Linker can't optimize R_386_GOT32 and R_386_GOT32X relocations if addend
isn't 0. It isn't valid to convert
movl foo@GOT+1(%ecx), %eax
to
leal foo@GOTOFF+1(%ecx), %eax
nor to convert
movq foo@GOTPCREL+1(%rip), %rax
to
leaq foo(%rip), %rax
for x86-64. We should check if addend is 0 before optimizing R_386_GOT32
and R_386_GOT32X relocations. Testcases are added for i386 and x86-64.
bfd/
* elf32-i386.c (elf_i386_convert_load): Skip if addend isn't 0.
(elf_i386_relocate_section): Skip R_386_GOT32X optimization if
addend isn't 0.
ld/testsuite/
* ld-i386/i386.exp: Run mov2a, mov2b and mov3.
* ld-i386/mov2.s: New file.
* ld-i386/mov2a.d: Likewise.
* ld-i386/mov2b.d: Likewise.
* ld-i386/mov3.d: Likewise.
* ld-i386/mov3.s: Likewise.
* ld-x86-64/mov2.s: Likewise.
* ld-x86-64/mov2a.d: Likewise.
* ld-x86-64/mov2b.d: Likewise.
* ld-x86-64/mov2c.d: Likewise.
* ld-x86-64/mov2d.d: Likewise.
* ld-x86-64/x86-64.exp: Run mov2a, mov2b, mov2c and mov2d.
Symbol defined by a linker assignment may have type bfd_link_hash_new
or bfd_link_hash_undefined. And h->def_regular is always set.
elf_i386_convert_load and elf_x86_64_convert_load should check
h->def_regular as well as bfd_link_hash_undefined and bfd_link_hash_new
to see if a symbol is defined by a linker script.
bfd/
PR ld/19319
* elf32-i386.c (elf_i386_convert_load): Check h->def_regular
instead of bfd_link_hash_new.
* elf64-x86-64.c (elf_x86_64_convert_load): Likewise. Skip
relocation overflow for bfd_link_hash_undefined and
bfd_link_hash_new if h->def_regular is set.
ld/testsuite/
PR ld/19319
* ld-i386/i386.exp: Run pr19319 test.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pr19319.dd: New file.
* ld-i386/pr19319a.S: Likewise.
* ld-i386/pr19319b.S: Likewise.
* ld-x86-64/pr19319.dd: Likewise.
* ld-x86-64/pr19319a.S: Likewise.
* ld-x86-64/pr19319b.S: Likewise.
Similar fix to "commit c316a17c40e44e8798b34ff84130904f2e7a53de".
* elf32-i386.c (elf_i386_relocate_section): Use read and write
pointers to reloc array, rather than memmove when deleting a
reloc. Don't use RELOC_AGAINST_DISCARDED_SECTION. Adjust
reloc counts at end of loop.
* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
Symbol symbol defined by an assignment in a linker script has type
bfd_link_hash_new. elf_i386_convert_load and elf_x86_64_convert_load
should check bfd_link_hash_new to see if a symbol is defined by a linker
script.
bfd/
PR ld/19175
* elf32-i386.c (elf_i386_convert_load): Check bfd_link_hash_new
instead of calling bfd_link_get_defined_symbol.
* elf64-x86-64.c (elf_x86_64_convert_load): Likewise. Skip
relocation overflow for bfd_link_hash_new.
* linker.c (bfd_link_get_defined_symbol): Removed.
* bfd-in2.h: Regenerated.
ld/testsuite/
PR ld/19175
* ld-i386/i386.exp: Run pr19175.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pr19175.d: New file.
* ld-i386/pr19175.s: Likewise.
* ld-i386/pr19175.t: Likewise.
* ld-x86-64/pr19175.d: Likewise.
* ld-x86-64/pr19175.s: Likewise.
* ld-x86-64/pr19175.t: Likewise.
Since __start_XXX and __stop_XXX symbols aren't defined when address
load is being converted, we need to check if there is an XXX output
section to get their section and value. This patch adds a new function,
bfd_link_get_defined_symbol, to search for the XXX output section to
check if __start_XXX and __stop_XXX symbols are defined.
bfd/
PR ld/19171
* elf32-i386.c (elf_i386_convert_load): Call
bfd_link_get_defined_symbol to check if a symbol is defined.
* elf64-x86-64.c (elf_x86_64_convert_load): Call
bfd_link_get_defined_symbol to get defined symbol section and
value.
* linker.c (bfd_link_get_defined_symbol): New function.
* bfd-in2.h: Regenerated.
ld/testsuite/
PR ld/19171
* ld-i386/lea1.s: Add tests for address load of __start_XXX
and __stop_XXX.
* ld-i386/mov1.s: Likewise.
* ld-x86-64/lea1.s: Likewise.
* ld-x86-64/mov1.s: Likewise.
* ld-i386/lea1a.d: Updated.
* ld-i386/lea1b.d: Likewise.
* ld-i386/lea1c.d: Likewise.
* ld-i386/mov1a.d: Likewise.
* ld-i386/mov1b.d: Likewise.
* ld-x86-64/lea1a.d: Likewise.
* ld-x86-64/lea1b.d: Likewise.
* ld-x86-64/lea1c.d: Likewise.
* ld-x86-64/lea1d.d: Likewise.
* ld-x86-64/lea1e.d: Likewise.
* ld-x86-64/lea1f.d: Likewise.
* ld-x86-64/mov1a.d: Likewise.
* ld-x86-64/mov1b.d: Likewise.
* ld-x86-64/mov1c.d: Likewise.
* ld-x86-64/mov1d.d: Likewise.
This patch adds support for the R_386_GOT32X relocation proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I
to gas and ld. It updates gas to generate R_386_GOT32X relocation for
memory operand, foo@GOT[(%reg)]. We must encode "mov foo@GOT, %eax"
with the 0x8b opcode, instead of the 0xb8 opcode, so that it can be
transformed to "lea foo, %eax". With the locally defined symbol, foo,
we convert
mov foo@GOT[(%reg1)], %reg2
to
lea foo[@GOTOFF(%reg1)], %reg2
and convert
call/jmp *foo@GOT[(%reg)]
to
nop call foo/jmp foo nop
When PIC is false, convert
test %reg1, foo@GOT[(%reg2)]
to
test $foo, %reg1
and convert
binop foo@GOT[(%reg1)], %reg2
to
binop $foo, %reg2
where binop is one of adc, add, and, cmp, or, sbb, sub, xor instructions.
bfd/
* elf32-i386.c: Include opcode/i386.h.
(elf_howto_table): Add R_386_GOT32X.
(R_386_ext2): Replace R_386_IRELATIVE with R_386_GOT32X.
(elf_i386_reloc_type_lookup): Handle BFD_RELOC_386_GOT32X.
(need_convert_mov_to_lea): Renamed to ...
(need_convert_load): This.
(elf_i386_check_relocs): Handle R_386_GOT32X. Replace
need_convert_mov_to_lea with need_convert_load.
(elf_i386_gc_sweep_hook): Handle R_386_GOT32X.
(elf_i386_size_dynamic_sections): Likewise.
(elf_i386_relocate_section): Likewise.
(elf_i386_convert_mov_to_lea): Renamed to ...
(elf_i386_convert_load): This. Replace need_convert_mov_to_lea
with need_convert_load. Support R_386_GOT32X transformations.
* reloc.c (BFD_RELOC_386_GOT32X): New.
* bfd-in2.h: Regenerated.
* libbfd.h: Likewise.
gas/
* config/tc-i386.c (tc_i386_fix_adjustable): Handle
BFD_RELOC_386_GOT32X.
(tc_gen_reloc): Likewise.
(match_template): Force 0x8b encoding for "mov foo@GOT, %eax".
(output_disp): Check for "call/jmp *mem", "mov mem, %reg",
"test %reg, mem" and "binop mem, %reg" where binop is one of
adc, add, and, cmp, or, sbb, sub, xor instructions. Set
fx_tcbit if the REX prefix is generated. Set fx_tcbit2 if
BFD_RELOC_386_GOT32X should be generated.
(i386_validate_fix): Generate BFD_RELOC_386_GOT32X if fx_tcbit2
is set.
gas/testsuite/
* gas/i386/got.d: New file.
* gas/i386/got.s: Likewise.
* gas/i386/i386.exp: Run got.
* gas/i386/localpic.d: Replace R_386_GOT32 with R_386_GOT32X.
* gas/i386/mixed-mode-reloc32.d: Likewise.
* gas/i386/reloc32.d: Likewise.
include/elf/
* i386.h (R_386_GOT32X): New relocation.
ld/testsuite/
* ld-i386/branch1.d: New file.
* ld-i386/branch1.s: Likewise.
* ld-i386/call1.d: Likewise.
* ld-i386/call1.s: Likewise.
* ld-i386/call2.d: Likewise.
* ld-i386/call2.s: Likewise.
* ld-i386/got1.dd: Likewise.
* ld-i386/got1.out: Likewise.
* ld-i386/got1a.S: Likewise.
* ld-i386/got1b.c: Likewise.
* ld-i386/got1c.c: Likewise.
* ld-i386/got1d.S: Likewise.
* ld-i386/jmp1.d: Likewise.
* ld-i386/jmp1.s: Likewise.
* ld-i386/jmp2.d: Likewise.
* ld-i386/jmp2.s: Likewise.
* ld-i386/load1.d: Likewise.
* ld-i386/load1.s: Likewise.
* ld-i386/load2.d: Likewise.
* ld-i386/load2.s: Likewise.
* ld-i386/load3.d: Likewise.
* ld-i386/load3.s: Likewise.
* ld-i386/load4.s: Likewise.
* ld-i386/load4a.d: Likewise.
* ld-i386/load4b.d: Likewise.
* ld-i386/load5.s: Likewise.
* ld-i386/load5a.d: Likewise.
* ld-i386/load5b.d: Likewise.
* ld-i386/load6.d: Likewise.
* ld-i386/load6.s: Likewise.
* ld-i386/i386.exp: Run branch1, call1, call2, jmp1, jmp2,
load1, load2, load3, load4a, load4b, load5a, load5b and load6
tests. Run got1 test.
We need to check if symbol is defined when converting mov to lea since
SYMBOL_REFERENCES_LOCAL may return true on hidden undefined symbols.
* elf32-i386.c (elf_i386_convert_mov_to_lea): Check if symbol
is defined.
* elf64-x86-64.c (elf_x86_64_convert_mov_to_lea): Likewise.
There is no need to check def_regular when converting mov to lea for
loading address of local symbols since def_regular may be false for
common symbols and SYMBOL_REFERENCES_LOCAL is sufficient.
bfd/
* elf32-i386.c (elf_i386_convert_mov_to_lea): Don't check
def_regular.
* elf64-x86-64.c (elf_x86_64_convert_mov_to_lea): Likewise.
ld/testsuite/
* ld-i386/lea1.s: Add a test for loading address of local common
symbol.
* ld-x86-64/lea1.s: Likewise.
* ld-i386/lea1a.d: Updated.
* ld-i386/lea1b.d: Likewise.
* ld-i386/lea1c.d: Likewise.
* ld-x86-64/lea1a.d: Likewise.
* ld-x86-64/lea1b.d: Likewise.
* ld-x86-64/lea1c.d: Likewise.
* ld-x86-64/lea1d.d: Likewise.
* ld-x86-64/lea1e.d: Likewise.
* ld-x86-64/lea1f.d: Likewise.
Since something like ".long foo - ." may be used as pointer, we make
sure that PLT is used if foo is a function defined in a shared library.
bfd/
PR ld/19031
* elf32-i386.c (elf_i386_check_relocs): Set
pointer_equality_needed for R_386_PC32 reloc in non-code
sections.
ld/testsuite/
PR ld/19031
* ld-i386/i386.exp: Run PR ld/19031 test.
* ld/testsuite/ld-i386/pr19031.out: New file.
* ld/testsuite/ld-i386/pr19031a.c: Likewise.
* ld/testsuite/ld-i386/pr19031b.S: Likewise.
* ld/testsuite/ld-i386/pr19031c.c: Likewise.
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.
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.
Since the .plt section and DT_PLTGOT are used by prelink to undo
prelinking for dynamic relocations, we must keep them even if there is
no PLT relocation. This patch reverted commit a3747075a.
bfd/
* elf32-i386.c (elf_i386_allocate_dynrelocs): Always allocate
space for the first .plt entry.
(elf_i386_size_dynamic_sections): Always add DT_PLTGOT for .plt
section. Add DT_PLTRELSZ, DT_PLTREL and DT_JMPREL only if
there are PLT relocations.
* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Always
allocate space for the first .plt entry.
(elf_x86_64_size_dynamic_sections): Always add DT_PLTGOT for
.plt section. Add DT_PLTRELSZ, DT_PLTREL and DT_JMPREL only if
there are PLT relocations.
ld/testsuite/
* ld-i386/i386.exp: Run pltgot-2 for Linux targets.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pltgot-1.d: Updated.
* ld-x86-64/pltgot-1.d: Likewise.
* ld-i386/pltgot-2.d: New file.
* ld-x86-64/pltgot-2.d: Likewise.
When pointer equality needed, we can't replace PLT relocations with
GOT relocations for -z now. This patch checks if pointer equality is
needed before converting PLT relocations to GOT relocations.
bfd/
PR binutils/18458
* elf32-i386.c (elf_i386_check_relocs): Create .plt.got section
for now binding only if pointer equality isn't needed.
(elf_i386_allocate_dynrelocs): Use .plt.got section for now
binding only if pointer equality isn't needed.
* elf64-x86-64.c (elf_x86_64_check_relocs): Create .plt.got
section for now binding only if pointer equality isn't needed.
(elf_x86_64_allocate_dynrelocs): Use .plt.got section for now
binding only if pointer equality isn't needed.
ld/testsuite/
PR binutils/18458
* ld-elf/shared.exp (build_tests): Build libpr18458a.so and
libpr18458b.so.
(run_tests): Run pr18458 test.
* ld-elf/pr18458a.c: New file.
* ld-elf/pr18458b.c: Likewise.
* ld-elf/pr18458c.c: Likewise.
Extra relocations may be added to the .rel.plt/.rela.plt section, which
are unrelated to PLT. We should skip them when retrieving PLT entry
symbol values.
PR binutils/18437
* elf32-i386.c (elf_i386_get_plt_sym_val): Skip extra relocations
in .rel.plt/.rela.plt.
* elf64-x86-64.c (elf_x86_64_get_plt_sym_val): Likewise.
There is no need for PLT relocations with -z now. We can use GOT
relocations, which take less space, instead and replace 16-byte .plt
entres with 8-byte .plt.got entries.
bfd/
* elf32-i386.c (elf_i386_check_relocs): Create .plt.got section
for now binding.
(elf_i386_allocate_dynrelocs): Use .plt.got section for now
binding.
* elf64-x86-64.c (elf_x86_64_check_relocs): Create .plt.got
section for now binding.
(elf_x86_64_allocate_dynrelocs): Use .plt.got section for now
binding.
ld/testsuite/
* ld-i386/i386.exp: Run PR ld/17689 tests with -z now.
* ld-x86-64/x86-64.exp: Likewise
* ld-i386/pr17689now.rd: New file.
* ld-x86-64/pr17689now.rd: Likewise
Commit dd7e64d45b may optimize out
i386/x86-64 JUMP_SLOT relocation. If there is no JUMP_SLOT relocation
left, we don't need to the first .plt entry. This patch allocates
space for the first .plt entry only if we also reserve space for a PLT
slot for JUMP_SLOT relocation.
bfd/
* elf32-i386.c (elf_i386_allocate_dynrelocs): Allocate space
for the first .plt entry only if needed.
* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Likewise.
ld/testsuite/
* ld-i386/i386.exp: Run pltgot-1 for Linux targets.
* ld-x86-64/x86-64.exp: Likewise.
* ld-i386/pltgot-1.d: New file.
* ld-i386/pltgot-1.s: Likewise.
* ld-x86-64/pltgot-1.d: Likewise.
* ld-x86-64/pltgot-1.s: Likewise.
The first argument to bfd_get_8/bfd_put_8 isn't used. But we should
use something real. Replace input_bfd and output_bfd with abfd.
* elf32-i386.c (elf_i386_convert_mov_to_lea): Replace input_bfd
and output_bfd with abfd.
* elf64-x86-64.c (elf_x86_64_convert_mov_to_lea): Likewise.
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.
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.
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.
We can convert mov to lea only if there are R_386_GOT32/R_X86_64_GOTPCREL
relocations against non IFUNC symbols.
* elf32-i386.c (need_convert_mov_to_lea): New.
(elf_i386_check_relocs): Set need_convert_mov_to_lea if needed.
(elf_i386_convert_mov_to_lea): Return TRUE if
need_convert_mov_to_lea is unset.
* elf64-x86-64.c (need_convert_mov_to_lea): New.
(elf_x86_64_check_relocs): Set need_convert_mov_to_lea if needed.
(elf_x86_64_convert_mov_to_lea): Return TRUE if
need_convert_mov_to_lea is unset.
PR binutils/17512
* nm.c (print_symbol): Add 'is_synthetic' parameter. Use it to
help initialize the info.elfinfo field.
(print_size_symbols): Add 'synth_count' parameter. Use it to set
the is_synthetic parameter when calling print_symbol.
(print_symbols): Likewise.
(display_rel_file): Pass synth_count to printing function.
(display_archive): Break loop if the last archive displayed
matches the current archive.
* size.c (display_archive): Likewise.
* archive.c (do_slurp_bsd_armap): Make sure that the parsed sized
is at least big enough for the header to be read.
* elf32-i386.c (elf_i386_get_plt_sym_val): Skip unknown relocs.
* mach-o.c (bfd_mach_o_get_synthetic_symtab): Add range checks.
(bfd_mach_o_read_command): Prevetn duplicate error messages about
unrecognized commands.
* syms.c (_bfd_stab_section_find_nearest_line): Add range checks
when indexing into the string table.
Copy relocs are used in a scheme to avoid dynamic text relocations in
non-PIC executables that refer to variables defined in shared
libraries. The idea is to have the linker define any such variable in
the executable, with a copy reloc copying the initial value, then have
both the executable and shared library refer to the executable copy.
If the shared library defines the variable as protected then we have
two copies of the variable being used.
PR 15228
* elflink.c (_bfd_elf_adjust_dynamic_copy): Add "info" param.
Error on copy relocs against protected symbols.
(elf_merge_st_other): Set h->protected_def.
* elf-bfd.h (struct elf_link_hash_entry): Add "protected_def".
(_bfd_elf_adjust_dynamic_copy): Update prototype.
* elf-m10300.c (_bfd_mn10300_elf_adjust_dynamic_symbol): Update
_bfd_elf_adjust_dynamic_copy call.
* elf32-arm.c (elf32_arm_adjust_dynamic_symbol): Likewise.
* elf32-cr16.c (_bfd_cr16_elf_adjust_dynamic_symbol): Likewise.
* elf32-cris.c (elf_cris_adjust_dynamic_symbol): Likewise.
* elf32-hppa.c (elf32_hppa_adjust_dynamic_symbol): Likewise.
* elf32-i370.c (i370_elf_adjust_dynamic_symbol): Likewise.
* elf32-i386.c (elf_i386_adjust_dynamic_symbol): Likewise.
* elf32-lm32.c (lm32_elf_adjust_dynamic_symbol): Likewise.
* elf32-m32r.c (m32r_elf_adjust_dynamic_symbol): Likewise.
* elf32-m68k.c (elf_m68k_adjust_dynamic_symbol): Likewise.
* elf32-metag.c (elf_metag_adjust_dynamic_symbol): Likewise.
* elf32-or1k.c (or1k_elf_adjust_dynamic_symbol): Likewise.
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Likewise.
* elf32-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
* elf32-sh.c (sh_elf_adjust_dynamic_symbol): Likewise.
* elf32-tic6x.c (elf32_tic6x_adjust_dynamic_symbol): Likewise.
* elf32-tilepro.c (tilepro_elf_adjust_dynamic_symbol): Likewise.
* elf32-vax.c (elf_vax_adjust_dynamic_symbol): Likewise.
* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Likewise.
* elf64-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
* elf64-sh64.c (sh64_elf64_adjust_dynamic_symbol): Likewise.
* elf64-x86-64.c (elf_x86_64_adjust_dynamic_symbol): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_adjust_dynamic_symbol): Likewise.
* elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol): Likewise.
* elfxx-sparc.c (_bfd_sparc_elf_adjust_dynamic_symbol): Likewise.
* elfxx-tilegx.c (tilegx_elf_adjust_dynamic_symbol): Likewise.
In i386 and x86-64 binaries with ifunc, relocations against .got.plt
section may not be in the same order as entries in PLT section. This
patch adds _bfd_elf_ifunc_get_synthetic_symtab. It takes a function
pointer which returns an array of PLT entry symbol values. It calls
the function pointer to get the PLT entry symbol value array indexed
by relocation index, instead of calling plt_sym_val on each relocation
index.
PR binutils/17677
* elf-bfd.h (_bfd_elf_ifunc_get_synthetic_symtab): New prototype.
* elf-ifunc.c (_bfd_elf_ifunc_get_synthetic_symtab): New
function.
* elf32-i386.c (elf_i386_plt_sym_val): Removed.
(elf_backend_plt_sym_val): Likewise.
(elf_i386_get_plt_sym_val): New.
(elf_i386_get_synthetic_symtab): Likewise.
(bfd_elf32_get_synthetic_symtab): Likewise.
* elf64-x86-64.c (elf_x86_64_plt_sym_val): Removed.
(elf_x86_64_plt_sym_val_offset_plt_bnd): Likewise.
(elf_backend_plt_sym_val): Likewise.
(elf_x86_64_get_plt_sym_val): New.
(elf_x86_64_get_synthetic_symtab): Use
_bfd_elf_ifunc_get_synthetic_symtab.
(bfd_elf64_get_synthetic_symtab): Don't undefine for NaCl.
PR binutils/17512
* dwarf.h (struct dwarf_section): Add user_data field.
* dwarf.c (frame_need_space): Check for an over large register
number.
(display_debug_frames): Check the return value from
frame_need_space. Check for a CFA expression that is so long the
start address wraps around.
(debug_displays): Initialise the user_data field.
* objdump.c (load_specific_debug_section): Save the BFD section
pointer in the user_data field of the dwarf_section structure.
(free_debug_section): Update BFD section data when freeing section
contents.
* readelf.c (load_specific_debug_section): Initialise the
user_data field.
* archive.c (do_slurp_coff_armap): Add range checks to prevent
running off the end of the string table.
* compress.c (bfd_get_full_section_contents): Return a NULL
pointer for zero sized sections. Do not attempt to copy a buffer
onto itself.
* elf-attrs.c (_bfd_elf_parse_attributes): Check for an empty
header. Add range checks to avoid running off the end of the
section.
* elf.c (bfd_elf_get_str_section): Seek before allocating so that
if the seek fails, no memory is allocated.
(bfd_elf_string_from_elf_section): Do not allocate a string from a
non string section. It only leads to trouble later on.
(_bfd_elf_print_private_bfd_data): Check for there being too
little external dynamic data.
(bfd_section_from_shdr): Replace assertion with a failure mode.
(bfd_section_from_shdr): When walking a loaded group section use
the internal structure size, not the external size. Check for the
group section being empty.
* elf32-i386.c (elf_i386_rtype_to_howto): Replace assertion with a
failure mode.
* elfcode.h (elf_slurp_reloc_table): Likewise.
* reloc.c (bfd_perform_relocation): Avoid seg-fault if the howto
parameter is NULL.
When there are both PLT and GOT references to the same function symbol,
linker will create a GOTPLT slot for PLT entry and a GOT slot for GOT
reference. A run-time JUMP_SLOT relocation is created to update the
GOTPLT slot and a run-time GLOB_DAT relocation is created to update the
GOT slot. Both JUMP_SLOT and GLOB_DAT relocations will apply the same
symbol value to GOTPLT and GOT slots, respectively, at run-time.
This optimization combines GOTPLT and GOT slots into a single GOT slot
and removes the run-time JUMP_SLOT relocation. It replaces the regular
PLT entry:
indirect jump [GOTPLT slot]
push relocation index
jump PLT0
with an GOT PLT entry with an indirect jump via the GOT slot:
indirect jump [GOT slot]
nop
and resolves PLT reference to the GOT PLT entry.
We must avoid this optimization if pointer equality is needed since
we don't clear symbol value in this case and the dynamic linker won't
update the GOT slot. Otherwise, the resulting binary will get into an
infinite loop at run-time.
bfd/
* elf32-i386.c (elf_i386_got_plt_entry): New.
(elf_i386_pic_got_plt_entry): Likewise.
(elf_i386_link_hash_entry): Add plt_got.
(elf_i386_link_hash_table): Likewise.
(elf_i386_link_hash_newfunc): Initialize plt_got.offset to -1.
(elf_i386_get_local_sym_hash): Likewise.
(elf_i386_check_relocs): Create the GOT PLT if there are both
PLT and GOT references when the regular PLT is used.
(elf_i386_allocate_dynrelocs): Use the GOT PLT if there are
both PLT and GOT references unless pointer equality is needed.
(elf_i386_relocate_section): Also check the GOT PLT when
resolving R_386_PLT32.
(elf_i386_finish_dynamic_symbol): Use the GOT PLT if it is
available.
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add plt_got.
(elf_x86_64_link_hash_table): Likewise.
(elf_x86_64_link_hash_newfunc): Initialize plt_got.offset to -1.
(elf_x86_64_get_local_sym_hash): Likewise.
(elf_x86_64_check_relocs): Create the GOT PLT if there are both
PLT and GOT references when the regular PLT is used.
(elf_x86_64_allocate_dynrelocs): Use the GOT PLT if there are
both PLT and GOT references unless pointer equality is needed.
(elf_x86_64_relocate_section): Also check the GOT PLT when
resolving R_X86_64_PLT32.
(elf_x86_64_finish_dynamic_symbol): Use the GOT PLT if it is
available.
ld/
* emulparams/elf_i386.sh (TINY_READONLY_SECTION): New.
* emulparams/elf_x86_64.sh (TINY_READONLY_SECTION): Add .plt.got.
ld/testsuite/
* ld-i386/i386.exp: Add run-time relocation tests for plt-main.
* ld-i386/plt-main.rd: New file.
* ld-x86-64/plt-main-bnd.dd: Likewise.
* ld-x86-64/plt-main.rd: Likewise.
* ld-x86-64/x86-64.exp: Add run-time relocation tests for
plt-main.
H.J. Lu