I was looking at elf_backend_section_flags as a means of setting
SEC_SMALL_DATA for .sdata, .sbss and the like, and condidered adding
an asection* parameter to access the section name easily before
realising that hdr->bfd_section of course makes the section
available. So no new parameter needed. In fact the flagword*
parameter isn't needed either, so out it goes.
The patch also tidies some horrible code in _bfd_elf_new_section_hook
that can change whether known ABI sections have sh_type and sh_flags
set up depending on which of the bfd_make_section functions is used.
(Some of those set section flags before _bfd_elf_new_section_hook is
called, others leave the flags zero.) The function also had some
hacks for .init_array and .fini_array to affect how
_bfd_elf_init_private_section_data behaved for those sections. It's
cleaner to do that in _bfd_elf_init_private_section_data. So that all
goes and we now init sh_type and sh_flags for all known ABI sections
in _bfd_elf_new_section_hook. _bfd_elf_init_private_section_data is
changed to suit, and now doesn't just single out SHT_INIT_ARRAY and
SHT_FINI_ARRAY but rather any of the special section types.
The _bfd_elf_new_section_hook change resulting in
+FAIL: ld-aarch64/erratum835769-843419
exposing some errors in the aarch64 backend. elfNN_aarch64_size_stubs
should not be looking at linker created sections in the stub bfd. Nor
should code like "symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr" be
run without first checking that input_bfd is ELF.
* elf-bfd.h (elf_backend_section_flags): Remove flagword* param.
* elf.c (_bfd_elf_make_section_from_shdr): Set section flags before
calling elf_backend_section_flags with adjusted params. Use
newsect->flags past that point.
(_bfd_elf_new_section_hook): Always set sh_type and sh_flags for
special sections.
(_bfd_elf_init_private_section_data): Allow normal sh_type sections
to have their type overridden, and all sh_flags but processor and
os specific.
* elf32-arm.c (elf32_arm_section_flags): Adjust for changed params.
* elf32-mep.c (mep_elf_section_flags): Likewise.
* elf32-nios2.c (nios2_elf32_section_flags): Likewise.
* elf64-alpha.c (elf64_alpha_section_flags): Likewise.
* elf64-ia64-vms.c (elf64_ia64_section_flags): Likewise.
* elfnn-ia64.c (elfNN_ia64_section_flags): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_size_stubs): Exclude the linker
stub BFD and non-aarch64 input files when scanning for stubs.
I closed this bug as invalid, but I think it is worth mentioning in NEWS
that older linkers didn't check PT_PHDR very well. The patch also allows
people to force an output file with --noinhibit-exec after the error.
bfd/
PR 25585
* elf.c (assign_file_positions_for_load_sections): Continue linking
on "PHDR segment not covered by LOAD segment" errors.
ld/
PR 25585
* NEWS: Mention better "PHDR segment not covered by LOAD segment"
checking.
* elf-bfd.h (struct elf_backend_data): Add symbol_section_index
callback.
* elfxx-target.h (elf_backend_symbol_section_index): Provide
default definition.
(elfNN_bed): Initialise the symbol_section_index field.
* elf.c (swap_out_syms): Call symbol_section_index, if defined, on
OS and PROC specific section indicies. Warn if converting other
reserved incidies to SHN_ABS.
The bfd_alloc2 series of functions were invented to handle cases where
nmemb * size can overflow. This patch changes some places where the
calculation can't overflow.
* elf.c (bfd_section_from_shdr): Use bfd_zalloc rather than
bfd_zalloc2.
(assign_section_numbers): Likewise.
(elf_map_symbols): Likewise, and bfd_alloc rather than bfd_alloc2.
(_bfd_elf_map_sections_to_segments): Use bfd_malloc rather than
bfd_malloc2, size_t amt, and unsigned tls_count.
(rewrite_elf_program_header): Use bfd_malloc and size_t amt.
* elflink.c (elf_create_symbuf): Use bfd_malloc.
(elf_output_implib): Use bfd_alloc.
This fixes a number of places that call a memory allocation function
without checking for a NULL return before using.
* mach-o.c (bfd_mach_o_flatten_sections): Return a bfd_boolean,
FALSE if memory alloc fails. Adjust calls.
* som.c (som_prep_for_fixups): Likewise.
* vms-alpha.c (alpha_vms_add_fixup_lp, alpha_vms_add_fixup_ca),
(alpha_vms_add_fixup_qr, alpha_vms_add_fixup_lr),
(alpha_vms_add_lw_reloc, alpha_vms_add_qw_reloc): Likewise.
* som.c (som_build_and_write_symbol_table): Return via error_return
on seek failure.
* vms-alpha.c (VEC_APPEND): Adjust for vector_grow1 changes.
(VEC_APPEND_EL): Delete.
(vector_grow1): Return pointer to element. Catch overflow.
Return NULL on memory allocation failure.
(alpha_vms_add_fixup_lp): Replace VEC_APPEND_EL with VEC_APPEND.
(alpha_vms_add_fixup_ca): Likewise.
(alpha_vms_link_add_object_symbols): Check VEC_APPEND result
before using.
* elf.c (bfd_section_from_shdr): Check bfd_zalloc2 result.
We alloc, seek and read using section sizes in object files. Fuzzed
objects can have silly sizes, but that's OK if the system supports
memory over-commit. The read fails because we hit EOF and that
usually results in a graceful exit.
But if we memset before the read then the invalid size results in
attempting to write to a huge number of memory pages, and an eventual
Out Of Memory after probably swapping like crazy. So don't memset.
There really isn't a need to clear the section contents anyway. All
bytes are written with a good object file by the read and following
loop converting section index in target order to ELF section header
pointer, and the only untidy bytes are the 4 bytes past the group
flags when pointers are 8 bytes. Those don't matter but the patch
clears them for anyone poking around in a debugger. On error paths
it's as good to free section contents as it is to clear them.
Noticed when looking at PR4110 fourth test case.
PR 4110
* elf.c (setup_group): Don't clear entire section contents,
just the padding after group flags. Release alloc'd memory
after a seek or read failure.
PR 25237
* elf.c (assign_file_positions_for_load_sections): Attempt to
keep meaningless p_offset for PT_LOAD segments without file
contents within file size.
Sometimes DWARF info for a function is incomplete, and the function
can be retrieved by examining symbols. However, when separate debug
files are used it may be that the original file is completely
stripped of symbols. This patch teaches BFD to look at symbols from
the debug file in that case.
The patch also removes arm_elf_find_function, instead implementing
elf_backend_maybe_function_sym. arm_elf_find_function was written
before the generic _bfd_elf_find_function called maybe_function_sym.
aarch64 copied arm, so that file gets the same treatment. There is
some chance this will speed up arm and aarch64 lookup of function/line.
PR 23652
* dwarf2.c (_bfd_dwarf2_stash_syms): New function.
(_bfd_dwarf2_find_nearest_line): Use it here, passing syms to
_bfd_elf_find_function. Call _bfd_elf_find_function in cases
where _bfd_elf_find_nearest_line would do so.
* elf.c (_bfd_elf_find_nearest_line): Omit _bfd_elf_find_function
for dwarf2.
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Similarly. Tidy.
* elf32-arm.c (elf32_arm_maybe_function_sym): New function.
(elf_backend_maybe_function_sym): Define.
(arm_elf_find_function, elf32_arm_find_nearest_line): Delete.
(bfd_elf32_find_nearest_line): Don't define.
* elfnn-aarch64.c (elfNN_aarch64_maybe_function_sym): New function.
(elf_backend_maybe_function_sym): Define.
(aarch64_elf_find_function, elfNN_aarch64_find_nearest_line): Delete.
(bfd_elfNN_find_nearest_line): Don't define.
and other tidies. I think it's better to default to passing the
section to bfd_octets_per_byte, even in cases where we know it won't
make a difference.
A number of the coff reloc functions used bfd_octets_per_byte wrongly,
not factoring it into the offset into the data buffer. As it happens,
the targets using those files always had bfd_octets_per_byte equal to
one, so there wasn't any detectable wrong behaviour. However, it is
wrong in the source and might cause trouble for anyone creating a new
target. Besides fixing that, the patch also defines OCTETS_PER_BYTE
as one in target files where that is appropriate.
bfd/
* archures.c (bfd_octets_per_byte): Tail call
bfd_arch_mach_octets_per_byte.
* coff-arm.c (OCTETS_PER_BYTE): Define.
(coff_arm_reloc): Introduce new "octets" temp. Use OCTETS_PER_BYTE
with section. Correct "addr". Remove ATTRIBUTE_UNUSED.
* coff-i386.c (coff_i386_reloc): Similarly.
* coff-mips.c (mips_reflo_reloc): Similarly.
* coff-x86_64.c (coff_amd64_reloc): Similarly.
* elf32-msp430.c (OCTETS_PER_BYTE): Define.
(rl78_sym_diff_handler): Use OCTETS_PER_BYTE, with section.
* elf32-nds32.c (nds32_elf_get_relocated_section_contents): Similarly.
* elf32-ppc.c (ppc_elf_addr16_ha_reloc): Similarly.
* elf32-pru.c (pru_elf32_do_ldi32_relocate): Similarly.
* elf32-s12z.c (opru18_reloc): Similarly.
* elf32-sh.c (sh_elf_reloc): Similarly.
* elf32-spu.c (spu_elf_rel9): Similarly.
* elf32-xtensa.c (bfd_elf_xtensa_reloc): Similarly.
* elf64-ppc.c (ppc64_elf_ha_reloc, ppc64_elf_brtaken_reloc),
(ppc64_elf_toc64_reloc): Similarly.
* bfd.c (bfd_get_section_limit): Pass section to bfd_octets_per_byte.
* cofflink.c (_bfd_coff_link_input_bfd),
(_bfd_coff_reloc_link_order): Likewise.
* elf.c (_bfd_elf_section_offset): Likewise.
* elflink.c (resolve_section, bfd_elf_perform_complex_relocation),
(elf_link_input_bfd, elf_reloc_link_order, elf_fixup_link_order),
(bfd_elf_final_link): Likewise.
* elf.c (_bfd_elf_make_section_from_shdr): Don't strncmp twice
to set SEC_ELF_OCTETS.
* reloc.c (bfd_perform_relocation): Tidy SEC_ELF_OCTETS special case.
(bfd_install_relocation): Likewise.
(_bfd_final_link_relocate): Don't recalculate octets.
* syms.c (_bfd_stab_section_find_nearest_line): Introduc new
"octets" temp.
* bfd-in2.h: Regenerate.
ld/
* ldexp.c (fold_name): Pass section to bfd_octets_per_byte.
* ldlang.c (init_opb): Don't call bfd_arch_mach_octets_per_byte
unnecessarily.
All symbols, sizes and relocations in this section are octets instead of
bytes. Required for DWARF debug sections as DWARF information is
organized in octets, not bytes.
bfd/
* section.c (struct bfd_section): New flag SEC_ELF_OCTETS.
* archures.c (bfd_octets_per_byte): New parameter sec.
If section is not NULL and SEC_ELF_OCTETS is set, one octet es
returned [ELF targets only].
* bfd.c (bfd_get_section_limit): Provide section parameter to
bfd_octets_per_byte.
* bfd-in2.h: regenerate.
* binary.c (binary_set_section_contents): Move call to
bfd_octets_per_byte into section loop. Provide section parameter
to bfd_octets_per_byte.
* coff-arm.c (coff_arm_reloc): Provide section parameter
to bfd_octets_per_byte.
* coff-i386.c (coff_i386_reloc): likewise.
* coff-mips.c (mips_reflo_reloc): likewise.
* coff-x86_64.c (coff_amd64_reloc): likewise.
* cofflink.c (_bfd_coff_link_input_bfd): likewise.
(_bfd_coff_reloc_link_order): likewise.
* elf.c (_bfd_elf_section_offset): likewise.
(_bfd_elf_make_section_from_shdr): likewise.
Set SEC_ELF_OCTETS for sections with names .gnu.build.attributes,
.debug*, .zdebug* and .note.gnu*.
* elf32-msp430.c (rl78_sym_diff_handler): Provide section parameter
to bfd_octets_per_byte.
* elf32-nds.c (nds32_elf_get_relocated_section_contents): likewise.
* elf32-ppc.c (ppc_elf_addr16_ha_reloc): likewise.
* elf32-pru.c (pru_elf32_do_ldi32_relocate): likewise.
* elf32-s12z.c (opru18_reloc): likewise.
* elf32-sh.c (sh_elf_reloc): likewise.
* elf32-spu.c (spu_elf_rel9): likewise.
* elf32-xtensa.c (bfd_elf_xtensa_reloc): likewise
* elf64-ppc.c (ppc64_elf_brtaken_reloc): likewise.
(ppc64_elf_addr16_ha_reloc): likewise.
(ppc64_elf_toc64_reloc): likewise.
* elflink.c (bfd_elf_final_link): likewise.
(bfd_elf_perform_complex_relocation): likewise.
(elf_fixup_link_order): likewise.
(elf_link_input_bfd): likewise.
(elf_link_sort_relocs): likewise.
(elf_reloc_link_order): likewise.
(resolve_section): likewise.
* linker.c (_bfd_generic_reloc_link_order): likewise.
(bfd_generic_define_common_symbol): likewise.
(default_data_link_order): likewise.
(default_indirect_link_order): likewise.
* srec.c (srec_set_section_contents): likewise.
(srec_write_section): likewise.
* syms.c (_bfd_stab_section_find_nearest_line): likewise.
* reloc.c (_bfd_final_link_relocate): likewise.
(bfd_generic_get_relocated_section_contents): likewise.
(bfd_install_relocation): likewise.
For section which have SEC_ELF_OCTETS set, multiply output_base
and output_offset with bfd_octets_per_byte.
(bfd_perform_relocation): likewise.
include/
* coff/ti.h (GET_SCNHDR_SIZE, PUT_SCNHDR_SIZE, GET_SCN_SCNLEN),
(PUT_SCN_SCNLEN): Adjust bfd_octets_per_byte calls.
binutils/
* objdump.c (disassemble_data): Provide section parameter to
bfd_octets_per_byte.
(dump_section): likewise
(dump_section_header): likewise. Show SEC_ELF_OCTETS flag if set.
gas/
* as.h: Define SEC_OCTETS as SEC_ELF_OCTETS if OBJ_ELF.
* dwarf2dbg.c: (dwarf2_finish): Set section flag SEC_OCTETS for
.debug_line, .debug_info, .debug_abbrev, .debug_aranges, .debug_str
and .debug_ranges sections.
* write.c (maybe_generate_build_notes): Set section flag
SEC_OCTETS for .gnu.build.attributes section.
* frags.c (frag_now_fix): Don't divide by OCTETS_PER_BYTE if
SEC_OCTETS is set.
* symbols.c (resolve_symbol_value): Likewise.
ld/
* ldexp.c (fold_name): Provide section parameter to
bfd_octets_per_byte.
* ldlang (init_opb): New argument s. Set opb_shift to 0 if
SEC_ELF_OCTETS for the current section is set.
(print_input_section): Pass current section to init_opb.
(print_data_statement,print_reloc_statement,
print_padding_statement): Likewise.
(lang_check_section_addresses): Call init_opb for each
section.
(lang_size_sections_1,lang_size_sections_1,
lang_do_assignments_1): Likewise.
(lang_process): Pass NULL to init_opb.
This patch renames elf_backend_modify_program_headers and moves the
elf.c code tweaking the ELF file header for -pie -Ttext-segment to a
new function, _bfd_elf_modify_headers, which then becomes the default
elf_backed_modify_headers and is called from any other target
elf_backed_modify_headers.
* elf-bfd.h (struct elf_backend_data <elf_backend_modify_headers>):
Rename from elf_backend_modify_program_headers.
(_bfd_elf_modify_headers): Declare.
* elf.c (assign_file_positions_except_relocs): Set
elf_program_header_size. Always call elf_backend_modify_headers.
Extract code modifying file header..
(_bfd_elf_modify_headers): ..to here. New function.
* elf32-arm.c (elf_backend_modify_headers): Renamed from
elf_backend_modify_program_headers.
* elf32-i386.c: Similarly.
* elf64-x86-64.c: Similarly.
* elfxx-target.h: Similarly. Default elf_backend_modify_headers
to _bfd_elf_modify_headers.
* elf-nacl.h (nacl_modify_headers): Rename from
nacl_modify_program_headers.
* elf-nacl.c (nacl_modify_headers): Rename from
nacl_modify_program_headers and call _bfd_elf_modify_headers.
* elf32-rx.c (elf32_rx_modify_headers): Similarly.
* elf32-spu.c (spu_elf_modify_headers): Similarly.
* elfnn-ia64.c (elfNN_ia64_modify_headers): Similarly.
* elf32-sh.c (elf_backend_modify_program_headers): Don't undef.
This patch introduces a new "sorry, cannot handle this file" bfd error
status. The idea is to use this error in cases where bfd hasn't found
a bfd_bad_value error, ie. an input file or set of options that are
invalid, but rather an input file that is simply too difficult to
process. Typically this might happen with fuzzed object files such as
the one in the PR, a wildly improbable core file. Some things are
just not worth wasting time over to fix "properly".
PR 25196
* bfd.c (bfd_error_type): Add bfd_error_sorry.
(bfd_errmsgs): Likewise.
* elf.c (rewrite_elf_program_header): Don't abort on confused
lma/alignment. Replace bfd_error_bad_value with bfd_error_sorry.
(_bfd_elf_validate_reloc): Use bfd_error_sorry.
(_bfd_elf_final_write_processing): Likewise.
* bfd-in2.h: Regenerate.
* elf-bfd.h (elf_backend_data) <elf_backend_core_find_build_id>:
New field.
(_bfd_elf32_core_find_build_id, _bfd_elf64_core_find_build_id):
New functions.
(elf_read_notes): Add declaration.
* elf.c (elf_read_notes): Move elf-bfd.h.
(_bfd_elf_core_find_build_id): New function.
(bfd_section_from_phdr): Scan core file PT_LOAD segments for
build-id if none is known.
(elf_parse_notes): For core files, scan for notes.
* elfcore.h (elf_core_file_matches_executable_p): If both
BFDs have identical build-ids, then they match.
(_bfd_elf_core_find_build_id): New function.
* elfxx-target.h (elf_backend_core_find_build_id): Define.
(elfNN_bed): Add elf_backend_core_find_build_id.
This rewrites much of assign_file_positions_for_non_load_sections to
allow objcopy and strip to handle cases like that in PR4499 where
program headers were not in their usual position immediately after the
ELF file header, and PT_LOAD headers were not sorted by paddr.
PR 4499
include/
* elf/internal.h (struct elf_segment_map): Delete header_size.
Add no_sort_lma and idx.
bfd/
* elf-nacl.c (nacl_modify_segment_map): Set no_sort_lma for all
PT_LOAD segments.
* elf32-spu.c (spu_elf_modify_segment_map): Likewise on overlay
PT_LOAD segments.
* elf.c (elf_sort_segments): New function.
(assign_file_positions_except_relocs): Use shortcuts to elfheader
and elf_tdata. Seek to e_phoff not sizeof_ehdr to write program
headers. Move PT_PHDR check..
(assign_file_positions_for_non_load_sections): ..and code setting
PT_PHDR p_vaddr and p_paddr, and code setting __ehdr_start value..
(assign_file_positions_for_load_sections): ..to here. Sort
PT_LOAD headers. Delete header_pad code. Use actual number of
headers rather than allocated in calculating size for program
headers. Don't assume program headers follow ELF file header.
Simplify pt_load_count code. Only set "off" for PT_LOAD or
PT_NOTE in cores.
(rewrite_elf_program_header): Set p_vaddr_offset for segments
that include file and program headers.
(copy_elf_program_header): Likewise, replacing header_size code.
elf_sort_sections tried to ensure a stable qsort by using target_index
as the final comparison, but target_index hasn't been set by anything
at the time elf_sort_sections was run. This patch arrange to have
target_index set.
* elf.c (_bfd_elf_map_sections_to_segments): Init target_index
for sections about to be sorted.
(assign_file_positions_for_load_sections): Likewise.
(elf_sort_sections): Don't bother optimising both TOEND case.
* elflink.c (bfd_elf_final_link): Reset target_index.
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 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.
PR 24456
* elf.c (bfd_section_from_shdr): Issue an informative warning
message and continue processing other sections after encountering
a reloc section for a section which already has other relocs
associated with it.
This parameter might appear to be used to set up offset_size, but
since git commit 024b2372f5 offset_size is either set from the
debug_info data or is set to 4.
* dwarf2.c (_bfd_dwarf2_find_nearest_line): Remove addr_size parameter.
* libbfd-in.h (_bfd_dwarf2_find_nearest_line): Update prototype.
* coffgen.c (coff_find_nearest_line_with_names): Adjust
_bfd_dwarf2_find_nearest_line calls.
* elf.c (_bfd_elf_find_nearest_line, _bfd_elf_find_line): Likewise.
* elf32-arm.c (elf32_arm_find_nearest_line): Likewise.
* elf64-alpha.c (elf64_alpha_find_nearest_line): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_find_nearest_line): Likewise.
* elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Likewise.
* mach-o.c (bfd_mach_o_find_nearest_line): Likewise.
* libbfd.h: Regenerate.
When SHF_GNU_MBIND was added in the SHF_LOOS to SHF_HIOS range, it
should have required ELFOSABI_GNU since these flags are already in use
by other OSes. HPUX SHF_HP_TLS in fact has the same value. That
means no place in binutils should test SHF_GNU_MBIND without first
checking OSABI, and SHF_GNU_MBIND should not be set without also
setting OSABI. At least, that's the ideal, but the patch accepts
SHF_GNU_MBIND on ELFOSABI_NONE object files since gas didn't always
set OSABI. However, to reinforce the fact that SHF_GNU_MBIND isn't
proper without a non-zero OSABI, readelf will display the flag as
LOOS+0 if OSABI isn't set.
The clash with SHF_HP_TLS means that hppa64-linux either has that flag
on .tbss sections or supports GNU_MBIND, not both. (hppa64-linux
users, if there are any, may have noticed that GNU ld since 2017
mysteriously aligned their .tbss sections to a 4k boundary. That was
one consequence of SHF_HP_TLS being blindly interpreted as
SHF_GNU_MBIND.) Since it seems that binutils, gdb, gcc, glibc, and
the linux kernel don't care about SHF_HP_TLS I took that flag out of
.tbss for hppa64-linux.
bfd/
* elf-bfd.h (enum elf_gnu_osabi): Add elf_gnu_osabi_mbind.
* elf.c (_bfd_elf_make_section_from_shdr): Set elf_gnu_osabi_mbind.
(get_program_header_size): Formatting. Only test SH_GNU_MBIND
when elf_gnu_osabi_mbind is set.
(_bfd_elf_map_sections_to_segments): Likewise.
(_bfd_elf_init_private_section_data): Likewise.
(_bfd_elf_final_write_processing): Update comment.
* elf64-hppa.c (elf64_hppa_special_sections): Move .tbss entry.
(elf_backend_special_sections): Define without .tbss for linux.
binutils/
* readelf.c (get_parisc_segment_type): Split off hpux entries..
(get_ia64_segment_type): ..and these..
(get_hpux_segment_type): ..to here.
(get_segment_type): Condition GNU_MBIND on osabi. Use
get_hpux_segment_type.
(get_symbol_binding): Do not print UNIQUE for ELFOSABI_NONE.
(get_symbol_type): Do not print IFUNC for ELFOSABI_NONE.
gas/
* config/obj-elf.c (obj_elf_change_section): Don't emit a fatal
error for non-SHF_ALLOC SHF_GNU_MBIND here.
(obj_elf_parse_section_letters): Return SHF_GNU_MBIND in new
gnu_attr param.
(obj_elf_section): Adjust obj_elf_parse_section_letters call.
Formatting. Set SHF_GNU_MBIND and elf_osabi from gnu_attr.
Emit normal error for non-SHF_ALLOC SHF_GNU_MBIND and wrong osabi.
(obj_elf_type): Set elf_osabi for ifunc.
* testsuite/gas/elf/section12a.d: xfail msp430 and hpux.
* testsuite/gas/elf/section12b.d: Likewise.
* testsuite/gas/elf/section13.d: Likewise.
* testsuite/gas/elf/section13.l: Adjust expected error.
ld/
* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Condition
SHF_GNU_MBIND on osabi. Set output elf_gnu_osabi_mbind.
PR 24717
* elf.c (is_debuginfo_file): New function.
(assign_file_positions_for_non_load_sections): Do not warn about
allocated sections outside of loadable segments if they are found
in a debuginfo file.
* elf-bfd.h (is_debuginfo_file): Prototype.
PR 24708
* elf.c (_bfd_elf_slurp_version_tables): Check for an excessively
large version reference section.
* compress.c (bfd_get_full_section_contents): Check for an
uncompressed section whose size is larger than the file size.
PR 24650
* elf.c (elfcore_make_auxv_note_section): New function.
(elfcore_grok_note): Use it.
(elfcore_grok_freebsd_note): Likewise.
(elfcore_grok_openbsd_note): Likewise.
(elfcore_grok_netbsd_note): Likewise. Plus add support for
NT_NETBSDCORE_AUXV notes.
After fixing the ld-elf/pr22836-1a segmentation fault we run into an
assertion failure due to the generic ELF target not removing empty
SHT_GROUP sections. Avoid that.
* elf.c (bfd_elf_set_group_contents): Exit on zero size section.
Reverts commit 1ff31e135f, fixing the problem more generally. There
are likely other place that will segfault on a NULL section.
PR 24337
* elf.c (_bfd_elf_rela_local_sym): Revert last change.
(_bfd_elf_rel_local_sym): Likewise.
* elflink.c (elf_link_input_bfd): Use bfd_und_section for
section of symbols with unrecognized shndx.
Compressed debug sections can have uncompressed sizes that exceed the
original file size, so we can't use bfd_get_file_size. objdump also
used bfd_get_file_size to limit reloc section size, but I believe the
underlying bug causing the PR22508 out of bounds buffer access was
that we had an integer overflow when calculating the reloc buffer
size. I've fixed that instead in most of the backends, som and
vms-alpha being the exceptions. SOM and vmd-alpha have rather more
serious bugs in their slurp_relocs routines that would need fixing
first if we want to fuss about making them safe against fuzzed object
files.
The patch also fixes a number of other potential overflows by using
the bfd_alloc2/malloc2/zalloc2 memory allocation functions.
bfd/
* coffcode.h (buy_and_read): Delete unnecessary forward decl. Add
nmemb parameter. Use bfd_alloc2.
(coff_slurp_line_table): Use bfd_alloc2. Update buy_and_read calls.
Delete assertion.
(coff_slurp_symbol_table): Use bfd_alloc2 and bfd_zalloc2.
(coff_slurp_reloc_table): Use bfd_alloc2. Update buy_and_read calls.
* coffgen.c (coff_get_reloc_upper_bound): Ensure size calculation
doesn't overflow.
* elf.c (bfd_section_from_shdr): Use bfd_zalloc2. Style fix.
(assign_section_numbers): Style fix.
(swap_out_syms): Use bfd_malloc2.
(_bfd_elf_get_reloc_upper_bound): Ensure size calculation doesn't
overflow.
(_bfd_elf_make_empty_symbol): Style fix.
(elfobj_grok_stapsdt_note_1): Formatting.
* elfcode.h (elf_object_p): Use bfd_alloc2.
(elf_write_relocs, elf_write_shdrs_and_ehdr): Likewise.
(elf_slurp_symbol_table): Use bfd_zalloc2.
(elf_slurp_reloc_table): Use bfd_alloc2.
(_bfd_elf_bfd_from_remote_memory): Use bfd_malloc2.
* elf64-sparc (elf64_sparc_get_reloc_upper_bound): Ensure
size calculation doesn't overflow.
(elf64_sparc_get_dynamic_reloc_upper_bound): Likewise.
* mach-o.c (bfd_mach_o_get_reloc_upper_bound): Likewise.
* pdp11.c (get_reloc_upper_bound): Copy aoutx.h version.
binutils/
* objdump.c (load_specific_debug_section): Don't compare section
size against file size.
(dump_relocs_in_section): Don't compare reloc size against file size.
Print "failed to read relocs" on bfd_get_reloc_upper_bound error.
Used for the AArch64 pointer authentication code mask registers in Arm v8.3-a.
NT_ARM_PAC_MASK matches the value in Linux include/uapi/linux/elf.h
include/ChangeLog:
* elf/common.h (NT_ARM_PAC_MASK): Add define.
bfd/ChangeLog:
* elf-bfd.h (elfcore_write_aarch_pauth): Add declaration.
* elf.c (elfcore_grok_aarch_pauth): New function.
(elfcore_grok_note): Check for NT_ARM_PAC_MASK.
(elfcore_write_aarch_pauth): New function.
(elfcore_write_register_note): Check for AArch64 pauth section.
Commit 2bf2bf23da exposed a bug on targets that create common sections
other than the standard ELF SHN_COMMON. If these are output by ld -r,
then their type becomes SHT_PROGBITS unless the target handles them
specially (eg. by elf_backend_special_sections), and if they are
merged into .bss/.sbss by ld -r then that section becomes SHT_PROGBITS.
Worse, if they are output by ld -r, then their size is increased by
bfd_generic_define_common_symbol during final link, which leads to
bogus file contents being copied to output.
For mips, it seems to me that the .scommon section should not be
output for ld -r, but I haven't made that change in this patch.
PR 24015
* elf.c (bfd_elf_get_default_section_type): Make common sections
SHT_NOBITS.
* linker.c (bfd_generic_define_common_symbol): Clear
SEC_HAS_CONTENTS.
Alan Modra
Nick Clifton
Christian Eggers
Keith Seitz
Nick Alcock
Martin Liska
Christos Zoulas
Alan Hayward