blob: dc416a7f7120070f384de0e92a7dd4cff0455ad2 [file] [log] [blame]
/* X86-64 specific support for ELF
Copyright (C) 2000-2021 Free Software Foundation, Inc.
Contributed by Jan Hubicka <jh@suse.cz>.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "elfxx-x86.h"
#include "dwarf2.h"
#include "libiberty.h"
#include "opcode/i386.h"
#include "elf/x86-64.h"
#ifdef CORE_HEADER
#include <stdarg.h>
#include CORE_HEADER
#endif
/* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */
#define MINUS_ONE (~ (bfd_vma) 0)
/* Since both 32-bit and 64-bit x86-64 encode relocation type in the
identical manner, we use ELF32_R_TYPE instead of ELF64_R_TYPE to get
relocation type. We also use ELF_ST_TYPE instead of ELF64_ST_TYPE
since they are the same. */
/* The relocation "howto" table. Order of fields:
type, rightshift, size, bitsize, pc_relative, bitpos, complain_on_overflow,
special_function, name, partial_inplace, src_mask, dst_mask, pcrel_offset. */
static reloc_howto_type x86_64_elf_howto_table[] =
{
HOWTO(R_X86_64_NONE, 0, 3, 0, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_NONE", false, 0, 0x00000000,
false),
HOWTO(R_X86_64_64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_PC32, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PC32", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_GOT32, 0, 2, 32, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOT32", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_PLT32, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PLT32", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_COPY, 0, 2, 32, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_COPY", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_RELATIVE, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_RELATIVE", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_GOTPCREL, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_32, 0, 2, 32, false, 0, complain_overflow_unsigned,
bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_32S, 0, 2, 32, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_32S", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_16, 0, 1, 16, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_16", false, 0, 0xffff, false),
HOWTO(R_X86_64_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0, 0xffff, true),
HOWTO(R_X86_64_8, 0, 0, 8, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_8", false, 0, 0xff, false),
HOWTO(R_X86_64_PC8, 0, 0, 8, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PC8", false, 0, 0xff, true),
HOWTO(R_X86_64_DTPMOD64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_DTPMOD64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_DTPOFF64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_DTPOFF64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_TPOFF64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_TPOFF64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_TLSGD, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_TLSGD", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_TLSLD, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_TLSLD", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_DTPOFF32, 0, 2, 32, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_DTPOFF32", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_GOTTPOFF, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTTPOFF", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_TPOFF32, 0, 2, 32, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_TPOFF32", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_PC64, 0, 4, 64, true, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_PC64", false, 0, MINUS_ONE,
true),
HOWTO(R_X86_64_GOTOFF64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_GOTOFF64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_GOTPC32, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTPC32", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_GOT64, 0, 4, 64, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOT64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_GOTPCREL64, 0, 4, 64, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTPCREL64", false, 0, MINUS_ONE,
true),
HOWTO(R_X86_64_GOTPC64, 0, 4, 64, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTPC64", false, 0, MINUS_ONE,
true),
HOWTO(R_X86_64_GOTPLT64, 0, 4, 64, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTPLT64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_PLTOFF64, 0, 4, 64, false, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PLTOFF64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_SIZE32, 0, 2, 32, false, 0, complain_overflow_unsigned,
bfd_elf_generic_reloc, "R_X86_64_SIZE32", false, 0, 0xffffffff,
false),
HOWTO(R_X86_64_SIZE64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_SIZE64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 2, 32, true, 0,
complain_overflow_bitfield, bfd_elf_generic_reloc,
"R_X86_64_GOTPC32_TLSDESC", false, 0, 0xffffffff, true),
HOWTO(R_X86_64_TLSDESC_CALL, 0, 3, 0, false, 0,
complain_overflow_dont, bfd_elf_generic_reloc,
"R_X86_64_TLSDESC_CALL",
false, 0, 0, false),
HOWTO(R_X86_64_TLSDESC, 0, 4, 64, false, 0,
complain_overflow_dont, bfd_elf_generic_reloc,
"R_X86_64_TLSDESC", false, 0, MINUS_ONE, false),
HOWTO(R_X86_64_IRELATIVE, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_IRELATIVE", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_RELATIVE64, 0, 4, 64, false, 0, complain_overflow_dont,
bfd_elf_generic_reloc, "R_X86_64_RELATIVE64", false, 0, MINUS_ONE,
false),
HOWTO(R_X86_64_PC32_BND, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PC32_BND", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_PLT32_BND, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PLT32_BND", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_GOTPCRELX, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_GOTPCRELX", false, 0, 0xffffffff,
true),
HOWTO(R_X86_64_REX_GOTPCRELX, 0, 2, 32, true, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_REX_GOTPCRELX", false, 0, 0xffffffff,
true),
/* We have a gap in the reloc numbers here.
R_X86_64_standard counts the number up to this point, and
R_X86_64_vt_offset is the value to subtract from a reloc type of
R_X86_64_GNU_VT* to form an index into this table. */
#define R_X86_64_standard (R_X86_64_REX_GOTPCRELX + 1)
#define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard)
/* GNU extension to record C++ vtable hierarchy. */
HOWTO (R_X86_64_GNU_VTINHERIT, 0, 4, 0, false, 0, complain_overflow_dont,
NULL, "R_X86_64_GNU_VTINHERIT", false, 0, 0, false),
/* GNU extension to record C++ vtable member usage. */
HOWTO (R_X86_64_GNU_VTENTRY, 0, 4, 0, false, 0, complain_overflow_dont,
_bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0,
false),
/* Use complain_overflow_bitfield on R_X86_64_32 for x32. */
HOWTO(R_X86_64_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff,
false)
};
#define X86_PCREL_TYPE_P(TYPE) \
( ((TYPE) == R_X86_64_PC8) \
|| ((TYPE) == R_X86_64_PC16) \
|| ((TYPE) == R_X86_64_PC32) \
|| ((TYPE) == R_X86_64_PC32_BND) \
|| ((TYPE) == R_X86_64_PC64))
#define X86_SIZE_TYPE_P(TYPE) \
((TYPE) == R_X86_64_SIZE32 || (TYPE) == R_X86_64_SIZE64)
/* Map BFD relocs to the x86_64 elf relocs. */
struct elf_reloc_map
{
bfd_reloc_code_real_type bfd_reloc_val;
unsigned char elf_reloc_val;
};
static const struct elf_reloc_map x86_64_reloc_map[] =
{
{ BFD_RELOC_NONE, R_X86_64_NONE, },
{ BFD_RELOC_64, R_X86_64_64, },
{ BFD_RELOC_32_PCREL, R_X86_64_PC32, },
{ BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,},
{ BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,},
{ BFD_RELOC_X86_64_COPY, R_X86_64_COPY, },
{ BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, },
{ BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, },
{ BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, },
{ BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, },
{ BFD_RELOC_32, R_X86_64_32, },
{ BFD_RELOC_X86_64_32S, R_X86_64_32S, },
{ BFD_RELOC_16, R_X86_64_16, },
{ BFD_RELOC_16_PCREL, R_X86_64_PC16, },
{ BFD_RELOC_8, R_X86_64_8, },
{ BFD_RELOC_8_PCREL, R_X86_64_PC8, },
{ BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, },
{ BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, },
{ BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, },
{ BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, },
{ BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, },
{ BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, },
{ BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, },
{ BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, },
{ BFD_RELOC_64_PCREL, R_X86_64_PC64, },
{ BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, },
{ BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, },
{ BFD_RELOC_X86_64_GOT64, R_X86_64_GOT64, },
{ BFD_RELOC_X86_64_GOTPCREL64,R_X86_64_GOTPCREL64, },
{ BFD_RELOC_X86_64_GOTPC64, R_X86_64_GOTPC64, },
{ BFD_RELOC_X86_64_GOTPLT64, R_X86_64_GOTPLT64, },
{ BFD_RELOC_X86_64_PLTOFF64, R_X86_64_PLTOFF64, },
{ BFD_RELOC_SIZE32, R_X86_64_SIZE32, },
{ BFD_RELOC_SIZE64, R_X86_64_SIZE64, },
{ BFD_RELOC_X86_64_GOTPC32_TLSDESC, R_X86_64_GOTPC32_TLSDESC, },
{ BFD_RELOC_X86_64_TLSDESC_CALL, R_X86_64_TLSDESC_CALL, },
{ BFD_RELOC_X86_64_TLSDESC, R_X86_64_TLSDESC, },
{ BFD_RELOC_X86_64_IRELATIVE, R_X86_64_IRELATIVE, },
{ BFD_RELOC_X86_64_PC32_BND, R_X86_64_PC32_BND, },
{ BFD_RELOC_X86_64_PLT32_BND, R_X86_64_PLT32_BND, },
{ BFD_RELOC_X86_64_GOTPCRELX, R_X86_64_GOTPCRELX, },
{ BFD_RELOC_X86_64_REX_GOTPCRELX, R_X86_64_REX_GOTPCRELX, },
{ BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, },
{ BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, },
};
static reloc_howto_type *
elf_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type)
{
unsigned i;
if (r_type == (unsigned int) R_X86_64_32)
{
if (ABI_64_P (abfd))
i = r_type;
else
i = ARRAY_SIZE (x86_64_elf_howto_table) - 1;
}
else if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
|| r_type >= (unsigned int) R_X86_64_max)
{
if (r_type >= (unsigned int) R_X86_64_standard)
{
/* xgettext:c-format */
_bfd_error_handler (_("%pB: unsupported relocation type %#x"),
abfd, r_type);
bfd_set_error (bfd_error_bad_value);
return NULL;
}
i = r_type;
}
else
i = r_type - (unsigned int) R_X86_64_vt_offset;
BFD_ASSERT (x86_64_elf_howto_table[i].type == r_type);
return &x86_64_elf_howto_table[i];
}
/* Given a BFD reloc type, return a HOWTO structure. */
static reloc_howto_type *
elf_x86_64_reloc_type_lookup (bfd *abfd,
bfd_reloc_code_real_type code)
{
unsigned int i;
for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map);
i++)
{
if (x86_64_reloc_map[i].bfd_reloc_val == code)
return elf_x86_64_rtype_to_howto (abfd,
x86_64_reloc_map[i].elf_reloc_val);
}
return NULL;
}
static reloc_howto_type *
elf_x86_64_reloc_name_lookup (bfd *abfd,
const char *r_name)
{
unsigned int i;
if (!ABI_64_P (abfd) && strcasecmp (r_name, "R_X86_64_32") == 0)
{
/* Get x32 R_X86_64_32. */
reloc_howto_type *reloc
= &x86_64_elf_howto_table[ARRAY_SIZE (x86_64_elf_howto_table) - 1];
BFD_ASSERT (reloc->type == (unsigned int) R_X86_64_32);
return reloc;
}
for (i = 0; i < ARRAY_SIZE (x86_64_elf_howto_table); i++)
if (x86_64_elf_howto_table[i].name != NULL
&& strcasecmp (x86_64_elf_howto_table[i].name, r_name) == 0)
return &x86_64_elf_howto_table[i];
return NULL;
}
/* Given an x86_64 ELF reloc type, fill in an arelent structure. */
static bool
elf_x86_64_info_to_howto (bfd *abfd, arelent *cache_ptr,
Elf_Internal_Rela *dst)
{
unsigned r_type;
r_type = ELF32_R_TYPE (dst->r_info);
cache_ptr->howto = elf_x86_64_rtype_to_howto (abfd, r_type);
if (cache_ptr->howto == NULL)
return false;
BFD_ASSERT (r_type == cache_ptr->howto->type || cache_ptr->howto->type == R_X86_64_NONE);
return true;
}
/* Support for core dump NOTE sections. */
static bool
elf_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note)
{
int offset;
size_t size;
switch (note->descsz)
{
default:
return false;
case 296: /* sizeof(istruct elf_prstatus) on Linux/x32 */
/* pr_cursig */
elf_tdata (abfd)->core->signal = bfd_get_16 (abfd, note->descdata + 12);
/* pr_pid */
elf_tdata (abfd)->core->lwpid = bfd_get_32 (abfd, note->descdata + 24);
/* pr_reg */
offset = 72;
size = 216;
break;
case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */
/* pr_cursig */
elf_tdata (abfd)->core->signal
= bfd_get_16 (abfd, note->descdata + 12);
/* pr_pid */
elf_tdata (abfd)->core->lwpid
= bfd_get_32 (abfd, note->descdata + 32);
/* pr_reg */
offset = 112;
size = 216;
break;
}
/* Make a ".reg/999" section. */
return _bfd_elfcore_make_pseudosection (abfd, ".reg",
size, note->descpos + offset);
}
static bool
elf_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note)
{
switch (note->descsz)
{
default:
return false;
case 124: /* sizeof(struct elf_prpsinfo) on Linux/x32 */
elf_tdata (abfd)->core->pid
= bfd_get_32 (abfd, note->descdata + 12);
elf_tdata (abfd)->core->program
= _bfd_elfcore_strndup (abfd, note->descdata + 28, 16);
elf_tdata (abfd)->core->command
= _bfd_elfcore_strndup (abfd, note->descdata + 44, 80);
break;
case 136: /* sizeof(struct elf_prpsinfo) on Linux/x86_64 */
elf_tdata (abfd)->core->pid
= bfd_get_32 (abfd, note->descdata + 24);
elf_tdata (abfd)->core->program
= _bfd_elfcore_strndup (abfd, note->descdata + 40, 16);
elf_tdata (abfd)->core->command
= _bfd_elfcore_strndup (abfd, note->descdata + 56, 80);
}
/* Note that for some reason, a spurious space is tacked
onto the end of the args in some (at least one anyway)
implementations, so strip it off if it exists. */
{
char *command = elf_tdata (abfd)->core->command;
int n = strlen (command);
if (0 < n && command[n - 1] == ' ')
command[n - 1] = '\0';
}
return true;
}
#ifdef CORE_HEADER
# if GCC_VERSION >= 8000
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wstringop-truncation"
# endif
static char *
elf_x86_64_write_core_note (bfd *abfd, char *buf, int *bufsiz,
int note_type, ...)
{
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
va_list ap;
const char *fname, *psargs;
long pid;
int cursig;
const void *gregs;
switch (note_type)
{
default:
return NULL;
case NT_PRPSINFO:
va_start (ap, note_type);
fname = va_arg (ap, const char *);
psargs = va_arg (ap, const char *);
va_end (ap);
if (bed->s->elfclass == ELFCLASS32)
{
prpsinfo32_t data;
memset (&data, 0, sizeof (data));
strncpy (data.pr_fname, fname, sizeof (data.pr_fname));
strncpy (data.pr_psargs, psargs, sizeof (data.pr_psargs));
return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type,
&data, sizeof (data));
}
else
{
prpsinfo64_t data;
memset (&data, 0, sizeof (data));
strncpy (data.pr_fname, fname, sizeof (data.pr_fname));
strncpy (data.pr_psargs, psargs, sizeof (data.pr_psargs));
return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type,
&data, sizeof (data));
}
/* NOTREACHED */
case NT_PRSTATUS:
va_start (ap, note_type);
pid = va_arg (ap, long);
cursig = va_arg (ap, int);
gregs = va_arg (ap, const void *);
va_end (ap);
if (bed->s->elfclass == ELFCLASS32)
{
if (bed->elf_machine_code == EM_X86_64)
{
prstatusx32_t prstat;
memset (&prstat, 0, sizeof (prstat));
prstat.pr_pid = pid;
prstat.pr_cursig = cursig;
memcpy (&prstat.pr_reg, gregs, sizeof (prstat.pr_reg));
return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type,
&prstat, sizeof (prstat));
}
else
{
prstatus32_t prstat;
memset (&prstat, 0, sizeof (prstat));
prstat.pr_pid = pid;
prstat.pr_cursig = cursig;
memcpy (&prstat.pr_reg, gregs, sizeof (prstat.pr_reg));
return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type,
&prstat, sizeof (prstat));
}
}
else
{
prstatus64_t prstat;
memset (&prstat, 0, sizeof (prstat));
prstat.pr_pid = pid;
prstat.pr_cursig = cursig;
memcpy (&prstat.pr_reg, gregs, sizeof (prstat.pr_reg));
return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type,
&prstat, sizeof (prstat));
}
}
/* NOTREACHED */
}
# if GCC_VERSION >= 8000
# pragma GCC diagnostic pop
# endif
#endif
/* Functions for the x86-64 ELF linker. */
/* The size in bytes of an entry in the global offset table. */
#define GOT_ENTRY_SIZE 8
/* The size in bytes of an entry in the lazy procedure linkage table. */
#define LAZY_PLT_ENTRY_SIZE 16
/* The size in bytes of an entry in the non-lazy procedure linkage
table. */
#define NON_LAZY_PLT_ENTRY_SIZE 8
/* The first entry in a lazy procedure linkage table looks like this.
See the SVR4 ABI i386 supplement and the x86-64 ABI to see how this
works. */
static const bfd_byte elf_x86_64_lazy_plt0_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */
0x0f, 0x1f, 0x40, 0x00 /* nopl 0(%rax) */
};
/* Subsequent entries in a lazy procedure linkage table look like this. */
static const bfd_byte elf_x86_64_lazy_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
0x68, /* pushq immediate */
0, 0, 0, 0, /* replaced with index into relocation table. */
0xe9, /* jmp relative */
0, 0, 0, 0 /* replaced with offset to start of .plt0. */
};
/* The first entry in a lazy procedure linkage table with BND prefix
like this. */
static const bfd_byte elf_x86_64_lazy_bnd_plt0_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
0xf2, 0xff, 0x25, 16, 0, 0, 0, /* bnd jmpq *GOT+16(%rip) */
0x0f, 0x1f, 0 /* nopl (%rax) */
};
/* Subsequent entries for branches with BND prefx in a lazy procedure
linkage table look like this. */
static const bfd_byte elf_x86_64_lazy_bnd_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0x68, 0, 0, 0, 0, /* pushq immediate */
0xf2, 0xe9, 0, 0, 0, 0, /* bnd jmpq relative */
0x0f, 0x1f, 0x44, 0, 0 /* nopl 0(%rax,%rax,1) */
};
/* The first entry in the IBT-enabled lazy procedure linkage table is the
the same as the lazy PLT with BND prefix so that bound registers are
preserved when control is passed to dynamic linker. Subsequent
entries for a IBT-enabled lazy procedure linkage table look like
this. */
static const bfd_byte elf_x86_64_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
0x68, 0, 0, 0, 0, /* pushq immediate */
0xf2, 0xe9, 0, 0, 0, 0, /* bnd jmpq relative */
0x90 /* nop */
};
/* The first entry in the x32 IBT-enabled lazy procedure linkage table
is the same as the normal lazy PLT. Subsequent entries for an
x32 IBT-enabled lazy procedure linkage table look like this. */
static const bfd_byte elf_x32_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
0x68, 0, 0, 0, 0, /* pushq immediate */
0xe9, 0, 0, 0, 0, /* jmpq relative */
0x66, 0x90 /* xchg %ax,%ax */
};
/* Entries in the non-lazey procedure linkage table look like this. */
static const bfd_byte elf_x86_64_non_lazy_plt_entry[NON_LAZY_PLT_ENTRY_SIZE] =
{
0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
0x66, 0x90 /* xchg %ax,%ax */
};
/* Entries for branches with BND prefix in the non-lazey procedure
linkage table look like this. */
static const bfd_byte elf_x86_64_non_lazy_bnd_plt_entry[NON_LAZY_PLT_ENTRY_SIZE] =
{
0xf2, 0xff, 0x25, /* bnd jmpq *name@GOTPC(%rip) */
0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
0x90 /* nop */
};
/* Entries for branches with IBT-enabled in the non-lazey procedure
linkage table look like this. They have the same size as the lazy
PLT entry. */
static const bfd_byte elf_x86_64_non_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
0xf2, 0xff, 0x25, /* bnd jmpq *name@GOTPC(%rip) */
0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
0x0f, 0x1f, 0x44, 0x00, 0x00 /* nopl 0x0(%rax,%rax,1) */
};
/* Entries for branches with IBT-enabled in the x32 non-lazey procedure
linkage table look like this. They have the same size as the lazy
PLT entry. */
static const bfd_byte elf_x32_non_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 /* nopw 0x0(%rax,%rax,1) */
};
/* The TLSDESC entry in a lazy procedure linkage table. */
static const bfd_byte elf_x86_64_tlsdesc_plt_entry[LAZY_PLT_ENTRY_SIZE] =
{
0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */
0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
0xff, 0x25, 16, 0, 0, 0 /* jmpq *GOT+TDG(%rip) */
};
/* .eh_frame covering the lazy .plt section. */
static const bfd_byte elf_x86_64_eh_frame_lazy_plt[] =
{
PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */
0, 0, 0, 0, /* CIE ID */
1, /* CIE version */
'z', 'R', 0, /* Augmentation string */
1, /* Code alignment factor */
0x78, /* Data alignment factor */
16, /* Return address column */
1, /* Augmentation size */
DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */
DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */
DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */
DW_CFA_nop, DW_CFA_nop,
PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */
PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */
0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */
0, 0, 0, 0, /* .plt size goes here */
0, /* Augmentation size */
DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */
DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */
DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */
DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */
DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */
11, /* Block length */
DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */
DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */
DW_OP_lit15, DW_OP_and, DW_OP_lit11, DW_OP_ge,
DW_OP_lit3, DW_OP_shl, DW_OP_plus,
DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop
};
/* .eh_frame covering the lazy BND .plt section. */
static const bfd_byte elf_x86_64_eh_frame_lazy_bnd_plt[] =
{
PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */
0, 0, 0, 0, /* CIE ID */
1, /* CIE version */
'z', 'R', 0, /* Augmentation string */
1, /* Code alignment factor */
0x78, /* Data alignment factor */
16, /* Return address column */
1, /* Augmentation size */
DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */
DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */
DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */
DW_CFA_nop, DW_CFA_nop,
PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */
PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */
0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */
0, 0, 0, 0, /* .plt size goes here */
0, /* Augmentation size */
DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */
DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */
DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */
DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */
DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */
11, /* Block length */
DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */
DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */
DW_OP_lit15, DW_OP_and, DW_OP_lit5, DW_OP_ge,
DW_OP_lit3, DW_OP_shl, DW_OP_plus,
DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop
};
/* .eh_frame covering the lazy .plt section with IBT-enabled. */
static const bfd_byte elf_x86_64_eh_frame_lazy_ibt_plt[] =
{
PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */
0, 0, 0, 0, /* CIE ID */
1, /* CIE version */
'z', 'R', 0, /* Augmentation string */
1, /* Code alignment factor */
0x78, /* Data alignment factor */
16, /* Return address column */
1, /* Augmentation size */
DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */
DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */
DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */
DW_CFA_nop, DW_CFA_nop,
PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */
PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */
0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */
0, 0, 0, 0, /* .plt size goes here */
0, /* Augmentation size */
DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */
DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */
DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */
DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */
DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */
11, /* Block length */
DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */
DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */
DW_OP_lit15, DW_OP_and, DW_OP_lit10, DW_OP_ge,
DW_OP_lit3, DW_OP_shl, DW_OP_plus,
DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop
};
/* .eh_frame covering the x32 lazy .plt section with IBT-enabled. */
static const bfd_byte elf_x32_eh_frame_lazy_ibt_plt[] =
{
PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */
0, 0, 0, 0, /* CIE ID */
1, /* CIE version */
'z', 'R', 0, /* Augmentation string */
1, /* Code alignment factor */
0x78, /* Data alignment factor */
16, /* Return address column */
1, /* Augmentation size */
DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */
DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */
DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */
DW_CFA_nop, DW_CFA_nop,
PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */
PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */
0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */
0, 0, 0, 0, /* .plt size goes here */
0, /* Augmentation size */
DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */
DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */
DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */
DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */
DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */
11, /* Block length */
DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */
DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */
DW_OP_lit15, DW_OP_and, DW_OP_lit9, DW_OP_ge,
DW_OP_lit3, DW_OP_shl, DW_OP_plus,
DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop
};
/* .eh_frame covering the non-lazy .plt section. */
static const bfd_byte elf_x86_64_eh_frame_non_lazy_plt[] =
{
#define PLT_GOT_FDE_LENGTH 20
PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */
0, 0, 0, 0, /* CIE ID */
1, /* CIE version */
'z', 'R', 0, /* Augmentation string */
1, /* Code alignment factor */
0x78, /* Data alignment factor */
16, /* Return address column */
1, /* Augmentation size */
DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */
DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */
DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */
DW_CFA_nop, DW_CFA_nop,
PLT_GOT_FDE_LENGTH, 0, 0, 0, /* FDE length */
PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */
0, 0, 0, 0, /* the start of non-lazy .plt goes here */
0, 0, 0, 0, /* non-lazy .plt size goes here */
0, /* Augmentation size */
DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop,
DW_CFA_nop, DW_CFA_nop, DW_CFA_nop
};
/* These are the standard parameters. */
static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_plt =
{
elf_x86_64_lazy_plt0_entry, /* plt0_entry */
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_lazy_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
6, /* plt_tlsdesc_got1_offset */
12, /* plt_tlsdesc_got2_offset */
10, /* plt_tlsdesc_got1_insn_end */
16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
12, /* plt0_got2_insn_end */
2, /* plt_got_offset */
7, /* plt_reloc_offset */
12, /* plt_plt_offset */
6, /* plt_got_insn_size */
LAZY_PLT_ENTRY_SIZE, /* plt_plt_insn_end */
6, /* plt_lazy_offset */
elf_x86_64_lazy_plt0_entry, /* pic_plt0_entry */
elf_x86_64_lazy_plt_entry, /* pic_plt_entry */
elf_x86_64_eh_frame_lazy_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_lazy_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_non_lazy_plt_layout elf_x86_64_non_lazy_plt =
{
elf_x86_64_non_lazy_plt_entry, /* plt_entry */
elf_x86_64_non_lazy_plt_entry, /* pic_plt_entry */
NON_LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
2, /* plt_got_offset */
6, /* plt_got_insn_size */
elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_bnd_plt =
{
elf_x86_64_lazy_bnd_plt0_entry, /* plt0_entry */
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_lazy_bnd_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
6, /* plt_tlsdesc_got1_offset */
12, /* plt_tlsdesc_got2_offset */
10, /* plt_tlsdesc_got1_insn_end */
16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
1+8, /* plt0_got2_offset */
1+12, /* plt0_got2_insn_end */
1+2, /* plt_got_offset */
1, /* plt_reloc_offset */
7, /* plt_plt_offset */
1+6, /* plt_got_insn_size */
11, /* plt_plt_insn_end */
0, /* plt_lazy_offset */
elf_x86_64_lazy_bnd_plt0_entry, /* pic_plt0_entry */
elf_x86_64_lazy_bnd_plt_entry, /* pic_plt_entry */
elf_x86_64_eh_frame_lazy_bnd_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_lazy_bnd_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_non_lazy_plt_layout elf_x86_64_non_lazy_bnd_plt =
{
elf_x86_64_non_lazy_bnd_plt_entry, /* plt_entry */
elf_x86_64_non_lazy_bnd_plt_entry, /* pic_plt_entry */
NON_LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
1+2, /* plt_got_offset */
1+6, /* plt_got_insn_size */
elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_ibt_plt =
{
elf_x86_64_lazy_bnd_plt0_entry, /* plt0_entry */
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x86_64_lazy_ibt_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
6, /* plt_tlsdesc_got1_offset */
12, /* plt_tlsdesc_got2_offset */
10, /* plt_tlsdesc_got1_insn_end */
16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
1+8, /* plt0_got2_offset */
1+12, /* plt0_got2_insn_end */
4+1+2, /* plt_got_offset */
4+1, /* plt_reloc_offset */
4+1+6, /* plt_plt_offset */
4+1+6, /* plt_got_insn_size */
4+1+5+5, /* plt_plt_insn_end */
0, /* plt_lazy_offset */
elf_x86_64_lazy_bnd_plt0_entry, /* pic_plt0_entry */
elf_x86_64_lazy_ibt_plt_entry, /* pic_plt_entry */
elf_x86_64_eh_frame_lazy_ibt_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_lazy_ibt_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_lazy_plt_layout elf_x32_lazy_ibt_plt =
{
elf_x86_64_lazy_plt0_entry, /* plt0_entry */
LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */
elf_x32_lazy_ibt_plt_entry, /* plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */
6, /* plt_tlsdesc_got1_offset */
12, /* plt_tlsdesc_got2_offset */
10, /* plt_tlsdesc_got1_insn_end */
16, /* plt_tlsdesc_got2_insn_end */
2, /* plt0_got1_offset */
8, /* plt0_got2_offset */
12, /* plt0_got2_insn_end */
4+2, /* plt_got_offset */
4+1, /* plt_reloc_offset */
4+6, /* plt_plt_offset */
4+6, /* plt_got_insn_size */
4+5+5, /* plt_plt_insn_end */
0, /* plt_lazy_offset */
elf_x86_64_lazy_plt0_entry, /* pic_plt0_entry */
elf_x32_lazy_ibt_plt_entry, /* pic_plt_entry */
elf_x32_eh_frame_lazy_ibt_plt, /* eh_frame_plt */
sizeof (elf_x32_eh_frame_lazy_ibt_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_non_lazy_plt_layout elf_x86_64_non_lazy_ibt_plt =
{
elf_x86_64_non_lazy_ibt_plt_entry, /* plt_entry */
elf_x86_64_non_lazy_ibt_plt_entry, /* pic_plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
4+1+2, /* plt_got_offset */
4+1+6, /* plt_got_insn_size */
elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */
};
static const struct elf_x86_non_lazy_plt_layout elf_x32_non_lazy_ibt_plt =
{
elf_x32_non_lazy_ibt_plt_entry, /* plt_entry */
elf_x32_non_lazy_ibt_plt_entry, /* pic_plt_entry */
LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */
4+2, /* plt_got_offset */
4+6, /* plt_got_insn_size */
elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */
sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */
};
static bool
elf64_x86_64_elf_object_p (bfd *abfd)
{
/* Set the right machine number for an x86-64 elf64 file. */
bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64);
return true;
}
static bool
elf32_x86_64_elf_object_p (bfd *abfd)
{
/* Set the right machine number for an x86-64 elf32 file. */
bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x64_32);
return true;
}
/* Return TRUE if the TLS access code sequence support transition
from R_TYPE. */
static bool
elf_x86_64_check_tls_transition (bfd *abfd,
struct bfd_link_info *info,
asection *sec,
bfd_byte *contents,
Elf_Internal_Shdr *symtab_hdr,
struct elf_link_hash_entry **sym_hashes,
unsigned int r_type,
const Elf_Internal_Rela *rel,
const Elf_Internal_Rela *relend)
{
unsigned int val;
unsigned long r_symndx;
bool largepic = false;
struct elf_link_hash_entry *h;
bfd_vma offset;
struct elf_x86_link_hash_table *htab;
bfd_byte *call;
bool indirect_call;
htab = elf_x86_hash_table (info, X86_64_ELF_DATA);
offset = rel->r_offset;
switch (r_type)
{
case R_X86_64_TLSGD:
case R_X86_64_TLSLD:
if ((rel + 1) >= relend)
return false;
if (r_type == R_X86_64_TLSGD)
{
/* Check transition from GD access model. For 64bit, only
.byte 0x66; leaq foo@tlsgd(%rip), %rdi
.word 0x6666; rex64; call __tls_get_addr@PLT
or
.byte 0x66; leaq foo@tlsgd(%rip), %rdi
.byte 0x66; rex64
call *__tls_get_addr@GOTPCREL(%rip)
which may be converted to
addr32 call __tls_get_addr
can transit to different access model. For 32bit, only
leaq foo@tlsgd(%rip), %rdi
.word 0x6666; rex64; call __tls_get_addr@PLT
or
leaq foo@tlsgd(%rip), %rdi
.byte 0x66; rex64
call *__tls_get_addr@GOTPCREL(%rip)
which may be converted to
addr32 call __tls_get_addr
can transit to different access model. For largepic,
we also support:
leaq foo@tlsgd(%rip), %rdi
movabsq $__tls_get_addr@pltoff, %rax
addq $r15, %rax
call *%rax
or
leaq foo@tlsgd(%rip), %rdi
movabsq $__tls_get_addr@pltoff, %rax
addq $rbx, %rax
call *%rax */
static const unsigned char leaq[] = { 0x66, 0x48, 0x8d, 0x3d };
if ((offset + 12) > sec->size)
return false;
call = contents + offset + 4;
if (call[0] != 0x66
|| !((call[1] == 0x48
&& call[2] == 0xff
&& call[3] == 0x15)
|| (call[1] == 0x48
&& call[2] == 0x67
&& call[3] == 0xe8)
|| (call[1] == 0x66
&& call[2] == 0x48
&& call[3] == 0xe8)))
{
if (!ABI_64_P (abfd)
|| (offset + 19) > sec->size
|| offset < 3
|| memcmp (call - 7, leaq + 1, 3) != 0
|| memcmp (call, "\x48\xb8", 2) != 0
|| call[11] != 0x01
|| call[13] != 0xff
|| call[14] != 0xd0
|| !((call[10] == 0x48 && call[12] == 0xd8)
|| (call[10] == 0x4c && call[12] == 0xf8)))
return false;
largepic = true;
}
else if (ABI_64_P (abfd))
{
if (offset < 4
|| memcmp (contents + offset - 4, leaq, 4) != 0)
return false;
}
else
{
if (offset < 3
|| memcmp (contents + offset - 3, leaq + 1, 3) != 0)
return false;
}
indirect_call = call[2] == 0xff;
}
else
{
/* Check transition from LD access model. Only
leaq foo@tlsld(%rip), %rdi;
call __tls_get_addr@PLT
or
leaq foo@tlsld(%rip), %rdi;
call *__tls_get_addr@GOTPCREL(%rip)
which may be converted to
addr32 call __tls_get_addr
can transit to different access model. For largepic
we also support:
leaq foo@tlsld(%rip), %rdi
movabsq $__tls_get_addr@pltoff, %rax
addq $r15, %rax
call *%rax
or
leaq foo@tlsld(%rip), %rdi
movabsq $__tls_get_addr@pltoff, %rax
addq $rbx, %rax
call *%rax */
static const unsigned char lea[] = { 0x48, 0x8d, 0x3d };
if (offset < 3 || (offset + 9) > sec->size)
return false;
if (memcmp (contents + offset - 3, lea, 3) != 0)
return false;
call = contents + offset + 4;
if (!(call[0] == 0xe8
|| (call[0] == 0xff && call[1] == 0x15)
|| (call[0] == 0x67 && call[1] == 0xe8)))
{
if (!ABI_64_P (abfd)
|| (offset + 19) > sec->size
|| memcmp (call, "\x48\xb8", 2) != 0
|| call[11] != 0x01
|| call[13] != 0xff
|| call[14] != 0xd0
|| !((call[10] == 0x48 && call[12] == 0xd8)
|| (call[10] == 0x4c && call[12] == 0xf8)))
return false;
largepic = true;
}
indirect_call = call[0] == 0xff;
}
r_symndx = htab->r_sym (rel[1].r_info);
if (r_symndx < symtab_hdr->sh_info)
return false;
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
if (h == NULL
|| !((struct elf_x86_link_hash_entry *) h)->tls_get_addr)
return false;
else
{
r_type = (ELF32_R_TYPE (rel[1].r_info)
& ~R_X86_64_converted_reloc_bit);
if (largepic)
return r_type == R_X86_64_PLTOFF64;
else if (indirect_call)
return r_type == R_X86_64_GOTPCRELX;
else
return (r_type == R_X86_64_PC32 || r_type == R_X86_64_PLT32);
}
case R_X86_64_GOTTPOFF:
/* Check transition from IE access model:
mov foo@gottpoff(%rip), %reg
add foo@gottpoff(%rip), %reg
*/
/* Check REX prefix first. */
if (offset >= 3 && (offset + 4) <= sec->size)
{
val = bfd_get_8 (abfd, contents + offset - 3);
if (val != 0x48 && val != 0x4c)
{
/* X32 may have 0x44 REX prefix or no REX prefix. */
if (ABI_64_P (abfd))
return false;
}
}
else
{
/* X32 may not have any REX prefix. */
if (ABI_64_P (abfd))
return false;
if (offset < 2 || (offset + 3) > sec->size)
return false;
}
val = bfd_get_8 (abfd, contents + offset - 2);
if (val != 0x8b && val != 0x03)
return false;
val = bfd_get_8 (abfd, contents + offset - 1);
return (val & 0xc7) == 5;
case R_X86_64_GOTPC32_TLSDESC:
/* Check transition from GDesc access model:
leaq x@tlsdesc(%rip), %rax <--- LP64 mode.
rex leal x@tlsdesc(%rip), %eax <--- X32 mode.
Make sure it's a leaq adding rip to a 32-bit offset
into any register, although it's probably almost always
going to be rax. */
if (offset < 3 || (offset + 4) > sec->size)
return false;
val = bfd_get_8 (abfd, contents + offset - 3);
val &= 0xfb;
if (val != 0x48 && (ABI_64_P (abfd) || val != 0x40))
return false;
if (bfd_get_8 (abfd, contents + offset - 2) != 0x8d)
return false;
val = bfd_get_8 (abfd, contents + offset - 1);
return (val & 0xc7) == 0x05;
case R_X86_64_TLSDESC_CALL:
/* Check transition from GDesc access model:
call *x@tlsdesc(%rax) <--- LP64 mode.
call *x@tlsdesc(%eax) <--- X32 mode.
*/
if (offset + 2 <= sec->size)
{
unsigned int prefix;
call = contents + offset;
prefix = 0;
if (!ABI_64_P (abfd))
{
/* Check for call *x@tlsdesc(%eax). */
if (call[0] == 0x67)
{
prefix = 1;
if (offset + 3 > sec->size)
return false;
}
}
/* Make sure that it's a call *x@tlsdesc(%rax). */
return call[prefix] == 0xff && call[1 + prefix] == 0x10;
}
return false;
default:
abort ();
}
}
/* Return TRUE if the TLS access transition is OK or no transition
will be performed. Update R_TYPE if there is a transition. */
static bool
elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd,
asection *sec, bfd_byte *contents,
Elf_Internal_Shdr *symtab_hdr,
struct elf_link_hash_entry **sym_hashes,
unsigned int *r_type, int tls_type,
const Elf_Internal_Rela *rel,
const Elf_Internal_Rela *relend,
struct elf_link_hash_entry *h,
unsigned long r_symndx,
bool from_relocate_section)
{
unsigned int from_type = *r_type;
unsigned int to_type = from_type;
bool check = true;
/* Skip TLS transition for functions. */
if (h != NULL
&& (h->type == STT_FUNC
|| h->type == STT_GNU_IFUNC))
return true;
switch (from_type)
{
case R_X86_64_TLSGD:
case R_X86_64_GOTPC32_TLSDESC:
case R_X86_64_TLSDESC_CALL:
case R_X86_64_GOTTPOFF:
if (bfd_link_executable (info))
{
if (h == NULL)
to_type = R_X86_64_TPOFF32;
else
to_type = R_X86_64_GOTTPOFF;
}
/* When we are called from elf_x86_64_relocate_section, there may
be additional transitions based on TLS_TYPE. */
if (from_relocate_section)
{
unsigned int new_to_type = to_type;
if (TLS_TRANSITION_IE_TO_LE_P (info, h, tls_type))
new_to_type = R_X86_64_TPOFF32;
if (to_type == R_X86_64_TLSGD
|| to_type == R_X86_64_GOTPC32_TLSDESC
|| to_type == R_X86_64_TLSDESC_CALL)
{
if (tls_type == GOT_TLS_IE)
new_to_type = R_X86_64_GOTTPOFF;
}
/* We checked the transition before when we were called from
elf_x86_64_check_relocs. We only want to check the new
transition which hasn't been checked before. */
check = new_to_type != to_type && from_type == to_type;
to_type = new_to_type;
}
break;
case R_X86_64_TLSLD:
if (bfd_link_executable (info))
to_type = R_X86_64_TPOFF32;
break;
default:
return true;
}
/* Return TRUE if there is no transition. */
if (from_type == to_type)
return true;
/* Check if the transition can be performed. */
if (check
&& ! elf_x86_64_check_tls_transition (abfd, info, sec, contents,
symtab_hdr, sym_hashes,
from_type, rel, relend))
{
reloc_howto_type *from, *to;
const char *name;
from = elf_x86_64_rtype_to_howto (abfd, from_type);
to = elf_x86_64_rtype_to_howto (abfd, to_type);
if (from == NULL || to == NULL)
return false;
if (h)
name = h->root.root.string;
else
{
struct elf_x86_link_hash_table *htab;
htab = elf_x86_hash_table (info, X86_64_ELF_DATA);
if (htab == NULL)
name = "*unknown*";
else
{
Elf_Internal_Sym *isym;
isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache,
abfd, r_symndx);
name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL);
}
}
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: TLS transition from %s to %s against `%s' at %#" PRIx64
" in section `%pA' failed"),
abfd, from->name, to->name, name, (uint64_t) rel->r_offset, sec);
bfd_set_error (bfd_error_bad_value);
return false;
}
*r_type = to_type;
return true;
}
/* Rename some of the generic section flags to better document how they
are used here. */
#define check_relocs_failed sec_flg0
static bool
elf_x86_64_need_pic (struct bfd_link_info *info,
bfd *input_bfd, asection *sec,
struct elf_link_hash_entry *h,
Elf_Internal_Shdr *symtab_hdr,
Elf_Internal_Sym *isym,
reloc_howto_type *howto)
{
const char *v = "";
const char *und = "";
const char *pic = "";
const char *object;
const char *name;
if (h)
{
name = h->root.root.string;
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_HIDDEN:
v = _("hidden symbol ");
break;
case STV_INTERNAL:
v = _("internal symbol ");
break;
case STV_PROTECTED:
v = _("protected symbol ");
break;
default:
if (((struct elf_x86_link_hash_entry *) h)->def_protected)
v = _("protected symbol ");
else
v = _("symbol ");
pic = NULL;
break;
}
if (!SYMBOL_DEFINED_NON_SHARED_P (h) && !h->def_dynamic)
und = _("undefined ");
}
else
{
name = bfd_elf_sym_name (input_bfd, symtab_hdr, isym, NULL);
pic = NULL;
}
if (bfd_link_dll (info))
{
object = _("a shared object");
if (!pic)
pic = _("; recompile with -fPIC");
}
else
{
if (bfd_link_pie (info))
object = _("a PIE object");
else
object = _("a PDE object");
if (!pic)
pic = _("; recompile with -fPIE");
}
/* xgettext:c-format */
_bfd_error_handler (_("%pB: relocation %s against %s%s`%s' can "
"not be used when making %s%s"),
input_bfd, howto->name, und, v, name,
object, pic);
bfd_set_error (bfd_error_bad_value);
sec->check_relocs_failed = 1;
return false;
}
/* With the local symbol, foo, we convert
mov foo@GOTPCREL(%rip), %reg
to
lea foo(%rip), %reg
and convert
call/jmp *foo@GOTPCREL(%rip)
to
nop call foo/jmp foo nop
When PIC is false, convert
test %reg, foo@GOTPCREL(%rip)
to
test $foo, %reg
and convert
binop foo@GOTPCREL(%rip), %reg
to
binop $foo, %reg
where binop is one of adc, add, and, cmp, or, sbb, sub, xor
instructions. */
static bool
elf_x86_64_convert_load_reloc (bfd *abfd,
bfd_byte *contents,
unsigned int *r_type_p,
Elf_Internal_Rela *irel,
struct elf_link_hash_entry *h,
bool *converted,
struct bfd_link_info *link_info)
{
struct elf_x86_link_hash_table *htab;
bool is_pic;
bool no_overflow;
bool relocx;
bool to_reloc_pc32;
bool abs_symbol;
bool local_ref;
asection *tsec;
bfd_signed_vma raddend;
unsigned int opcode;
unsigned int modrm;
unsigned int r_type = *r_type_p;
unsigned int r_symndx;
bfd_vma roff = irel->r_offset;
bfd_vma abs_relocation;
if (roff < (r_type == R_X86_64_REX_GOTPCRELX ? 3 : 2))
return true;
raddend = irel->r_addend;
/* Addend for 32-bit PC-relative relocation must be -4. */
if (raddend != -4)
return true;
htab = elf_x86_hash_table (link_info, X86_64_ELF_DATA);
is_pic = bfd_link_pic (link_info);
relocx = (r_type == R_X86_64_GOTPCRELX
|| r_type == R_X86_64_REX_GOTPCRELX);
/* TRUE if --no-relax is used. */
no_overflow = link_info->disable_target_specific_optimizations > 1;
r_symndx = htab->r_sym (irel->r_info);
opcode = bfd_get_8 (abfd, contents + roff - 2);
/* Convert mov to lea since it has been done for a while. */
if (opcode != 0x8b)
{
/* Only convert R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX
for call, jmp or one of adc, add, and, cmp, or, sbb, sub,
test, xor instructions. */
if (!relocx)
return true;
}
/* We convert only to R_X86_64_PC32:
1. Branch.
2. R_X86_64_GOTPCREL since we can't modify REX byte.
3. no_overflow is true.
4. PIC.
*/
to_reloc_pc32 = (opcode == 0xff
|| !relocx
|| no_overflow
|| is_pic);
abs_symbol = false;
abs_relocation = 0;
/* Get the symbol referred to by the reloc. */
if (h == NULL)
{
Elf_Internal_Sym *isym
= bfd_sym_from_r_symndx (&htab->elf.sym_cache, abfd, r_symndx);
/* Skip relocation against undefined symbols. */
if (isym->st_shndx == SHN_UNDEF)
return true;
local_ref = true;
if (isym->st_shndx == SHN_ABS)
{
tsec = bfd_abs_section_ptr;
abs_symbol = true;
abs_relocation = isym->st_value;
}
else if (isym->st_shndx == SHN_COMMON)
tsec = bfd_com_section_ptr;
else if (isym->st_shndx == SHN_X86_64_LCOMMON)
tsec = &_bfd_elf_large_com_section;
else
tsec = bfd_section_from_elf_index (abfd, isym->st_shndx);
}
else
{
/* Undefined weak symbol is only bound locally in executable
and its reference is resolved as 0 without relocation
overflow. We can only perform this optimization for
GOTPCRELX relocations since we need to modify REX byte.
It is OK convert mov with R_X86_64_GOTPCREL to
R_X86_64_PC32. */
struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
abs_symbol = ABS_SYMBOL_P (h);
abs_relocation = h->root.u.def.value;
/* NB: Also set linker_def via SYMBOL_REFERENCES_LOCAL_P. */
local_ref = SYMBOL_REFERENCES_LOCAL_P (link_info, h);
if ((relocx || opcode == 0x8b)
&& (h->root.type == bfd_link_hash_undefweak
&& !eh->linker_def
&& local_ref))
{
if (opcode == 0xff)
{
/* Skip for branch instructions since R_X86_64_PC32
may overflow. */
if (no_overflow)
return true;
}
else if (relocx)
{
/* For non-branch instructions, we can convert to
R_X86_64_32/R_X86_64_32S since we know if there
is a REX byte. */
to_reloc_pc32 = false;
}
/* Since we don't know the current PC when PIC is true,
we can't convert to R_X86_64_PC32. */
if (to_reloc_pc32 && is_pic)
return true;
goto convert;
}
/* Avoid optimizing GOTPCREL relocations againt _DYNAMIC since
ld.so may use its link-time address. */
else if (h->start_stop
|| eh->linker_def
|| ((h->def_regular
|| h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& h != htab->elf.hdynamic
&& local_ref))
{
/* bfd_link_hash_new or bfd_link_hash_undefined is
set by an assignment in a linker script in
bfd_elf_record_link_assignment. start_stop is set
on __start_SECNAME/__stop_SECNAME which mark section
SECNAME. */
if (h->start_stop
|| eh->linker_def
|| (h->def_regular
&& (h->root.type == bfd_link_hash_new
|| h->root.type == bfd_link_hash_undefined
|| ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& h->root.u.def.section == bfd_und_section_ptr))))
{
/* Skip since R_X86_64_32/R_X86_64_32S may overflow. */
if (no_overflow)
return true;
goto convert;
}
tsec = h->root.u.def.section;
}
else
return true;
}
/* Don't convert GOTPCREL relocation against large section. */
if (elf_section_data (tsec) != NULL
&& (elf_section_flags (tsec) & SHF_X86_64_LARGE) != 0)
return true;
/* Skip since R_X86_64_PC32/R_X86_64_32/R_X86_64_32S may overflow. */
if (no_overflow)
return true;
convert:
if (opcode == 0xff)
{
/* We have "call/jmp *foo@GOTPCREL(%rip)". */
unsigned int nop;
unsigned int disp;
bfd_vma nop_offset;
/* Convert R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX to
R_X86_64_PC32. */
modrm = bfd_get_8 (abfd, contents + roff - 1);
if (modrm == 0x25)
{
/* Convert to "jmp foo nop". */
modrm = 0xe9;
nop = NOP_OPCODE;
nop_offset = irel->r_offset + 3;
disp = bfd_get_32 (abfd, contents + irel->r_offset);
irel->r_offset -= 1;
bfd_put_32 (abfd, disp, contents + irel->r_offset);
}
else
{
struct elf_x86_link_hash_entry *eh
= (struct elf_x86_link_hash_entry *) h;
/* Convert to "nop call foo". ADDR_PREFIX_OPCODE
is a nop prefix. */
modrm = 0xe8;
/* To support TLS optimization, always use addr32 prefix for
"call *__tls_get_addr@GOTPCREL(%rip)". */
if (eh && eh->tls_get_addr)
{
nop = 0x67;
nop_offset = irel->r_offset - 2;
}
else
{
nop = htab->params->call_nop_byte;
if (htab->params->call_nop_as_suffix)
{
nop_offset = irel->r_offset + 3;
disp = bfd_get_32 (abfd, contents + irel->r_offset);
irel->r_offset -= 1;
bfd_put_32 (abfd, disp, contents + irel->r_offset);
}
else
nop_offset = irel->r_offset - 2;
}
}
bfd_put_8 (abfd, nop, contents + nop_offset);
bfd_put_8 (abfd, modrm, contents + irel->r_offset - 1);
r_type = R_X86_64_PC32;
}
else
{
unsigned int rex;
unsigned int rex_mask = REX_R;
if (r_type == R_X86_64_REX_GOTPCRELX)
rex = bfd_get_8 (abfd, contents + roff - 3);
else
rex = 0;
if (opcode == 0x8b)
{
if (abs_symbol && local_ref && relocx)
to_reloc_pc32 = false;
if (to_reloc_pc32)
{
/* Convert "mov foo@GOTPCREL(%rip), %reg" to
"lea foo(%rip), %reg". */
opcode = 0x8d;
r_type = R_X86_64_PC32;
}
else
{
/* Convert "mov foo@GOTPCREL(%rip), %reg" to
"mov $foo, %reg". */
opcode = 0xc7;
modrm = bfd_get_8 (abfd, contents + roff - 1);
modrm = 0xc0 | (modrm & 0x38) >> 3;
if ((rex & REX_W) != 0
&& ABI_64_P (link_info->output_bfd))
{
/* Keep the REX_W bit in REX byte for LP64. */
r_type = R_X86_64_32S;
goto rewrite_modrm_rex;
}
else
{
/* If the REX_W bit in REX byte isn't needed,
use R_X86_64_32 and clear the W bit to avoid
sign-extend imm32 to imm64. */
r_type = R_X86_64_32;
/* Clear the W bit in REX byte. */
rex_mask |= REX_W;
goto rewrite_modrm_rex;
}
}
}
else
{
/* R_X86_64_PC32 isn't supported. */
if (to_reloc_pc32)
return true;
modrm = bfd_get_8 (abfd, contents + roff - 1);
if (opcode == 0x85)
{
/* Convert "test %reg, foo@GOTPCREL(%rip)" to
"test $foo, %reg". */
modrm = 0xc0 | (modrm & 0x38) >> 3;
opcode = 0xf7;
}
else
{
/* Convert "binop foo@GOTPCREL(%rip), %reg" to
"binop $foo, %reg". */
modrm = 0xc0 | (modrm & 0x38) >> 3 | (opcode & 0x3c);
opcode = 0x81;
}
/* Use R_X86_64_32 with 32-bit operand to avoid relocation
overflow when sign-extending imm32 to imm64. */
r_type = (rex & REX_W) != 0 ? R_X86_64_32S : R_X86_64_32;
rewrite_modrm_rex:
if (abs_relocation)
{
/* Check if R_X86_64_32S/R_X86_64_32 fits. */
if (r_type == R_X86_64_32S)
{
if ((abs_relocation + 0x80000000) > 0xffffffff)
return true;
}
else
{
if (abs_relocation > 0xffffffff)
return true;
}
}
bfd_put_8 (abfd, modrm, contents + roff - 1);
if (rex)
{
/* Move the R bit to the B bit in REX byte. */
rex = (rex & ~rex_mask) | (rex & REX_R) >> 2;
bfd_put_8 (abfd, rex, contents + roff - 3);
}
/* No addend for R_X86_64_32/R_X86_64_32S relocations. */
irel->r_addend = 0;
}
bfd_put_8 (abfd, opcode, contents + roff - 2);
}
*r_type_p = r_type;
irel->r_info = htab->r_info (r_symndx,
r_type | R_X86_64_converted_reloc_bit);
*converted = true;
return true;
}
/* Look through the relocs for a section during the first phase, and
calculate needed space in the global offset table, procedure
linkage table, and dynamic reloc sections. */
static bool
elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
asection *sec,
const Elf_Internal_Rela *relocs)
{
struct elf_x86_link_hash_table *htab;
Elf_Internal_Shdr *symtab_hdr;
struct elf_link_hash_entry **sym_hashes;
const Elf_Internal_Rela *rel;
const Elf_Internal_Rela *rel_end;
asection *sreloc;
bfd_byte *contents;
bool converted;
if (bfd_link_relocatable (info))
return true;
htab = elf_x86_hash_table (info, X86_64_ELF_DATA);
if (htab == NULL)
{
sec->check_relocs_failed = 1;
return false;
}
BFD_ASSERT (is_x86_elf (abfd, htab));
/* Get the section contents. */
if (elf_section_data (sec)->this_hdr.contents != NULL)
contents = elf_section_data (sec)->this_hdr.contents;
else if (!bfd_malloc_and_get_section (abfd, sec, &contents))
{
sec->check_relocs_failed = 1;
return false;
}
symtab_hdr = &elf_symtab_hdr (abfd);
sym_hashes = elf_sym_hashes (abfd);
converted = false;
sreloc = NULL;
rel_end = relocs + sec->reloc_count;
for (rel = relocs; rel < rel_end; rel++)
{
unsigned int r_type;
unsigned int r_symndx;
struct elf_link_hash_entry *h;
struct elf_x86_link_hash_entry *eh;
Elf_Internal_Sym *isym;
const char *name;
bool size_reloc;
bool converted_reloc;
bool no_dynreloc;
r_symndx = htab->r_sym (rel->r_info);
r_type = ELF32_R_TYPE (rel->r_info);
if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr))
{
/* xgettext:c-format */
_bfd_error_handler (_("%pB: bad symbol index: %d"),
abfd, r_symndx);
goto error_return;
}
if (r_symndx < symtab_hdr->sh_info)
{
/* A local symbol. */
isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache,
abfd, r_symndx);
if (isym == NULL)
goto error_return;
/* Check relocation against local STT_GNU_IFUNC symbol. */
if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
{
h = _bfd_elf_x86_get_local_sym_hash (htab, abfd, rel,
true);
if (h == NULL)
goto error_return;
/* Fake a STT_GNU_IFUNC symbol. */
h->root.root.string = bfd_elf_sym_name (abfd, symtab_hdr,
isym, NULL);
h->type = STT_GNU_IFUNC;
h->def_regular = 1;
h->ref_regular = 1;
h->forced_local = 1;
h->root.type = bfd_link_hash_defined;
}
else
h = NULL;
}
else
{
isym = NULL;
h = sym_hashes[r_symndx - symtab_hdr->sh_info];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
}
/* Check invalid x32 relocations. */
if (!ABI_64_P (abfd))
switch (r_type)
{
default:
break;
case R_X86_64_DTPOFF64:
case R_X86_64_TPOFF64:
case R_X86_64_PC64:
case R_X86_64_GOTOFF64:
case R_X86_64_GOT64:
case R_X86_64_GOTPCREL64:
case R_X86_64_GOTPC64:
case R_X86_64_GOTPLT64:
case R_X86_64_PLTOFF64:
{
if (h)
name = h->root.root.string;
else
name = bfd_elf_sym_name (abfd, symtab_hdr, isym,
NULL);
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: relocation %s against symbol `%s' isn't "
"supported in x32 mode"), abfd,
x86_64_elf_howto_table[r_type].name, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
break;
}
eh = (struct elf_x86_link_hash_entry *) h;
if (h != NULL)
{
/* It is referenced by a non-shared object. */
h->ref_regular = 1;
}
converted_reloc = false;
if ((r_type == R_X86_64_GOTPCREL
|| r_type == R_X86_64_GOTPCRELX
|| r_type == R_X86_64_REX_GOTPCRELX)
&& (h == NULL || h->type != STT_GNU_IFUNC))
{
Elf_Internal_Rela *irel = (Elf_Internal_Rela *) rel;
if (!elf_x86_64_convert_load_reloc (abfd, contents, &r_type,
irel, h, &converted_reloc,
info))
goto error_return;
if (converted_reloc)
converted = true;
}
if (!_bfd_elf_x86_valid_reloc_p (sec, info, htab, rel, h, isym,
symtab_hdr, &no_dynreloc))
return false;
if (! elf_x86_64_tls_transition (info, abfd, sec, contents,
symtab_hdr, sym_hashes,
&r_type, GOT_UNKNOWN,
rel, rel_end, h, r_symndx, false))
goto error_return;
/* Check if _GLOBAL_OFFSET_TABLE_ is referenced. */
if (h == htab->elf.hgot)
htab->got_referenced = true;
switch (r_type)
{
case R_X86_64_TLSLD:
htab->tls_ld_or_ldm_got.refcount = 1;
goto create_got;
case R_X86_64_TPOFF32:
if (!bfd_link_executable (info) && ABI_64_P (abfd))
return elf_x86_64_need_pic (info, abfd, sec, h, symtab_hdr, isym,
&x86_64_elf_howto_table[r_type]);
if (eh != NULL)
eh->zero_undefweak &= 0x2;
break;
case R_X86_64_GOTTPOFF:
if (!bfd_link_executable (info))
info->flags |= DF_STATIC_TLS;
/* Fall through */
case R_X86_64_GOT32:
case R_X86_64_GOTPCREL:
case R_X86_64_GOTPCRELX:
case R_X86_64_REX_GOTPCRELX:
case R_X86_64_TLSGD:
case R_X86_64_GOT64:
case R_X86_64_GOTPCREL64:
case R_X86_64_GOTPLT64:
case R_X86_64_GOTPC32_TLSDESC:
case R_X86_64_TLSDESC_CALL:
/* This symbol requires a global offset table entry. */
{
int tls_type, old_tls_type;
switch (r_type)
{
default:
tls_type = GOT_NORMAL;
if (h)
{
if (ABS_SYMBOL_P (h))
tls_type = GOT_ABS;
}
else if (isym->st_shndx == SHN_ABS)
tls_type = GOT_ABS;
break;
case R_X86_64_TLSGD:
tls_type = GOT_TLS_GD;
break;
case R_X86_64_GOTTPOFF:
tls_type = GOT_TLS_IE;
break;
case R_X86_64_GOTPC32_TLSDESC:
case R_X86_64_TLSDESC_CALL:
tls_type = GOT_TLS_GDESC;
break;
}
if (h != NULL)
{
h->got.refcount = 1;
old_tls_type = eh->tls_type;
}
else
{
bfd_signed_vma *local_got_refcounts;
/* This is a global offset table entry for a local symbol. */
local_got_refcounts = elf_local_got_refcounts (abfd);
if (local_got_refcounts == NULL)
{
bfd_size_type size;
size = symtab_hdr->sh_info;
size *= sizeof (bfd_signed_vma)
+ sizeof (bfd_vma) + sizeof (char);
local_got_refcounts = ((bfd_signed_vma *)
bfd_zalloc (abfd, size));
if (local_got_refcounts == NULL)
goto error_return;
elf_local_got_refcounts (abfd) = local_got_refcounts;
elf_x86_local_tlsdesc_gotent (abfd)
= (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info);
elf_x86_local_got_tls_type (abfd)
= (char *) (local_got_refcounts + 2 * symtab_hdr->sh_info);
}
local_got_refcounts[r_symndx] = 1;
old_tls_type
= elf_x86_local_got_tls_type (abfd) [r_symndx];
}
/* If a TLS symbol is accessed using IE at least once,
there is no point to use dynamic model for it. */
if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN
&& (! GOT_TLS_GD_ANY_P (old_tls_type)
|| tls_type != GOT_TLS_IE))
{
if (old_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (tls_type))
tls_type = old_tls_type;
else if (GOT_TLS_GD_ANY_P (old_tls_type)
&& GOT_TLS_GD_ANY_P (tls_type))
tls_type |= old_tls_type;
else
{
if (h)
name = h->root.root.string;
else
name = bfd_elf_sym_name (abfd, symtab_hdr,
isym, NULL);
_bfd_error_handler
/* xgettext:c-format */
(_("%pB: '%s' accessed both as normal and"
" thread local symbol"),
abfd, name);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
}
if (old_tls_type != tls_type)
{
if (eh != NULL)
eh->tls_type = tls_type;
else
elf_x86_local_got_tls_type (abfd) [r_symndx] = tls_type;
}
}
/* Fall through */
case R_X86_64_GOTOFF64:
case R_X86_64_GOTPC32:
case R_X86_64_GOTPC64:
create_got:
if (eh != NULL)
eh->zero_undefweak &= 0x2;
break;
case R_X86_64_PLT32:
case R_X86_64_PLT32_BND:
/* This symbol requires a procedure linkage table entry. We
actually build the entry in adjust_dynamic_symbol,
because this might be a case of linking PIC code which is
never referenced by a dynamic object, in which case we
don't need to generate a procedure linkage table entry
after all. */
/* If this is a local symbol, we resolve it directly without
creating a procedure linkage table entry. */
if (h == NULL)
continue;
eh->zero_undefweak &= 0x2;
h->needs_plt = 1;
h->plt.refcount = 1;
break;
case R_X86_64_PLTOFF64:
/* This tries to form the 'address' of a function relative
to GOT. For global symbols we need a PLT entry. */
if (h != NULL)
{
h->needs_plt = 1;
h->plt.refcount = 1;
}
goto create_got;
case R_X86_64_SIZE32:
case R_X86_64_SIZE64:
size_reloc = true;
goto do_size;
case R_X86_64_32:
if (!ABI_64_P (abfd))
goto pointer;
/* Fall through. */
case R_X86_64_8:
case R_X86_64_16:
case R_X86_64_32S:
/* Check relocation overflow as these relocs may lead to
run-time relocation overflow. Don't error out for
sections we don't care about, such as debug sections or
when relocation overflow check is disabled. */
if (!htab->params->no_reloc_overflow_check
&& !converted_reloc
&& (bfd_link_pic (info)
|| (bfd_link_executable (info)
&& h != NULL
&& !h->def_regular
&& h->def_dynamic
&& (sec->flags & SEC_READONLY) == 0)))
return elf_x86_64_need_pic (info, abfd, sec, h, symtab_hdr, isym,
&x86_64_elf_howto_table[r_type]);
/* Fall through. */
case R_X86_64_PC8:
case R_X86_64_PC16:
case R_X86_64_PC32:
case R_X86_64_PC32_BND:
case R_X86_64_PC64:
case R_X86_64_64:
pointer:
if (eh != NULL && (sec->flags & SEC_CODE) != 0)
eh->zero_undefweak |= 0x2;
/* We are called after all symbols have been resolved. Only
relocation against STT_GNU_IFUNC symbol must go through
PLT. */
if (h != NULL
&& (bfd_link_executable (info)
|| h->type == STT_GNU_IFUNC))
{
bool func_pointer_ref = false;
if (r_type == R_X86_64_PC32)
{
/* Since something like ".long foo - ." may be used
as pointer, make sure that PLT is used if foo is
a function defined in a shared library. */
if ((sec->flags & SEC_CODE) == 0)
{
h->pointer_equality_needed = 1;
if (bfd_link_pie (info)
&& h->type == STT_FUNC
&& !h->def_regular
&& h->def_dynamic)
{
h->needs_plt = 1;
h->plt.refcount = 1;
}
}
}
else if (r_type != R_X86_64_PC32_BND
&& r_type != R_X86_64_PC64)
{
h->pointer_equality_needed = 1;
/* At run-time, R_X86_64_64 can be resolved for both
x86-64 and x32. But R_X86_64_32 and R_X86_64_32S
can only be resolved for x32. */
if ((sec->flags & SEC_READONLY) == 0
&& (r_type == R_X86_64_64
|| (!ABI_64_P (abfd)
&& (r_type == R_X86_64_32
|| r_type == R_X86_64_32S))))
func_pointer_ref = true;
}
if (!func_pointer_ref)
{
/* If this reloc is in a read-only section, we might
need a copy reloc. We can't check reliably at this
stage whether the section is read-only, as input
sections have not yet been mapped to output sections.
Tentatively set the flag for now, and correct in
adjust_dynamic_symbol. */
h->non_got_ref = 1;
if (!elf_has_indirect_extern_access (sec->owner))
eh->non_got_ref_without_indirect_extern_access = 1;
/* We may need a .plt entry if the symbol is a function
defined in a shared lib or is a function referenced
from the code or read-only section. */
if (!h->def_regular
|| (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
h->plt.refcount = 1;
}
}
size_reloc = false;
do_size:
if (!no_dynreloc
&& NEED_DYNAMIC_RELOCATION_P (info, true, h, sec, r_type,
htab->pointer_r_type))
{
struct elf_dyn_relocs *p;
struct elf_dyn_relocs **head;
/* We must copy these reloc types into the output file.
Create a reloc section in dynobj and make room for
this reloc. */
if (sreloc == NULL)
{
sreloc = _bfd_elf_make_dynamic_reloc_section
(sec, htab->elf.dynobj, ABI_64_P (abfd) ? 3 : 2,
abfd, /*rela?*/ true);
if (sreloc == NULL)
goto error_return;
}
/* If this is a global symbol, we count the number of
relocations we need for this symbol. */
if (h != NULL)
head = &h->dyn_relocs;
else
{
/* Track dynamic relocs needed for local syms too.
We really need local syms available to do this
easily. Oh well. */
asection *s;
void **vpp;
isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache,
abfd, r_symndx);
if (isym == NULL)
goto error_return;
s = bfd_section_from_elf_index (abfd, isym->st_shndx);
if (s == NULL)
s = sec;
/* Beware of type punned pointers vs strict aliasing
rules. */
vpp = &(elf_section_data (s)->local_dynrel);
head = (struct elf_dyn_relocs **)vpp;
}
p = *head;
if (p == NULL || p->sec != sec)
{
size_t amt = sizeof *p;
p = ((struct elf_dyn_relocs *)
bfd_alloc (htab->elf.dynobj, amt));
if (p == NULL)
goto error_return;
p->next = *head;
*head = p;
p->sec = sec;
p->count = 0;
p->pc_count = 0;
}
p->count += 1;
/* Count size relocation as PC-relative relocation. */
if (X86_PCREL_TYPE_P (r_type) || size_reloc)
p->pc_count += 1;
}
break;
/* This relocation describes the C++ object vtable hierarchy.
Reconstruct it for later use during GC. */
case R_X86_64_GNU_VTINHERIT:
if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
goto error_return;
break;
/* This relocation describes which C++ vtable entries are actually
used. Record for later use during GC. */
case R_X86_64_GNU_VTENTRY:
if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
goto error_return;
break;
default:
break;
}
}
if (elf_section_data (sec)->this_hdr.contents != contents)
{
if (!converted && !_bfd_link_keep_memory (info))
free (contents);
else
{
/* Cache the section contents for elf_link_input_bfd if any
load is converted or --no-keep-memory isn't used. */
elf_section_data (sec)->this_hdr.contents = contents;
info->cache_size += sec->size;
}
}
/* Cache relocations if any load is converted. */
if (elf_section_data (sec)->relocs != relocs && converted)
elf_section_data (sec)->relocs = (Elf_Internal_Rela *) relocs;
return true;
error_return:
if (elf_section_data (sec)->this_hdr.contents != contents)
free (contents);
sec->check_relocs_failed = 1;
return false;
}
/* Return the relocation value for @tpoff relocation
if STT_TLS virtual address is ADDRESS. */
static bfd_vma
elf_x86_64_tpoff (struct bfd_link_info *info, bfd_vma address)
{
struct elf_link_hash_table *htab = elf_hash_table (info);
const struct elf_backend_data *bed = get_elf_backend_data (info->output_bfd);
bfd_vma static_tls_size;
/* If tls_segment is NULL, we should have signalled an error already. */
if (htab->tls_sec == NULL)
return 0;
/* Consider special static TLS alignment requirements. */
static_tls_size = BFD_ALIGN (htab->tls_size, bed->static_tls_alignment);
return address - static_tls_size - htab->tls_sec->vma;
}
/* Relocate an x86_64 ELF section. */
static int
elf_x86_64_relocate_section (bfd *output_bfd,
struct bfd_link_info *info,
bfd *input_bfd,
asection *input_section,
bfd_byte *contents,
Elf_Internal_Rela *relocs,
Elf_Internal_Sym *local_syms,
asection **local_sections)
{
struct elf_x86_link_hash_table *htab;
Elf_Internal_Shdr *symtab_hdr;
struct elf_link_hash_entry **sym_hashes;
bfd_vma *local_got_offsets;
bfd_vma *local_tlsdesc_gotents;
Elf_Internal_Rela *rel;
Elf_Internal_Rela *wrel;
Elf_Internal_Rela *relend;
unsigned int plt_entry_size;
bool status;
/* Skip if check_relocs failed. */
if (input_section->check_relocs_failed)
return false;
htab = elf_x86_hash_table (info, X86_64_ELF_DATA);
if (htab == NULL)
return false;
if (!is_x86_elf (input_bfd, htab))
{
bfd_set_error (bfd_error_wrong_format);
return false;
}
plt_entry_size = htab->plt.plt_entry_size;
symtab_hdr = &elf_symtab_hdr (input_bfd);
sym_hashes = elf_sym_hashes (input_bfd);
local_got_offsets = elf_local_got_offsets (input_bfd);
local_tlsdesc_gotents = elf_x86_local_tlsdesc_gotent (input_bfd);
_bfd_x86_elf_set_tls_module_base (info);
status = true;
rel = wrel = relocs;
relend = relocs + input_section->reloc_count;
for (; rel < relend; wrel++, rel++)
{
unsigned int r_type, r_type_tls;
reloc_howto_type *howto;
unsigned long r_symndx;
struct elf_link_hash_entry *h;
struct elf_x86_link_hash_entry *eh;
Elf_Internal_Sym *sym;
asection *sec;
bfd_vma off, offplt, plt_offset;
bfd_vma relocation;
bool unresolved_reloc;
bfd_reloc_status_type r;
int tls_type;
asection *base_got, *resolved_plt;
bfd_vma st_size;
bool resolved_to_zero;
bool relative_reloc;
bool converted_reloc;
bool need_copy_reloc_in_pie;
bool no_copyreloc_p;
r_type = ELF32_R_TYPE (rel->r_info);
if (r_type == (int) R_X86_64_GNU_VTINHERIT
|| r_type == (int) R_X86_64_GNU_VTENTRY)
{
if (wrel != rel)
*wrel = *rel;
continue;
}
r_symndx = htab->r_sym (rel->r_info);
converted_reloc = (r_type & R_X86_64_converted_reloc_bit) != 0;
if (converted_reloc)
{
r_type &= ~R_X86_64_converted_reloc_bit;
rel->r_info = htab->r_info (r_symndx, r_type);
}
howto = elf_x86_64_rtype_to_howto (input_bfd, r_type);
if (howto == NULL)
return _bfd_unrecognized_reloc (input_bfd, input_section, r_type);
h = NULL;
sym = NULL;
sec = NULL;
unresolved_reloc = false;
if (r_symndx < symtab_hdr->sh_info)
{
sym = local_syms + r_symndx;
sec = local_sections[r_symndx];
relocation = _bfd_elf_rela_local_sym (output_bfd, sym,
&sec, rel);
st_size = sym->st_size;
/* Relocate against local STT_GNU_IFUNC symbol. */
if (!bfd_link_relocatable (info)
&& ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
{
h = _bfd_elf_x86_get_local_sym_hash (htab, input_bfd,
rel, false);
if (h == NULL)
abort ();
/* Set STT_GNU_IFUNC symbol value. */
h->root.u.def.value = sym->st_value;
h->root.u.def.section = sec;
}
}
else
{
bool warned ATTRIBUTE_UNUSED;
bool ignored ATTRIBUTE_UNUSED;
RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
r_symndx, symtab_hdr, sym_hashes,
h, sec, relocation,
unresolved_reloc, warned, ignored);
st_size = h->size;
}
if (sec != NULL && discarded_section (sec))
{
_bfd_clear_contents (howto, input_bfd, input_section,
contents, rel->r_offset);
wrel->r_offset = rel->r_offset;
wrel->r_info = 0;
wrel->r_addend = 0;
/* For ld -r, remove relocations in debug sections against
sections defined in discarded sections. Not done for
eh_frame editing code expects to be present. */
if (bfd_link_relocatable (info)
&& (input_section->flags & SEC_DEBUGGING))
wrel--;
continue;
}
if (bfd_link_relocatable (info))
{
if (wrel != rel)
*wrel = *rel;
continue;
}
if (rel->r_addend == 0 && !ABI_64_P (output_bfd))
{
if (r_type == R_X86_64_64)
{
/* For x32, treat R_X86_64_64 like R_X86_64_32 and
zero-extend it to 64bit if addend is zero. */
r_type = R_X86_64_32;
memset (contents + rel->r_offset + 4, 0, 4);
}
else if (r_type == R_X86_64_SIZE64)
{
/* For x32, treat R_X86_64_SIZE64 like R_X86_64_SIZE32 and
zero-extend it to 64bit if addend is zero. */
r_type = R_X86_64_SIZE32;
memset (contents + rel->r_offset + 4, 0, 4);
}
}
eh = (struct elf_x86_link_hash_entry *) h;
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle
it here if it is defined in a non-shared object. */
if (h != NULL
&& h->type == STT_GNU_IFUNC
&& h->def_regular)
{
bfd_vma plt_index;
const char *name;
if ((input_section->flags & SEC_ALLOC) == 0)
{
/* If this is a SHT_NOTE section without SHF_ALLOC, treat
STT_GNU_IFUNC symbol as STT_FUNC. */
if (elf_section_type (input_section) == SHT_NOTE)
goto skip_ifunc;
/* Dynamic relocs are not propagated for SEC_DEBUGGING
sections because such sections are not SEC_ALLOC and
thus ld.so will not process them. */
if ((input_section->flags & SEC_DEBUGGING) != 0)
continue;
abort ();
}
switch (r_type)
{
default:
break;
case R_X86_64_GOTPCREL:
case R_X86_64_GOTPCRELX:
case R_X86_64_REX_GOTPCRELX:
case R_X86_64_GOTPCREL64:
base_got = htab->elf.sgot;
off = h->got.offset;
if (base_got == NULL)
abort ();
if (off == (bfd_vma) -1)
{
/* We can't use h->got.offset here to save state, or
even just remember the offset, as finish_dynamic_symbol
would use that as offset into .got. */
if (h->plt.offset == (bfd_vma) -1)
abort ();
if (htab->elf.splt != NULL)
{
plt_index = (h->plt.offset / plt_entry_size
- htab->plt.has_plt0);
off = (plt_index + 3) * GOT_ENTRY_SIZE;
base_got = htab->elf.sgotplt;
}
else
{
plt_index = h->plt.offset / plt_entry_size;
off = plt_index * GOT_ENTRY_SIZE;
base_got = htab->elf.igotplt;
}
if (h->dynindx == -1
|| h->forced_local
|| info->symbolic)
{
/* This references the local defitionion. We must
initialize this entry in the global offset table.
Since the offset must always be a multiple of 8,
we use the least significant bit to record
whether we have initialized it already.
When doing a dynamic link, we create a .rela.got
relocation entry to initialize the value. This
is done in the finish_dynamic_symbol routine. */
if ((off & 1) != 0)
off &= ~1;
else
{
bfd_put_64 (output_bfd, relocation,
base_got->contents + off);
/* Note that this is harmless for the GOTPLT64
case, as -1 | 1 still is -1. */