If IFUNC symbol is defined in position-dependent executable, we should
change it to the normal function and set its address to its PLT entry
which should be resolved by R_*_IRELATIVE at run-time. All external
references should be resolved to its PLT in executable.
bfd/
PR ld/23169
* elf-ifunc.c (_bfd_elf_allocate_ifunc_dyn_relocs): Don't issue
an error on IFUNC pointer defined in PDE.
* elf32-i386.c (elf_i386_finish_dynamic_symbol): Call
_bfd_x86_elf_link_fixup_ifunc_symbol.
* elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Likewise.
* elfxx-x86.c (_bfd_x86_elf_link_fixup_ifunc_symbol): New
function.
* elfxx-x86.h (_bfd_x86_elf_link_fixup_ifunc_symbol): New.
ld/
PR ld/23169
* testsuite/ld-ifunc/ifunc-9-i386.d: New file.
* testsuite/ld-ifunc/ifunc-9-x86-64.d: Likewise.
* testsuite/ld-ifunc/pr23169a.c: Likewise.
* testsuite/ld-ifunc/pr23169a.rd: Likewise.
* testsuite/ld-ifunc/pr23169b.c: Likewise.
* testsuite/ld-ifunc/pr23169b.c: Likewise.
* testsuite/ld-ifunc/pr23169c.rd: Likewise.
* testsuite/ld-ifunc/pr23169c.rd: Likewise.
* testsuite/ld-ifunc/ifunc-9-x86.d: Removed.
* testsuite/ld-ifunc/ifunc.exp: Run PR ld/23169 tests.
__bss_start, _end and _edata are defined by linker to mark regions
within executables and shared libraries. All references within
executables should be locally resolved.
This patch doesn't change how their references within shared libraries
are resolved.
bfd/
PR ld/23162
* elfxx-x86.c (elf_x86_linker_defined): New function.
(_bfd_x86_elf_link_check_relocs): Use it to mark __bss_start,
_end and _edata locally defined within executables.
ld/
PR ld/23162
* testsuite/ld-elf/pr23162.map: New file.
* testsuite/ld-elf/pr23162.rd: Likewise.
* testsuite/ld-elf/pr23162a.c: Likewise.
* testsuite/ld-elf/pr23162b.c: Likewise.
* testsuite/ld-elf/shared.exp: Run PR ld/23162 tests.
Sections may well belong in multiple segments. The testcase in the PR
saw an allocated section being assigned to an ABIFLAGS segment, then
not being assigned to a LOAD segment because it had already been
handled. To fix that particular problem this patch sets and tests
segment_mark only for LOAD segments. I kept the segment_mark test for
LOAD segments because I think there may otherwise be a problem with
zero size sections.
A few other problems showed up with the testcase. Some targets align
.dynamic, resulting in the test failing with "section .dynamic lma
0x800000c0 adjusted to 0x800000cc" and similar messages. I've tried
to handle that with some more hacks to the segment lma, which do the
right thing for the testcase, but may well fail in other situations.
I've also removed the tests of segment lma (p_paddr) and code involved
in deciding that an adjusted segment no longer covers the file or
program headers. Those test can't be correct in the face of objcopy
--change-section-lma. It may be necessary to reinstate the tests but
do them modulo page size, but we'll see how this goes.
PR 20659
bfd/
* elf.c (rewrite_elf_program_header): Use segment_mark only for
PT_LOAD headers. Delete first_matching_lma and first_suggested_lma.
Instead make matching_lma and suggested_lma pointers to the
sections. Align section vma and lma calculated from segment.
Don't clear includes_phdrs or includes_filehdr based on p_paddr
test. Try to handle alignment padding before first section by
adjusting new segment lma down. Adjust PT_PHDR map p_paddr.
ld/
* testsuite/ld-elf/changelma.d,
* testsuite/ld-elf/changelma.lnk,
* testsuite/ld-elf/changelma.s: New test.
My original implementation for LDI32 pseudo does not conform to
the TI ABI. I wrongly documented my TI PRU ELF object files inspection,
which got propagated into my binutils implementation.
Issue was exposed when running the GCC ABI testsuite against TI toolchain.
According to TI ABI, LDI32 must use first LDI instruction to load
the MSB 16bits, and second LDI instruction for the LSB 16bits.
This patch will break binary compatibility with previously released
binutils versions for PRU. Still, I think it is better to fix
binutils to conform to the chip vendor ABI.
bfd * elf32-pru.c (pru_elf32_do_ldi32_relocate): Make LDI32 relocation
conformant to TI ABI.
(pru_elf32_relax_section): Likewise.
(pru_elf_relax_delete_bytes): Fix offsets for new LDI32 code.
* elf32-pru.c (pru_elf32_do_ldi32_relocate): Ignore addend.
(pru_elf32_pmem_relocate): Trap - should not get here.
(pru_elf32_relocate_section): Add support for REL relocations.
(elf_info_to_howto_rel): Enable REL.
(elf_backend_may_use_rel_p): Likewise.
(elf_backend_may_use_rela_p): Likewise.
(elf_backend_default_use_rela_p): Likewise.
gas * config/tc-pru.c (md_apply_fix): Make LDI32 relocation conformant
to TI ABI.
(pru_assemble_arg_i): Likewise.
(output_insn_ldi32): Likewise.
* testsuite/gas/pru/ldi.d: Update test for the now fixed LDI32.
* gas/config/tc-pru.c (pru_assemble_arg_b): Check imm8 operand range.
* gas/testsuite/gas/pru/illegal2.l: New test.
* gas/testsuite/gas/pru/illegal2.s: New test.
* gas/testsuite/gas/pru/pru.exp: Register new illegal2 test.
ld * scripttempl/pru.sc: Add LD sections to allow linking TI
toolchain object files.
* scripttempl/pru.sc: Switch to init_array.
* testsuite/ld-pru/ldi32.d: Update LDI32 test to conform to TI ABI.
* testsuite/ld-pru/norelax_ldi32-data.d: Likewise.
* testsuite/ld-pru/norelax_ldi32-dis.d: Likewise.
* testsuite/ld-pru/relax_ldi32-data.d: Likewise.
* testsuite/ld-pru/relax_ldi32-dis.d: Likewise.
PR 22809
* elf.c (bfd_elf_get_str_section): Check for an excessively large
string section.
* elf-attrs.c (_bfd_elf_parse_attributes): Issue an error if the
attribute section is larger than the size of the file.
Avoids gcc pr85623 for these calls.
* cofflink.c (_bfd_coff_link_input_bfd): Use memcmp rather than
strncmp when checking for ".bf" special symbol.
* prXXigen.c (_bfd_XXi_swap_scnhdr_out): Make pe_required_section_flags
section name a char array, remove sentinal known_sections entry,
and adjust loop over known_sections to suit. Use memcmp rather
than strncmp.
This patch is aimed at silencing gcc8 -Wstringop-truncation warnings.
Unfortunately adding __attribute__ ((__nonstring)) doesn't work in a
number of the places patched here, (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85643) so if you have
recent glibc headers installed you'll need to configure binutils with
--disable-werror to compile using gcc8 or gcc9.
include/
* ansidecl.h: Import from gcc.
* coff/internal.h (struct internal_scnhdr): Add ATTRIBUTE_NONSTRING
to s_name.
(struct internal_syment): Add ATTRIBUTE_NONSTRING to _n_name.
bfd/
* elf-linux-core.h (struct elf_external_linux_prpsinfo32_ugid32),
(struct elf_external_linux_prpsinfo32_ugid16),
(struct elf_external_linux_prpsinfo64_ugid32),
(struct elf_external_linux_prpsinfo64_ugid16): Add ATTRIBUTE_NONSTRING
to pr_fname and pr_psargs fields. Remove GCC diagnostic pragmas.
Move comment to..
* elf.c (elfcore_write_prpsinfo): ..here. Indent nested preprocessor
directives.
* elf32-arm.c (elf32_arm_nabi_write_core_note): Add ATTRIBUTE_NONSTRING
to data.
* elf32-ppc.c (ppc_elf_write_core_note): Likewise.
* elf32-s390.c (elf_s390_write_core_note): Likewise.
* elf64-s390.c (elf_s390_write_core_note): Likewise.
* elfxx-aarch64.c (_bfd_aarch64_elf_write_core_note): Likewise.
* elf64-x86-64.c (elf_x86_64_write_core_note): Add GCC diagnostic
pragmas.
* peXXigen.c (_bfd_XXi_swap_scnhdr_out): Use strnlen to avoid
false positive gcc-8 warning.
gas/
* config/obj-evax.c (shorten_identifier): Use memcpy in place
of strncpy.
* config/obj-macho.c (obj_mach_o_make_or_get_sect): Ensure
segname and sectname fields are NUL terminated.
When IBM long double is used, the .gnu_attribute 4 is set to 1 | (1 *
4). IEEE long double sets the same .gnu_attribute to 1 | (3 * 4).
* elf32-ppc.c (_bfd_elf_ppc_merge_fp_attributes): Fix the order
of arguments when warning about different long double types.
The _gp_disp is a magic symbol, always implicitly defined by the linker.
It does not make a sense to write it into symbol tables for output files.
Moreover, now if the linker gets a version script, the _gp_disp symbol
gets zero version definition index. The zero index means[1]:
"The symbol is local, not available outside the object."
But the _gp_disp symbol has GLOBAL binding. That confuses some tools
like for example the LLD linker when they get such files as inputs.
This patch fixes the problem - it prevents writing the _gp_disp symbol
in regular and dynamic symbol tables.
This was tested by running LD test suite on a mipsel-linux board.
References:
[1] "Linux Standard Base Specification", Section "10.7.2 Symbol
Version Table", p. 32
2018-05-03 Simon Atanasyan <simon@atanasyan.com>
bfd/
* elf32-mips.c: (elf32_mips_fixup_symbol): New function.
(elf_backend_fixup_symbol): New macro.
* elfxx-mips.c: (mips_elf_output_extsym): Discard _gp_disp
handling.
(_bfd_mips_elf_finish_dynamic_symbol): Likewise.
ld/
* testsuite/ld-mips-elf/gp-disp-sym.d: New test.
* testsuite/ld-mips-elf/gp-disp-sym.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new test.
* testsuite/ld-mips-elf/mips16-pic-2.ad: Update for _gp_disp
symbol removal.
* testsuite/ld-mips-elf/mips16-pic-2.nd: Likewise.
* testsuite/ld-mips-elf/pic-and-nonpic-3a.dd: Likewise.
* testsuite/ld-mips-elf/tlslib-o32-hidden.got: Likewise.
* testsuite/ld-mips-elf/tlslib-o32-ver.got: Likewise.
* testsuite/ld-mips-elf/tlslib-o32.got: Likewise.
Two of the gcc ifunc tests fail for ppc32, due to my pr22374 fix being
a little too enthusiastic in trimming PLT entries. ppc64 doesn't have
the same failures because ppc64_elf_check_relocs happens to set
needs_plt for any ifunc reloc.
PR 23123
PR 22374
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Don't drop plt
relocs for ifuncs.
* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Comment fixes.
If you create an ifunc using GCC's __attribute__ ifunc, like:
extern int gnu_ifunc (int arg);
static int gnu_ifunc_target (int arg) { return 0; }
__typeof (gnu_ifunc) *gnu_ifunc_resolver (unsigned long hwcap) { return gnu_ifunc_target; }
__typeof (gnu_ifunc) gnu_ifunc __attribute__ ((ifunc ("gnu_ifunc_resolver")));
then you end up with two (function descriptor) symbols, one for the
ifunc itself, and another for the resolver:
(...)
12: 0000000000020060 104 FUNC GLOBAL DEFAULT 18 gnu_ifunc_resolver
(...)
16: 0000000000020060 104 GNU_IFUNC GLOBAL DEFAULT 18 gnu_ifunc
(...)
Both ifunc and resolver symbols have the same address/value, so
ppc64_elf_get_synthetic_symtab only creates a synthetic text symbol
for one of them. In the case above, it ends up being created for the
resolver, only:
(gdb) maint print msymbols
(...)
[ 7] t 0x980 .frame_dummy section .text
[ 8] T 0x9e4 .gnu_ifunc_resolver section .text
[ 9] T 0xa58 __glink_PLTresolve section .text
(...)
GDB needs to know when a program stepped into an ifunc resolver, so
that it can know whether to step past the resolver into the target
function without the user noticing. The way GDB does it is my
checking whether the current PC points to an ifunc symbol (since
resolver and ifunc have the same address by design).
The problem is then that ppc64_elf_get_synthetic_symtab never creates
the synchetic symbol for the ifunc, so GDB stops stepping at the
resolver (in a test added by the following patch):
(gdb) step
gnu_ifunc_resolver (hwcap=21) at gdb/testsuite/gdb.base/gnu-ifunc-lib.c:33
33 {
(gdb) FAIL: gdb.base/gnu-ifunc.exp: resolver_attr=1: resolver_debug=1: final_debug=0: step
After this commit, we get:
[ 8] i 0x9e4 .gnu_ifunc section .text
[ 9] T 0x9e4 .gnu_ifunc_resolver section .text
And stepping an ifunc call takes to the final function:
(gdb) step
0x00000000100009e8 in .final ()
(gdb) PASS: gdb.base/gnu-ifunc.exp: resolver_attr=1: resolver_debug=1: final_debug=0: step
An alternative to touching bfd I considered was for GDB to check
whether there's an ifunc data symbol / function descriptor that points
to the current PC, whenever the program stops, but discarded it
because we'd have to do a linear scan over .opd over an over to find a
matching function descriptor for the current PC. At that point I
considered caching that info, but quickly dismissed it as then that
has no advantage (memory or performance) over just creating the
synthetic ifunc text symbol in the first place.
I ran the binutils and ld testsuites on PPC64 ELFv1 (machine gcc110 on
the GCC compile farm), and saw no regressions. This commit is part of
a GDB patch series that includes GDB tests that fail without this fix.
bfd/ChangeLog:
2018-04-26 Pedro Alves <palves@redhat.com>
* elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Don't consider
ifunc and non-ifunc symbols duplicates.
The size of the stack segment defaults to 32KB, and can be overridden
by defining the __stacksize symbol.
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/
* elf32-arm.c (DEFAULT_STACK_SIZE): New.
(elf32_arm_always_size_sections): Create stack segment.
Define and handle TLS relocations for FDPIC in BFD and gas.
In gas, the new relocations are rejected if the --fdpic option was not
specified.
We also define the __tdata_start symbol to mark the start of the
.tdata section. This allows FDPIC static binaries to find the start of
.tdata section, since phdr->p_vaddr of TLS segment is not a valid
value for FDPIC.
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/:
* bfd-in2.h (BFD_RELOC_ARM_TLS_GD32_FDPIC)
(BFD_RELOC_ARM_TLS_LDM32_FDPIC, BFD_RELOC_ARM_TLS_IE32_FDPIC): New
relocations.
* elf32-arm.c (elf32_arm_howto_table_2): Add R_ARM_TLS_GD32_FDPIC,
R_ARM_TLS_LDM32_FDPIC, R_ARM_TLS_IE32_FDPIC relocations.
(elf32_arm_reloc_map): Add R_ARM_TLS_GD32_FDPIC,
R_ARM_TLS_LDM32_FDPIC, R_ARM_TLS_IE32_FDPIC.
(struct elf32_arm_link_hash_table): Update comment.
(elf32_arm_final_link_relocate): Handle TLS FDPIC relocations.
(IS_ARM_TLS_RELOC): Likewise.
(elf32_arm_check_relocs): Likewise.
(allocate_dynrelocs_for_symbol): Likewise.
(elf32_arm_size_dynamic_sections): Update comment.
* reloc.c: Add BFD_RELOC_ARM_TLS_GD32_FDPIC,
BFD_RELOC_ARM_TLS_LDM32_FDPIC, BFD_RELOC_ARM_TLS_IE32_FDPIC.
gas/
* config/tc-arm.c (reloc_names): Add TLSGD_FDPIC, TLSLDM_FDPIC,
GOTTPOFF_FDIC relocations.
(md_apply_fix): Handle the new TLS FDPIC relocations.
(tc_gen_reloc): Likewise.
(arm_fix_adjustable): Likewise.
include/
* elf/arm.h: Add R_ARM_TLS_GD32_FDPIC, R_ARM_TLS_LDM32_FDPIC,
R_ARM_TLS_IE32_FDPIC.
ld/
* scripttempl/elf.sc: Define __tdata_start for .tdata section.
FDPIC requires special PLT entries, defined in this patch.
Note that lazy binding is not supported because of a race condition
for lack of an atomic 64-bits load instruction.
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/
* elf32-arm.c (elf32_arm_fdpic_plt_entry): New.
(elf32_arm_create_dynamic_sections): Handle FDPIC.
(elf32_arm_allocate_plt_entry): Likewise.
(elf32_arm_populate_plt_entry): Likewise.
(elf32_arm_output_plt_map_1): Likewise.
ELF files targetting ARM FDPIC use the ELFOSABI_ARM_FDPIC flag.
Set it appropriately in file generators (eg. gas), and handle it in
readers (eg. readelf).
2018-04-25 Christophe Lyon <christophe.lyon@st.com>
Mickaël Guêné <mickael.guene@st.com>
bfd/
* elf32-arm.c (elf32_arm_print_private_bfd_data): Support
EF_ARM_PIC and ELFOSABI_ARM_FDPIC.
(elf32_arm_post_process_headers): Support ELFOSABI_ARM_FDPIC.
(ELF_OSABI): Define to ELFOSABI_ARM_FDPIC.
binutils/
* readelf.c (decode_ARM_machine_flags): Support EF_ARM_PIC.
(get_osabi_name): Support ELFOSABI_ARM_FDPIC.
gas/
* config/tc-arm.c (arm_fdpic): New.
(elf32_arm_target_format): Support FDPIC.
(OPTION_FDPIC): New.
(md_longopts): Support FDPIC.
(md_parse_option): Likewise.
(md_show_usage): Likewise.
include/
* elf/arm.h (EF_ARM_FDPIC): New.
This seems to work with gcc-8 and a bunch of prior gcc versions I tested.
* elf-linux-core.h: Disable gcc-8 string truncation warning.
* elf.c (elfcore_write_prpsinfo): Likewise.
