We use its PLT entry to initialize function pointer at run-time. If
there is no other usage for the PLT entry, we can generate run-time
function pointer relocations in read-write section, which can be
resolved by dynamic linker, to initialize function pointers. It avoids
the extra indirect branch overhead in PLT.
bfd/
PR ld/18900
* elf32-i386.c (elf_i386_link_hash_entry): Add
func_pointer_refcount.
(elf_i386_link_hash_newfunc): Clear func_pointer_refcount.
(elf_i386_get_local_sym_hash): Likewise.
(elf_i386_copy_indirect_symbol): Also copy
func_pointer_refcount.
(elf_i386_check_relocs): Increment func_pointer_refcount.
(elf_i386_gc_sweep_hook): Decrement func_pointer_refcount.
(elf_i386_allocate_dynrelocs): Don't create the PLT entry if
there are only function pointer relocations which can be
resolved at run-time. Keep dynanamic relocations for run-time
function pointer initialization.
(elf_i386_relocate_section): Copy dynamic function pointer
relocations.
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
func_pointer_refcount.
(elf_x86_64_link_hash_newfunc): Clear func_pointer_refcount.
(elf_x86_64_get_local_sym_hash): Likewise.
(elf_x86_64_copy_indirect_symbol): Also copy
func_pointer_refcount.
(elf_x86_64_check_relocs): Increment func_pointer_refcount.
(elf_x86_64_gc_sweep_hook): Decrement func_pointer_refcount.
(elf_x86_64_allocate_dynrelocs): Don't create the PLT entry if
there are only function pointer relocations which can be
resolved at run-time. Keep dynanamic relocations for run-time
function pointer initialization.
(elf_x86_64_relocate_section): Copy dynamic function pointer
relocations.
ld/testsuite/
PR ld/18900
* ld-i386/i386.exp: Run tests for PR ld/18900.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pr18900.out: New file.
* ld-i386/pr18900a.c: Likewise.
* ld-i386/pr18900a.c: Likewise.
* ld-i386/pr18900a.rd: Likewise.
* ld-i386/pr18900b.c: Likewise.
* ld-i386/pr18900b.rd: Likewise.
* ld-i386/pr18900c.c: Likewise.
* ld-x86-64/pr18900.out: Likewise.
* ld-x86-64/pr18900a.c: Likewise.
* ld-x86-64/pr18900a.rd: Likewise.
* ld-x86-64/pr18900b.c: Likewise.
* ld-x86-64/pr18900b.rd: Likewise.
* ld-x86-64/pr18900c.c: Likewise.
* ld-x86-64/mpx3.dd: Updated.
OPD lookup goes awry when .opd has been shuffled to remove unused
functions.
* elf64-ppc.c (ppc64_elf_maybe_function_sym): Adjust symbol value
if .opd section has been edited.
Don't emit long branch or plt branch stubs to save/restore functions.
Copy them instead. The problem is that plt branch stubs currently
trash r12, one of the parameters to some of the save/restore
functions, and there is no free register available to use instead of
r12.
6f20ed8a is prerequisite for this patch.
PR 18878
* elf64-ppc.c (ARRAY_SIZE): Define. Use throughout.
(enum ppc_stub_type): Add ppc_stub_save_res.
(struct map_stub): Add "next" and "needs_save_res".
(struct ppc_link_hash_entry): Add "save_res" flag.
(struct ppc_link_hash_table): Add "group".
(sfpr_define): Add stub_sec param. Define symbol in stub_sec if
stub_sec is non-null. Set "save_res".
(save_res_funcs): Make file scope, rename from funcs. Adjust uses.
(ppc64_elf_adjust_dynamic_symbol): Prohibit plt call to save_res syms.
(ppc_build_one_stub): Handle ppc_stub_save_res.
(ppc_size_one_stub): Set stub type to ppc_size_one_stub on finding
stub for linker defined save_res sym.
(group_sections): Init new fields of struct map_stub.
(ppc64_elf_size_stubs): Reserve space for save/restore func copy.
(ppc64_elf_build_stubs): Copy save/restore funcs to groups. Emit
alias syms too.
(ppc64_elf_relocate_section): Set destination for ppc_stub_save_res.
Sometimes these stubs don't need to change the low 16-bits of r2, so in
that case omit a useless addi r2,r2,0 insn. Also, change the get_r2off
error return from 0 to -1 since 0 is a valid return for ELFv2 -R objects.
* elf64-ppc.c (get_r2off): Return -1 on error.
(ppc_build_one_stub): Adjust for get_r2off change. Don't emit
addi r2,r2,0 on r2off stubs when the low 16-bit delta is zero.
(ppc_size_one_stub): Corresponding size changes for r2off stubs.
Add condition in test for -R objects.
Two organizational changes to the array of additional info kept for
sections.
1) Move group info into a per-group allocated struct, in preparation
for future changes that need per-group accounting.
2) Expand the array to include output sections, which simplifies
sizing and removes the need for a separate output section array.
* section.c (section_id): Make file scope.
(bfd_get_next_section_id): New function.
* elf64-ppc.c (struct map_stub): Remove toc_off field. Move decl.
(struct ppc_stub_hash_entry): Delete stub_sec and id_sec. Add
group. Update all uses.
(struct ppc_link_hash_table): Delete top_id, top_index, and
input_list. Add sec_info_arr_size. Rename stub_group to
sec_info, and make group info indirect. Update stub_group refs
throughout file.
(ppc_add_stub): Don't look for stub_sec on link_sec stub_group
entry.
(ppc_build_one_stub): Delete FIXME.
(ppc64_elf_setup_section_lists): Size htab->sec_info for all
sections, not just input sections. Don't create htab->input_list.
(ppc64_elf_next_input_section): Update to use sec_info union as
list pointer.
(PREV_SEC): Delete.
(group_sections): Pass "info" param rather than "htab". Iterate
over output sections rather than input_list. Use sec_info union
as list pointers. Alloc atruct map_stub, and return fail status.
* bfd-in2.h: Regenerate.
These int vars are really unsigned, so make them so.
* section.c (struct bfd_section): Make "id" and "index" unsigned.
* coff-rs6000.c (_bfd_xcoff_sizeof_headers): Adjust local var to suit.
* elf.c (elf_map_symbols): Likewise.
* elf64-ppc.c (sym_exists_at): Make "id" param unsigned.
(struct ppc_link_hash_table): Make "top_id" and "top_index" unsigned.
(ppc64_elf_setup_section_lists): Ditto for local vars.
* elf32-arm.c: Similarly to elf64-ppc.c.
* elf32-avr.c: Likewise.
* elf32-hppa.c: Likewise.
* elf32-m68hc1x.c: Likewise.
* elf32-metag.c: Likewise.
* elf32-nios2.c: Likewise.
* elfnn-aarch64.c: Likewise.
* simple.c (struct saved_offsets): Make "section_count" unsigned.
* bfd-in2.h: Regenerate.
A number of targets emit multiple relocs at a given r_offset, and
depend on those relocs staying in their original order.
PR 18867
* elflink.c (cmp_ext32l_r_offset, cmp_ext32b_r_offset): Delete.
(cmp_ext64l_r_offset, cmp_ext64b_r_offset): Delete.
(ext32l_r_offset, ext32b_r_offset, ext64l_r_offset, ext64b_r_offset):
New functions.
(elf_link_adjust_relocs): Use an insertion sort to sort relocs.
bfd PR ld/18401
* elfxx-mips.c (bfd_mips_isa_ext_mach): New function: Converts an
ISA value to a bfd machine number.
(bfd_mips_isa_ext): Update the ISA level and revision if
necessary. Use mips_mach_extends_p to decide if the ISA extension
needs to be set.
(_bfd_mips_elf_merge_private_bfd_data): Allow the ISA extension to
be inferred from the ABI setting. Set the ISA level from the
maximum of the incoming and outgoing ISA levels.
tests
* ld-mips-elf/mips-elf-flags.exp: Add more ISA conflict tests.
Belt and braces fix. Either of the changes here is sufficient to
ensure vd_nodename is initialized properly.
* elf.c (_bfd_elf_slurp_version_tables): Always init vd_nodename.
Don't copy fields not set by _bfd_elf_swap_verdef_in.
This patch done two types of cleanup:
* in aarch64_reloc_got_type and elfNN_aarch64_relocate_section
We don't need those redundant "case" check, as they can be merged
with the "default" which just "break".
* in elfNN_aarch64_gc_sweep_hook and elfNN_aarch64_check_relocs
All TLS local executable relocations and some local dynamic
relocations (those calculate module offset) actually don't need GOT
entry, so remove them from GOT entry counting.
2015-08-18 Jiong Wang <jiong.wang@arm.com>
bfd/
* elfnn-aarch64.c (aarch64_reloc_got_type): Delete useless check.
(elfNN_aarch64_relocate_section): Likewise.
(elfNN_aarch64_gc_sweep_hook): Likewise.
(elfNN_aarch64_check_relocs): Likewise.
bfd/
* elf64-ppc.c (ppc64_elf_func_desc_adjust): Don't redefine .TOC.
if already defined, and set linker_def.
(ppc64_elf_set_toc): Use .TOC. value if defined other than by
the backend.
ld/
* ldexp.c (exp_fold_tree_1): Clear linker_def on symbol assignment.
