ppc*_elf_tls_optimize decrements the PLT refcount for __tls_get_addr
when a GD or LD sequence can be optimized. Without tls marker relocs
this must be done when processing the argument setup relocations.
With marker relocs it's better done when processing the marker reloc.
But don't count them both ways.
Seen as "unresolvable R_PPC_REL24 relocation against symbol
`__tls_get_addr_opt'" (and other branch relocs).
* elf32-ppc.c (ppc_elf_tls_optimize): Don't process R_PPC_TLSLD
with non-local symbol. Don't double count __tls_get_addr calls
with marker relocs.
* elf64-ppc.c (ppc64_elf_tls_optimize): Likewise.
has_tls_get_addr_call is no longer named correctly as the flag is
only set on finding a __tls_get_addr call without tlsld/tlsgd marker
relocations.
* elf32-ppc.c (nomark_tls_get_addr): Rename from has_tls_get_addr_call
throughout.
* elf64-ppc.c (nomark_tls_get_addr): Likewise.
1) GOT entries generated for any of the GOT TLS relocations don't need
dynamic relocations for locally defined symbols in PIEs. In the case
of a tls_index doubleword, the dtpmod entry is known to be 1, and the
dtprel entry is also known at link time and relative. Similarly,
dtprel and tprel words are known at link time and relative. (GOT
entries for other than TLS symbols are not relative and thus need
dynamic relocations in PIEs.)
2) Local dynamic TLS code is really only meant for accesses local to
the current binary. There was a cheapskate test for this before using
the common tlsld_got slot, but the test wasn't exactly correct and
might confuse anyone looking at the code. The proper test,
SYMBOL_REFERENCES_LOCAL isn't so expensive that it should be avoided.
3) The same cheap test for local syms when optimising TLS sequences
should be SYMBOL_REFERENCES_LOCAL too.
bfd/
* elf64-ppc.c (ppc64_elf_check_relocs): Move initialisation of vars.
(ppc64_elf_tls_optimize): Correct is_local condition.
(allocate_got): Don't reserve dynamic relocations for any of the
tls got relocs in PIEs when the symbol is local.
(allocate_dynrelocs): Correct validity test for local sym using
tlsld_got slot.
(ppc64_elf_size_dynamic_sections): Don't reserve dynamic relocations
for any of the tls got relocs in PIEs.
(ppc64_elf_layout_multitoc): Likewise.
(ppc64_elf_relocate_section): Correct validity test for local sym
using tlsld_got slot. Don't emit dynamic relocations for any of
the tls got relocs in PIEs when the symbol is local.
* elf32-ppc.c (ppc_elf_tls_optimize): Correct is_local condition.
(got_relocs_needed): Delete.
(allocate_dynrelocs): Correct validity test for local sym using
tlsld_got slot. Don't reserve dynamic relocations for any of the
tls got relocs in PIEs when the symbol is local.
(ppc_elf_size_dynamic_sections): Don't reserve dynamic relocations
for any of the tls got relocs in PIEs.
(ppc_elf_relocate_section): Correct validity test for local sym
using tlsld_got slot. Don't emit dynamic relocations for any of
the tls got relocs in PIEs when the symbol is local.
ld/
* testsuite/ld-powerpc/tlsso.d: Adjust to suit tlsld_got usage change.
* testsuite/ld-powerpc/tlsso.g: Likewise.
* testsuite/ld-powerpc/tlsso.r: Likewise.
* testsuite/ld-powerpc/tlsso32.d: Likewise.
* testsuite/ld-powerpc/tlsso32.g: Likewise.
* testsuite/ld-powerpc/tlsso32.r: Likewise.
Dynamic relocs are only needed in an executable for TLS symbols if
those are defined in an external module and even then TLS access
can be relaxed to use IE model instead of GD.
Several bfd_link_pic checks are turned into bfd_link_dll checks
to fix TLS handling in PIE, for the same fix some other targets
used !bfd_link_executable checks, but that includes relocatable
objects so dll seems safer (in most cases either should work, since
dynamic relocations are not applied in relocatable objects).
On arm* fixes
FAIL: Build pr22263-1
bfd/
PR ld/22263
PR ld/25056
* elf32-arm.c (elf32_arm_tls_transition): Use bfd_link_dll instead of
bfd_link_pic for TLS checks.
(elf32_arm_final_link_relocate): Likewise.
(allocate_dynrelocs_for_symbol): Likewise.
On 64-bit host the 32-bit addend was loaded without sign extension into
an unsigned long.
bfd/ChangeLog:
PR ld/25062
* elf32-arm.c (elf32_arm_final_link_relocate): Sign extend data.
ld/ChangeLog:
PR ld/25062
* testsuite/ld-arm/arm-elf.exp: Update.
* testsuite/ld-arm/tls-gdesc-neg.d: New test.
* testsuite/ld-arm/tls-gdesc-neg.s: New test.
This is quite complicated because the CTF section's contents depend on
the final contents of the symtab and strtab, because it has two sections
whose contents are shuffled to be in 1:1 correspondence with the symtab,
and an internal strtab that gets deduplicated against the ELF strtab
(with offsets adjusted to point into the ELF strtab instead). It is
also compressed if large enough, so its size depends on its contents!
So we cannot construct it as early as most sections: we cannot even
*begin* construction until after the symtab and strtab are finalized.
Thankfully there is already one section treated similarly: compressed
debugging sections: the only differences are that compressed debugging
sections have extra handling to deal with their changing name if
compressed (CTF sections are always called ".ctf" for now, though we
have reserved ".ctf.*" against future use), and that compressed
debugging sections have previously-uncompressed content which has to be
stashed away for later compression, while CTF sections have no content
at all until we generate it (very late).
BFD also cannot do the link itself: libctf knows how to do it, and BFD
cannot call libctf directly because libctf already depends on bfd for
file I/O. So we have to use a pair of callbacks, one, examine_strtab,
which allows a caller to examine the symtab and strtab after
finalization (called from elf_link_swap_symbols_out(), right before the
symtabs are written, and after the strtab has been finalized), and one
which actually does the emission (called emit_ctf simply because it is
grouped with a bunch of section-specific late-emission function calls at
the bottom of bfd_elf_final_link, and a section-specific name seems best
for that). emit_ctf is actually called *twice*: once from lang_process
if the emulation suggests that this bfd target does not examine the
symtab or strtab, and once via a bfd callback if it does. (This means
that non-ELF targets still get CTF emitted, even though the late CTF
emission stage is never called for them).
v2: merged with non-ELF support patch: slight commit message
adjustments.
v3: do not spend time merging CTF, or crash, if the CTF section is
explicitly discarded. Do not try to merge or compress CTF unless
linking.
v4: add CTF_COMPRESSION_THRESHOLD. Annul the freed input ctf_file_t's
after writeout: set SEC_IN_MEMORY on the output contents so a future
bfd enhancement knows it could free it. Add SEC_LINKER_CREATED |
SEC_KEEP to avoid having to add .ctf to the linker script. Drop
now-unnecessary ldlang.h-level elf-bfd.h include and hackery around
it. Adapt to elf32.em->elf.em and elf-generic.em->ldelf*.c
changes.
v5: fix tabdamage. Drop #inclusions in .h files: include in .c files,
.em files, and use struct forwards instead. Use bfd_section_is_ctf
inline function rather than SECTION_IS_CTF macro. Move a few
comments.
* Makefile.def (dependencies): all-ld depends on all-libctf.
* Makefile.in: Regenerated.
include/
* bfdlink.h (elf_strtab_hash): New forward.
(elf_sym_strtab): Likewise.
(struct bfd_link_callbacks <examine_strtab>): New.
(struct bfd_link_callbacks <emit_ctf>): Likewise.
bfd/
* elf-bfd.h (bfd_section_is_ctf): New inline function.
* elf.c (special_sections_c): Add ".ctf".
(assign_file_positions_for_non_load_sections): Note that
compressed debugging sections etc are not assigned here. Treat
CTF sections like SEC_ELF_COMPRESS sections when is_linker_output:
sh_offset -1.
(assign_file_positions_except_relocs): Likewise.
(find_section_in_list): Note that debugging and CTF sections, as
well as reloc sections, are assigned later.
(_bfd_elf_assign_file_positions_for_non_load): CTF sections get
their size and contents updated.
(_bfd_elf_set_section_contents): Skip CTF sections: unlike
compressed sections, they have no uncompressed content to copy at
this stage.
* elflink.c (elf_link_swap_symbols_out): Call the examine_strtab
callback right before the strtab is written out.
(bfd_elf_final_link): Don't cache the section contents of CTF
sections: they are not populated yet. Call the emit_ctf callback
right at the end, after all the symbols and strings are flushed
out.
ld/
* ldlang.h: (struct lang_input_statement_struct): Add the_ctf.
(struct elf_sym_strtab): Add forward.
(struct elf_strtab_hash): Likewise.
(ldlang_ctf_apply_strsym): Declare.
(ldlang_write_ctf_late): Likewise.
* ldemul.h (ldemul_emit_ctf_early): New.
(ldemul_examine_strtab_for_ctf): Likewise.
(ld_emulation_xfer_type) <emit_ctf_early>: Likewise.
(ld_emulation_xfer_type) <examine_strtab_for_ctf>: Likewise.
* ldemul.c (ldemul_emit_ctf_early): New.
(ldemul_examine_strtab_for_ctf): Likewise.
* ldlang.c: Include ctf-api.h.
(CTF_COMPRESSION_THRESHOLD): New.
(ctf_output): New. Initialized in...
(ldlang_open_ctf): ... this new function. Open all the CTF
sections in the input files: mark them non-loaded and empty
so as not to copy their contents to the output, but linker-created
so the section gets created in the target.
(ldlang_merge_ctf): New, merge types via ctf_link_add_ctf and
ctf_link.
(ldlang_ctf_apply_strsym): New, an examine_strtab callback: wrap
ldemul_examine_strtab_for_ctf.
(lang_write_ctf): New, write out the CTF section.
(ldlang_write_ctf_late): New, late call via bfd's emit_ctf hook.
(lang_process): Call ldlang_open_ctf, ldlang_merge_ctf, and
lang_write_ctf.
* ldmain.c (link_callbacks): Add ldlang_ctf_apply_strsym,
ldlang_write_ctf_late.
* emultempl/aix.em: Add ctf-api.h.
* emultempl/armcoff.em: Likewise.
* emultempl/beos.em: Likewise.
* emultempl/elf.em: Likewise.
* emultempl/generic.em: Likewise.
* emultempl/linux.em: Likewise.
* emultempl/msp430.em: Likewise.
* emultempl/pe.em: Likewise.
* emultempl/pep.em: Likewise.
* emultempl/ticoff.em: Likewise.
* emultempl/vanilla.em: Likewise.
* ldcref.c: Likewise.
* ldctor.c: Likewise.
* ldelf.c: Likewise.
* ldelfgen.c: Likewise.
* ldemul.c: Likewise.
* ldexp.c: Likewise.
* ldfile.c: Likewise.
* ldgram.c: Likewise.
* ldlex.l: Likewise.
* ldmain.c: Likewise.
* ldmisc.c: Likewise.
* ldver.c: Likewise.
* ldwrite.c: Likewise.
* lexsup.c: Likewise.
* mri.c: Likewise.
* pe-dll.c: Likewise.
* plugin.c: Likewise.
* ldelfgen.c (ldelf_emit_ctf_early): New.
(ldelf_examine_strtab_for_ctf): tell libctf about the symtab and
strtab.
(struct ctf_strsym_iter_cb_arg): New, state to do so.
(ldelf_ctf_strtab_iter_cb): New: tell libctf about
each string in the strtab in turn.
(ldelf_ctf_symbols_iter_cb): New, tell libctf
about each symbol in the symtab in turn.
* ldelfgen.h (struct elf_sym_strtab): Add forward.
(struct elf_strtab_hash): Likewise.
(struct ctf_file): Likewise.
(ldelf_emit_ctf_early): Declare.
(ldelf_examine_strtab_for_ctf): Likewise.
* emultempl/elf-generic.em (LDEMUL_EMIT_CTF_EARLY): Set it.
(LDEMUL_EXAMINE_STRTAB_FOR_CTF): Likewise.
* emultempl/aix.em (ld_${EMULATION_NAME}_emulation): Add
emit_ctf_early and examine_strtab_for_ctf, NULL by default.
* emultempl/armcoff.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/beos.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/elf.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/generic.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/linux.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/msp430.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/pe.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/pep.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/ticoff.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/vanilla.em (ld_vanilla_emulation): Likewise.
* Makefile.am: Pull in libctf (and zlib, a transitive requirement
for compressed CTF section emission). Pass it on to DejaGNU.
* configure.ac: Add AM_ZLIB.
* aclocal.m4: Added zlib.m4.
* Makefile.in: Regenerated.
* testsuite/ld-bootstrap/bootstrap.exp: Use it when relinking ld.
The CTF linking process wants to deduplicate the CTF strtab against the
ELF strtab, for which it needs to know the number of strings in the
strtab and it needs to be able to extract them one by one.
The BFD strtab functions only support returning the
size-or-section-length of the strtab (with _bfd_elf_strtab_size)
and returning the offset (but not string!) and decrementing the refcount
at the same time.
So add new functions _bfd_elf_strtab_len (that just returns the length
in strings of the strtab, never the section size) and bfd_elf_strtab_str
(which returns the string at a given strtab index, and its offset,
without touching the refcount).
It is probably a mistake to use _bfd_elf_strtab_str in particular before
_bfd_elf_strtab_finalize is called, and will not produce useful output
if you do so.
v5: fix tabdamage.
bfd/
* elf-strtab.c (_bfd_elf_strtab_len): New.
(_bfd_elf_strtab_str): Likewise.
* bfd-elf.h: Declare them.
The code in ctf_bfdopen_ctfsect (which is the ultimate place where you
end up if you use ctf_open to open a CTF file and pull in the ELF string
and symbol tables) was written before it was possible to actually test
it, since the linker was not written. Now it is, it turns out that the
previous code was completely nonfunctional: it assumed that you could
load the symbol table via bfd_section_from_elf_index (...,elf_onesymtab())
and the string table via bfd_section_from_elf_index on the sh_link.
Unfortunately BFD loads neither of these sections in the conventional
fashion it uses for most others: the symbol table is immediately
converted into internal form (which is useless for our purposes, since
we also have to work in the absence of BFD for readelf, etc) and the
string table is loaded specially via bfd_elf_get_str_section which is
private to bfd/elf.c.
So make this function public, export it in elf-bfd.h, and use it from
libctf, which does something similar to what bfd_elf_sym_name and
bfd_elf_string_from_elf_section do. Similarly, load the symbol table
manually using bfd_elf_get_elf_syms and throw away the internal form
it generates for us (we never use it).
BFD allocates the strtab for us via bfd_alloc, so we can leave BFD to
deallocate it: we allocate the symbol table ourselves before calling
bfd_elf_get_elf_syms, so we still have to free it.
Also change the rules around what you are allowed to provide: It is
useful to provide a string section but no symbol table, because CTF
sections can legitimately have no function info or data object sections
while relying on the ELF strtab for some of their strings. So allow
that combination.
v4: adjust to upstream changes. ctf_bfdopen_ctfsect's first parameter
is potentially unused again (if BFD is not in use for this link
due to not supporting an ELF target).
v5: fix tabdamage.
bfd/
* elf-bfd.h (bfd_elf_get_str_section): Add.
* elf.c (bfd_elf_get_str_section): No longer static.
libctf/
* ctf-open-bfd.c: Add <assert.h>.
(ctf_bfdopen_ctfsect): Open string and symbol tables using
techniques borrowed from bfd_elf_sym_name.
(ctf_new_archive_internal): Improve comment.
* ctf-archive.c (ctf_arc_close): Do not free the ctfi_strsect.
* ctf-open.c (ctf_bufopen): Allow opening with a string section but
no symbol section, but not vice versa.
In check_relocs, bfd_link_pic true means ld is producing a shared
library or a position independent executable. !bfd_link_pic means a
fixed position (ie. static) executable since the relocatable linking
case is excluded. So it is appropriate to continue using bfd_link_pic
when testing whether non-pcrelative relocations should be dynamic, and
!bfd_link_pic for the special case of ifunc in static executables.
However, -Bsymbolic shouldn't affect PIEs (they are executables so
none of their symbols should be overridden) and PIEs can support copy
relocations, thus bfd_link_executable should be used in those cases
rather than bfd_link_pic.
I've also removed the test of ELIMINATE_COPY_RELOCS in check_relocs.
We can sort out what to do regarding copy relocs later, which allows
the code in check_relocs to be simplified.
* elf64-ppc.c (ppc64_elf_check_relocs): Use bfd_link_executable
in choosing between different actions for shared library and
non-shared library cases. Delete ELIMINATE_COPY_RELOCS test.
(dec_dynrel_count): Likewise. Account for ifunc special case.
(ppc64_elf_adjust_dynamic_symbol): Copy relocs are for executables,
not non-pic.
(allocate_dynrelocs): Comment fixes. Delete ELIMINATE_COPY_RELOCS
test.
bfd/
* bfd-in.h: Move arm declaraions..
* cpu-arm.h: ..to here, new file..
* coff-arm.h: ..and here, new file..
* elf32-arm.h: ..and here, new file.
* cpu-arm.c: Include cpu-arm.h.
* coff-arm.c: Include cpu-arm.h and coff-arm.h.
* elf32-arm.c: Include cpu-arm.h and elf32-arm.h.
* pe-arm.c: Move function rename defines later.
* pe-arm-wince.c: Likewise and include sysdep.h and bfd.h early.
* bfd-in2.h: Regenerate.
gas/
* config/tc-arm.c: Include cpu-arm.h.
ld/
* emultempl/armelf.em: Include elf32-arm.h.
* emultempl/pe.em: Move func defines later and include coff-arm.h.
For the lui and auipc relaxations, since the symbol value of an undefined weak
symbol is always be zero, we can optimize the patterns into a single LI/MV/ADDI
instruction.
bfd/
* elfnn-riscv.c (riscv_pcgp_hi_reloc): Add new field undefined_weak.
(riscv_record_pcgp_hi_reloc): New parameter undefined_weak.
Set undefined_weak field from it.
(relax_func_t): New parameter undefined_weak.
(_bfd_riscv_relax_call): New ignored parameter undefined_weak.
(_bfd_riscv_relax_tls_le): Likewise.
(_bfd_riscv_relax_align): Likewise.
(_bfd_riscv_relax_delete): Likewise.
(_bfd_riscv_relax_lui): New parameter undefined_weak. If true,
allow relaxing. For LO12* relocs, set rs1 to x0 when undefined_weak.
(_bfd_riscv_relax_pc): New parameter undefined_weak. For LO12* relocs,
set undefined_weak from hi_reloc. If true, allow relaxing. For LO12*
relocs, set rs1 to x0 when undefined_weak and change to non-pcrel
reloc.
(_bfd_riscv_relax_section): New local undefined_weak. Set for
undef weak relocs that can be relaxed. Pass to relax_func call.
ld/
* testsuite/ld-riscv-elf/weakref32.s: Add relaxable undef weak code.
* testsuite/ld-riscv-elf/weakref64.s: Likewise.
* testsuite/ld-riscv-elf/weakref32.d: Updated.
* testsuite/ld-riscv-elf/weakref64.d: Updated.
This one exposed a bug in tic6x gas, found with inline function
parameter type checking. struct bfd_section and struct bfd_symbol
both have a flags field, so bfd_is_com_section (symbol) compiled OK
when bfd_is_com_section was a macro but didn't special case common
symbols.
bfd/
* bfd-in.h (bfd_section_name, bfd_section_size, bfd_section_vma),
(bfd_section_lma, bfd_section_alignment, bfd_section_flags),
(bfd_section_userdata, bfd_is_com_section, discarded_section),
(bfd_get_section_limit_octets, bfd_get_section_limit): Delete macros.
* bfd.c (bfd_get_section_limit_octets, bfd_get_section_limit),
(bfd_section_list_remove, bfd_section_list_append),
(bfd_section_list_prepend, bfd_section_list_insert_after),
(bfd_section_list_insert_before, bfd_section_removed_from_list):
New inline functions.
* section.c (bfd_is_und_section, bfd_is_abs_section),
(bfd_is_ind_section, bfd_is_const_section, bfd_section_list_remove),
(bfd_section_list_append, bfd_section_list_prepend),
(bfd_section_list_insert_after, bfd_section_list_insert_before),
(bfd_section_removed_from_list): Delete macros.
(bfd_section_name, bfd_section_size, bfd_section_vma),
(bfd_section_lma, bfd_section_alignment, bfd_section_flags),
(bfd_section_userdata, bfd_is_com_section, bfd_is_und_section),
(bfd_is_abs_section, bfd_is_ind_section, bfd_is_const_section),
(discarded_section): New inline functions.
* bfd-in2.h: Regenerate.
gas/
* config/tc-tic6x.c (tc_gen_reloc): Correct common symbol check.
ld/
* emultempl/xtensaelf.em (xtensa_get_section_deps): Comment.
Use bfd_section_userdata.
(xtensa_set_section_deps): Use bfd_set_section_userdata.
* ldlang.c (lang_output_section_get): Use bfd_section_userdata.
(sort_def_symbol): Likewise, and bfd_set_section_userdata.
(init_os): Use bfd_set_section_userdata.
(print_all_symbols): Use bfd_section_userdata.
* ldlang.h (get_userdata): Delete.
This patch corrects the set of dynamic relocations recognised by gold
as supported by glibc, and teaches ld.bfd to report an error similar
to the gold error. Note that ld --noinhibit-exec can be used to
produce an output, supporting older ld with newer glibc if the set of
supported glibc dynamic relocations changes.
bfd/
* elf64-ppc.c (ppc64_glibc_dynamic_reloc): New function.
(ppc64_elf_relocate_section): Error if emitting unsupported
dynamic relocations.
gold/
* powerpc.cc (Target_powerpc::Scan::check_non_pic): Move REL24
to 32-bit supported.
I get some spurious changes when running autoconf/automake for various
projects in the tree. This is likely because they were generated using
distro-patched tools last time.
I ran `autoreconf -f` in the various automake projects of the
binutils-gdb tree, and this is the result. The tools I am using have
been compiled from source, from the upstream release.
bfd/ChangeLog:
* Makefile.in: Re-generate.
* configure: Re-generate.
* doc/Makefile.in: Re-generate.
binutils/ChangeLog:
* Makefile.in: Re-generate.
* configure: Re-generate.
* doc/Makefile.in: Re-generate.
gas/ChangeLog:
* Makefile.in: Re-generate.
* configure: Re-generate.
* doc/Makefile.in: Re-generate.
gold/ChangeLog:
* testsuite/Makefile.in: Re-generate.
gprof/ChangeLog:
* Makefile.in: Re-generate.
* configure: Re-generate.
ld/ChangeLog:
* Makefile.in: Re-generate.
* configure: Re-generate.
opcodes/ChangeLog:
* Makefile.in: Re-generate.
* configure: Re-generate.
Fixes a few leaks in bfd and ld.
bfd/
* mach-o.c (bfd_mach_o_fat_member_init): Likewise. Replace
xstrdup and xmalloc with bfd_strdup and bfd_malloc. Return an
error status. Adjust calls.
* vms-lib.c (_bfd_vms_lib_get_module): Test mhd->id earlier.
Close bfd on failure. Replace xstrdup/bfd_alloc use with
bfd_malloc. Use bfd_set_filename.
gdb/
* solib-spu.c (spu_bfd_open): Use bfd_set_filename.
* spu-linux-nat.c (spu_bfd_open): Likewise.
ld/
* emultempl/pe.em (after_open): Use bfd_set_filename.
* emultempl/pep.em (after_open): Use bfd_set_filename.
Some versions of clang apparently generate non-PIC on powerpc64le to
access common symbols. Since a common symbol and a strong definition
with the same name should resolve to the strong definition we have the
possibility of non-PIC attempting to access shared library variables.
This is really a clanger since powerpc64le is supposed to be PIC by
default, but let's see if ld can cope by generating .dynbss copies.
* elf64-ppc.c (must_be_dyn_reloc): Return 0 for TOC16 relocs.
(ppc64_elf_check_relocs): Support dynamic/copy relocs for TOC16.
(ppc64_elf_adjust_dynamic_symbol): Don't keep dynamic reloc when
needs_copy even if all relocs are in rw sections.
(dec_dynrel_count): Handle TOC16 relocs.
(ppc64_elf_relocate_section): Support dynamic relocs for TOC16.
(ppc64_elf_finish_dynamic_symbol): Adjust to handle needs_copy
semantic change.
This introduces a new bfd_set_filename function, which is then used in
various spots in gdb. This allows for the removal of some casts.
bfd/ChangeLog
2019-09-11 Tom Tromey <tom@tromey.com>
* opncls.c (bfd_set_filename): New function.
* bfd-in2.h: Regenerate.
gdb/ChangeLog
2019-09-11 Tom Tromey <tom@tromey.com>
* symfile-mem.c (symbol_file_add_from_memory): Use
bfd_set_filename.
* solib-darwin.c (darwin_bfd_open): Use bfd_set_filename.
* solib-aix.c (solib_aix_bfd_open): Use bfd_set_filename.
PC-relative relocs typically use the addend in adjusting what they are
relative to. For example:
bcl 20,31,1f
1: mflr 12
addi 12,12,xxx-1b
generates "R_PPC64_REL16 xxx+0x4" for the addi (when little-endian).
The addend reflects the fact that you want the offset relative to the
previous insn not the current one in this case.
So the question is, will we ever want to do something like that for an
instruction using R_PPC64_GOT_PCREL34? I thought so at the time I
first implemented support in ld but at the time I think the hardware
was possibly going to support pcrel+offset+reg addressing. In which
case you might want something like:
load_big_offset_into_r2
pld 3,sym-big_offset@got@pcrel(2)
which would be a way of supporting more than 8G offsets from code to
the GOT. We could do the same with
load_big_offset_into_r2
pla 9,sym-big_offset@got@pcrel
ldx 3,9,2
However, this is really a poor version of TOC-pointer relative code.
So let's go with an addend on R_PPC64_GOT_PCREL34 meaning that
sym+addend should be put in a GOT entry, and the relocation calculate
the pc-relative offset to that GOT entry.
Note that this is an extension to the ABI, which says (by the
expression given for GOT relocs) that non-zero addends on GOT and PLT
relocs are ignored. This is true for all GOT/PLT relocs, not just the
pcrel ones.
* elf64-ppc.c (ppc64_elf_check_relocs): Interpret an addend in
GOT_PCREL and PLT_PCREL relocs as affecting the value stored
in the GOT/PLT entry rather than affecting the offset to that
GOI/PLT entry.
(ppc64_elf_edit_toc, ppc64_elf_relocate_section): Likewise.
The loads and stores handled in the second instruction of a sequence
marked by R_PPC64_PCREL_OPT may be a prefix instruction. For example:
pld ra,symbol@got@pcrel
0:
pld rt,off(ra)
.reloc 0b-8,R_PPC64_PCREL_OPT,(.-8)-(0b-8)
can be optimised to
pld rt,symbol+off@pcrel
pnop
* elf64-ppc.c (xlate_pcrel_opt): Handle prefix loads and stores
in second instruction.
(ppc64_elf_relocate_section): Likewise.
