Power8 fuses addis,addi and addis,ld sequences when the target of the
addis is the same as the addi/ld. Thus
addis r12,r2,xxx@ha
addi r12,r12,xxx@l / ld r12,xxx@l(r12)
is faster than
addis r11,r2,xxx@ha
addi r12,r11,xxx@l / ld r12,xxx@l(r11)
So use the form that allows fusion in plt call and branch stubs.
bfd/
* elf64-ppc.c (ADDIS_R12_R2): Define.
(build_plt_stub): Support fusion on ELFv2 stub.
(ppc_build_one_stub): Likewise for plt branch stubs.
gold/
* powerpc.cc (addis_12_2): Define.
(Stub_table::do_write): Support fusion on ELFv2 stubs.
ld/testsuite/
* ld-powerpc/elfv2exe.d: Update for changed plt call stubs.
gdb/
* ppc64-tdep.c (ppc64_standard_linkage8): New.
(ppc64_skip_trampoline_code): Recognise ELFv2 stub supporting fusion.
ld/testsuite/
* lib/ld-lib.exp: Add objcopy_objects command to run_dump_test.
This allows each input object to be optionally run through
objcopy before linking.
aarch64 does not support building non-PIC shared objects, so mark
tests for these as xfail.
ld/testsuite/ChangeLog:
2014-05-20 Will Newton <will.newton@linaro.org>
* ld-shared/shared.exp: Mark non-PIC shared object tests
as xfail on aarch64.
* ld-elf/shared.exp: Introduce the extralibs variable to control
the libraries to be linked. Don't link -ldl on *-*-freebsd*.
* ld-bootstrap/bootstrap.exp: Do not add -ldl to the extralibs on
*-*-freebsd*.
ld:
* ldlang.c (lang_finish): Don't call bfd_link_hash_table_free here.
(output_bfd_hash_table_free_fn): New variable.
(open_output): Save the _bfd_link_hash_table_free function for the
output_bfd into output_bfd_hash_table_free_fn.
* ldmain.c (ld_cleanup): If set, call output_bfd_hash_table_free_fn
on link_info.hash.
* ldlang.h (output_bfd_hash_table_free_fn): Declare.
ld/testsuite:
* ld-mmix/wrap1.d, ld-mmix/wrap1a.s, ld-mmix/wrap1b.s,
ld-mmix/wrap1c.s, ld-mmix/wrap2.d, ld-mmix/wrap3.d,
ld-mmix/wrap3a.s, ld-mmix/wrap3b.s, ld-mmix/wrap4.d: New
tests.
R_XTENSA_DIFF relocation offsets are in fact signed. Treat them as such.
Add testcase that examines ld behaviour on R_XTENSA_DIFF relocation
changing sign during relaxation.
2014-05-02 Volodymyr Arbatov <arbatov@cadence.com>
David Weatherford <weath@cadence.com>
Max Filippov <jcmvbkbc@gmail.com>
bfd/
* elf32-xtensa.c (relax_section): treat R_XTENSA_DIFF* relocations as
signed.
gas/
* config/tc-xtensa.c (md_apply_fix): mark BFD_RELOC_XTENSA_DIFF*
fixups as signed.
ld/testsuite/
* ld-xtensa/diff_overflow.exp, * ld-xtensa/diff_overflow1.s,
* ld-xtensa/diff_overflow2.s: Add test for DIFF* relocation
signedness and overflow checking.
be placed towards the front of local GOT space, while entries addressed
via a 32-bit index are placed towards the rear.
Provided that there are fewer than ~16K local GOT entries addressed via
a 16-bit index in total, this should eliminate any relocation overflows
caused by such GOT entries being allocated beyond the addressable range.
bfd/
* elfxx-mips.c (struct mips_got_info): Delete assigned_gotno
field. Add assigned_low_gotno and assigned_high_gotno fields.
(mips_elf_create_local_got_entry): Update out-of-space condition.
Set index of new GOT entry to assigned_low_gotno if required by
the current relocation, else set it to assigned_high_gotno.
(mips_elf_set_global_gotidx): Replace uses of assigned_gotno
with assigned_low_gotno.
(mips_elf_multi_got): Initialize assigned_low_gotno and
assigned_high_gotno in secondary GOTs. Use assigned_low_gotno
in place of assigned_gotno when handling global GOT entries.
(mips_elf_lay_out_got): Initialize assigned_low_gotno and
assigned_high_gotno.
(_bfd_mips_elf_finish_dynamic_sections): Account for a possible
gap in the middle of local GOT space.
ld/testsuite/
* ld-mips-elf/elf-rel-xgot-n32.d: Update for new GOT layout.
* ld-mips-elf/elf-rel-xgot-n32-embed.d: Likewise.
* ld-mips-elf/elf-rel-xgot-n64.d: Likewise.
* ld-mips-elf/elf-rel-xgot-n64-embed.d: Likewise.
* ld-mips-elf/elf-rel-xgot-n64-linux.d: Likewise.
The AArch64 TLSDESC to IE relaxation code uses a bit mask intended to
ensure that destination register in a relaxed ldr instruction is
always X0. The mask has an off by one error resulting in the most
significant bit of the destination register being retained in the
relaxed instruction. The issue generally appears when the compiler
emits TLS accesses code under high register pressure resulting in a
broken code sequence.
When aligning input sections, we are supposed to take the fill pattern
from a FILL statement, if there is one in the output section statement.
ld/
* ldlang.c (lang_size_sections_1 <lang_input_section_enum>): Use
current "fill", not "output_section_statement->fill".
ld/testsuite/
* ld-scripts/fill.d, * ld-scripts/fill.t, * ld-scripts/fill_0.s,
* ld-scripts/fill_1.s, * ld-scripts/fill_2.s: New test.
* ld-scripts/data.exp: Run it.
This patch scans all input files for symbol reference warning if the
symbol reference doesn't exist in the current input file.
ld/
PR ld/16756
* ldmain.c (symbol_warning): New function.
(warning_callback): Use it. Scan all input files for a reference
to SYMBOL.
ld/testsuite/
PR ld/16756
* ld-plugin/lto.exp: Expect filename and line number for PR
ld/12760 test.
ELFv2 needs to create plt entries in a non-PIC executable for an
address reference to a function defined in a shared object. It's
possible that an object file has no features that distinguish it as
ELFv1 or ELFv2, eg. an object only containing data. Such files need
to be handled like those that are known to be ELFv2.
However, this unnecessarily creates plt entries for the analogous
ELFv1 case, so arrange to set output abi version earlier, and use the
output abi version to further distinguish ambiguous input files.
bfd/
* elf64-ppc.c (ppc64_elf_check_relocs): Account for possibly
needed plt entries when taking the address of functions for
abiversion == 0 (ie. unknown) as well as abiversion == 2.
Move opd setup and abiversion checks to..
(ppc64_elf_before_check_relocs): ..here. Renamed from
ppc64_elf_process_dot_syms. Set output abiversion from input and
input abiversion from output, if either is not set.
(ppc64_elf_merge_private_bfd_data): Don't merge flags here.
(elf_backend_check_directives): Update.
ld/testsuite/
* ld-powerpc/startv1.s, * ld-powerpc/startv2.s, * ld-powerpc/funref.s,
* ld-powerpc/funv1.s, * ld-powerpc/funv2.s,
* ld-powerpc/ambiguousv1.d, * ld-powerpc/ambiguousv2.d: New test files.
* ld-powerpc/powerpc.exp: Run new tests.
The current code subtracts the size of the output section containing
relplt from RELASZ. In some cases this will be the same output
section as the dynamic relocs causing a value of zero to be output.
Calculating the size from input sections seems to make more sense.
bfd/ChangeLog:
2014-03-25 Will Newton <will.newton@linaro.org>
* elfnn-aarch64.c (elfNN_aarch64_finish_dynamic_sections):
Set value of DT_PLTRELSZ and DT_RELASZ based on the size
of input sections rather than output sections.
ld/testsuite/ChangeLog:
2014-03-25 Will Newton <will.newton@linaro.org>
* ld-aarch64/aarch64-elf.exp: Add relasz dump test.
* ld-aarch64/relasz.d: New file.
* ld-aarch64/relasz.s: Likewise.
Unless pointer_equality_needed is set then set st_value to be zero
for undefined symbols.
bfd/ChangeLog:
2014-03-20 Will Newton <will.newton@linaro.org>
PR ld/16715
* elf32-arm.c (elf32_arm_check_relocs): Set
pointer_equality_needed for absolute references within
executable links.
(elf32_arm_finish_dynamic_symbol): Set st_value to zero
unless pointer_equality_needed is set.
ld/testsuite/ChangeLog:
2014-03-20 Will Newton <will.newton@linaro.org>
* ld-arm/ifunc-14.rd: Update symbol values.
ld/testsuite/
* ld-arm/gc-hidden-1.d: Remove target, add not-target to match
other ELF-only tests in this directory. Loosen regexps so they
don't care what the exact addresses are.
This adds support for "func@localentry", an expression that returns the
ELFv2 local entry point address of function "func". I've excluded
dynamic relocation support because that obviously would require glibc
changes.
include/elf/
* ppc64.h (R_PPC64_REL24_NOTOC, R_PPC64_ADDR64_LOCAL): Define.
bfd/
* elf64-ppc.c (ppc64_elf_howto_raw): Add R_PPC64_ADDR64_LOCAL entry.
(ppc64_elf_reloc_type_lookup): Support R_PPC64_ADDR64_LOCAL.
(ppc64_elf_check_relocs): Likewise.
(ppc64_elf_relocate_section): Likewise.
* Add BFD_RELOC_PPC64_ADDR64_LOCAL.
* bfd-in2.h: Regenerate.
* libbfd.h: Regenerate.
gas/
* config/tc-ppc.c (ppc_elf_suffix): Support @localentry.
(md_apply_fix): Support R_PPC64_ADDR64_LOCAL.
ld/testsuite/
* ld-powerpc/elfv2-2a.s, ld-powerpc/elfv2-2b.s: New files.
* ld-powerpc/elfv2-2exe.d, ld-powerpc/elfv2-2so.d: New files.
* ld-powerpc/powerpc.exp: Run new test.
elfcpp/
* powerpc.h (R_PPC64_REL24_NOTOC, R_PPC64_ADDR64_LOCAL): Define.
gold/
* powerpc.cc (Target_powerpc::Scan::local, global): Support
R_PPC64_ADDR64_LOCAL.
(Target_powerpc::Relocate::relocate): Likewise.
Enabled via the use of a new linker command line option: --long-plt.
* bfd-in.h: Add export of bfd_elf32_arm_use_long_plt.
* bfd-in2.h: Regenerate.
* elf32-arm.c (elf32_arm_plt_entry_long): New array.
(elf32_arm_link_hash_table_create): Set plt_entry_size to 16 if
using long PLT entries.
(bfd_elf32_arm_use_long_plt): New function.
(elf32_arm_populate_plt_entry): Add support for long PLT entries.
* emultempl/armelf.em (OPTION_LONG_PLT): Define.
(PARSE_AND_LIST_LONGOPTS): Add long-plt.
(PARSE_AND_LIST_OPTIONS): Likewise.
(PARSE_AND_LIST_ARGS_CASES): Handle long-plt.
* ld.texinfo: Document --long-plt.
* ld-arm/long-plt-format.s: New test case.
* ld-arm/long-plt-format.d: Expected disassembly.
* ld-arm/arm-elf.exp: Run the new test.
The manifest is necessary in order for the linked binaries to be executed in a Windows 8 environment.
The manifest is added using a linker script so that this feature will be compiler-neutral. The resource
merging code in the linker means that if an application provides its own manifest then the default
manifest will be ignored.
* configure.in (all_emul_extra_binaries): New variable. Populated
by invoking configure.tgt.
(EMUL_EXTRA_BINARIES): New substitution.
* configure: Regenerate.
* configure.tgt (target_extra_binaries): New variable. Set to
default-manifest.o for Cygwin and MinGW targets.
* Makefile.am (EMUL_EXTRA_BINARIES): New variable. Initialised
by the configure script.
(ALL_EMUL_EXTRA_BINARIES): New variable.
(default-manifest.o): New rule to build the default manifest.
(ld_new_DEPENDENCIES): Add EMUL_EXTRA_BINARIES.
(install-data-local): Add EMUL_EXTRA_BINARIES.
* Makefile.in: Regenerate.
* ld.texinfo: Document default manifest support.
* emulparams/i386pe.sh (DEFAULT_MANIFEST): Define.
* emulparams/i386pep.sh (DEFAULT_MANIFEST): Define.
* emultempl/default-manifest.rc: New file.
* scripttempl/pe.sc (R_RSRC): Include DEFAULT_MANIFEST, if defined.
* scripttempl/pep.sc (R_RSRC): Likewise.
* ld-pe/longsecn-1.d: Allow for extra sections.
* ld-pe/longsecn-2.d: Likewise.
* ld-pe/longsecn.d: Likewise.
* ld-pe/secrel.d: Likewise.
I was running this by hand to test out --ppc476-workaround. Another
bootstrap test doesn't take all that long, so let's add it to the
testsuite.
* ld-bootstrap/bootstrap.exp: Add ppc476 workaround test.
* ld-bootstrap/ppc476.t: New file.
Intel MPX introduces 4 bound registers, which will be used for parameter
passing in x86-64. Bound registers are cleared by branch instructions.
Branch instructions with BND prefix will keep bound register contents.
This leads to 2 requirements to 64-bit MPX run-time:
1. Dynamic linker (ld.so) should save and restore bound registers during
symbol lookup.
2. Change the current 16-byte PLT0:
ff 35 08 00 00 00 pushq GOT+8(%rip)
ff 25 00 10 00 jmpq *GOT+16(%rip)
0f 1f 40 00 nopl 0x0(%rax)
and 16-byte PLT1:
ff 25 00 00 00 00 jmpq *name@GOTPCREL(%rip)
68 00 00 00 00 pushq $index
e9 00 00 00 00 jmpq PLT0
which clear bound registers, to preserve bound registers.
We use 2 new relocations:
to mark branch instructions with BND prefix.
When linker sees any R_X86_64_PC32_BND or R_X86_64_PLT32_BND relocations,
it switches to a different PLT0:
ff 35 08 00 00 00 pushq GOT+8(%rip)
f2 ff 25 00 10 00 bnd jmpq *GOT+16(%rip)
0f 1f 00 nopl (%rax)
to preserve bound registers for symbol lookup and it also creates an
external PLT section, .pl.bnd. Linker will create a BND PLT1 entry
in .plt:
68 00 00 00 00 pushq $index
f2 e9 00 00 00 00 bnd jmpq PLT0
0f 1f 44 00 00 nopl 0(%rax,%rax,1)
and a 8-byte BND PLT entry in .plt.bnd:
f2 ff 25 00 00 00 00 bnd jmpq *name@GOTPCREL(%rip)
90 nop
Otherwise, linker will create a legacy PLT1 entry in .plt:
68 00 00 00 00 pushq $index
e9 00 00 00 00 jmpq PLT0
66 0f 1f 44 00 00 nopw 0(%rax,%rax,1)
and a 8-byte legacy PLT in .plt.bnd:
ff 25 00 00 00 00 jmpq *name@GOTPCREL(%rip)
66 90 xchg %ax,%ax
The initial value of the GOT entry for "name" will be set to the the
"pushq" instruction in the corresponding entry in .plt. Linker will
resolve reference of symbol "name" to the entry in the second PLT,
.plt.bnd.
Prelink stores the offset of pushq of PLT1 (plt_base + 0x10) in GOT[1]
and GOT[1] is stored in GOT[3]. We can undo prelink in GOT by computing
the corresponding the pushq offset with
GOT[1] + (GOT offset - &GOT[3]) * 2
Since for each entry in .plt except for PLT0 we create a 8-byte entry in
.plt.bnd, there is extra 8-byte per PLT symbol.
We also investigated the 16-byte entry for .plt.bnd. We compared the
8-byte entry vs the the 16-byte entry for .plt.bnd on Sandy Bridge.
There are no performance differences in SPEC CPU 2000/2006 as well as
micro benchmarks.
Pros:
No change to undo prelink in dynamic linker.
Only 8-byte memory overhead for each PLT symbol.
Cons:
Extra .plt.bnd section is needed.
Extra 8 byte for legacy branches to PLT.
GDB is unware of the new layout of .plt and .plt.bnd.
bfd/
* elf64-x86-64.c (elf_x86_64_bnd_plt0_entry): New.
(elf_x86_64_legacy_plt_entry): Likewise.
(elf_x86_64_bnd_plt_entry): Likewise.
(elf_x86_64_legacy_plt2_entry): Likewise.
(elf_x86_64_bnd_plt2_entry): Likewise.
(elf_x86_64_bnd_arch_bed): Likewise.
(elf_x86_64_link_hash_entry): Add has_bnd_reloc and plt_bnd.
(elf_x86_64_link_hash_table): Add plt_bnd.
(elf_x86_64_link_hash_newfunc): Initialize has_bnd_reloc and
plt_bnd.
(elf_x86_64_copy_indirect_symbol): Also copy has_bnd_reloc.
(elf_x86_64_check_relocs): Create the second PLT for Intel MPX
in 64-bit mode.
(elf_x86_64_allocate_dynrelocs): Handle the second PLT for IFUNC
symbols. Resolve call to the second PLT if it is created.
(elf_x86_64_size_dynamic_sections): Keep the second PLT section.
(elf_x86_64_relocate_section): Resolve PLT references to the
second PLT if it is created.
(elf_x86_64_finish_dynamic_symbol): Use BND PLT0 and fill the
second PLT entry for BND relocation.
(elf_x86_64_finish_dynamic_sections): Use MPX backend data if
the second PLT is created.
(elf_x86_64_get_synthetic_symtab): New.
(bfd_elf64_get_synthetic_symtab): Likewise. Undefine for NaCl.
ld/
* emulparams/elf_x86_64.sh (TINY_READONLY_SECTION): New.
ld/testsuite/
* ld-x86-64/mpx.exp: Run bnd-ifunc-1 and bnd-plt-1.
* ld-x86-64/bnd-ifunc-1.d: New file.
* ld-x86-64/bnd-ifunc-1.s: Likewise.
* ld-x86-64/bnd-plt-1.d: Likewise.
execute permission regardless of the underlying PT_LOAD segment permissions.
Deleting this code allows the default linker behavior which is to set the
dynamic segment to the same permissions as the sections that make it up.
This change alters one existing test case to check the segment flags for
PT_DYNAMIC.
bfd/ChangeLog
* elfxx-mips.c(_bfd_mips_elf_modify_segment_map): Deleted hard coding of
PT_DYNAMIC segment flags.
ld/testsuite/ChangeLog
* ld-mips-elf/pic-and-nonpic-3a.sd: Check DYNAMIC segment flags.
It is added for
commit 409ff343a4
Author: Alan Modra <amodra@gmail.com>
Date: Tue Nov 8 13:49:11 2011 +0000
* elflink.c (bfd_elf_gc_mark_dynamic_ref_symbol): Mark syms in
executables when export_dynamic.
* ld-elf/rdynamic-1.c: New file.
* ld-elf/rdynamic-1.rd: Likewise.
* ld-elf/shared.exp (build_tests): Add rdynamic-1.
