aec6b87e0b
[x86] Resolve non-PIC undefweak symbols in executable
...
For i386 and x86-64, non-PIC references to undefined weak symbols are
resolved without dynamic relocation when creating executable. Resolved
undefined weak symbols are removed from the dynamic symbol table in
executable. One exception is on i386, we need resolved undefined weak
symbols in the dynamic symbol table in PIE if input relocatable files
contain branchs without PLT so that we can branch to 0 with dynamic
relocation in text section.
This makes behaviors of dynamic executable and position independent
executable predictable with mixed PIC and non-PIC references to undefined
weak symbols. If all references to undefined weak symbols are PIC,
dynamic relocations against undefined weak symbols will be generated
in executable unless -z nodynamic-undefined-weak is passed to linker.
bfd/
PR ld/19636
PR ld/19704
PR ld/19719
* elf32-i386.c (UNDEFINED_WEAK_RESOLVED_TO_ZERO): New.
(elf_i386_link_hash_entry): Add has_got_reloc and
has_non_got_reloc.
(elf_i386_link_hash_table): Add interp.
(elf_i386_link_hash_newfunc): Initialize has_got_reloc and
has_non_got_reloc.
(elf_i386_copy_indirect_symbol): Copy has_got_reloc and
has_non_got_reloc.
(elf_i386_check_relocs): Set has_got_reloc and has_non_got_reloc.
(elf_i386_fixup_symbol): New function.
(elf_i386_pie_finish_undefweak_symbol): Likewise.
(elf_i386_allocate_dynrelocs): Don't allocate space for dynamic
relocations and discard relocations against resolved undefined
weak symbols in executable. Don't make resolved undefined weak
symbols in executable dynamic. Keep dynamic non-GOT/non-PLT
relocation against undefined weak symbols in PIE.
(elf_i386_size_dynamic_sections): Set interp to .interp section.
(elf_i386_relocate_section): Don't generate dynamic relocations
against resolved undefined weak symbols in PIE, except for
R_386_PC32.
(elf_i386_finish_dynamic_symbol): Keep PLT/GOT entries without
dynamic PLT/GOT relocations for resolved undefined weak symbols.
Don't generate dynamic relocation against resolved undefined weak
symbol in executable.
(elf_i386_finish_dynamic_sections): Call
elf_i386_pie_finish_undefweak_symbol on all symbols in PIE.
(elf_backend_fixup_symbol): New.
* elf64-x86-64.c (UNDEFINED_WEAK_RESOLVED_TO_ZERO): New.
(elf_x86_64_link_hash_entry): Add has_got_reloc and
has_non_got_reloc.
(elf_x86_64_link_hash_table): Add interp.
(elf_x86_64_link_hash_newfunc): Initialize has_got_reloc and
has_non_got_reloc.
(elf_x86_64_copy_indirect_symbol): Copy has_got_reloc and
has_non_got_reloc.
(elf_x86_64_check_relocs): Set has_got_reloc and
has_non_got_reloc.
(elf_x86_64_fixup_symbol): New function.
(elf_x86_64_pie_finish_undefweak_symbol): Likewise.
(elf_x86_64_allocate_dynrelocs): Don't allocate space for dynamic
relocations and discard relocations against resolved undefined
weak symbols in executable. Don't make resolved undefined weak
symbols in executable dynamic.
(elf_x86_64_size_dynamic_sections): Set interp to .interp section.
(elf_x86_64_relocate_section): Check relocation overflow for
dynamic relocations against unresolved weak undefined symbols.
Don't generate dynamic relocations against resolved weak
undefined symbols in PIE.
(elf_x86_64_finish_dynamic_symbol): Keep PLT/GOT entries without
dynamic PLT/GOT relocations for resolved undefined weak symbols.
Don't generate dynamic relocation against resolved undefined weak
symbol in executable.
(elf_x86_64_finish_dynamic_sections): Call
elf_x86_64_pie_finish_undefweak_symbol on all symbols in PIE.
(elf_backend_fixup_symbol): New.
include/
PR ld/19636
PR ld/19704
PR ld/19719
* bfdlink.h (bfd_link_info): Add dynamic_undefined_weak.
ld/
PR ld/19636
PR ld/19704
PR ld/19719
* Makefile.am (ELF_X86_DEPS): Add dynamic_undefined_weak.sh.
* Makefile.in: Regenerated.
* NEWS: Mention -z nodynamic-undefined-weak.
* ld.texinfo: Document -z nodynamic-undefined-weak.
* ldmain.c (main): Initialize dynamic_undefined_weak to -1.
* emulparams/dynamic_undefined_weak.sh: New file.
* emulparams/elf32_x86_64.sh: Source dynamic_undefined_weak.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_i386_be.sh: Likewise.
* emulparams/elf_i386_chaos.sh: Likewise.
* emulparams/elf_i386_ldso.sh: Likewise.
* emulparams/elf_i386_vxworks.sh: Likewise.
* emulparams/elf_iamcu.sh: Likewise.
* emulparams/elf_k1om.sh: Likewise.
* emulparams/elf_l1om.sh: Likewise.
* emulparams/elf_x86_64.sh: Likewise.
* emulparams/extern_protected_data.sh (PARSE_AND_LIST_OPTIONS):
Append.
(PARSE_AND_LIST_ARGS_CASE_Z): Likewise.
* testsuite/ld-elf/pr19719a.c: New file.
* testsuite/ld-elf/pr19719b.c: Likewise.
* testsuite/ld-elf/pr19719c.c: Likewise.
* testsuite/ld-elf/pr19719d.c: Likewise.
* testsuite/ld-i386/pr19636-1.s: Likewise.
* testsuite/ld-i386/pr19636-1a.d: Likewise.
* testsuite/ld-i386/pr19636-1b.d: Likewise.
* testsuite/ld-i386/pr19636-1c.d: Likewise.
* testsuite/ld-i386/pr19636-1d-nacl.d: Likewise.
* testsuite/ld-i386/pr19636-1d.d: Likewise.
* testsuite/ld-i386/pr19636-1e.d: Likewise.
* testsuite/ld-i386/pr19636-1f.d: Likewise.
* testsuite/ld-i386/pr19636-1g.d: Likewise.
* testsuite/ld-i386/pr19636-1h.d: Likewise.
* testsuite/ld-i386/pr19636-1i.d: Likewise.
* testsuite/ld-i386/pr19636-2.s: Likewise.
* testsuite/ld-i386/pr19636-2a.d: Likewise.
* testsuite/ld-i386/pr19636-2b.d: Likewise.
* testsuite/ld-i386/pr19636-2c-nacl.d: Likewise.
* testsuite/ld-i386/pr19636-2c.d: Likewise.
* testsuite/ld-i386/pr19636-2d-nacl.d: Likewise.
* testsuite/ld-i386/pr19636-2d.d: Likewise.
* testsuite/ld-i386/pr19636-2e-nacl.d: Likewise.
* testsuite/ld-i386/pr19636-2e.d: Likewise.
* testsuite/ld-i386/pr19636-3.s: Likewise.
* testsuite/ld-i386/pr19636-3a.d: Likewise.
* testsuite/ld-i386/pr19636-3b.d: Likewise.
* testsuite/ld-i386/pr19636-3c.d: Likewise.
* testsuite/ld-i386/pr19636-3d.d: Likewise.
* testsuite/ld-i386/pr19636-3e.d: Likewise.
* testsuite/ld-i386/pr19636-3f.d: Likewise.
* testsuite/ld-i386/pr19636-3g.d: Likewise.
* testsuite/ld-i386/pr19636-4.s: Likewise.
* testsuite/ld-i386/pr19636-4a.d: Likewise.
* testsuite/ld-i386/pr19636-4b.d: Likewise.
* testsuite/ld-i386/pr19636-4c.d: Likewise.
* testsuite/ld-i386/pr19636-4d.d: Likewise.
* testsuite/ld-i386/pr19704.out: Likewise.
* testsuite/ld-i386/pr19704a.c: Likewise.
* testsuite/ld-i386/pr19704b.c: Likewise.
* testsuite/ld-x86-64/pr19636-1.s: Likewise.
* testsuite/ld-x86-64/pr19636-1a.d: Likewise.
* testsuite/ld-x86-64/pr19636-1b.d: Likewise.
* testsuite/ld-x86-64/pr19636-1c.d: Likewise.
* testsuite/ld-x86-64/pr19636-1d.d: Likewise.
* testsuite/ld-x86-64/pr19636-1e.d: Likewise.
* testsuite/ld-x86-64/pr19636-1f.d: Likewise.
* testsuite/ld-x86-64/pr19636-1g.d: Likewise.
* testsuite/ld-x86-64/pr19636-2.s: Likewise.
* testsuite/ld-x86-64/pr19636-2a.d: Likewise.
* testsuite/ld-x86-64/pr19636-2b.d: Likewise.
* testsuite/ld-x86-64/pr19636-2c.d: Likewise.
* testsuite/ld-x86-64/pr19636-2d-nacl.d: Likewise.
* testsuite/ld-x86-64/pr19636-2d.d: Likewise.
* testsuite/ld-x86-64/pr19636-2e.d: Likewise.
* testsuite/ld-x86-64/pr19636-2f.d: Likewise.
* testsuite/ld-x86-64/pr19636-2g.d: Likewise.
* testsuite/ld-x86-64/pr19636-2h.d: Likewise.
* testsuite/ld-x86-64/pr19636-2i.d: Likewise.
* testsuite/ld-x86-64/pr19636-3.s: Likewise.
* testsuite/ld-x86-64/pr19636-3a.d: Likewise.
* testsuite/ld-x86-64/pr19636-3b.d: Likewise.
* testsuite/ld-x86-64/pr19636-3c.d: Likewise.
* testsuite/ld-x86-64/pr19636-3d.d: Likewise.
* testsuite/ld-x86-64/pr19704.out: Likewise.
* testsuite/ld-x86-64/pr19704a.c: Likewise.
* testsuite/ld-x86-64/pr19704b.c: Likewise.
* testsuite/ld-elf/shared.exp (mix_pic_and_non_pic): New.
Run mix_pic_and_non_pic.
* testsuite/ld-i386/i386.exp (undefined_weak): New.
Run undefined_weak and PR ld/19636 tests.
* testsuite/ld-x86-64/x86-64.exp: Likewise.
* testsuite/ld-x86-64/pr13082-3b.d: Updated.
* testsuite/ld-x86-64/pr13082-4b.d: Likewise.
2016-02-26 04:55:57 -08:00
889c2a6796
Add -z noextern-protected-data to ld for ELF/x86
...
Address of protected data defined in the shared library may be external,
i.e., due to copy relocation. By default, linker backend checks if
relocations against protected data symbols are valid for building shared
library and issues an error if relocation isn't allowed. The new option
override linker backend default. When -z noextern-protected-data is used,
updates on protected data symbols by another module won't be visibile
to the resulting shared library. This option is specific to ELF/i386
and ELF/x86-64.
bfd/
PR ld/pr17709
* elflink.c (_bfd_elf_adjust_dynamic_copy): Check
info->extern_protected_data when warning copy relocs against
protected symbols.
(_bfd_elf_symbol_refs_local_p): Check info->extern_protected_data
when checking protected non-function symbols.
include/
PR ld/pr17709
* bfdlink.h (bfd_link_info): Add extern_protected_data.
ld/
PR ld/pr17709
* ld.texinfo: Document "-z noextern-protected-data".
* ldmain.c (main): Initialize link_info.extern_protected_data
to -1.
* lexsup.c (elf_shlib_list_options): Add
"-z [no]extern-protected-data".
* emulparams/elf32_x86_64.sh: Source extern_protected_data.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_i386_be.sh: Likewise.
* emulparams/elf_i386_chaos.sh: Likewise.
* emulparams/elf_i386_ldso.sh: Likewise.
* emulparams/elf_i386_vxworks.sh: Likewise.
* emulparams/elf_k1om.sh: Likewise.
* emulparams/elf_l1om.sh: Likewise.
* emulparams/elf_x86_64.sh: Source extern_protected_data.sh.
(PARSE_AND_LIST_OPTIONS): Renamed to ...
(PARSE_AND_LIST_OPTIONS_BNDPLT): This.
(PARSE_AND_LIST_ARGS_CASE_Z): Renamed to ...
(PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT): This.
(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_BNDPLT.
(PARSE_AND_LIST_ARGS_CASE_Z): Append
$PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT.
* emulparams/extern_protected_data.sh: New file.
ld/testsuite/
PR ld/pr17709
* ld-i386/i386.exp: Run protected6b.
* ld-i386/protected6b.d: New file.
* ld-x86-64/protected6b.d: Likewise.
* ld-x86-64/x86-64.exp: Run protected6b.
2015-04-14 04:13:11 -07:00
H.J. Lu