This tightens the condition under which ld optimizes PIC entry code
to non-PIC.
bfd/
* elf64-ppc.c (ppc64_elf_relocate_section): Further restrict
ELFv2 entry optimization.
gold/
* powerpc.cc (relocate): Further restrict ELFv2 entry optimization.
For MIPS-64, the r_info field in the relocation format is
replaced by several individual fields, including r_sym and
r_type. To enable support for this format, I've refactored
target-independent code to remove almost all uses of the r_info
field. (I've left alone a couple of routines used only for
incremental linking, which I can update if/when the MIPS target
adds support for incremental linking.)
For routines that are already templated on a Classify_reloc class
(namely, gc_process_relocs, relocate_section, and
relocate_relocs), I've extended the Classify_reloc interface to
include sh_type (which no longer needs to be a separate template
parameter) as well as get_r_sym() and get_r_type() methods for
extracting the r_sym and r_type fields. For
scan_relocatable_relocs, I've extended the
Default_scan_relocatable_relocs class by converting it to a class
template with Classify_reloc as a template parameter. For the
remaining routines that need to access r_sym, I've added a
virtual Target::get_r_sym() method with an override for the MIPS
target.
In elfcpp, I've added Mips64_rel, etc., accessor classes and
corresponding internal data structures. The MIPS target uses
these new classes within its own Mips_classify_reloc class.
The Mips64_ accessor classes also expose the r_ssym, r_type2,
and r_type3 fields from the relocation.
These changes should be functionally the same for all but the
MIPS target.
elfcpp/
* elfcpp.h (Mips64_rel, Mips64_rel_write): New classes.
(Mips64_rela, Mips64_rela_write): New classes.
* elfcpp_internal.h (Mips64_rel_data, Mips64_rela_data): New structs.
gold/
* gc.h (get_embedded_addend_size): Remove sh_type parameter.
(gc_process_relocs): Remove sh_type template parameter.
Use Classify_reloc to access r_sym, r_type, and r_addend fields.
* object.h (Sized_relobj_file::split_stack_adjust): Add target
parameter.
(Sized_relobj_file::split_stack_adjust_reltype): Likewise.
* reloc-types.h (Reloc_types::copy_reloc_addend): (SHT_REL and SHT_RELA
specializations) Remove.
* reloc.cc (Emit_relocs_strategy): Rename and move to target-reloc.h.
(Sized_relobj_file::emit_relocs_scan): Call Target::emit_relocs_scan().
(Sized_relobj_file::emit_relocs_scan_reltype): Remove.
(Sized_relobj_file::split_stack_adjust): Add target parameter.
Adjust all callers.
(Sized_relobj_file::split_stack_adjust_reltype): Likewise. Call
Target::get_r_sym() to get r_sym field from relocations.
(Track_relocs::next_symndx): Call Target::get_r_sym().
* target-reloc.h (scan_relocs): Remove sh_type template parameter;
add Classify_reloc template parameter. Use for accessing r_sym and
r_type.
(relocate_section): Likewise.
(Default_classify_reloc): New class (renamed and moved from reloc.cc).
(Default_scan_relocatable_relocs): Remove sh_type template parameter.
(Default_scan_relocatable_relocs::Reltype): New typedef.
(Default_scan_relocatable_relocs::reloc_size): New const.
(Default_scan_relocatable_relocs::sh_type): New const.
(Default_scan_relocatable_relocs::get_r_sym): New method.
(Default_scan_relocatable_relocs::get_r_type): New method.
(Default_emit_relocs_strategy): New class.
(scan_relocatable_relocs): Replace sh_type template parameter with
Scan_relocatable_relocs class. Use it to access r_sym and r_type
fields.
(relocate_relocs): Replace sh_type template parameter with
Classify_reloc class. Use it to access r_sym and r_type fields.
* target.h (Target::is_call_to_non_split): Replace r_type parameter
with pointer to relocation. Adjust all callers.
(Target::do_is_call_to_non_split): Likewise.
(Target::emit_relocs_scan): New virtual method.
(Sized_target::get_r_sym): New virtual method.
* target.cc (Target::do_is_call_to_non_split): Replace r_type parameter
with pointer to relocation.
* aarch64.cc (Target_aarch64::emit_relocs_scan): New method.
(Target_aarch64::Relocatable_size_for_reloc): Remove.
(Target_aarch64::gc_process_relocs): Use Default_classify_reloc.
(Target_aarch64::scan_relocs): Likewise.
(Target_aarch64::relocate_section): Likewise.
(Target_aarch64::Relocatable_size_for_reloc::get_size_for_reloc):
Remove.
(Target_aarch64::scan_relocatable_relocs): Use Default_classify_reloc.
(Target_aarch64::relocate_relocs): Use Default_classify_reloc.
* arm.cc (Target_arm::Arm_scan_relocatable_relocs): Remove sh_type
template parameter.
(Target_arm::emit_relocs_scan): New method.
(Target_arm::Relocatable_size_for_reloc): Replace with...
(Target_arm::Classify_reloc): ...this.
(Target_arm::gc_process_relocs): Use Classify_reloc.
(Target_arm::scan_relocs): Likewise.
(Target_arm::relocate_section): Likewise.
(Target_arm::scan_relocatable_relocs): Likewise.
(Target_arm::relocate_relocs): Likewise.
* i386.cc (Target_i386::emit_relocs_scan): New method.
(Target_i386::Relocatable_size_for_reloc): Replace with...
(Target_i386::Classify_reloc): ...this.
(Target_i386::gc_process_relocs): Use Classify_reloc.
(Target_i386::scan_relocs): Likewise.
(Target_i386::relocate_section): Likewise.
(Target_i386::scan_relocatable_relocs): Likewise.
(Target_i386::relocate_relocs): Likewise.
* mips.cc (Mips_scan_relocatable_relocs): Remove sh_type template
parameter.
(Mips_reloc_types): New class template.
(Mips_classify_reloc): New class template.
(Target_mips::Reltype): New typedef.
(Target_mips::Relatype): New typedef.
(Target_mips::emit_relocs_scan): New method.
(Target_mips::get_r_sym): New method.
(Target_mips::Relocatable_size_for_reloc): Replace with
Mips_classify_reloc.
(Target_mips::copy_reloc): Use Mips_classify_reloc.
(Target_mips::gc_process_relocs): Likewise.
(Target_mips::scan_relocs): Likewise.
(Target_mips::relocate_section): Likewise.
(Target_mips::scan_relocatable_relocs): Likewise.
(Target_mips::relocate_relocs): Likewise.
(mips_get_size_for_reloc): New function, factored out from
Relocatable_size_for_reloc::get_size_for_reloc.
(Target_mips::Scan::local): Use Mips_classify_reloc.
(Target_mips::Scan::global): Likewise.
(Target_mips::Relocate::relocate): Likewise.
* powerpc.cc (Target_powerpc::emit_relocs_scan): New method.
(Target_powerpc::Relocatable_size_for_reloc): Remove.
(Target_powerpc::gc_process_relocs): Use Default_classify_reloc.
(Target_powerpc::scan_relocs): Likewise.
(Target_powerpc::relocate_section): Likewise.
(Powerpc_scan_relocatable_reloc): Convert to class template.
(Powerpc_scan_relocatable_reloc::Reltype): New typedef.
(Powerpc_scan_relocatable_reloc::reloc_size): New const.
(Powerpc_scan_relocatable_reloc::sh_type): New const.
(Powerpc_scan_relocatable_reloc::get_r_sym): New method.
(Powerpc_scan_relocatable_reloc::get_r_type): New method.
(Target_powerpc::scan_relocatable_relocs): Use
Powerpc_scan_relocatable_reloc.
(Target_powerpc::relocate_relocs): Use Default_classify_reloc.
* s390.cc (Target_s390::emit_relocs_scan): New method.
(Target_s390::Relocatable_size_for_reloc): Remove.
(Target_s390::gc_process_relocs): Use Default_classify_reloc.
(Target_s390::scan_relocs): Likewise.
(Target_s390::relocate_section): Likewise.
(Target_s390::Relocatable_size_for_reloc::get_size_for_reloc):
Remove.
(Target_s390::scan_relocatable_relocs): Use Default_classify_reloc.
(Target_s390::relocate_relocs): Use Default_classify_reloc.
* sparc.cc (Target_sparc::emit_relocs_scan): New method.
(Target_sparc::Relocatable_size_for_reloc): Remove.
(Target_sparc::gc_process_relocs): Use Default_classify_reloc.
(Target_sparc::scan_relocs): Likewise.
(Target_sparc::relocate_section): Likewise.
(Target_sparc::Relocatable_size_for_reloc::get_size_for_reloc):
Remove.
(Target_sparc::scan_relocatable_relocs): Use Default_classify_reloc.
(Target_sparc::relocate_relocs): Use Default_classify_reloc.
* tilegx.cc (Target_tilegx::emit_relocs_scan): New method.
(Target_tilegx::Relocatable_size_for_reloc): Remove.
(Target_tilegx::gc_process_relocs): Use Default_classify_reloc.
(Target_tilegx::scan_relocs): Likewise.
(Target_tilegx::relocate_section): Likewise.
(Target_tilegx::Relocatable_size_for_reloc::get_size_for_reloc):
Remove.
(Target_tilegx::scan_relocatable_relocs): Use Default_classify_reloc.
(Target_tilegx::relocate_relocs): Use Default_classify_reloc.
* x86_64.cc (Target_x86_64::emit_relocs_scan): New method.
(Target_x86_64::Relocatable_size_for_reloc): Remove.
(Target_x86_64::gc_process_relocs): Use Default_classify_reloc.
(Target_x86_64::scan_relocs): Likewise.
(Target_x86_64::relocate_section): Likewise.
(Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc):
Remove.
(Target_x86_64::scan_relocatable_relocs): Use Default_classify_reloc.
(Target_x86_64::relocate_relocs): Use Default_classify_reloc.
* testsuite/testfile.cc (Target_test::emit_relocs_scan): New method.
In an fixed position executable, the entry code does not need to be
PIC and can thus lose a dependency on r12.
* powerpc.cc (Target_powerpc::Relocate::relocate): Edit ELFv2
entry code.
(Target_powerpc::relocate_relocs): Edit relocs to suit.
Some linker code editing needs to change multiple insns. In some
cases multiple relocations are involved and it is not sufficient to
make the changes independently as relocations are processed, because
doing so might lead to a partial edit. So in order to safely edit we
need all the relocations available in relocate(). Also, to emit
edited relocs corresponding to the edited code sequence we need some
way to pass information from relocate() to relocate_relocs(),
particularly if the edit depends on insns. We can't modify input
relocs in relocate() as they are mmapped PROT_READ, nor it is
particularly clean to write relocs to the output at that stage. So
add a Relocatable_relocs* field to relinfo to mark edited relocs.
Given that relocate is passed the raw reloc pointer, it makes sense to
remove the rel/rela parameter and r_type too. However, that means the
mips relocate() needs to know whether SHT_REL or SHT_RELA relocs are
being processed. So add a rel_type for mips, which also has the
benefit of removing relocate() overloading there.
This patch adds the infrastructure without making use of it.
Note that relinfo->rr will be NULL if not outputting relocations.
* object.h (struct Relocate_info): Add "rr".
* reloc.h (Relocatable_relocs::set_strategy): New accessor.
* reloc.cc (Sized_relobj_file::do_relocate_sections): Init
relinfo.rr for relocate_section and relocate_relocs.
* powerpc.cc (relocate): Add rel_type and preloc parameters.
Delete rela and r_type params, instead recalculate these from
preloc.
(relocate_relocs): Delete Relocatable_relocs* param, instead
use relinfo->rr.
* aarch64.cc: Likewise.
* arm.cc: Likewise.
* i386.cc: Likewise.
* mips.cc: Likewise.
* s390.cc: Likewise.
* sparc.cc: Likewise.
* target.h: Likewise.
* tilegx.cc: Likewise.
* x86_64.cc: Likewise.
* testsuite/testfile.cc: Likewise.
* target-reloc.h (relocate_section): Adjust to suit.
(apply_relocation, relocate_relocs): Likewise.
Gold version of a4b6fadd. Don't emit long branch or plt branch stubs
to save/restore functions. Copy them instead.
PR 18878
* powerpc.cc (Target_powerpc): Add savres_section_ and accessor.
(Target_powerpc::Branch_info::make_stub): Determine whether long
branch stub is for save/restore function.
(Branch_stub_ent): Add save_res_, and extra parm to constructor.
(Stub_table): Add need_save_res_.
(Stub_table:clear_stubs): Clear need_save_res_.
(Stub_table:set_address_and_size): Add save/restore section size.
(Stub_table::add_long_branch_entry): Add save_res param. Set
need_save_res_, but don't add space for save/restore stubs.
(Stub_table::find_long_branch_entry): Return offset to local copy
of save/restore func.
(Stub_table::do_write): Don't output save/restore stubs. Instead
copy the save/restore functions.
(Output_data_save_res:contents): New accessor.
(Target_powerpc::define_save_restore_funcs): Set savres_section_.
A symbol value in an ELF final linked binary is absolute, in contrast
to a relocatable object file where the value is section relative. For
--emit-relocs it is therefore incorrect to use the value of a section
symbol as the addend when adjusting relocs against input section
symbols to output section symbols.
PR gold/18846
* target-reloc.h (relocate_relocs <RELOC_ADJUST_FOR_SECTION_RELA>):
Subtract os->address() from addend.
* powerpc.cc (relocate_relocs): Likewise.
PowerPC64 ELFv1 requires a tweak to find_functions in order to return
code addresses, rather than OPD entry addresses.
* reloc.cc (Sized_relobj_file::find_functions): Use function_location.
* powerpc.cc (Target_powerpc::do_calls_non_split): New function.
(addi_12_1, addis_2_12, addis_12_1, cmpld_7_12_0): New constants.
(lis_0): Rename from lis_0_0.
Completely removing the assert probably wasn't the best idea, so
reinstate it for allocated sections. Also cope with debug info
potentially referring to a missing plt call stub.
And a tidy. find_global_entry now returns an Address, so make temps
holding the return value of type Address, and compare against
invalid_address.
* powerpc.cc (Target_powerpc::do_dynsym_value): Use Address rather
than unsigned int for find_global_entry result temp. Compare
against invalid_address.
(Target_powerpc::do_plt_address_for_global): Likewise.
(Target_powerpc::Relocate::relocate): Likewise. Don't assert
on plt call stub existence for debug info. Do assert for plt
and global entry stub existence if an alloc section.
Global entry stubs are used on ELFv2 to provide addresses for
functions not defined in a non-PIC executable but whose address is
taken, in much the same way as PLT stub code is used on other
targets to provide function addresses. We don't want to insert a
global entry stub just because (bogus) debug info refers to the
address of a non-local function, but we also don't want gold to die.
* powerpc.cc (Target_powerpc::Relocate::relocate): Don't assert
on missing global entry stub due to bogus debug info.
If ignoring unresolved symbols, ignore reloc overflows too. If not
ignoring unresolved symbols we will report an error about the symbol
being undefined, making any report about reloc overflow superfluous.
PR18147
* powerpc.cc (Target_powerpc::Relocate::relocate): Don't report
relocation errors for branches to strong undefined symbols.
PR 18010
* powerpc.cc (Powerpc_relocate_functions::addr16_ds): Always
complain if value is not a multiple of four.
(Target_powerpc::Relocate::relocate): Correct handling of
R_POWERPC_GOT_TPREL16 and R_POWERPC_GOT_TPREL16_LO for ppc64.
Found when applying relocs in .debug that reference removed functions.
PR 17954
* powerpc.cc (Global_symbol_visitor_opd::operator()): Set default
visibility.
Found when attempting to build an ELFv2 Linux kernel. We don't
generally need a plt entry for ELFv2 got relocs, only on ifunc, just
like ppc32.
* powerpc.cc (Target_powerpc::Scan::local <got relocs>): Correct
condition for need of ifunc plt entry.
(Target_powerpc::Scan::global <got relocs>): Likewise.
Mixing 64-bit and 32-bit types led to the wrong promotions. Keep
calculation in same type. Also fix a case where PLTREL25 reloc addend
should be ignored.
* Powerpc.cc (Target_powerpc::Branch_info::make_stub): Ignore
addend of PLTREL24 reloc when not generating a plt stub. Make
max_branch_offset an "Address".
(Stub_table::can_read_stub): Make max_branch_offset an "Address".
(Target_powerpc::Relocate::relocate): Likewise.
pr17670 is about an assert triggering on a branch to an undefined
weak symbol, the symbol being undefined due to dropping its comdat
group section. (Well sort of. The symbol is actually defined in
an .opd section which isn't part of the group, but the code section
the opd entry points at is dropped.) So don't assert.
Also, don't make long branch stubs to such symbols, and arrange to
have target-reloc.h code warn when applying relocs that use the sym.
PR 17670
* symtab.cc (Symbol::set_undefined): Remove assertion.
* powerpc.cc (Target_powerpc::symval_for_branch): Don't assert
on symbols defined in discarded sections, instead return false.
Rearrange params, update all callers.
(Target_powerpc::Branch_info::make_stub): Don't make stubs for
branches to syms in discarded sections.
(Global_symbol_visitor_opd::operator()): Set discarded opd syms
undefined and flag as discarded.
(Target_powerpc::Relocate::relocate): Localize variable.
Code stolen from arm.cc.
PR 17566
* powerpc.cc (Target_powerpc::Scan::local): Use add_local_section
when adding dynamic relocations against section symbols.
An unusually large number of stubs can result in the default section
group size being too large; sections plus stubs exceed the range of a
branch. Restarting the relaxation pass with a smaller group size can
sometimes help.
* powerpc.cc (struct Stub_table_owner): New.
(Powerpc_relobj): Rename stub_table_ to stub_table_index_, an
unsigned int vector. Update all references.
(powerpc_relobj::set_stub_table): Take an unsigned int param
rather than a Stub_table. Update callers.
(Powerpc_relobj::clear_stub_table): New function.
(Target_powerpc): Add relax_failed_, relax_fail_count_ and
stub_group_size_ vars.
(Target_powerpc::new_stub_table): Delete.
(max_branch_delta): New function, extracted from..
(Target_powerpc::Relocate::relocate): ..here..
(Target_powerpc::Branch_info::make_stub): ..and here. Return
status on whether stub created successfully.
(Stub_control::Stub_control): Add "no_size_errors" param. Move
default sizing to..
(Target_powerpc::do_relax): ..here. Init stub_group_size_ and
reduce on relax failure.
(Target_powerpc::group_sections): Add "no_size_errors" param.
Use stub_group_size_. Set up group info in a temp vector,
before building Stub_table vector. Account for input sections
possibly already converted to relaxed sections.
(Stub_table::init): Delete. Merge into..
(Stub_table::Stub_table): ..here.
(Stub_table::can_reach_stub): New function.
(Stub_table::add_plt_call_entry): Add "from" parameter and
return true iff stub could be reached.
(Stub_table::add_long_branch_entry): Similarly. Add "r_type"
param too.
(Stub_table::clear_stubs): Add "all" param.
It's possible for the section grouping code to decide that the last
section looked at (the first section by address) doesn't fit into a
group. In one case that section is already a group owner and that is
handled correctly. In other cases the section should be put into its
own group. Like this:
* powerpc.cc (Stub_control::set_output_and_owner): New function.
(Target_powerpc::group_sections): Use it.
Corrects overflow test for rel14, addr14, rel24, addr24 branch relocs,
and prints an information message to give a hint as to how a branch
that can't reach a stub might be cured.
bfd/
* elf64-ppc.c (group_sections): Init stub14_group_size from
--stub-group-size parameter divided by 1024.
gold/
* powerpc.cc (Stub_control::Stub_control): Init stub14_group_size_
from --stub-group-size parameter divided by 1024.
(Powerpc_relocate_functions::rela, rela_ua): Add fieldsize
template parameter. Update all uses.
(Target_powerpc::Relocate::relocate): Rename has_plt_value to
has_stub_value. Set for long branches. Don't report overflow for
branch to undefined weak symbols. Print info message on
overflowing branch to stub.
Go is multi-threaded, so use thread-safe plt stubs. __go_go doesn't
actually start threads, but is a convenient libgo function with a
reasonably unique name that is called by all Go executables. (Threads
are started by a static function of libgo, runtime_newosproc, called
by a whole lot of global functions, including runtime_starttheworld
and runtime_main.)
bfd/
* elf64-ppc.c (ppc64_elf_size_stubs): Add __go_go to thread_starters.
gold/
* powerpc.cc (Target_powerpc::do_relax): Add __go_go to thread_starters.
There are legitimate reasons to allow a signed value in a cmpli insn
field, for example to test for a "stw r1,lock@sdarel(r13)" instruction
in user code, a kernel might use
subis r3,r3,STW_R1_0R13@ha # subtract off high part
cmplwi r3,lock@sdarel # is low part accessing lock?
Since the lock@sdarel may take a range of -32768 to 32767,
the allowed range of cmpli immediate must be at least [-32768,65535].
bfd/
* elf32-ppc.c (ppc_elf_relocate_section): Treat field of cmpli
insn as a bitfield; Use complain_overflow_bitfield.
* elf64-ppc.c (ppc64_elf_relocate_section): Likewise.
opcodes/
* ppc-opc.c (UISIGNOPT): Define and use with cmpli.
gas/
* config/tc-ppc.c (ppc_insert_operand): Handle PPC_OPERAND_SIGNOPT
on unsigned fields. Comment on PPC_OPERAND_SIGNOPT signed fields
in 64-bit mode.
gold/
* powerpc.cc (relocate): Treat field of cmpli insn as a bitfield.
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.
ELFv2 doesn't use .opd, so folding function code can't be allowed
in safe mode if a function's address might be taken.
* powerpc.cc (Target_powerpc::local_reloc_may_be_function_pointer):
Only ignore relocs on ELFv1.
(Target_powerpc::global_reloc_may_be_function_pointer): Likewise.
When linking statically, it's possible to hit this warning with IFUNC
or very large executables, due to .glink being unused.
* powerpc.cc (do_plt_fde_location): Handle zero length .glink.
Compare FDE contents with DW_CFA_nop rather than 0.
to access a global as it expects a GOTPCREL relocation. This is really not
necessary as the linker could use a copy relocation to get around it. This
patch enables copy relocations with pie.
Context:
This is useful because currently the GCC compiler with option -fpie makes
every extern global access go through the GOT. That is because the compiler
cannot tell if a global will end up being defined in the executable or not
and is conservative. This ends up hurting performance when the binary is linked
as mostly static where most of the globals do end up being defined in the
executable. By allowing copy relocs with fPIE, the compiler need not generate
a GOTPCREL(GOT access) for any global access. It can safely assume that all
globals will be defined in the executable and generate a PC-relative access
instead. Gold can then create a copy reloc for only the undefined globals.
gold/
* symtab.h (may_need_copy_reloc): Remove check for position independent
code.
* x86_64.cc (Target_x86_64<size>::Scan::global): Add check for no
position independence before pc absolute may_need_copy_reloc call.
Add check for executable output befor pc relative may_need_copy_reloc
call.
* i386.cc: Ditto.
* arm.cc: Ditto.
* sparc.cc: Ditto.
* tilegx.cc: Ditto.
* powerpc.cc: Add check for no position independence before
may_need_copy_reloc calls.
* testsuite/pie_copyrelocs_test.cc: New file.
* testsuite/pie_copyrelocs_shared_test.cc: New file.
* Makefile.am (pie_copyrelocs_test): New test.
* Makefile.in: Regenerate.
R_PPC64_ADDR16 is used in three contexts:
- .short data relocation
- 16-bit signed insn fields, eg. addi
- 16-bit unsigned insn fields, eg. ori
In the first case we want to allow both signed and unsigned 16-bit
values, the latter two ought to error if the field exceeds the range
of values allowed for 16-bit signed and unsigned integers
respectively. These conflicting requirements meant that ld had to
choose the least restrictive overflow checks, and thus it is possible
to construct testcases where an addi field overflows but is not
reported by ld. Many relocations dealing with 16-bit insn fields have
this problem. What's more, some relocations that are only ever used
for signed fields of instructions woodenly copied the lax overflow
checking of R_PPC64_ADDR16.
bfd/
* elf64-ppc.c (ppc64_elf_howto_raw): Use complain_overflow_signed
for R_PPC64_ADDR14, R_PPC64_ADDR14_BRTAKEN, R_PPC64_ADDR14_BRNTAKEN,
R_PPC64_SECTOFF, R_PPC64_ADDR16_DS, R_PPC64_SECTOFF_DS,
R_PPC64_REL16 entries. Use complain_overflow_dont for R_PPC64_TOC.
(ppc64_elf_relocate_section): Modify overflow test for 16-bit
fields in instructions to signed/unsigned according to whether
the field takes a signed or unsigned value.
gold/
* powerpc.cc (Powerpc_relocate_functions::Overflow_check): Add
CHECK_UNSIGNED, CHECK_LOW_INSN, CHECK_HIGH_INSN.
(Powerpc_relocate_functions::has_overflow_unsigned): New function.
(Powerpc_relocate_functions::has_overflow_bitfield,
overflowed): Use the above.
(Target_powerpc::Relocate::relocate): Correct overflow checking
for a number of relocations. Modify overflow test for 16-bit
fields in instructions to signed/unsigned according to whether
the field takes a signed or unsigned value.
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.
* powerpc.cc (Target_powerpc::glink_section): Provide non-const
accessor.
(Target_powerpc::Branch_info::make_stub): Make global entry stubs.
Only call ppc64_local_entry_offset for 64-bit. Restrict
symval_for_branch lookup to ELFv1.
(Stub_table::add_plt_call_entry): Use unsigned int off.
(Output_data_glink::Address, invalid_address): New.
(Output_data_glink::add_eh_frame): Move out of line. Add
support for ELFv2.
(Output_data_glink::add_global_entry, find_global_entry,
global_entry_address): New functions.
(Output_data_glink::global_entry_stubs_, end_branch_table_,
ge_size): New variables.
(Output_data_glink::set_final_data_size): Add global entry
stub sizing.
(Output_data_glink::do_write): Write global entry stubs.
(Target_powerpc::Scan::reloc_needs_plt_for_ifunc): Add target
parameter. Return true for ELFv2. Adjust callers.
(Target_powerpc::Scan::local, global): Restrict opd lookup to
ELFv1. Similarly for ifunc and dynamic relocation processing
specific to ELFv1. Recognize that symbols are defined on
their plt entries for ELFv2.
(Target_powerpc::symval_for_branch): Assert if called for
ELFv2 or ppc32.
(Target_powerpc::Relocate::relocate): Use global entry plt
stub for symbol value if such exists on ELFv2.
(Target_powerpc::Relocate::relocate): Don't call
symval_for_branch when ELFv2. Do adjust for local entry
offset when ELFv2.
(Target_powerpc::do_dynsym_value): Set symbols to global entry
plt stub for ELFv2.
(Target_powerpc::do_plt_address_for_global): Similarly.
This adds an extra flag for needs_dynamic_reloc() in order to remove
the copy of this function and use_plt_offset() in powerpc.cc, and
tweaks the powerpc get_reference_flags() to return the flag as
appropriate. ELFv2 does not want ELFv1 behaviour here.
* symtab.h (Symbol::Reference_flags): Add FUNC_DESC_ABI.
(Symbol::needs_dynamic_reloc): Test new flag.
* powerpc.cc (needs_dynamic_reloc, use_plt_offset): Delete.
(Target_powerpc::Scan::get_reference_flags): Add target param.
Return FUNC_DESC_ABI for 64-bit ELFv1.
(Target_powerpc::Branch_info::make_stub): Adjust get_reference_flags
call.
(Target_powerpc::Scan::global): Use Symbol::needs_dynamic_reloc.
(Target_powerpc::Relocate::relocate): Use Symbol::use_plt_offset.
elfcpp/
* powerpc.h (EF_PPC64_ABI): New enum constant.
(STO_PPC64_LOCAL_BIT, STO_PPC64_LOCAL_MASK): Likewise.
(ppc64_decode_local_entry): New function.
(ppc64_encode_local_entry): Likewise.
gold/
* powerpc.cc (Powerpc_relobj::abiversion, set_abiversion,
ppc64_local_entry_offset, ppc64_local_entry_offset,
do_read_symbols): New functions.
(Powerpc_relobj::e_flags_, st_other_): New vars.
(Powerpc_relobj::Powerpc_relobj): Call set_abiversion.
(Powerpc_dynobj::abiversion, set_abiversion): New functions.
(Powerpc_relobj::e_flags_): New var.
(Target_powerpc::first_plt_entry_offset, plt_entry_size): Inline
and adjust for ELFv2.
(Target_powerpc::abiversion, set_abiversion, stk_toc): New functions.
(Powerpc_relobj::do_find_special_sections): Check no .opd in ELFv2.
(Powerpc_dynobj::do_find_special_sections): Likewise.
(Target_powerpc::do_define_standard_symbols): Define ".TOC.".
(Target_powerpc::Branch_info::make_stub): Adjust stub destination
to ELFv2 local entry.
(Target_powerpc::do_relax): No thread safe barriers needed for
ELFv2.
(Output_data_plt_powerpc::initial_plt_entry_size_,
plt_entry_size): Delete. Replace all uses with
first_plt_entry_offset() and plt_entry_size().
(Output_data_plt_powerpc::Output_data_plt_powerpc): Remove
reserved_size parm. Update callers.
(Output_data_plt_powerpc::entry_count): Update.
(Output_data_plt_powerpc::first_plt_entry_offset): Make private
and use Target_powerpc::first_plt_entry_offset().
(Output_data_plt_powerpc::get_plt_entry_size): Similarly and
rename to plt_entry_size.
(Output_data_plt_powerpc::add_ifunc_entry,
add_local_ifunc_entry): Adjust reloc for ELFv2.
(glink_eh_frame_fde_64): Rename to glink_eh_frame_fde_64v1.
(glink_eh_frame_fde_64v2): New.
(Stub_table::plt_call_size): Support ELFv2 sizing.
(Output_data_glink::add_eh_frame): Use the new FDE.
(Output_data_glink::set_final_data_size): Adjust for ELFv2 glink.
(Stub_table::do_write): Write ELFv2 stubs and glink.
(Target_powerpc::Relocate::relocate): Replaces nop after call
with ld 2,24(1) and adjust local offset destination for ELFv2.
This changes the behaviour of @h and @ha on PowerPC64 to report errors
on 32-bit overflow. The motivation for this change is that on
PowerPC64, most uses of @h and @ha modifiers and their corresponding
relocations are to build up 32-bit offsets. We'd like to know when
such offsets overflow. Only rarely do people use @h or @ha with the
high 32-bit modifiers to build a 64-bit constant. Those uses will now
need to use two new modifiers, @high and @higha, if the constant isn't
known at assembly time. For now, we won't report overflow at assembly
time..
This also fixes an error when applying some of the HIGHER and HIGHEST
relocations.
include/elf/
* ppc64.h (R_PPC64_ADDR16_HIGH, R_PPC64_ADDR16_HIGHA,
R_PPC64_TPREL16_HIGH, R_PPC64_TPREL16_HIGHA,
R_PPC64_DTPREL16_HIGH, R_PPC64_DTPREL16_HIGHA): New.
(IS_PPC64_TLS_RELOC): Match new tls relocs.
bfd/
* reloc.c (BFD_RELOC_PPC64_ADDR16_HIGH, BFD_RELOC_PPC64_ADDR16_HIGHA,
BFD_RELOC_PPC64_TPREL16_HIGH, BFD_RELOC_PPC64_TPREL16_HIGHA,
BFD_RELOC_PPC64_DTPREL16_HIGH, BFD_RELOC_PPC64_DTPREL16_HIGHA): New.
* elf64-ppc.c (ppc64_elf_howto_raw): Add entries for new relocs.
Make all _HA and _HI relocs report signed overflow.
(ppc64_elf_reloc_type_lookup): Handle new relocs.
(must_be_dyn_reloc, ppc64_elf_check_relocs): Likewise.
(dec_dynrel_count, ppc64_elf_relocate_section): Likewise.
(ppc64_elf_relocate_section): Don't apply 0x8000 adjust to
R_PPC64_TPREL16_HIGHER, R_PPC64_TPREL16_HIGHEST,
R_PPC64_DTPREL16_HIGHER, and R_PPC64_DTPREL16_HIGHEST.
* libbfd.h: Regenerate.
* bfd-in2.h: Regenerate.
gas/
* config/tc-ppc.c (SEX16): Don't mask.
(REPORT_OVERFLOW_HI): Define as zero.
(ppc_elf_suffix): Support @high, @higha, @dtprel@high, @dtprel@higha,
@tprel@high, and @tprel@higha modifiers.
(md_assemble): Ignore X_unsigned when applying 16-bit insn fields.
Add (disabled) code to check @h and @ha reloc overflow for powerpc64.
Handle new relocs.
(md_apply_fix): Similarly.
elfcpp/
* powerpc.h (R_PPC64_ADDR16_HIGH, R_PPC64_ADDR16_HIGHA,
R_PPC64_TPREL16_HIGH, R_PPC64_TPREL16_HIGHA,
R_PPC64_DTPREL16_HIGH, R_PPC64_DTPREL16_HIGHA): Define.
gold/
* powerpc.cc (Target_powerpc::Scan::check_non_pic): Handle new relocs.
(Target_powerpc::Scan::global, local): Likewise.
(Target_powerpc::Relocate::relocate): Likewise. Check for overflow
on all ppc64 @h and @ha relocs.
