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2009-06-06 H.J. Lu <hongjiu.lu@intel.com>

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* elf32-i386.c (elf_i386_check_relocs): Make room for dynamic
	relocation for R_386_32 against STT_GNU_IFUNC symbol when
	building shared object.  Check info->executable instead of
	!info->shared when setting non_got_ref.
	(elf_i386_allocate_dynrelocs): Allocate dynamic relocation
	for non-GOT reference of STT_GNU_IFUNC symbol in shared
	object. Allocate GOT relocation agsinst STT_GNU_IFUNC
	symbol if needed.
	(elf_i386_relocate_section): Output dynamic relocation for
	R_386_32 against STT_GNU_IFUNC symbol to get the real
	function address when building shared object.
	(elf_i386_finish_dynamic_symbol): Output R_386_GLOB_DAT
	relocation for STT_GNU_IFUNC symbol in shared object.

	* elf64-x86-64.c (elf64_x86_64_check_relocs): Make room for
	dynamic relocation for R_X86_64_64 against STT_GNU_IFUNC
	symbol when building shared object.  Check info->executable
	instead of !info->shared when setting non_got_ref.
	(elf64_x86_64_allocate_dynrelocs): Allocate dynamic relocation
	for non-GOT reference of STT_GNU_IFUNC symbol in shared
	library. Allocate GOT relocation agsinst STT_GNU_IFUNC symbol
	if needed.
	(elf64_x86_64_relocate_section): Output dynamic relocation
	for R_X86_64_64 against STT_GNU_IFUNC symbol to get the real
	function address when building shared object.
	(elf64_x86_64_finish_dynamic_symbol): Output R_X86_64_GLOB_DAT
	relocation for STT_GNU_IFUNC symbol in shared object.
This commit is contained in:
H.J. Lu 2009-06-06 11:48:11 +00:00
parent 9e93c730ef
commit 710ab2870f
3 changed files with 358 additions and 95 deletions
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30
bfd/ChangeLog
View File

@ -1,3 +1,33 @@
2009-06-06 H.J. Lu <hongjiu.lu@intel.com>
* elf32-i386.c (elf_i386_check_relocs): Make room for dynamic
relocation for R_386_32 against STT_GNU_IFUNC symbol when
building shared object. Check info->executable instead of
!info->shared when setting non_got_ref.
(elf_i386_allocate_dynrelocs): Allocate dynamic relocation
for non-GOT reference of STT_GNU_IFUNC symbol in shared
object. Allocate GOT relocation agsinst STT_GNU_IFUNC
symbol if needed.
(elf_i386_relocate_section): Output dynamic relocation for
R_386_32 against STT_GNU_IFUNC symbol to get the real
function address when building shared object.
(elf_i386_finish_dynamic_symbol): Output R_386_GLOB_DAT
relocation for STT_GNU_IFUNC symbol in shared object.
* elf64-x86-64.c (elf64_x86_64_check_relocs): Make room for
dynamic relocation for R_X86_64_64 against STT_GNU_IFUNC
symbol when building shared object. Check info->executable
instead of !info->shared when setting non_got_ref.
(elf64_x86_64_allocate_dynrelocs): Allocate dynamic relocation
for non-GOT reference of STT_GNU_IFUNC symbol in shared
library. Allocate GOT relocation agsinst STT_GNU_IFUNC symbol
if needed.
(elf64_x86_64_relocate_section): Output dynamic relocation
for R_X86_64_64 against STT_GNU_IFUNC symbol to get the real
function address when building shared object.
(elf64_x86_64_finish_dynamic_symbol): Output R_X86_64_GLOB_DAT
relocation for STT_GNU_IFUNC symbol in shared object.
2009-06-06 Jan Kratochvil <jan.kratochvil@redhat.com>
* Makefile.am: Run "make dep-am".

203
bfd/elf32-i386.c
View File

@ -1325,10 +1325,48 @@ elf_i386_check_relocs (bfd *abfd,
return FALSE;
case R_386_32:
h->non_got_ref = 1;
h->pointer_equality_needed = 1;
if (info->shared)
{
struct elf_i386_dyn_relocs *p;
struct elf_i386_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)
{
if (htab->elf.dynobj == NULL)
htab->elf.dynobj = abfd;
sreloc = _bfd_elf_make_dynamic_reloc_section
(sec, htab->elf.dynobj, 2, abfd, FALSE);
if (sreloc == NULL)
return FALSE;
}
head = &((struct elf_i386_link_hash_entry *) h)->dyn_relocs;
p = *head;
if (p == NULL || p->sec != sec)
{
bfd_size_type amt = sizeof *p;
p = bfd_alloc (htab->elf.dynobj, amt);
if (p == NULL)
return FALSE;
p->next = *head;
*head = p;
p->sec = sec;
p->count = 0;
p->pc_count = 0;
}
p->count += 1;
}
break;
case R_386_PC32:
h->non_got_ref = 1;
if (r_type != R_386_PC32)
h->pointer_equality_needed = 1;
break;
case R_386_PLT32:
@ -1501,7 +1539,7 @@ elf_i386_check_relocs (bfd *abfd,
case R_386_32:
case R_386_PC32:
if (h != NULL && !info->shared)
if (h != NULL && info->executable)
{
/* If this reloc is in a read-only section, we might
need a copy reloc. We can't check reliably at this
@ -1957,7 +1995,7 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
/* When building a static executable, use .iplt, .igot.plt and
.rel.iplt sections for STT_GNU_IFUNC symbols. */
if (htab->splt != 0)
if (htab->splt != NULL)
{
plt = htab->splt;
gotplt = htab->sgotplt;
@ -1992,34 +2030,50 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
relplt->size += sizeof (Elf32_External_Rel);
relplt->reloc_count++;
/* No need for dynamic relocation for local STT_GNU_IFUNC symbol.
Discard space for relocations against it. */
if (h->dynindx == -1 || h->forced_local)
/* We need dynamic relocation for STT_GNU_IFUNC symbol only
when there is a non-GOT reference in a shared object. */
if (!info->shared
|| !h->non_got_ref)
eh->dyn_relocs = NULL;
/* STT_GNU_IFUNC symbol uses .got.plt, not .got. But for
shared library, we must go through GOT and we can't
use R_386_IRELATIVE unless it is forced local. */
if (info->executable
|| info->symbolic
|| h->forced_local)
/* Finally, allocate space. */
for (p = eh->dyn_relocs; p != NULL; p = p->next)
{
if (h->pointer_equality_needed
&& htab->sgot != NULL)
{
/* We can't use .got.plt, which contains the real
function addres, since we need pointer equality.
We will load the GOT entry with the PLT entry
in elf_i386_finish_dynamic_symbol and don't
need GOT relocation. */
h->got.offset = htab->sgot->size;
htab->sgot->size += 4;
eh->tlsdesc_got = (bfd_vma) -1;
goto skip_relgot;
}
else
h->got.refcount = 0;
asection * sreloc = elf_section_data (p->sec)->sreloc;
sreloc->size += p->count * sizeof (Elf32_External_Rel);
}
/* For STT_GNU_IFUNC symbol, .got.plt has the real function
addres and .got has the PLT entry adddress. We will load
the GOT entry with the PLT entry in finish_dynamic_symbol if
it is used. For branch, it uses .got.plt. For symbol value,
1. Use .got.plt in a shared object if it is forced local or
not dynamic.
2. Use .got.plt in a non-shared object if pointer equality
isn't needed.
3. Use .got.plt if .got isn't used.
4. Otherwise use .got so that it can be shared among different
objects at run-time.
We only need to relocate .got entry in shared object. */
if ((info->shared
&& (h->dynindx == -1
|| h->forced_local))
|| (!info->shared
&& !h->pointer_equality_needed)
|| htab->sgot == NULL)
{
/* Use .got.plt. */
h->got.offset = (bfd_vma) -1;
}
else
{
h->got.offset = htab->sgot->size;
htab->sgot->size += 4;
if (info->shared)
htab->srelgot->size += sizeof (Elf32_External_Rel);
}
return TRUE;
}
else if (htab->elf.dynamic_sections_created
&& h->plt.refcount > 0)
@ -2166,7 +2220,6 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
else
h->got.offset = (bfd_vma) -1;
skip_relgot:
if (eh->dyn_relocs == NULL)
return TRUE;
@ -2920,6 +2973,57 @@ elf_i386_relocate_section (bfd *output_bfd,
return FALSE;
case R_386_32:
/* Generate dynamic relcoation only when there is a
non-GOF reference in a shared object. */
if (info->shared && h->non_got_ref)
{
Elf_Internal_Rela outrel;
bfd_byte *loc;
asection *sreloc;
bfd_vma offset;
/* Need a dynamic relocation get the the real
function adddress. */
offset = _bfd_elf_section_offset (output_bfd,
info,
input_section,
rel->r_offset);
if (offset == (bfd_vma) -1
|| offset == (bfd_vma) -2)
abort ();
outrel.r_offset = (input_section->output_section->vma
+ input_section->output_offset
+ offset);
if (h->dynindx == -1
|| h->forced_local)
{
/* This symbol is resolved locally. */
outrel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE);
bfd_put_32 (output_bfd,
(h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset),
contents + offset);
}
else
outrel.r_info = ELF32_R_INFO (h->dynindx, r_type);
sreloc = elf_section_data (input_section)->sreloc;
loc = sreloc->contents;
loc += (sreloc->reloc_count++
* sizeof (Elf32_External_Rel));
bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc);
/* If this reloc is against an external symbol, we
do not want to fiddle with the addend. Otherwise,
we need to include the symbol value so that it
becomes an addend for the dynamic reloc. For an
internal symbol, we have updated addend. */
continue;
}
case R_386_PC32:
case R_386_PLT32:
goto do_relocation;
@ -3950,7 +4054,7 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
/* When building a static executable, use .iplt, .igot.plt and
.rel.iplt sections for STT_GNU_IFUNC symbols. */
if (htab->splt != 0)
if (htab->splt != NULL)
{
plt = htab->splt;
gotplt = htab->sgotplt;
@ -4132,25 +4236,29 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
of a version file, we just want to emit a RELATIVE reloc.
The entry in the global offset table will already have been
initialized in the relocate_section function. */
if ((info->executable
|| info->symbolic
|| h->forced_local)
&& h->def_regular
&& h->pointer_equality_needed
if (h->def_regular
&& h->type == STT_GNU_IFUNC)
{
/* The STT_GNU_IFUNC symbol is locally defined. But we can't
use .got.plt, which contains the real function addres,
since we need pointer equality. We load the GOT entry
with the PLT entry without relocation. */
asection *plt = htab->splt ? htab->splt : htab->iplt;
if (htab->sgot == NULL
|| h->plt.offset == (bfd_vma) -1)
abort ();
bfd_put_32 (output_bfd, (plt->output_section->vma
+ plt->output_offset + h->plt.offset),
htab->sgot->contents + h->got.offset);
return TRUE;
if (info->shared)
{
/* Generate R_386_GLOB_DAT. */
goto do_glob_dat;
}
else
{
if (!h->pointer_equality_needed)
abort ();
/* For non-shared object, we can't use .got.plt, which
contains the real function addres if we need pointer
equality. We load the GOT entry with the PLT entry. */
asection *plt = htab->splt ? htab->splt : htab->iplt;
bfd_put_32 (output_bfd,
(plt->output_section->vma
+ plt->output_offset + h->plt.offset),
htab->sgot->contents + h->got.offset);
return TRUE;
}
}
else if (info->shared
&& SYMBOL_REFERENCES_LOCAL (info, h))
@ -4161,6 +4269,7 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd,
else
{
BFD_ASSERT((h->got.offset & 1) == 0);
do_glob_dat:
bfd_put_32 (output_bfd, (bfd_vma) 0,
htab->sgot->contents + h->got.offset);
rel.r_info = ELF32_R_INFO (h->dynindx, R_386_GLOB_DAT);

220
bfd/elf64-x86-64.c
View File

@ -1110,9 +1110,51 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
bfd_set_error (bfd_error_bad_value);
return FALSE;
case R_X86_64_64:
h->non_got_ref = 1;
h->pointer_equality_needed = 1;
if (info->shared)
{
struct elf64_x86_64_dyn_relocs *p;
struct elf64_x86_64_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)
{
if (htab->elf.dynobj == NULL)
htab->elf.dynobj = abfd;
sreloc = _bfd_elf_make_dynamic_reloc_section
(sec, htab->elf.dynobj, 3, abfd, TRUE);
if (sreloc == NULL)
return FALSE;
}
head = &((struct elf64_x86_64_link_hash_entry *) h)->dyn_relocs;
p = *head;
if (p == NULL || p->sec != sec)
{
bfd_size_type amt = sizeof *p;
p = ((struct elf64_x86_64_dyn_relocs *)
bfd_alloc (htab->elf.dynobj, amt));
if (p == NULL)
return FALSE;
p->next = *head;
*head = p;
p->sec = sec;
p->count = 0;
p->pc_count = 0;
}
p->count += 1;
}
break;
case R_X86_64_32S:
case R_X86_64_32:
case R_X86_64_64:
case R_X86_64_PC32:
case R_X86_64_PC64:
h->non_got_ref = 1;
@ -1329,7 +1371,7 @@ elf64_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
case R_X86_64_PC32:
case R_X86_64_PC64:
case R_X86_64_64:
if (h != NULL && !info->shared)
if (h != NULL && info->executable)
{
/* If this reloc is in a read-only section, we might
need a copy reloc. We can't check reliably at this
@ -1795,7 +1837,7 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
/* When building a static executable, use .iplt, .igot.plt and
.rela.iplt sections for STT_GNU_IFUNC symbols. */
if (htab->splt != 0)
if (htab->splt != NULL)
{
plt = htab->splt;
gotplt = htab->sgotplt;
@ -1830,34 +1872,50 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
relplt->size += sizeof (Elf64_External_Rela);
relplt->reloc_count++;
/* No need for dynamic relocation for local STT_GNU_IFUNC symbol.
Discard space for relocations against it. */
if (h->dynindx == -1 || h->forced_local)
/* We need dynamic relocation for STT_GNU_IFUNC symbol only
when there is a non-GOT reference in a shared object. */
if (!info->shared
|| !h->non_got_ref)
eh->dyn_relocs = NULL;
/* STT_GNU_IFUNC symbol uses .got.plt, not .got. But for
shared library, we must go through GOT and we can't
use R_X86_64_IRELATIVE unless it is forced local. */
if (info->executable
|| info->symbolic
|| h->forced_local)
/* Finally, allocate space. */
for (p = eh->dyn_relocs; p != NULL; p = p->next)
{
if (h->pointer_equality_needed
&& htab->sgot != NULL)
{
/* We can't use .got.plt, which contains the real
function addres, since we need pointer equality.
We will load the GOT entry with the PLT entry
in elf64_x86_64_finish_dynamic_symbol and don't
need GOT relocation. */
h->got.offset = htab->sgot->size;
htab->sgot->size += GOT_ENTRY_SIZE;
eh->tlsdesc_got = (bfd_vma) -1;
goto skip_relgot;
}
else
h->got.refcount = 0;
asection * sreloc = elf_section_data (p->sec)->sreloc;
sreloc->size += p->count * sizeof (Elf64_External_Rela);
}
/* For STT_GNU_IFUNC symbol, .got.plt has the real function
addres and .got has the PLT entry adddress. We will load
the GOT entry with the PLT entry in finish_dynamic_symbol if
it is used. For branch, it uses .got.plt. For symbol value,
1. Use .got.plt in a shared object if it is forced local or
not dynamic.
2. Use .got.plt in a non-shared object if pointer equality
isn't needed.
3. Use .got.plt if .got isn't used.
4. Otherwise use .got so that it can be shared among different
objects at run-time.
We only need to relocate .got entry in shared object. */
if ((info->shared
&& (h->dynindx == -1
|| h->forced_local))
|| (!info->shared
&& !h->pointer_equality_needed)
|| htab->sgot == NULL)
{
/* Use .got.plt. */
h->got.offset = (bfd_vma) -1;
}
else
{
h->got.offset = htab->sgot->size;
htab->sgot->size += GOT_ENTRY_SIZE;
if (info->shared)
htab->srelgot->size += sizeof (Elf64_External_Rela);
}
return TRUE;
}
else if (htab->elf.dynamic_sections_created
&& h->plt.refcount > 0)
@ -1984,7 +2042,6 @@ elf64_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
else
h->got.offset = (bfd_vma) -1;
skip_relgot:
if (eh->dyn_relocs == NULL)
return TRUE;
@ -2621,11 +2678,73 @@ elf64_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
return FALSE;
case R_X86_64_32S:
if (!info->executable)
if (info->shared)
abort ();
goto do_relocation;
case R_X86_64_64:
if (rel->r_addend != 0)
{
(*_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,
h->root.root.string, rel->r_addend);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
/* Generate dynamic relcoation only when there is a
non-GOF reference in a shared object. */
if (info->shared && h->non_got_ref)
{
Elf_Internal_Rela outrel;
bfd_byte *loc;
asection *sreloc;
/* Need a dynamic relocation get the the real
function address. */
outrel.r_offset = _bfd_elf_section_offset (output_bfd,
info,
input_section,
rel->r_offset);
if (outrel.r_offset == (bfd_vma) -1
|| outrel.r_offset == (bfd_vma) -2)
abort ();
outrel.r_offset += (input_section->output_section->vma
+ input_section->output_offset);
if (h->dynindx == -1
|| h->forced_local)
{
/* This symbol is resolved locally. */
outrel.r_info = ELF64_R_INFO (0, R_X86_64_IRELATIVE);
outrel.r_addend = (h->root.u.def.value
+ h->root.u.def.section->output_section->vma
+ h->root.u.def.section->output_offset);
}
else
{
outrel.r_info = ELF64_R_INFO (h->dynindx, r_type);
outrel.r_addend = 0;
}
sreloc = elf_section_data (input_section)->sreloc;
loc = sreloc->contents;
loc += (sreloc->reloc_count++
* sizeof (Elf64_External_Rela));
bfd_elf64_swap_reloca_out (output_bfd, &outrel, loc);
/* If this reloc is against an external symbol, we
do not want to fiddle with the addend. Otherwise,
we need to include the symbol value so that it
becomes an addend for the dynamic reloc. For an
internal symbol, we have updated addend. */
continue;
}
case R_X86_64_32:
case R_X86_64_64:
case R_X86_64_PC32:
case R_X86_64_PC64:
case R_X86_64_PLT32:
@ -3596,7 +3715,7 @@ elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
/* When building a static executable, use .iplt, .igot.plt and
.rela.iplt sections for STT_GNU_IFUNC symbols. */
if (htab->splt != 0)
if (htab->splt != NULL)
{
plt = htab->splt;
gotplt = htab->sgotplt;
@ -3741,25 +3860,29 @@ elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
of a version file, we just want to emit a RELATIVE reloc.
The entry in the global offset table will already have been
initialized in the relocate_section function. */
if ((info->executable
|| info->symbolic
|| h->forced_local)
&& h->def_regular
&& h->pointer_equality_needed
if (h->def_regular
&& h->type == STT_GNU_IFUNC)
{
/* The STT_GNU_IFUNC symbol is locally defined. But we can't
use .got.plt, which contains the real function addres,
since we need pointer equality. We load the GOT entry
with the PLT entry without relocation. */
asection *plt = htab->splt ? htab->splt : htab->iplt;
if (htab->sgot == NULL
|| h->plt.offset == (bfd_vma) -1)
abort ();
bfd_put_64 (output_bfd, (plt->output_section->vma
+ plt->output_offset + h->plt.offset),
htab->sgot->contents + h->got.offset);
return TRUE;
if (info->shared)
{
/* Generate R_X86_64_GLOB_DAT. */
goto do_glob_dat;
}
else
{
if (!h->pointer_equality_needed)
abort ();
/* For non-shared object, we can't use .got.plt, which
contains the real function addres if we need pointer
equality. We load the GOT entry with the PLT entry. */
asection *plt = htab->splt ? htab->splt : htab->iplt;
bfd_put_64 (output_bfd, (plt->output_section->vma
+ plt->output_offset
+ h->plt.offset),
htab->sgot->contents + h->got.offset);
return TRUE;
}
}
else if (info->shared
&& SYMBOL_REFERENCES_LOCAL (info, h))
@ -3775,6 +3898,7 @@ elf64_x86_64_finish_dynamic_symbol (bfd *output_bfd,
else
{
BFD_ASSERT((h->got.offset & 1) == 0);
do_glob_dat:
bfd_put_64 (output_bfd, (bfd_vma) 0,
htab->sgot->contents + h->got.offset);
rela.r_info = ELF64_R_INFO (h->dynindx, R_X86_64_GLOB_DAT);