): New.
Add R_X86_64_converted_reloc_bit to relocation type to indicate if a
relocation is converted from a GOTPCREL relocation. Linker now generates
failed to convert GOTPCREL relocation; relink with --no-relax
for all cases, including relocations against local symbols.
bfd/
* elf64-x86-64.c (R_X86_64_converted_reloc_bit): New.
(elf_x86_64_info_to_howto): Get the real relocation type by
masking out R_X86_64_converted_reloc_bit.
(elf_x86_64_check_tls_transition): Get the real relocation type
by masking out R_X86_64_converted_reloc_bit.
(elf_x86_64_convert_load_reloc): Set R_X86_64_converted_reloc_bit
instead of setting converted_reloc.
(elf_x86_64_relocate_section): Check R_X86_64_converted_reloc_bit
instead of converted_reloc. Get the real relocation type by
masking out R_X86_64_converted_reloc_bit.
(elf_x86_64_link_setup_gnu_properties): Verify that the value of
R_X86_64_converted_reloc_bit is valid.
* elfxx-x86.h (converted_reloc): Removed.
ld/
* testsuite/ld-x86-64/pr19609-2a.d: Updated.
* testsuite/ld-x86-64/pr19609-2b.d: Likewise.
* testsuite/ld-x86-64/pr19609-4a.d: Likewise.
* testsuite/ld-x86-64/pr19609-4c.d: Likewise.
Don't change r_type when performing TLS transitions to avoid getting
the relocation type with ELF32_R_TYPE again.
* elf32-i386.c (elf_i386_relocate_section): Don't change r_type
when calling elf_i386_tls_transition. Don't use ELF32_R_TYPE
to get the relocation type again.
* elf64-x86-64.c (elf_x86_64_relocate_section): Don't change
r_type when calling elf_x86_64_tls_transition. Don't use
ELF32_R_TYPE to get the relocation type again.
When GOTPCREL relocation conversion leads to relocation overflow, we
may get a mysterious linker message, like
relocation truncated to fit: R_X86_64_32S against symbol `foo'
This patch changes the linker message to
failed to convert GOTPCREL relocation; relink with --no-relax
bfd/
* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Remove the sec
argument. Don't check relocation overflow. Avoid relocation
overflow if --no-relax is used. Set converted_reloc on symbol
if a GOTPCREL relocation is converted.
(elf_x86_64_relocate_section): Issue a fatal error and suggest
--no-relax if GOTPCREL relocation conversion leads to relocation
overflow.
* elfxx-x86.h (elf_x86_link_hash_entry): Add converted_reloc.
ld/
* testsuite/ld-x86-64/pr19609-4e.d: Updated.
* testsuite/ld-x86-64/pr19609-6a.d: Likewise.
We need to set tlsdesc_plt for x86-64 if GOT_TLS_GDESC_P is true when
allocating dynamic relocations so that _bfd_x86_elf_size_dynamic_sections
will generate TLSDESC_PLT and TLSDESC_GOT in x86-64 output.
bfd/
PR ld/22071
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Set tlsdesc_plt
for x86-64 if GOT_TLS_GDESC_P is true.
ld/
PR ld/22071
* testsuite/ld-x86-64/pr22071.d: New file.
* testsuite/ld-x86-64/pr22071.s: Likewise.
* testsuite/ld-x86-64/x86-64.exp: Run pr22071.
Since elfxx-x86.lo needs elf64-x86-64.lo with 64-bit BFD now, add
elf64-x86-64.lo together with elfxx-x86.lo to bfd_backends for 64-bit
BFD.
* configure.ac (bfd_backends): Add elf64-x86-64.lo together
with elfxx-x86.lo for 64-bit BFD.
* configure: Regenerated.
elf_i386_size_dynamic_sections and elf_x86_64_size_dynamic_sections are
very similar, except for the followings:
1. elf_i386_size_dynamic_sections checks GOT_TLS_IE and GOT_TLS_IE_BOTH.
elf_x86_64_size_dynamic_sections checks only GOT_TLS_IE. Since
GOT_TLS_IE_BOTH is never true for x86-64, it is OK to check GOT_TLS_IE
for both i386 and x86-64.
2, x86-64 sets tlsdesc_plt, but i386 doesn't. We set tlsdesc_plt only
if target_id == X86_64_ELF_DATA.
3. x86-64 has
if (s != htab->elf.srelplt)
s->reloc_count = 0;
and i386 has
s->reloc_count = 0;
i386 did have
if (s != htab->srelplt)
s->reloc_count = 0;
in the original commit:
commit 67a4f2b710
Author: Alexandre Oliva <aoliva@redhat.com>
Date: Wed Jan 18 21:07:51 2006 +0000
But it was removed by
commit 5ae0bfb60a
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Tue Feb 28 07:16:12 2006 +0000
bfd/
* elf32-i386.c (elf_i386_link_hash_table): Add next_tls_desc_index.
(elf_i386_link_hash_table_create): Initialize it.
(elf_i386_compute_jump_table_size): Use it instead of
srelplt->reloc_count.
(allocate_dynrelocs): Likewise.
(elf_i386_size_dynamic_sections): Likewise.
(elf_i386_relocate_section): Likewise.
A later commit:
commit e1f987424b
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Oct 21 15:13:37 2011 +0000
Put IRELATIVE relocations after JUMP_SLOT.
bfd/
2011-10-21 H.J. Lu <hongjiu.lu@intel.com>
PR ld/13302
* elf32-i386.c (elf_i386_link_hash_table): Add next_jump_slot_index
and next_irelative_index.
(elf_i386_link_hash_table_create): Initialize next_jump_slot_index
and next_irelative_index.
(elf_i386_allocate_dynrelocs): Increment reloc_count instead of
next_tls_desc_index.
(elf_i386_size_dynamic_sections): Set next_tls_desc_index and
next_irelative_index from reloc_count.
(elf_i386_finish_dynamic_symbol): Put R_386_IRELATIVE after
R_386_JUMP_SLOT.
changed it back to use reloc_count again. So it is correct to use
if (s != htab->elf.srelplt)
s->reloc_count = 0;
for both i386 and x86-64 now.
4. i386 and x86-64 use different DT_XXXs. They are handled by adding
them to elf_x86_link_hash_table.
With these changes, we can share _bfd_x86_elf_size_dynamic_sections in
elf32-i386.c and elf64-x86-64.c.
* elf32-i386.c (elf_i386_convert_load): Renamed to ...
(_bfd_i386_elf_convert_load): This. Remove static.
(elf_i386_size_dynamic_sections): Removed.
(elf_backend_size_dynamic_sections): Likewise.
* elf64-x86-64.c (elf_x86_64_convert_load): Renamed to ...
(_bfd_x86_64_elf_convert_load): This. Remove static.
(elf_x86_64_size_dynamic_sections): Removed.
(elf_backend_size_dynamic_sections): Likewise.
* elfxx-x86.c (_bfd_x86_elf_allocate_dynrelocs): Renamed to ...
(elf_x86_allocate_dynrelocs): This. Make it static.
(_bfd_x86_elf_allocate_local_dynrelocs): Renamed to ...
(elf_x86_allocate_local_dynreloc): This. Make it static.
(elf_i386_is_reloc_section): New function.
(elf_x86_64_is_reloc_section): Likewise.
(_bfd_x86_elf_link_hash_table_create): Initialize convert_load,
is_reloc_section, dt_reloc, dt_reloc_sz and dt_reloc_ent.
Rearrange got_entry_size initialization.
(_bfd_x86_elf_size_dynamic_sections): New function.
* elfxx-x86.h (elf_x86_link_hash_table): Add convert_load,
is_reloc_section, dt_reloc, dt_reloc_sz and dt_reloc_ent.
(_bfd_i386_elf_convert_load): New.
(_bfd_x86_64_elf_convert_load): Likewise.
(_bfd_x86_elf_size_dynamic_sections): Likewise.
(elf_backend_size_dynamic_sections): Likewise.
(_bfd_x86_elf_allocate_dynrelocs): Removed.
(_bfd_x86_elf_allocate_local_dynrelocs): Likewise.
elf_i386_size_dynamic_sections has
htab->next_tls_desc_index = htab->elf.srelplt->reloc_count;
htab->sgotplt_jump_table_size = htab->next_tls_desc_index * 4;
This patch changes it to
htab->sgotplt_jump_table_size
= elf_x86_compute_jump_table_size (htab)
Since elf_x86_compute_jump_table_size is defined as
((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
there is no change in output. It makes elf_i386_size_dynamic_sections
the same as elf_x86_64_size_dynamic_sections.
* elf32-i386.c (elf_i386_size_dynamic_sections): Set
sgotplt_jump_table_size with elf_x86_compute_jump_table_size.
Since PLT_CIE_LENGTH, PLT_FDE_LENGTH, PLT_FDE_START_OFFSET and
PLT_FDE_LEN_OFFSET are identical in elf32-i386.c and elf64-x86-64.c,
they can be defined in elfxx-x86.h.
* elf32-i386.c (PLT_CIE_LENGTH, PLT_FDE_LENGTH,
PLT_FDE_START_OFFSET, PLT_FDE_LEN_OFFSET): Moved to ...
* elfxx-x86.h (PLT_CIE_LENGTH, PLT_FDE_LENGTH,
PLT_FDE_START_OFFSET, PLT_FDE_LEN_OFFSET): Here.
* elf64-x86-64.c (PLT_CIE_LENGTH, PLT_FDE_LENGTH,
PLT_FDE_START_OFFSET, PLT_FDE_LEN_OFFSET): Removed.
