Since we changed the default arch for objdump to zarch the following
testcase needs to check for the real instruction mnemonics instead of
just bytes.
This fixes the following testsuite fail on s390x:
FAIL: GOT: symbol address load from got to larl
Taking them out showed a bug in the powerpc64 backend with .branch_lt
being removed from output_bfd but not from previously set up segment
section maps. Removing the bfd sections meant their sh_flags (and
practically everything else) remaining zero, ie. not SHF_ALLOC,
triggering complaints about "`.branch_lt' can't be allocated in
segment".
include/elf/
* internal.h (ELF_SECTION_IN_SEGMENT_1): Ensure PT_LOAD and
similar segments only contain alloc sections.
ld/
* emultempl/ppc64elf.em (gld${EMULATION_NAME}_after_allocation):
Call gld${EMULATION_NAME}_map_segments regardless of need_laying_out.
ld/testsuite/
* ld-powerpc/tocnovar.d: Revert last change.
When we set up st_name for output section name in elf_fake_sections, we
don't know if the compressed DWARF debug section will be smaller. We may
end up with compressed DWARF debug sections which are bigger than the
uncompressed ones. This patch delays setting up st_name for output DWARF
debug section to _bfd_elf_assign_file_positions_for_non_load which will
compress the output debug section. We also postpone placement of shstrtab
section after DWARF debug sections have been compressed. The net effect
is .shstrtab section is now placed after .symtab and .strtab sections.
bfd/
PR ld/18277
* compress.c (bfd_compress_section_contents): Remove the
write_compress argument.
(bfd_init_section_compress_status): Updated.
(bfd_compress_section): Likewise.
* elf.c (_bfd_elf_set_reloc_sh_name): New.
(_bfd_elf_init_reloc_shdr): Add delay_st_name_p. Set sh_name
to (unsigned int) -1 if delay_st_name_p is TRUE. Use
_bfd_elf_set_reloc_sh_name.
(elf_fake_sections): Don't rename DWARF debug section for
linker output if it will be compressed. Instead, set
delay_st_name_p to TRUE and pass it to _bfd_elf_init_reloc_shdr.
(assign_section_numbers): Call _bfd_elf_strtab_addref only if
sh_name != (unsigned int) -1. Don't finalize nor assign
shstrtab section here. Delay setting output section names to
_bfd_elf_write_object_contents.
(_bfd_elf_compute_section_file_positions): Update comments on
sh_offset for shstrtab section.
(assign_file_positions_for_non_load_sections): Set sh_offset to
-1 for shstrtab section.
(assign_file_positions_except_relocs): Likewise.
(_bfd_elf_assign_file_positions_for_non_load): Set up sh_name
when compressing DWARF debug sections. Place shstrtab section
after DWARF debug sections have been compressed.
(_bfd_elf_write_object_contents): Setting sh_name for output
sections.
ld/testsuite/
PR ld/18277
* ld-elf/compressed1d.d: New.
* ld-elf/compressed1e.d: Likewise.
Change compressed input debug section name for objdump is very confusing.
But we need to change it for linker so that linker will consider the
input section as a debug section. This patch delays section rename to
elf_fake_sections for objcopy and avoids it for objdump.
bfd/
PR binutils/18209
* bfd.c (bfd): Add is_linker_input.
* elf.c (convert_debug_to_zdebug): New.
(convert_zdebug_to_debug): Likewise.
(_bfd_elf_make_section_from_shdr): Don't convert .debug_* to
.zdebug_* here. Use convert_zdebug_to_debug. Set SEC_ELF_RENAME.
(_bfd_elf_init_reloc_shdr): Pass a pointer to section name
instead of a pointer to section.
(elf_fake_sections): Rename the section name if SEC_ELF_RENAME
is set.
* section.c (SEC_ELF_RENAME): New.
* bfd-in2.h: Regenerated.
binutils/
PR binutils/18209
* objcopy.c (setup_section): Copy compress status.
binutils/testsuite/
PR binutils/18209
* binutils-all/compress.exp: Replace dw2-3.W with dw2-3gabi.W
on zlib-gabi output.
* binutils-all/dw2-1.W: Convert section names to .zdebug_*.
* binutils-all/dw2-3.W: Likewise.
* binutils-all/objdump.W: Likewise.
* binutils-all/dw2-3gabi.W: New file.
ld/
PR binutils/18209
* ldfile.c (ldfile_try_open_bfd): Set is_linker_input to 1.
I didn't commit this with the relro and powerpc .TOC. changes,
thinking that something should be done about the odd result of
.shstrtab appearing in PT_GNU_RELRO. On looking at it further,
I think that changing readelf would be wrong, so let's just
accept the results. Real binaries will always have other sections
past .got, so PT_GNU_RELRO won't finish past the end of loaded
sections.
* ld-powerpc/tocnovar.d: Adjust.
The linker tries to put the end of the last section in the relro
segment exactly on a page boundary, because the relro segment itself
must end on a page boundary. If for any reason this can't be done,
padding is inserted. Since the end of the relro segment is typically
between .got and .got.plt, padding effectively increases the size of
the GOT. This isn't nice for targets and code models with limited GOT
addressing.
The problem with the current code is that it doesn't cope very well
with aligned sections in the relro segment. When making .got aligned
to a 256 byte boundary for PowerPC64, I found that often the initial
alignment attempt failed and the fallback attempt to be less than
adequate. This is a particular problem for PowerPC64 since the
distance between .got and .plt affects the size of plt call stubs,
leading to "stubs don't match calculated size" errors.
So this rewrite takes a direct approach to calculating a new relro
base. Starting from the last section in the segment, we calculate
where it must start to position its end on the boundary, or as near as
possible considering alignment requirements. The new start then
becomes the goal for the previous section to end, and so on for all
sections. This of course ignores the possibility that user scripts
will place . = ALIGN(xxx); in the relro segment, or provide section
address expressions. In those cases we might fail, but the old code
probably did too, and a fallback is provided.
ld/
* ldexp.h (struct ldexp_control): Delete dataseg.min_base. Add
data_seg.relro_offset.
* ldexp.c (fold_binary <DATA_SEGMENT_ALIGN>): Don't set min_base.
(fold_binary <DATA_SEGMENT_RELRO_END>): Do set relro_offset.
* ldlang.c (lang_size_sections): Rewrite code adjusting relro
segment base to line up last section on page boundary.
ld/testsuite/
* ld-x86-64/pr18176.d: Update.
This patch adds --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]
to ld for ELF targets to support generating compressed DWARF debug
sections. We always generate .zdebug_* section since section names have
been finalized and they can't be changed easily when compression is
being performed.
bfd/
* bfd-in.h (compressed_debug_section_type): New.
* compress.c (bfd_compress_section_contents): Add an argument
for linker write compression and always generate .zdebug_*
section when linking.
(bfd_init_section_compress_status): Pass FALSE to
bfd_compress_section_contents.
(bfd_compress_section): New function.
* elf.c (elf_fake_sections): For linking, set SEC_ELF_COMPRESS
on DWARF debug sections if COMPRESS_DEBUG is set and rename
section if COMPRESS_DEBUG_GABI_ZLIB isn't set.
(assign_file_positions_for_non_load_sections): Set sh_offset
to -1 if SEC_ELF_COMPRESS is set.
(assign_file_positions_except_relocs): Likwise.
(_bfd_elf_assign_file_positions_for_relocs): Renamed to ...
(_bfd_elf_assign_file_positions_for_non_load): This. Change
return time to bfd_boolean. Compress the section if
SEC_ELF_COMPRESS is set.
(_bfd_elf_write_object_contents): Updated.
(_bfd_elf_set_section_contents): Write section contents to
the buffer if SEC_ELF_COMPRESS is set.
* merge.c: Include "elf-bfd.h".
(sec_merge_emit): Add arguments for contents and offset. Write
to contents with offset if contents isn't NULL.
(_bfd_write_merged_section): Write section contents to the
buffer if SEC_ELF_COMPRESS is set. Pass contents and
output_offset to sec_merge_emit.
* elflink.c (bfd_elf_final_link): Allocate the buffer for
output section contents if SEC_ELF_COMPRESS is set.
* section.c (SEC_ELF_COMPRESS): New.
* bfd-in2.h: Regenerated.
gas/
* as.h (compressed_debug_section_type): Removed.
include/
* bfdlink.h (bfd_link_info): Add compress_debug.
ld/
* ld.texinfo: Document --compress-debug-sections=.
* ldmain.c (main): Set BFD_COMPRESS on output_bfd if
COMPRESS_DEBUG is set. Set BFD_COMPRESS_GABI on output_bfd
for COMPRESS_DEBUG_GABI_ZLIB.
* lexsup.c (elf_static_list_options): Add
--compress-debug-sections=.
* emultempl/elf32.em (OPTION_COMPRESS_DEBUG): New.
(xtra_long): Add "compress-debug-sections".
(gld${EMULATION_NAME}_handle_option): Handle
OPTION_COMPRESS_DEBUG.
ld/testsuite/
* ld-elf/compress.exp (build_tests): Add tests for
--compress-debug-sections=.
(run_tests): Likewise.
Add additonal tests for --compress-debug-sections=.
* ld-elf/gabiend.rt: New file.
* ld-elf/gabinormal.rt: Likewise.
* ld-elf/gnubegin.rS: Likewise.
* ld-elf/gnunormal.rS: Likewise.
* ld-elf/zlibbegin.rS: Likewise.
* ld-elf/zlibnormal.rS: Likewise.
Address of protected data defined in the shared library may be external,
i.e., due to copy relocation. By default, linker backend checks if
relocations against protected data symbols are valid for building shared
library and issues an error if relocation isn't allowed. The new option
override linker backend default. When -z noextern-protected-data is used,
updates on protected data symbols by another module won't be visibile
to the resulting shared library. This option is specific to ELF/i386
and ELF/x86-64.
bfd/
PR ld/pr17709
* elflink.c (_bfd_elf_adjust_dynamic_copy): Check
info->extern_protected_data when warning copy relocs against
protected symbols.
(_bfd_elf_symbol_refs_local_p): Check info->extern_protected_data
when checking protected non-function symbols.
include/
PR ld/pr17709
* bfdlink.h (bfd_link_info): Add extern_protected_data.
ld/
PR ld/pr17709
* ld.texinfo: Document "-z noextern-protected-data".
* ldmain.c (main): Initialize link_info.extern_protected_data
to -1.
* lexsup.c (elf_shlib_list_options): Add
"-z [no]extern-protected-data".
* emulparams/elf32_x86_64.sh: Source extern_protected_data.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_i386_be.sh: Likewise.
* emulparams/elf_i386_chaos.sh: Likewise.
* emulparams/elf_i386_ldso.sh: Likewise.
* emulparams/elf_i386_vxworks.sh: Likewise.
* emulparams/elf_k1om.sh: Likewise.
* emulparams/elf_l1om.sh: Likewise.
* emulparams/elf_x86_64.sh: Source extern_protected_data.sh.
(PARSE_AND_LIST_OPTIONS): Renamed to ...
(PARSE_AND_LIST_OPTIONS_BNDPLT): This.
(PARSE_AND_LIST_ARGS_CASE_Z): Renamed to ...
(PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT): This.
(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_BNDPLT.
(PARSE_AND_LIST_ARGS_CASE_Z): Append
$PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT.
* emulparams/extern_protected_data.sh: New file.
ld/testsuite/
PR ld/pr17709
* ld-i386/i386.exp: Run protected6b.
* ld-i386/protected6b.d: New file.
* ld-x86-64/protected6b.d: Likewise.
* ld-x86-64/x86-64.exp: Run protected6b.
When checking R_386_GOTOFF/R_X86_64_GOTOFF64 for building shared library,
we should check SYMBOL_REFERENCES_LOCAL instead of SYMBOLIC_BIND to cover
more cases.
bfd/
* elf32-i386.c (elf_i386_relocate_section): Replace SYMBOLIC_BIND
with SYMBOL_REFERENCES_LOCAL when checking R_386_GOTOFF against
protected data symbol when building shared library.
* elf64-x86-64.c (elf_x86_64_relocate_section): Check
R_X86_64_GOTOFF64 against undefined symbol and replace
SYMBOLIC_BIND with SYMBOL_REFERENCES_LOCAL when checking
R_X86_64_GOTOFF64 against protected data symbol when building
shared library.
ld/testsuite/
* ld-i386/i386.exp: Run protected6a.
* ld-i386/protected6.d: Renamed to ...
* ld-i386/protected6a.d: This.
* ld-x86-64/hidden4.d: New file.
* ld-x86-64/hidden4.s: Likewise.
* ld-x86-64/hidden5.d: Likewise.
* ld-x86-64/hidden5.s: Likewise.
* ld-x86-64/protected6.d: Renamed to ...
* ld-x86-64/protected6a.d: This.
* ld-x86-64/x86-64.exp: Run hidden4, hidden5, protected6a,
protected7a and protected7b.
R_386_GOTOFF/R_X86_64_GOTOFF64 relocation shouldn't be used against
protected data symbol on x86 since with copy relocation, address of
protected data defined in the shared library may be external.
This patch will break building shared libraries with protected data
symbols using GCCs older than GCC 5 without the bug fix for
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248
GCC backport request should be made in the GCC bug report above.
bfd/
PR ld/pr17709
* elf32-i386.c (elf_i386_relocate_section): Also check R_386_GOTOFF
against protected data symbol when building shared library.
* elf64-x86-64.c (elf_x86_64_relocate_section): Also check
R_X86_64_GOTOFF64 against protected data symbol when building
shared library.
ld/testsuite/
PR ld/pr17709
* ld-i386/protected6.d: New file.
* ld-i386/protected6.s: Likewise.
* ld-x86-64/protected6.d: Likewise.
* ld-x86-64/protected6.s: Likewise.
* ld-x86-64/protected7.d: Likewise.
* ld-x86-64/protected7.s: Likewise.
* ld-x86-64/protected7a.d: Likewise.
* ld-x86-64/protected7b.d: Likewise.
Re-apply: commit ca3fe95e46
With copy relocation, address of protected data defined in the shared
library may be external. This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.
This patch will break building shared libraries with protected data
symbols using GCCs older than GCC 5 without the bug fix for
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248
GCC backport request should be made in the GCC bug report above.
To get correct run-time behavior on Linux, glibc 2.22 or above are
required, which have the bug fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=17711
Backports for glibc 2.21, 2.20, 2.19 and 2.18 are on hjl/pr17711/2.21,
hjl/pr17711/2.20, hjl/pr17711/2.19 and hjl/pr17711/2.18 branches,
respectively, at
https://sourceware.org/git/?p=glibc.git;a=summary
bfd/
PR ld/pr15228
PR ld/pr17709
* elf-bfd.h (elf_backend_data): Add extern_protected_data.
* elf32-i386.c (elf_backend_extern_protected_data): New.
Defined to 1.
* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
copy relocs against protected symbols if extern_protected_data
is true.
(_bfd_elf_symbol_refs_local_p): Don't return true on protected
non-function symbols if extern_protected_data is true.
* elfxx-target.h (elf_backend_extern_protected_data): New.
Default to 0.
(elfNN_bed): Initialize extern_protected_data with
elf_backend_extern_protected_data.
ld/testsuite/
PR ld/pr15228
PR ld/pr17709
* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
* ld-i386/pr17709-nacl.rd: New file.
* ld-i386/pr17709.rd: Likewise.
* ld-i386/pr17709a.s: Likewise.
* ld-i386/pr17709b.s: Likewise.
* ld-i386/protected3.d: Updated.
* ld-i386/protected3.s: Likewise.
* ld-x86-64/pr17709-nacl.rd: New file.
* ld-x86-64/pr17709.rd: Likewise.
* ld-x86-64/pr17709a.s: Likewise.
* ld-x86-64/pr17709b.s: Likewise.
* ld-x86-64/protected3.d: Updated.
* ld-x86-64/protected3.s: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
PR binutils/18198
* ld.texinfo (--be8): Add a note about the interaction of this
option with the assembler's -EB option.
* doc/c-arm.texi (ARM Options): Add a note about the interaction of
the -EB option with the linker's --be8 option.
gold marks _init and _fini via symbol, ld marks them via section
(default scripts set .init and .fini section KEEP). This makes it
possible for people to write their own _init and not bother to put the
function into the right section.
PR ld/18223
* ldlang.c (lang_process): Add _init and _fini to gc_sym_list.
When --enable-targets=all is used with non-ELF target, we should enable
ELF ld_list_options.
* configure.ac (elf_list_options): Set to TRUE for
--enable-targets=all.
(elf_shlib_list_options): Likewise.
(elf_plt_unwind_list_options): Likewise.
* configure: Regenerated.
This patch adds --compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}
options to gas and objcopy for ELF files. They control how DWARF debug
sections are compressed. --compress-debug-sections=none is equivalent to
--nocompress-debug-sections. --compress-debug-sections=zlib and
--compress-debug-sections=zlib-gnu are equivalent to
--compress-debug-sections. --compress-debug-sections=zlib-gabi compresses
DWARF debug sections with SHF_COMPRESSED from the ELF ABI. No linker
changes are required to support SHF_COMPRESSED.
bfd/
* archive.c (_bfd_get_elt_at_filepos): Also copy BFD_COMPRESS_GABI
bit.
* bfd.c (bfd::flags): Increase size to 18 bits.
(BFD_COMPRESS_GABI): New.
(BFD_FLAGS_SAVED): Add BFD_COMPRESS_GABI.
(BFD_FLAGS_FOR_BFD_USE_MASK): Likewise.
(bfd_update_compression_header): New fuction.
(bfd_check_compression_header): Likewise.
(bfd_get_compression_header_size): Likewise.
(bfd_is_section_compressed_with_header): Likewise.
* compress.c (MAX_COMPRESSION_HEADER_SIZE): New.
(bfd_compress_section_contents): Return the uncompressed size if
the full section contents is compressed successfully. Support
converting from/to .zdebug* sections.
(bfd_get_full_section_contents): Call
bfd_get_compression_header_size to get compression header size.
(bfd_is_section_compressed): Renamed to ...
(bfd_is_section_compressed_with_header): This. Add a pointer
argument to return compression header size.
(bfd_is_section_compressed): Use it.
(bfd_init_section_decompress_status): Call
bfd_get_compression_header_size to get compression header size.
Return FALSE if uncompressed section size is 0.
* elf.c (_bfd_elf_make_section_from_shdr): Support converting
from/to .zdebug* sections.
* bfd-in2.h: Regenerated.
binutils/
* objcopy.c (do_debug_sections): Add compress_zlib,
compress_gnu_zlib and compress_gabi_zlib.
(copy_options): Use optional_argument on compress-debug-sections.
(copy_usage): Update --compress-debug-sections.
(copy_file): Handle compress_zlib, compress_gnu_zlib and
compress_gabi_zlib.
(copy_main): Handle
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* doc/binutils.texi: Document
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
binutils/testsuite/
* compress.exp: Add tests for
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* binutils-all/dw2-3.rS: New file.
* binutils-all/dw2-3.rt: Likewise.
* binutils-all/libdw2-compressedgabi.out: Likewise.
gas/
* as.c (show_usage): Update --compress-debug-sections.
(std_longopts): Use optional_argument on compress-debug-sections.
(parse_args): Handle
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* as.h (compressed_debug_section_type): New.
(flag_compress_debug): Change type to compressed_debug_section_type.
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
* write.c (compress_debug): Set BFD_COMPRESS_GABI for
--compress-debug-sections=zlib-gabi. Call
bfd_get_compression_header_size to get compression header size.
Don't rename section name for --compress-debug-sections=zlib-gabi.
* config/tc-i386.c (compressed_debug_section_type): Set to
COMPRESS_DEBUG_ZLIB.
* doc/as.texinfo: Document
--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
gas/testsuite/
* gas/i386/dw2-compressed-1.d: New file.
* gas/i386/dw2-compressed-2.d: Likewise.
* gas/i386/dw2-compressed-3.d: Likewise.
* gas/i386/x86-64-dw2-compressed-2.d: Likewise.
* gas/i386/i386.exp: Run dw2-compressed-2, dw2-compressed-1,
dw2-compressed-3 and x86-64-dw2-compressed-2.
ld/testsuite/
* ld-elf/compress.exp: Add a test for
--compress-debug-sections=zlib-gabi.
(build_tests): Add 2 tests for --compress-debug-sections=zlib-gabi.
(run_tests): Likewise.
Verify linker output with zlib-gabi compressed debug input.
* ld-elf/compressed1a.d: New file.
* ld-elf/compressed1b.d: Likewise.
* ld-elf/compressed1c.d: Likewise.
ld * ld.h (struct ld_config_type): Add new field: warn_orphan.
* ldlex.h (enum option_values): Add OPTION_WARN_ORPHAN and
OPTION_NO_WARN_ORPHAN.
* lexsup.c (ld_options): Add --warn-orphan and --no-warn-orphan.
(parse_args): Handle the new options.
* ldemul.c (ldemul_place_orphan): If requested, generate a warning
message when an orphan section is placed in the output file.
* ld.texinfo: Document the new option.
* NEWS: Mention the new feature.
tests * ld-elf/orphan-5.l: New test - checks the linker's output with
--warn-orphan enabled.
* ld-elf/elf.exp: Run the new test.
Fixes tic6x testsuite failures due to .rela.plt having a zero sh_info.
I considered passing link_info to get_reloc_section so we could
directly return the .got.plt output section, but we need the fallback
to name lookup anyway for objcopy.
bfd/
* elf.c (_bfd_elf_get_reloc_section): Allow for .got.plt being
mapped to output .got section.
ld/testsuite/
* ld-arm/tls-gdesc-nlazy.g: Adjust for readelf note.
* ld-tic6x/shlib-1.rd: Expect corrected .rela.plt sh_info.
* ld-tic6x/shlib-1b.rd: Likewise.
* ld-tic6x/shlib-1r.rd: Likewise.
* ld-tic6x/shlib-1rb.rd: Likewise.
* ld-tic6x/shlib-app-1.rd: Likewise.
* ld-tic6x/shlib-app-1b.rd: Likewise.
* ld-tic6x/shlib-app-1r.rd: Likewise.
* ld-tic6x/shlib-app-1rb.rd: Likewise.
* ld-tic6x/shlib-noindex.rd: Likewise.
This is a linker-only solution to the incompatibility between shared
library protected visibility variables and using .dynbss and copy
relocs for non-PIC access to shared library variables.
bfd/
* elf32-ppc.c (struct ppc_elf_link_hash_entry): Add has_addr16_ha
and has_addr16_lo. Make has_sda_refs a bitfield.
(ppc_elf_check_relocs): Set new flags.
(ppc_elf_link_hash_table_create): Update default_params.
(ppc_elf_adjust_dynamic_symbol): Clear protected_def in cases
where we won't be making .dynbss entries or editing code. Set
params->pic_fixup when we'll edit code for protected var access.
(allocate_dynrelocs): Allocate got entry for edited code and
discard dyn_relocs.
(struct ppc_elf_relax_info): Add picfixup_size.
(ppc_elf_relax_section): Rename struct one_fixup to struct
one_branch_fixup. Rename fixups to branch_fixups. Size space for
pic fixups.
(ppc_elf_relocate_section): Edit non-PIC accessing protected
visibility variables to PIC. Don't emit dyn_relocs for code
we've edited.
* elf32-ppc.h (struct ppc_elf_params): Add pic_fixup.
ld/
* emultempl/ppc32elf.em: Handle --no-pic-fixup.
(params): Init new field.
(ppc_before_allocation): Enable relaxation for pic_fixup.
Some early revisions of the Cortex-A53 have an erratum (843419). The
details of the erratum are quite complex and involve dynamic
conditions. For the purposes of the workaround we have simplified the
static conditions to an ADRP in the last two instructions of a 4KByte
page, followed within four instructions by a load/store dependent on
the ADRP.
This patch adds support to conservatively scan for and workaround
Cortex A53 erratum 843419. There are two different workaround
strategies used. The first is to rewrite ADRP instructions which form
part of an erratum sequence with an ADR instruction. In situations
where the ADR provides insufficient offset the dependent load or store
instruction from the sequence is moved to a stub section and branches
are inserted from the original sequence to the relocated instruction
and back again.
Stub section sizes are rounded up to a multiple of 4096 in order to
ensure that the act of inserting work around stubs does not create
more errata sequences.
Workaround stubs are always inserted into the stub section associated
with the input section containing the erratum sequence. This ensures
that the fully relocated form of the veneered load store instruction
is available at the point in time when the stub section is written.
Adjusting the start of the relro segment in order to make it end
exactly on a page boundary runs into difficulties when sections in the
relro segment are aligned; Adjusting the start by (next_page - end)
sometimes results in more than that adjustment occurring at the end,
overrunning the page boundary. So when that occurs we try a new lower
start position by masking the adjusted start with the maximum section
alignment. However, we didn't consider that this masked start address
may in fact be before the initial relro base, which is silly since
that can only increase padding at the relro end.
I've also moved some calculations closer to where they are used, and
comments closer to the relevant statements.
* ldlang.c (lang_size_sections): When alignment of sections
results in relro base adjustment being too large, don't go lower
than the initial value.
* ldexp.c (fold_binary <DATA_SEGMENT_RELRO_END>): Comment.
* scripttempl/elf.sc (DATA_SEGMENT_ALIGN): Omit SEGMENT_SIZE
alignment when SEGMENT_SIZE is the same as MAXPAGESIZE.
Older compilers that warn wrongly will just need -Wno-error. No way
am I going to init every single field, then have to edit this code
whenever bfd_link_hash_entry changes. Another option, making the
struct static, isn't very nice since it means larger binaries and
worse code.
* emultempl/elf32.em (gld${EMULATION_NAME}_before_allocation): Don't
init ehdr_start_save.
The ehdr_start_save variable does not need to be initialized. However,
not initializing it will trigger a compiler warning when using older
versions of GCC. Self-assignment unfortunately doesn't work for Clang
as Clang has a warning similar to -Winit-self as part of -Wall.
* emultempl/elf32.em (gld*_before_allocation): Zero-initialize
the ehdr_start_save variable.
