#define elf_backend_arch_data &elf_x86_64_arch_bed
+/* Is a undefined weak symbol which is resolved to 0. Reference to an
+ undefined weak symbol is resolved to 0 when building executable if
+ it isn't dynamic and
+ 1. Has non-GOT/non-PLT relocations in text section. Or
+ 2. Has no GOT/PLT relocation.
+ */
+#define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
+ ((EH)->elf.root.type == bfd_link_hash_undefweak \
+ && bfd_link_executable (INFO) \
+ && (elf_x86_64_hash_table (INFO)->interp == NULL \
+ || !(EH)->has_got_reloc \
+ || (EH)->has_non_got_reloc \
+ || !(INFO)->dynamic_undefined_weak))
+
/* x86-64 ELF linker hash entry. */
struct elf_x86_64_link_hash_entry
/* TRUE if symbol has at least one BND relocation. */
unsigned int has_bnd_reloc : 1;
+ /* TRUE if symbol has GOT or PLT relocations. */
+ unsigned int has_got_reloc : 1;
+
+ /* TRUE if symbol has non-GOT/non-PLT relocations in text sections. */
+ unsigned int has_non_got_reloc : 1;
+
/* Reference count of C/C++ function pointer relocations in read-write
section which can be resolved at run-time. */
bfd_signed_vma func_pointer_refcount;
struct elf_link_hash_table elf;
/* Short-cuts to get to dynamic linker sections. */
+ asection *interp;
asection *sdynbss;
asection *srelbss;
asection *plt_eh_frame;
eh->tls_type = GOT_UNKNOWN;
eh->needs_copy = 0;
eh->has_bnd_reloc = 0;
+ eh->has_got_reloc = 0;
+ eh->has_non_got_reloc = 0;
eh->func_pointer_refcount = 0;
eh->plt_bnd.offset = (bfd_vma) -1;
eh->plt_got.offset = (bfd_vma) -1;
if (!edir->has_bnd_reloc)
edir->has_bnd_reloc = eind->has_bnd_reloc;
+ if (!edir->has_got_reloc)
+ edir->has_got_reloc = eind->has_got_reloc;
+
+ if (!edir->has_non_got_reloc)
+ edir->has_non_got_reloc = eind->has_non_got_reloc;
+
if (eind->dyn_relocs != NULL)
{
if (edir->dyn_relocs != NULL)
unsigned int r_type;
unsigned long r_symndx;
struct elf_link_hash_entry *h;
+ struct elf_x86_64_link_hash_entry *eh;
Elf_Internal_Sym *isym;
const char *name;
bfd_boolean size_reloc;
rel, rel_end, h, r_symndx))
return FALSE;
+ eh = (struct elf_x86_64_link_hash_entry *) h;
switch (r_type)
{
case R_X86_64_TLSLD:
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
+ if (eh != NULL)
+ eh->has_got_reloc = 1;
break;
case R_X86_64_GOTTPOFF:
if (h != NULL)
{
h->got.refcount += 1;
- old_tls_type = elf_x86_64_hash_entry (h)->tls_type;
+ old_tls_type = eh->tls_type;
}
else
{
if (old_tls_type != tls_type)
{
- if (h != NULL)
- elf_x86_64_hash_entry (h)->tls_type = tls_type;
+ if (eh != NULL)
+ eh->tls_type = tls_type;
else
elf_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type;
}
case R_X86_64_GOTPC32:
case R_X86_64_GOTPC64:
create_got:
+ if (eh != NULL)
+ eh->has_got_reloc = 1;
if (htab->elf.sgot == NULL)
{
if (htab->elf.dynobj == NULL)
if (h == NULL)
continue;
+ eh->has_got_reloc = 1;
h->needs_plt = 1;
h->plt.refcount += 1;
break;
/* Let's help debug shared library creation. These relocs
cannot be used in shared libs. Don't error out for
sections we don't care about, such as debug sections or
- non-constant sections. */
- if (bfd_link_pic (info)
+ non-constant sections, or when relocation overflow check
+ is disabled. */
+ if (!info->no_reloc_overflow_check
+ && bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& (sec->flags & SEC_READONLY) != 0)
{
case R_X86_64_PC64:
case R_X86_64_64:
pointer:
- if (h != NULL && bfd_link_executable (info))
+ if (eh != NULL && (sec->flags & SEC_CODE) != 0)
+ eh->has_non_got_reloc = 1;
+ /* STT_GNU_IFUNC symbol must go through PLT even if it is
+ locally defined and undefined symbol may turn out to be
+ a STT_GNU_IFUNC symbol later. */
+ if (h != NULL
+ && (bfd_link_executable (info)
+ || ((h->type == STT_GNU_IFUNC
+ || h->root.type == bfd_link_hash_undefweak
+ || h->root.type == bfd_link_hash_undefined)
+ && SYMBOLIC_BIND (info, h))))
{
/* If this reloc is in a read-only section, we might
need a copy reloc. We can't check reliably at this
|| (!ABI_64_P (abfd)
&& (r_type == R_X86_64_32
|| r_type == R_X86_64_32S))))
- {
- struct elf_x86_64_link_hash_entry *eh
- = (struct elf_x86_64_link_hash_entry *) h;
- eh->func_pointer_refcount += 1;
- }
+ eh->func_pointer_refcount += 1;
}
}
&& (sec->flags & SEC_ALLOC) != 0
&& (! IS_X86_64_PCREL_TYPE (r_type)
|| (h != NULL
- && (! SYMBOLIC_BIND (info, h)
+ && (! (bfd_link_pie (info)
+ || SYMBOLIC_BIND (info, h))
|| h->root.type == bfd_link_hash_defweak
|| !h->def_regular))))
|| (ELIMINATE_COPY_RELOCS
/* If this is a global symbol, we count the number of
relocations we need for this symbol. */
if (h != NULL)
- {
- head = &((struct elf_x86_64_link_hash_entry *) h)->dyn_relocs;
- }
+ head = &eh->dyn_relocs;
else
{
/* Track dynamic relocs needed for local syms too.
return TRUE;
}
+/* Remove undefined weak symbol from the dynamic symbol table if it
+ is resolved to 0. */
+
+static bfd_boolean
+elf_x86_64_fixup_symbol (struct bfd_link_info *info,
+ struct elf_link_hash_entry *h)
+{
+ if (h->dynindx != -1
+ && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info,
+ elf_x86_64_hash_entry (h)))
+ {
+ h->dynindx = -1;
+ _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
+ h->dynstr_index);
+ }
+ return TRUE;
+}
+
/* Adjust a symbol defined by a dynamic object and referenced by a
regular object. The current definition is in some section of the
dynamic object, but we're not including those sections. We have to
struct elf_dyn_relocs *p;
const struct elf_backend_data *bed;
unsigned int plt_entry_size;
+ bfd_boolean resolved_to_zero;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
bed = get_elf_backend_data (info->output_bfd);
plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd);
+ resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
+
/* We can't use the GOT PLT if pointer equality is needed since
finish_dynamic_symbol won't clear symbol value and the dynamic
linker won't update the GOT slot. We will get into an infinite
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
- && !h->forced_local)
+ && !h->forced_local
+ && !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
script. */
htab->elf.sgotplt->size += GOT_ENTRY_SIZE;
- /* We also need to make an entry in the .rela.plt
- section. */
- htab->elf.srelplt->size += bed->s->sizeof_rela;
- htab->elf.srelplt->reloc_count++;
+ /* There should be no PLT relocation against resolved
+ undefined weak symbol in executable. */
+ if (!resolved_to_zero)
+ {
+ /* We also need to make an entry in the .rela.plt
+ section. */
+ htab->elf.srelplt->size += bed->s->sizeof_rela;
+ htab->elf.srelplt->reloc_count++;
+ }
}
}
else
{
+ eh->plt_got.offset = (bfd_vma) -1;
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
}
else
{
+ eh->plt_got.offset = (bfd_vma) -1;
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
- && !h->forced_local)
+ && !h->forced_local
+ && !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
dyn = htab->elf.dynamic_sections_created;
/* R_X86_64_TLSGD needs one dynamic relocation if local symbol
- and two if global.
- R_X86_64_GOTTPOFF needs one dynamic relocation. */
+ and two if global. R_X86_64_GOTTPOFF needs one dynamic
+ relocation. No dynamic relocation against resolved undefined
+ weak symbol in executable. */
if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
|| tls_type == GOT_TLS_IE)
htab->elf.srelgot->size += bed->s->sizeof_rela;
else if (GOT_TLS_GD_P (tls_type))
htab->elf.srelgot->size += 2 * bed->s->sizeof_rela;
else if (! GOT_TLS_GDESC_P (tls_type)
- && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+ && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+ && !resolved_to_zero)
|| h->root.type != bfd_link_hash_undefweak)
&& (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
}
/* Also discard relocs on undefined weak syms with non-default
- visibility. */
+ visibility or in PIE. */
if (eh->dyn_relocs != NULL)
{
if (h->root.type == bfd_link_hash_undefweak)
{
- if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
+ /* Undefined weak symbol is never bound locally in shared
+ library. */
+ if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+ || resolved_to_zero)
eh->dyn_relocs = NULL;
-
- /* Make sure undefined weak symbols are output as a dynamic
- symbol in PIEs. */
else if (h->dynindx == -1
&& ! h->forced_local
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
dynamic. Keep dynamic relocations for run-time function
pointer initialization. */
- if ((!h->non_got_ref || eh->func_pointer_refcount > 0)
+ if ((!h->non_got_ref
+ || eh->func_pointer_refcount > 0
+ || (h->root.type == bfd_link_hash_undefweak
+ && !resolved_to_zero))
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
&& ! h->forced_local
+ && ! resolved_to_zero
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
bfd_boolean changed_relocs;
bfd_signed_vma *local_got_refcounts;
bfd_vma maxpagesize;
+ bfd_boolean is_pic;
+ bfd_boolean require_reloc_pc32;
/* Don't even try to convert non-ELF outputs. */
if (!is_elf_hash_table (link_info->hash))
goto error_return;
}
+ is_pic = bfd_link_pic (link_info);
+
+ /* TRUE if we can convert only to R_X86_64_PC32. Enable it for
+ --no-relax. */
+ require_reloc_pc32
+ = link_info->disable_target_specific_optimizations > 1;
+
irelend = internal_relocs + sec->reloc_count;
for (irel = internal_relocs; irel < irelend; irel++)
{
bfd_signed_vma raddend;
unsigned int opcode;
unsigned int modrm;
+ bfd_boolean relocx;
+ bfd_boolean to_reloc_pc32;
- if (r_type != R_X86_64_GOTPCREL
- && r_type != R_X86_64_GOTPCRELX
- && r_type != R_X86_64_REX_GOTPCRELX)
+ relocx = (r_type == R_X86_64_GOTPCRELX
+ || r_type == R_X86_64_REX_GOTPCRELX);
+ if (!relocx && r_type != R_X86_64_GOTPCREL)
continue;
roff = irel->r_offset;
opcode = bfd_get_8 (abfd, contents + roff - 2);
- /* It is OK to convert mov to lea. */
+ /* 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 mov call, jmp or one of adc, add, and, cmp, or, sbb,
- sub, test, xor instructions. */
- if (r_type != R_X86_64_GOTPCRELX
- && r_type != R_X86_64_REX_GOTPCRELX)
+ for call, jmp or one of adc, add, and, cmp, or, sbb, sub,
+ test, xor instructions. */
+ if (!relocx)
continue;
-
- /* It is OK to convert indirect branch to direct branch. */
- if (opcode != 0xff)
- {
- /* It is OK to convert adc, add, and, cmp, or, sbb, sub,
- test, xor only when PIC is false. */
- if (bfd_link_pic (link_info))
- continue;
- }
}
+ /* We convert only to R_X86_64_PC32:
+ 1. Branch.
+ 2. R_X86_64_GOTPCREL since we can't modify REX byte.
+ 3. require_reloc_pc32 is true.
+ 4. PIC.
+ */
+ to_reloc_pc32 = (opcode == 0xff
+ || !relocx
+ || require_reloc_pc32
+ || is_pic);
+
/* Get the symbol referred to by the reloc. */
if (r_symndx < symtab_hdr->sh_info)
{
/* STT_GNU_IFUNC must keep GOTPCREL relocations. We also
avoid optimizing GOTPCREL relocations againt _DYNAMIC
since ld.so may use its link-time address. */
- if ((h->def_regular
- || h->root.type == bfd_link_hash_defined
- || h->root.type == bfd_link_hash_defweak)
- && h->type != STT_GNU_IFUNC
- && h != htab->elf.hdynamic
- && SYMBOL_REFERENCES_LOCAL (link_info, h))
+ if (h->type == STT_GNU_IFUNC)
+ continue;
+
+ /* 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. */
+ if ((relocx || opcode == 0x8b)
+ && UNDEFINED_WEAK_RESOLVED_TO_ZERO (link_info,
+ elf_x86_64_hash_entry (h)))
+ {
+ if (opcode == 0xff)
+ {
+ /* Skip for branch instructions since R_X86_64_PC32
+ may overflow. */
+ if (require_reloc_pc32)
+ continue;
+ }
+ 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)
+ continue;
+
+ goto convert;
+ }
+ else if ((h->def_regular
+ || h->root.type == bfd_link_hash_defined
+ || h->root.type == bfd_link_hash_defweak)
+ && h != htab->elf.hdynamic
+ && SYMBOL_REFERENCES_LOCAL (link_info, h))
{
/* bfd_link_hash_new or bfd_link_hash_undefined is
- set by an assignment in a linker script in
- bfd_elf_record_link_assignment. FIXME: If we
- ever get a linker error due relocation overflow,
- we will skip this optimization. */
+ set by an assignment in a linker script in
+ bfd_elf_record_link_assignment. */
if (h->def_regular
&& (h->root.type == bfd_link_hash_new
|| h->root.type == bfd_link_hash_undefined))
- goto convert;
+ {
+ /* Skip since R_X86_64_32/R_X86_64_32S may overflow. */
+ if (require_reloc_pc32)
+ continue;
+ goto convert;
+ }
tsec = h->root.u.def.section;
toff = h->root.u.def.value;
symtype = h->type;
continue;
}
+ /* We can only estimate relocation overflow for R_X86_64_PC32. */
+ if (!to_reloc_pc32)
+ goto convert;
+
if (tsec->sec_info_type == SEC_INFO_TYPE_MERGE)
{
/* At this stage in linking, no SEC_MERGE symbol has been
}
else
{
- asection *asect;
- bfd_size_type size;
+ bfd_signed_vma distance;
/* At this point, we don't know the load addresses of TSEC
section nor SEC section. We estimate the distrance between
- SEC and TSEC. */
- size = 0;
- for (asect = sec->output_section;
- asect != NULL && asect != tsec->output_section;
- asect = asect->next)
+ SEC and TSEC. We store the estimated distances in the
+ compressed_size field of the output section, which is only
+ used to decompress the compressed input section. */
+ if (sec->output_section->compressed_size == 0)
{
- asection *i;
- for (i = asect->output_section->map_head.s;
- i != NULL;
- i = i->map_head.s)
+ asection *asect;
+ bfd_size_type size = 0;
+ for (asect = link_info->output_bfd->sections;
+ asect != NULL;
+ asect = asect->next)
{
- size = align_power (size, i->alignment_power);
- size += i->size;
+ asection *i;
+ for (i = asect->map_head.s;
+ i != NULL;
+ i = i->map_head.s)
+ {
+ size = align_power (size, i->alignment_power);
+ size += i->size;
+ }
+ asect->compressed_size = size;
}
}
/* Don't convert GOTPCREL relocations if TSEC isn't placed
after SEC. */
- if (asect == NULL)
+ distance = (tsec->output_section->compressed_size
+ - sec->output_section->compressed_size);
+ if (distance < 0)
continue;
/* Take PT_GNU_RELRO segment into account by adding
maxpagesize. */
- if ((toff + size + maxpagesize - roff + 0x80000000)
+ if ((toff + distance + maxpagesize - roff + 0x80000000)
> 0xffffffff)
continue;
}
}
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)
{
- /* Convert "mov foo@GOTPCREL(%rip), %reg" to
- "lea foo(%rip), %reg". */
- opcode = 0x8d;
- r_type = R_X86_64_PC32;
+ 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)
+ continue;
+
modrm = bfd_get_8 (abfd, contents + roff - 1);
if (opcode == 0x85)
{
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:
bfd_put_8 (abfd, modrm, contents + roff - 1);
- if (r_type == R_X86_64_REX_GOTPCRELX)
+ if (rex)
{
/* Move the R bit to the B bit in REX byte. */
- unsigned int rex = bfd_get_8 (abfd, contents + roff - 3);
- rex = (rex & ~REX_R) | (rex & REX_R) >> 2;
+ rex = (rex & ~rex_mask) | (rex & REX_R) >> 2;
bfd_put_8 (abfd, rex, contents + roff - 3);
}
- /* No addend for R_X86_64_32S relocation. */
+
+ /* No addend for R_X86_64_32/R_X86_64_32S relocations. */
irel->r_addend = 0;
- r_type = R_X86_64_32S;
}
bfd_put_8 (abfd, opcode, contents + roff - 2);
abort ();
s->size = htab->dynamic_interpreter_size;
s->contents = (unsigned char *) htab->dynamic_interpreter;
+ htab->interp = s;
}
}
&& (contents [offset - 1] & 0xf0) == 0x80));
}
+static bfd_boolean
+elf_x86_64_need_pic (bfd *input_bfd, struct elf_link_hash_entry *h,
+ reloc_howto_type *howto)
+{
+ const char *fmt;
+ const char *v;
+ const char *pic = "";
+
+ 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:
+ v = _("symbol");
+ pic = _("; recompile with -fPIC");
+ break;
+ }
+
+ if (h->def_regular)
+ fmt = _("%B: relocation %s against %s `%s' can not be used when making a shared object%s");
+ else
+ fmt = _("%B: relocation %s against undefined %s `%s' can not be used when making a shared object%s");
+
+ (*_bfd_error_handler) (fmt, input_bfd, howto->name,
+ v, h->root.root.string, pic);
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+}
+
/* Relocate an x86_64 ELF section. */
static bfd_boolean
int tls_type;
asection *base_got, *resolved_plt;
bfd_vma st_size;
+ bfd_boolean resolved_to_zero;
r_type = ELF32_R_TYPE (rel->r_info);
if (r_type == (int) R_X86_64_GNU_VTINHERIT
(*_bfd_error_handler)
(_("%B: relocation %s against STT_GNU_IFUNC "
"symbol `%s' isn't handled by %s"), input_bfd,
- x86_64_elf_howto_table[r_type].name,
- name, __FUNCTION__);
+ howto->name, name, __FUNCTION__);
bfd_set_error (bfd_error_bad_value);
return FALSE;
(*_bfd_error_handler)
(_("%B: relocation %s against STT_GNU_IFUNC "
"symbol `%s' has non-zero addend: %d"),
- input_bfd, x86_64_elf_howto_table[r_type].name,
- name, rel->r_addend);
+ input_bfd, howto->name, name, rel->r_addend);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
}
}
+ resolved_to_zero = (eh != NULL
+ && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh));
+
/* When generating a shared object, the relocations handled here are
copied into the output file to be resolved at run time. */
switch (r_type)
case R_X86_64_PC32:
case R_X86_64_PC32_BND:
/* Don't complain about -fPIC if the symbol is undefined when
- building executable. */
- if (bfd_link_pic (info)
- && (input_section->flags & SEC_ALLOC) != 0
+ building executable unless it is unresolved weak symbol. */
+ if ((input_section->flags & SEC_ALLOC) != 0
&& (input_section->flags & SEC_READONLY) != 0
&& h != NULL
- && !(bfd_link_executable (info)
- && h->root.type == bfd_link_hash_undefined))
+ && ((bfd_link_executable (info)
+ && h->root.type == bfd_link_hash_undefweak
+ && !resolved_to_zero)
+ || (bfd_link_pic (info)
+ && !(bfd_link_pie (info)
+ && h->root.type == bfd_link_hash_undefined))))
{
bfd_boolean fail = FALSE;
bfd_boolean branch
defined locally or for a branch. */
fail = !h->def_regular && !branch;
}
- else if (!(bfd_link_executable (info)
+ else if (!(bfd_link_pie (info)
&& (h->needs_copy || eh->needs_copy)))
{
/* Symbol doesn't need copy reloc and isn't referenced
}
if (fail)
- {
- const char *fmt;
- const char *v;
- const char *pic = "";
-
- 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:
- v = _("symbol");
- pic = _("; recompile with -fPIC");
- break;
- }
-
- if (h->def_regular)
- fmt = _("%B: relocation %s against %s `%s' can not be used when making a shared object%s");
- else
- fmt = _("%B: relocation %s against undefined %s `%s' can not be used when making a shared object%s");
-
- (*_bfd_error_handler) (fmt, input_bfd,
- x86_64_elf_howto_table[r_type].name,
- v, h->root.root.string, pic);
- bfd_set_error (bfd_error_bad_value);
- return FALSE;
- }
+ return elf_x86_64_need_pic (input_bfd, h, howto);
}
/* Fall through. */
/* Don't copy a pc-relative relocation into the output file
if the symbol needs copy reloc or the symbol is undefined
when building executable. Copy dynamic function pointer
- relocations. */
+ relocations. Don't generate dynamic relocations against
+ resolved undefined weak symbols in PIE. */
if ((bfd_link_pic (info)
- && !(bfd_link_executable (info)
+ && !(bfd_link_pie (info)
&& h != NULL
&& (h->needs_copy
|| eh->needs_copy
|| h->root.type == bfd_link_hash_undefined)
&& IS_X86_64_PCREL_TYPE (r_type))
&& (h == NULL
- || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
- || h->root.type != bfd_link_hash_undefweak)
+ || ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+ && !resolved_to_zero)
+ || h->root.type != bfd_link_hash_undefweak))
&& ((! IS_X86_64_PCREL_TYPE (r_type)
&& r_type != R_X86_64_SIZE32
&& r_type != R_X86_64_SIZE64)
&& !bfd_link_pic (info)
&& h != NULL
&& h->dynindx != -1
- && (!h->non_got_ref || eh->func_pointer_refcount > 0)
- && ((h->def_dynamic
- && !h->def_regular)
- || h->root.type == bfd_link_hash_undefweak
+ && (!h->non_got_ref
+ || eh->func_pointer_refcount > 0
+ || (h->root.type == bfd_link_hash_undefweak
+ && !resolved_to_zero))
+ && ((h->def_dynamic && !h->def_regular)
+ /* Undefined weak symbol is bound locally when
+ PIC is false. */
|| h->root.type == bfd_link_hash_undefined)))
{
Elf_Internal_Rela outrel;
else if (h != NULL
&& h->dynindx != -1
&& (IS_X86_64_PCREL_TYPE (r_type)
- || ! bfd_link_pic (info)
- || ! SYMBOLIC_BIND (info, h)
+ || !(bfd_link_executable (info)
+ || SYMBOLIC_BIND (info, h))
|| ! h->def_regular))
{
+ if ((r_type != R_X86_64_PC64 && r_type != R_X86_64_64)
+ && bfd_link_executable (info)
+ && h->root.type == bfd_link_hash_undefweak
+ && !resolved_to_zero)
+ return elf_x86_64_need_pic (input_bfd, h, howto);
outrel.r_info = htab->r_info (h->dynindx, r_type);
outrel.r_addend = rel->r_addend;
}
else
{
- /* This symbol is local, or marked to become local. */
- if (r_type == htab->pointer_r_type)
+ /* This symbol is local, or marked to become local.
+ When relocation overflow check is disabled, we
+ convert R_X86_64_32 to dynamic R_X86_64_RELATIVE. */
+ if (r_type == htab->pointer_r_type
+ || (r_type == R_X86_64_32
+ && info->no_reloc_overflow_check))
{
relocate = TRUE;
outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);
"symbol `%s' at 0x%lx in section `%A' is "
"out of range"),
input_bfd, input_section, addend,
- x86_64_elf_howto_table[r_type].name,
- name, (unsigned long) rel->r_offset);
+ howto->name, name,
+ (unsigned long) rel->r_offset);
else
(*_bfd_error_handler)
(_("%B: addend 0x%x in relocation %s against "
"symbol `%s' at 0x%lx in section `%A' is "
"out of range"),
input_bfd, input_section, addend,
- x86_64_elf_howto_table[r_type].name,
- name, (unsigned long) rel->r_offset);
+ howto->name, name,
+ (unsigned long) rel->r_offset);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
elf_x86_64_finish_dynamic_symbol (bfd *output_bfd,
struct bfd_link_info *info,
struct elf_link_hash_entry *h,
- Elf_Internal_Sym *sym ATTRIBUTE_UNUSED)
+ Elf_Internal_Sym *sym)
{
struct elf_x86_64_link_hash_table *htab;
const struct elf_x86_64_backend_data *abed;
bfd_boolean use_plt_bnd;
struct elf_x86_64_link_hash_entry *eh;
+ bfd_boolean local_undefweak;
htab = elf_x86_64_hash_table (info);
if (htab == NULL)
eh = (struct elf_x86_64_link_hash_entry *) h;
+ /* We keep PLT/GOT entries without dynamic PLT/GOT relocations for
+ resolved undefined weak symbols in executable so that their
+ references have value 0 at run-time. */
+ local_undefweak = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
+
if (h->plt.offset != (bfd_vma) -1)
{
bfd_vma plt_index;
/* This symbol has an entry in the procedure linkage table. Set
it up. */
if ((h->dynindx == -1
+ && !local_undefweak
&& !((h->forced_local || bfd_link_executable (info))
&& h->def_regular
&& h->type == STT_GNU_IFUNC))
resolved_plt->contents + plt_offset + plt_got_offset);
/* Fill in the entry in the global offset table, initially this
- points to the second part of the PLT entry. */
- bfd_put_64 (output_bfd, (plt->output_section->vma
- + plt->output_offset
- + h->plt.offset + abed->plt_lazy_offset),
- gotplt->contents + got_offset);
-
- /* Fill in the entry in the .rela.plt section. */
- rela.r_offset = (gotplt->output_section->vma
- + gotplt->output_offset
- + got_offset);
- if (h->dynindx == -1
- || ((bfd_link_executable (info)
- || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
- && h->def_regular
- && h->type == STT_GNU_IFUNC))
+ points to the second part of the PLT entry. Leave the entry
+ as zero for undefined weak symbol in PIE. No PLT relocation
+ against undefined weak symbol in PIE. */
+ if (!local_undefweak)
{
- /* If an STT_GNU_IFUNC symbol is locally defined, generate
- R_X86_64_IRELATIVE instead of R_X86_64_JUMP_SLOT. */
- rela.r_info = htab->r_info (0, R_X86_64_IRELATIVE);
- rela.r_addend = (h->root.u.def.value
- + h->root.u.def.section->output_section->vma
- + h->root.u.def.section->output_offset);
- /* R_X86_64_IRELATIVE comes last. */
- plt_index = htab->next_irelative_index--;
- }
- else
- {
- rela.r_info = htab->r_info (h->dynindx, R_X86_64_JUMP_SLOT);
- rela.r_addend = 0;
- plt_index = htab->next_jump_slot_index++;
- }
+ bfd_put_64 (output_bfd, (plt->output_section->vma
+ + plt->output_offset
+ + h->plt.offset
+ + abed->plt_lazy_offset),
+ gotplt->contents + got_offset);
+
+ /* Fill in the entry in the .rela.plt section. */
+ rela.r_offset = (gotplt->output_section->vma
+ + gotplt->output_offset
+ + got_offset);
+ if (h->dynindx == -1
+ || ((bfd_link_executable (info)
+ || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
+ && h->def_regular
+ && h->type == STT_GNU_IFUNC))
+ {
+ /* If an STT_GNU_IFUNC symbol is locally defined, generate
+ R_X86_64_IRELATIVE instead of R_X86_64_JUMP_SLOT. */
+ rela.r_info = htab->r_info (0, R_X86_64_IRELATIVE);
+ rela.r_addend = (h->root.u.def.value
+ + h->root.u.def.section->output_section->vma
+ + h->root.u.def.section->output_offset);
+ /* R_X86_64_IRELATIVE comes last. */
+ plt_index = htab->next_irelative_index--;
+ }
+ else
+ {
+ rela.r_info = htab->r_info (h->dynindx, R_X86_64_JUMP_SLOT);
+ rela.r_addend = 0;
+ plt_index = htab->next_jump_slot_index++;
+ }
- /* Don't fill PLT entry for static executables. */
- if (plt == htab->elf.splt)
- {
- bfd_vma plt0_offset = h->plt.offset + plt_plt_insn_end;
-
- /* Put relocation index. */
- bfd_put_32 (output_bfd, plt_index,
- plt->contents + h->plt.offset + abed->plt_reloc_offset);
-
- /* Put offset for jmp .PLT0 and check for overflow. We don't
- check relocation index for overflow since branch displacement
- will overflow first. */
- if (plt0_offset > 0x80000000)
- info->callbacks->einfo (_("%F%B: branch displacement overflow in PLT entry for `%s'\n"),
- output_bfd, h->root.root.string);
- bfd_put_32 (output_bfd, - plt0_offset,
- plt->contents + h->plt.offset + plt_plt_offset);
- }
+ /* Don't fill PLT entry for static executables. */
+ if (plt == htab->elf.splt)
+ {
+ bfd_vma plt0_offset = h->plt.offset + plt_plt_insn_end;
+
+ /* Put relocation index. */
+ bfd_put_32 (output_bfd, plt_index,
+ (plt->contents + h->plt.offset
+ + abed->plt_reloc_offset));
+
+ /* Put offset for jmp .PLT0 and check for overflow. We don't
+ check relocation index for overflow since branch displacement
+ will overflow first. */
+ if (plt0_offset > 0x80000000)
+ info->callbacks->einfo (_("%F%B: branch displacement overflow in PLT entry for `%s'\n"),
+ output_bfd, h->root.root.string);
+ bfd_put_32 (output_bfd, - plt0_offset,
+ plt->contents + h->plt.offset + plt_plt_offset);
+ }
- bed = get_elf_backend_data (output_bfd);
- loc = relplt->contents + plt_index * bed->s->sizeof_rela;
- bed->s->swap_reloca_out (output_bfd, &rela, loc);
+ bed = get_elf_backend_data (output_bfd);
+ loc = relplt->contents + plt_index * bed->s->sizeof_rela;
+ bed->s->swap_reloca_out (output_bfd, &rela, loc);
+ }
}
else if (eh->plt_got.offset != (bfd_vma) -1)
{
plt->contents + plt_offset + plt_got_offset);
}
- if (!h->def_regular
+ if (!local_undefweak
+ && !h->def_regular
&& (h->plt.offset != (bfd_vma) -1
|| eh->plt_got.offset != (bfd_vma) -1))
{
sym->st_value = 0;
}
+ /* Don't generate dynamic GOT relocation against undefined weak
+ symbol in executable. */
if (h->got.offset != (bfd_vma) -1
&& ! GOT_TLS_GD_ANY_P (elf_x86_64_hash_entry (h)->tls_type)
- && elf_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE)
+ && elf_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE
+ && !local_undefweak)
{
Elf_Internal_Rela rela;
info, h, NULL);
}
+/* Finish up undefined weak symbol handling in PIE. Fill its PLT entry
+ here since undefined weak symbol may not be dynamic and may not be
+ called for elf_x86_64_finish_dynamic_symbol. */
+
+static bfd_boolean
+elf_x86_64_pie_finish_undefweak_symbol (struct bfd_hash_entry *bh,
+ void *inf)
+{
+ struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) bh;
+ struct bfd_link_info *info = (struct bfd_link_info *) inf;
+
+ if (h->root.type != bfd_link_hash_undefweak
+ || h->dynindx != -1)
+ return TRUE;
+
+ return elf_x86_64_finish_dynamic_symbol (info->output_bfd,
+ info, h, NULL);
+}
+
/* Used to decide how to sort relocs in an optimal manner for the
dynamic linker, before writing them out. */
elf_x86_64_finish_local_dynamic_symbol,
info);
+ /* Fill PLT entries for undefined weak symbols in PIE. */
+ if (bfd_link_pie (info))
+ bfd_hash_traverse (&info->hash->table,
+ elf_x86_64_pie_finish_undefweak_symbol,
+ info);
+
return TRUE;
}
elf_x86_64_additional_program_headers
#define elf_backend_hash_symbol \
elf_x86_64_hash_symbol
+#define elf_backend_omit_section_dynsym \
+ ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true)
+#define elf_backend_fixup_symbol \
+ elf_x86_64_fixup_symbol
#include "elf64-target.h"
projects / binutils-gdb.git / blobdiff