We use its PLT entry to initialize function pointer at run-time. If
there is no other usage for the PLT entry, we can generate run-time
function pointer relocations in read-write section, which can be
resolved by dynamic linker, to initialize function pointers. It avoids
the extra indirect branch overhead in PLT.
bfd/
PR ld/18900
* elf32-i386.c (elf_i386_link_hash_entry): Add
func_pointer_refcount.
(elf_i386_link_hash_newfunc): Clear func_pointer_refcount.
(elf_i386_get_local_sym_hash): Likewise.
(elf_i386_copy_indirect_symbol): Also copy
func_pointer_refcount.
(elf_i386_check_relocs): Increment func_pointer_refcount.
(elf_i386_gc_sweep_hook): Decrement func_pointer_refcount.
(elf_i386_allocate_dynrelocs): Don't create the PLT entry if
there are only function pointer relocations which can be
resolved at run-time. Keep dynanamic relocations for run-time
function pointer initialization.
(elf_i386_relocate_section): Copy dynamic function pointer
relocations.
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
func_pointer_refcount.
(elf_x86_64_link_hash_newfunc): Clear func_pointer_refcount.
(elf_x86_64_get_local_sym_hash): Likewise.
(elf_x86_64_copy_indirect_symbol): Also copy
func_pointer_refcount.
(elf_x86_64_check_relocs): Increment func_pointer_refcount.
(elf_x86_64_gc_sweep_hook): Decrement func_pointer_refcount.
(elf_x86_64_allocate_dynrelocs): Don't create the PLT entry if
there are only function pointer relocations which can be
resolved at run-time. Keep dynanamic relocations for run-time
function pointer initialization.
(elf_x86_64_relocate_section): Copy dynamic function pointer
relocations.
ld/testsuite/
PR ld/18900
* ld-i386/i386.exp: Run tests for PR ld/18900.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pr18900.out: New file.
* ld-i386/pr18900a.c: Likewise.
* ld-i386/pr18900a.c: Likewise.
* ld-i386/pr18900a.rd: Likewise.
* ld-i386/pr18900b.c: Likewise.
* ld-i386/pr18900b.rd: Likewise.
* ld-i386/pr18900c.c: Likewise.
* ld-x86-64/pr18900.out: Likewise.
* ld-x86-64/pr18900a.c: Likewise.
* ld-x86-64/pr18900a.rd: Likewise.
* ld-x86-64/pr18900b.c: Likewise.
* ld-x86-64/pr18900b.rd: Likewise.
* ld-x86-64/pr18900c.c: Likewise.
* ld-x86-64/mpx3.dd: Updated.
bfd PR ld/18401
* elfxx-mips.c (bfd_mips_isa_ext_mach): New function: Converts an
ISA value to a bfd machine number.
(bfd_mips_isa_ext): Update the ISA level and revision if
necessary. Use mips_mach_extends_p to decide if the ISA extension
needs to be set.
(_bfd_mips_elf_merge_private_bfd_data): Allow the ISA extension to
be inferred from the ABI setting. Set the ISA level from the
maximum of the incoming and outgoing ISA levels.
tests
* ld-mips-elf/mips-elf-flags.exp: Add more ISA conflict tests.
bfd/
* elf64-ppc.c (ppc64_elf_func_desc_adjust): Don't redefine .TOC.
if already defined, and set linker_def.
(ppc64_elf_set_toc): Use .TOC. value if defined other than by
the backend.
ld/
* ldexp.c (exp_fold_tree_1): Clear linker_def on symbol assignment.
To load an ELF binary with DT_TEXTREL tag, the dynamic linker calls
__mprotect on the read-only segment with PROT_READ|PROT_WRITE before
applying dynamic relocation. It leads to segfault when performing
IFUNC relocations since the read-only segment has no execute permission.
This patch changes x86 linker to issue an error for read-only segment
with dynamic IFUNC relocations. Other backends with IFUNC support
may need a similar change.
bfd/
PR ld/18801
* elf32-i386.c (elf_i386_size_dynamic_sections): Issue an error
for read-only segment with dynamic IFUNC relocations.
* elf64-x86-64.c (elf_x86_64_size_dynamic_sections): Likewise.
ld/testsuite/
PR ld/18801
* ld-i386/i386.exp: Run pr18801.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pr18801.d: New file.
* ld-i386/pr18801.s: Likewise.
* ld-x86-64/pr18801.d: Likewise.
* ld-x86-64/pr18801.s: Likewise.
Since the backend elf_add_symbol_hook isn't called on local symbols,
the EI_OSABI field isn't to ELFOSABI_GNU where are local IFUNC symbols.
This patch changes the x86 backends to set has_gnu_symbols if there are
relocations against IFUNC symbols. Other backends with IFUNC support
may need a similar change.
This patch also changes the type of has_gnu_symbols from bfd_boolean to
enum elf_gnu_symbols.
bfd/
PR ld/18815
* elf-bfd.h (elf_gnu_symbols): New enum.
(elf_obj_tdata): Use elf_gnu_symbols on has_gnu_symbols.
* elf-s390-common.c (elf_s390_add_symbol_hook): Set
has_gnu_symbols to elf_gnu_symbol_any.
* elf32-arm.c (elf32_arm_add_symbol_hook): Likewise.
* elf32-m68k.c (elf_m68k_add_symbol_hook): Likewise.
* elf32-ppc.c (ppc_elf_add_symbol_hook): Likewise.
* elf32-sparc.c (elf32_sparc_add_symbol_hook): Likewise.
* elf64-ppc.c (ppc64_elf_add_symbol_hook): Likewise.
* elf64-sparc.c (elf64_sparc_add_symbol_hook): Likewise.
* lfxx-aarch64.c (_bfd_aarch64_elf_add_symbol_hook): Likewise.
* elf32-i386.c (elf_i386_check_relocs): Update has_gnu_symbols
if there are relocations against IFUNC symbols.
(elf_i386_add_symbol_hook): Don't check STT_GNU_IFUNC here.
* elf64-x86-64. (elf_x86_64_check_relocs): Update has_gnu_symbols
if there are relocations against IFUNC symbols.
(elf_x86_64_add_symbol_hook): Don't check STT_GNU_IFUNC here.
ld/testsuite/
PR ld/18815
* ld-i386/i386.exp: Run pr18815.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pr18815.d: New file.
* ld-i386/pr18815.s: Likewise.
* ld-x86-64/pr18815.d: Likewise.
* ld-x86-64/pr18815.s: Likewise.
This patch fixed those failures on elf configuration by:
* Improve the ILP32 target selector "aarch64_choose_ilp32_emul",
makes it more robust. Target triples copied from configure.tgt
* Updated emit-relocs-86/-overflow.d to use aarch64_choose_ilp32_emul
which is following what have done with emit-relocs-28.
* Those instruction encoding mismatch is because those encoding
contains pc-relative address. As for elf, we may have different
start address. relaxed encodind check, especially for
aarch64-farcall-b/bl-plt, as the main purpose of those check are
ELF text/data layout, we just want to make sure veneer to plt stub
is generated.
2015-08-12 Jiong Wang <jiong.wang@arm.com>
ld/testsuite/
* ld-aarch64/aarch64-elf.exp (aarch64_choose_ilp32_emul): Support all
four triple shapes: aarch64-*-linux*, aarch64-*-elf,
aarch64_be-*-linux*, aarch64_be-*-elf.
* ld-aarch64/emit-relocs-86.d: Use aarch64_choose_ilp32_emul.
* ld-aarch64/emit-relocs-86-overflow.d: Likewise.
* ld-aarch64/ld-aarch64/farcall-b-plt.d: Relax instrucion encoding
check when they reflect address.
* ld-aarch64/ld-aarch64/farcall-bl-plt.d: Likewise.
2015-08-11 Jiong Wang <jiong.wang@arm.com>
bfd/
* bfd/elfnn-aarch64.c (aarch64_type_of_stub): New parameter "sym_sec".
Loose the check for symbol from ABS section.
(elfNN_aarch64_size_stubs): Pass sym_sec.
ld/testsuite/
* ld-aarch64/farcall-b-defsym.s: New test.
* ld-aarch64/farcall-bl-defsym.s: Likewise.
* ld-aarch64/farcall-b-defsym.d: New expectation.
* ld-aarch64/farcall-bl-defsym.d: Likewise.
The hidden versioned symbol can only be merged with the versioned
symbol with the same symbol version. _bfd_elf_merge_symbol should
check the symbol version before merging the new hidden versioned
symbol with the existing symbol. _bfd_elf_link_hash_copy_indirect can't
copy any references to the hidden versioned symbol. We need to
bind a symbol locally when linking executable if it is locally defined,
hidden versioned, not referenced by shared library and not exported.
bfd/
PR ld/18720
* elflink.c (_bfd_elf_merge_symbol): Add a parameter to indicate
if the new symbol matches the existing one. The new hidden
versioned symbol matches the existing symbol if they have the
same symbol version. Update the existing symbol only if they
match.
(_bfd_elf_add_default_symbol): Update call to
_bfd_elf_merge_symbol.
(_bfd_elf_link_assign_sym_version): Don't set the hidden field
here.
(elf_link_add_object_symbols): Override a definition only if the
new symbol matches the existing one.
(_bfd_elf_link_hash_copy_indirect): Don't copy any references to
the hidden versioned symbol.
(elf_link_output_extsym): Bind a symbol locally when linking
executable if it is locally defined, hidden versioned, not
referenced by shared library and not exported. Turn on
VERSYM_HIDDEN only if the hidden vesioned symbol is defined
locally.
ld/testsuite/
PR ld/18720
* ld-elf/indirect.exp: Run tests for PR ld/18720.
* ld-elf/pr18720.out: New file.
* ld-elf/pr18720a.c: Likewise.
* ld-elf/pr18720b.c: Likewise.
* ld-elf/pr18720c.c: Likewise.
Reverts a2c59f28 and e474ab13. Since the unary form of ALIGN only
references "dot" implicitly, there isn't really a strong argument for
making ALIGN use a relative value when inside an output section.
* ldexp.c (align_dot_val): Delete.
(fold_unary <ALIGN_K, NEXT>): Revert 2015-07-10 change.
(is_align_conditional): Revert 2015-07-20 change.
(exp_fold_tree_1): Likewise, but keep expanded comment.
* scripttempl/elf.sc (.ldata, .bss): Revert 2015-07-20 change.
* ld.texinfo (<ALIGN>): Correct description.
When using run_dump_test with the map option to compare the linker map
file produced, no additional dump program should be required. A dump
program can still be given if needed, but leaving it off will no longer
produce an error.
ld/testsuite/ChangeLog:
* ld/ld-lib.exp (run_dump_test): When using the map option, no
program is required.
The run_dump_test mechanism supports options error and warning, which
allow regexp to be specified within the test file, these regexp are
matched against the stderr output from the linker.
Similar dump test style functions for gas and gdb also support file
based matching versions of these options; the patterns are placed into a
file which the test driver then references. It is sometimes clearer,
when the pattern to be matched spans multiple lines if the patterns can
be placed into a separate file.
This patch adds new options error_output and warning_output for the
linker run_dump_test function. These new options take a filename
parameter, this file is then used (with regexp_diff) to compare against
the linker output.
ld/testsuite/ChangeLog:
* ld/ld-lib.exp (run_dump_test): Add error_output and
warning_output options.
Add a new command line option '--require-defined' to the linker. This
option operates identically to the '--undefined' option, except that if
the symbol is not defined in the final output file then the linker will
exit with an error.
When making use of --gc-section, or just when trying to pull in parts of
a library, it is not uncommon for a user to use the '--undefined'
command line option to specify a symbol that the user then expects to be
defined by one of the object files supplied to the link.
However, if for any reason the symbol is not satisfied by an object
provided to the link the user will be left with an undefined symbol in
the output file, instead of a defined symbol.
In some cases the above behaviour is what the user wants, in other cases
though we can do better. The '--require-defined' option tries to fill
this gap. The symbol passed to the '--require-defined' option is
treated exactly as if the symbol was passed to '--undefined', however,
before the linker exits a check is made that all symbols passed to
'--require-defined' are actually defined, if any are not then the link
will fail with an error.
ld/ChangeLog:
* ld.texinfo (Options): Document --require-defined option.
* ldlang.c (struct require_defined_symbol): New structure.
(require_defined_symbol_list): New variable.
(ldlang_add_require_defined): New function.
(ldlang_check_require_defined_symbols): New function.
(lang_process): Check required symbols are defined.
* ldlang.h (ldlang_add_require_defined): Declare.
* ldlex.h (enum option_values): Add OPTION_REQUIRE_DEFINED_SYMBOL.
* lexsup.c (ld_options): Add '--require-defined' entry.
(parse_args): Handle '--require-defined' entry.
* NEWS: Mention new '--require-defined' option.
ld/testsuite/ChangeLog:
* ld-undefined/require-defined-1.d: New file.
* ld-undefined/require-defined-2.d: New file.
* ld-undefined/require-defined-3.d: New file.
* ld-undefined/require-defined-4.d: New file.
* ld-undefined/require-defined-5.d: New file.
* ld-undefined/require-defined.exp: New file.
* ld-undefined/require-defined.s: New file.
The linker documentation explicitly states that there can be only one
MEMORY command. This is not true. Multiple MEMORY commands are
allowed, the contents of all will be treated as if a single MEMORY
command was given.
Update the documentation to make this clear to the users.
ld/ChangeLog:
* ld.texinfo (MEMORY): Explain that multiple MEMORY commands are
acceptable.
We should change the default symbol for the versioned symbol only when
not performing a relocatable link.
bfd/
PR ld/18735
* elflink.c (_bfd_elf_add_default_symbol): Add the default
symbol if not performing a relocatable link.
(elf_link_add_object_symbols): Adjust the default symbol if
not performing a relocatable link.
ld/testsuite/
PR ld/18735
* ld-elf/pr18735.d: New file.
* ld-elf/pr18735.s: Likewise.
noclone attribute was added to GCC 4.5. We should check GCC version
before using it.
* ld-elf/pr18718.c (bar): Use noclone attribute only for GCC
4.5 or newer.
This patch changes "ld -r" not to set link_info.executable. It
removes !info->relocatable check for info->executable and adds it
for !info->executable in elflink.c.
bfd/
* elflink.c (elf_link_add_object_symbols): Remove
!info->relocatable check for info->executable. Add
!info->relocatable check for !info->executable.
(elf_link_output_extsym): Remove
!info->relocatable check for info->executable.
ld/
* lexsup.c (parse_args): Don't set link_info.executable to
TRUE for link_info.relocatable.
Commit 23283c1b changed the layout of some bss style sections on
powerpc64, but neglected to add a page gap before the third PT_LOAD
segment created by this reording. Without a page gap we get two
PT_LOAD headers that overlap by one page in memory. That shouldn't be
allowed because the dynamic loader will load garbage from the first
page of the last segment over the last page of the previous segment.
bfd/
* elf.c (_bfd_elf_map_sections_to_segments): Do not make a new
segment for loaded sections after nonloaded sections if the
sections are on the same page.
ld/testsuite/
* ld-powerpc/elfv2so.d: Update
GCC 6 can be configured to generate PIE by default. But some linker
size tests expect non-PIE. This patch defines NOPIE_CFLAGS to
"-fno-PIE" and NOPIE_LDFLAGS to "-no-pie" if target compiler supports
them. Add $NOPIE_CFLAGS and $NOPIE_LDFLAGS to linker size tests if
needed.
* config/default.exp (NOPIE_CFLAGS): New.
(NOPIE_LDFLAGS): Likewise.
* ld-size/size.exp (run_cc_link_tests): Add $NOPIE_CFLAGS and
$NOPIE_LDFLAGS if needed.
(run_ld_link_exec_tests): Add $NOPIE_CFLAGS if needed.
Since GCC 5 folds symbol address comparison, assuming each symbol has a
different address, &foo == &bar is always false for GCC 5. This patch
adds check_ptr_eq if 2 addresses are the same and uses it to check the
address of versined symbol.
PR ld/18718
* ld-elf/check-ptr-eq.c: New file.
* ld-elf/pr18718.c (main): Call check_ptr_eq.
* ld-elf/shared.exp: Add check-ptr-eq.c to PR ld/18718 tests.
S-records tests don't work with -fno-plt. This path appends $PLT_CFLAGS
to CC and CXX for S-records tests.
* ld-srec/srec.exp (CC): Save and restore. Append $PLT_CFLAGS.
(CXX): Likewise.
Some linker shard library tests without PIC expect PLT. This patch
passes $PLT_CFLAGS to ld_compile.
* ld-shared/shared.exp: Pass $PLT_CFLAGS to ld_compile.
NOCROSSREFS tests don't work with -fno-plt. This path appends
$PLT_CFLAGS to CC for NOCROSSREFS tests.
* ld-scripts/crossref.exp (CC): Save and restore. Append
$PLT_CFLAGS.
Some x86 linker tests expect PLT. This patch adds $PLT_CFLAGS to -fPIC
for run_cc_link_tests.
* ld-i386/i386.exp (run_cc_link_tests): Add $PLT_CFLAGS to
-fPIC if needed.
* ld-x86-64/mpx.exp (run_cc_link_tests): Likewise.
* ld-x86-64/x86-64.exp (run_cc_link_tests): Likewise.
Some linker visibility tests without PIC expect PLT. This patch passes
$PLT_CFLAGS to ld_compile.
* ld-elfvsb/elfvsb.exp (visibility_run): Pass $PLT_CFLAGS to
ld_compile.
Some linker symbol version tests without PIC expect PLT. This patch
adds $PLT_CFLAGS to CFLAGS.
* ld-elfvers/vers.exp (build_vers_lib_no_pic): Pass $PLT_CFLAGS
to build_binary.
GCC 6 supports -fno-plt. But some linker tests expect PLT. This patch
defines PLT_CFLAGS to "-fplt" if target compiler supports it.
* config/default.exp (PLT_CFLAGS): New.
Emit *GLOB_DAT instead of *RELATIVE relocs for protected data
in shared objects.
This is needed for the fix of glibc bug 17711:
https://sourceware.org/bugzilla/show_bug.cgi?id=17711
bfd:
PR ld/18705
* elfnn-aarch64.c (elf_backend_extern_protected_data): Define.
ld/testsuite:
PR ld/18705
* ld-aarch64/protected-data.d: New.
* ld-aarch64/protected-data.s: New.
* ld-aarch64/aarch64-elf.exp: Add new test.
Emit *GLOB_DAT instead of *RELATIVE relocs for protected data
in shared objects.
This is needed for the fix of glibc bug 17711:
https://sourceware.org/bugzilla/show_bug.cgi?id=17711
bfd:
PR ld/18705
* elf32-arm.c (elf_backend_extern_protected_data): Define.
ld/testsuite:
PR ld/18705
* ld-arm/protected-data.d: New.
* ld-arm/protected-data.s: New.
* ld-arm/arm-elf.exp: Add new test.
