Commit graph

3 commits

Author SHA1 Message Date
H.J. Lu
bae420ef26 Optimize x86 GOT32X/GOTPCRELX relocations
R_386_GOT32X, R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX relocations
retrieve the symbol address via its GOT slot.  If the symbol address is
known at the link-time, we can use it directly by changing instruction
encoding.  Indirect branch can only be converted to PC relative direct
branch.  MOV can be changed to LEA or encoded differently with signed
address.  The subset of binary operations can be encoded only with
signed address.

If undefined weak symbol is resolved to zero link-time, we can use it
as address.  Zero addresss can't used with PC relative direct branch
when PIC is true since the current PC is unknown.  In 64-bit, 32-bit
relocation for PC relatiave direct branch to zero may also overflow.

If this optimization causes relocation overflow, --no-relax can be used
to work around it.

bfd/

	PR ld/19609
	* elf32-i386.c (elf_i386_convert_load): Convert to R_386_32 for
	load with locally bound symbols if PIC is false or there is no
	base register.  Optimize branch to 0 if PIC is false.
	(elf_i386_relocate_section): Don't generate dynamic relocations
	against undefined weak symbols if PIC is false.
	* elf64-x86-64.c (elf_x86_64_convert_load): Disable optimization
	if we can't estimate relocation overflow with --no-relax.
	Convert to R_X86_64_32S/R_X86_64_32 for load with locally bound
	symbols if PIC is false.  Optimize branch to 0 if PIC is false.
	(elf_x86_64_relocate_section): Don't generate dynamic relocations
	against undefined weak symbols if PIC is false.

ld/

	PR ld/19609
	* testsuite/ld-i386/got1.dd: Updated.
	* testsuite/ld-i386/lea1c.d: Likewise.
	* testsuite/ld-i386/load1-nacl.d: Likewise.
	* testsuite/ld-i386/load1.d: Likewise.
	* testsuite/ld-i386/load4b.d: Likewise.
	* testsuite/ld-i386/load5b.d: Likewise.
	* testsuite/ld-i386/mov1b.d: Likewise.
	* testsuite/ld-x86-64/mov1b.d: Likewise.
	* testsuite/ld-x86-64/mov1d.d: Likewise.
	* testsuite/ld-ifunc/ifunc-21-i386.d: Likewise.
	* testsuite/ld-ifunc/ifunc-21-x86-64.d: Likewise.
	* testsuite/ld-ifunc/ifunc-22-i386.d: Likewise.
	* testsuite/ld-ifunc/ifunc-22-x86-64.d: Likewise.
	* testsuite/ld-x86-64/gotpcrel1.dd: Likewise.
	* testsuite/ld-x86-64/lea1a.d: Likewise.
	* testsuite/ld-x86-64/lea1b.d: Likewise.
	* testsuite/ld-x86-64/lea1c.d: Likewise.
	* testsuite/ld-x86-64/lea1d.d: Likewise.
	* testsuite/ld-x86-64/lea1e.d: Likewise.
	* testsuite/ld-x86-64/lea1f.d: Likewise.
	* testsuite/ld-x86-64/mov1b.d: Likewise.
	* testsuite/ld-x86-64/mov1d.d: Likewise.
	* testsuite/ld-x86-64/pr13082-3b.d: Likewise.
	* testsuite/ld-x86-64/pr13082-4b.d: Likewise.
	* testsuite/ld-x86-64/lea1.s: Add tests for 32-bit registers.
	* testsuite/ld-i386/pr19609-1.s: New file.
	* testsuite/ld-i386/pr19609-1a.d: Likewise.
	* testsuite/ld-i386/pr19609-1b.d: Likewise.
	* testsuite/ld-i386/pr19609-1c.d: Likewise.
	* testsuite/ld-i386/pr19609-1d.d: Likewise.
	* testsuite/ld-i386/pr19609-1e.d: Likewise.
	* testsuite/ld-i386/pr19609-1f.d: Likewise.
	* testsuite/ld-i386/pr19609-1g.d: Likewise.
	* testsuite/ld-i386/pr19609-1h.d: Likewise.
	* testsuite/ld-i386/pr19609-1i.d: Likewise.
	* testsuite/ld-i386/pr19609-2.s: Likewise.
	* testsuite/ld-i386/pr19609-2a.d: Likewise.
	* testsuite/ld-i386/pr19609-2b.d: Likewise.
	* testsuite/ld-i386/pr19609-2c.d: Likewise.
	* testsuite/ld-i386/undefweak.s: Likewise.
	* testsuite/ld-i386/undefweaka.d: Likewise.
	* testsuite/ld-i386/undefweakb.d: Likewise.
	* testsuite/ld-x86-64/pr13082-3c.d: Likewise.
	* testsuite/ld-x86-64/pr13082-3d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1.s: Likewise.
	* testsuite/ld-x86-64/pr19609-1a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1e.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1f.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1g.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1h.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1i.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1j.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1k.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1l.d: Likewise.
	* testsuite/ld-x86-64/pr19609-1m.d: Likewise.
	* testsuite/ld-x86-64/pr19609-2.s: Likewise.
	* testsuite/ld-x86-64/pr19609-2a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-2b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-2c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-2d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-3.s: Likewise.
	* testsuite/ld-x86-64/pr19609-3a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-3b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4.s: Likewise.
	* testsuite/ld-x86-64/pr19609-4a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4e.d: Likewise.
	* testsuite/ld-x86-64/pr19609-5.s: Likewise.
	* testsuite/ld-x86-64/pr19609-5a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-5b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-5c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-5d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-5e.d: Likewise.
	* testsuite/ld-x86-64/pr19609-6.s: Likewise.
	* testsuite/ld-x86-64/pr19609-6a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-6b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-6c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-6d.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7.s: Likewise.
	* testsuite/ld-x86-64/pr19609-7a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7d.d: Likewise.
	* testsuite/ld-i386/i386.exp: Run undefweak tests and tests for
	PR ld/19609.
	* testsuite/ld-x86-64/x86-64.exp: Run pr13082-3c, pr13082-3d
	and tests for PR ld/19609.
2016-02-26 09:39:24 -08:00
H.J. Lu
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
H.J. Lu
64d25c4414 Add R_X86_64_RELATIVE64 and handle R_X86_64_64 for x32.
bfd/

2011-08-12  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/13082
	* elf64-x86-64.c (x86_64_elf_howto_table): Add R_X86_64_RELATIVE64.
	(elf_x86_64_relocate_section): Treat R_X86_64_64 like R_X86_64_32
	and zero-extend it to 64bit if addend is zero for x32.  Generate
	R_X86_64_RELATIVE64 for x32.

include/elf/

2011-08-12  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/13082
	* x86-64.h (R_X86_64_RELATIVE64): New.

ld/testsuite/

2011-08-12  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/13082
	* ld-x86-64/pr13082-1.s: New.
	* ld-x86-64/pr13082-1a.d: Likewise.
	* ld-x86-64/pr13082-1b.d: Likewise.
	* ld-x86-64/pr13082-2.s: Likewise.
	* ld-x86-64/pr13082-2a.d: Likewise.
	* ld-x86-64/pr13082-2b.d: Likewise.
	* ld-x86-64/pr13082-3.s: Likewise.
	* ld-x86-64/pr13082-3a.d: Likewise.
	* ld-x86-64/pr13082-3b.d: Likewise.
	* ld-x86-64/pr13082-4.s: Likewise.
	* ld-x86-64/pr13082-4a.d: Likewise.
	* ld-x86-64/pr13082-4b.d: Likewise.
	* ld-x86-64/pr13082-5.s: Likewise.
	* ld-x86-64/pr13082-5a.d: Likewise.
	* ld-x86-64/pr13082-5b.d: Likewise.
	* ld-x86-64/pr13082-6.s: Likewise.
	* ld-x86-64/pr13082-6a.d: Likewise.
	* ld-x86-64/pr13082-6b.d: Likewise.

	* ld-x86-64/x86-64.exp: Run pr13082-[1-6][ab].
2011-08-12 19:42:39 +00:00