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x86: Add _bfd_x86_elf_allocate_dynrelocs 

Share _bfd_x86_elf_allocate_dynrelocs in elf32-i386.c and elf64-x86-64.c.

	* elf32-i386.c (elf_i386_allocate_dynrelocs): Removed.
	(elf_i386_allocate_local_dynrelocs): Likewise.
	(elf_i386_size_dynamic_sections): Replace
	elf_i386_allocate_dynrelocs/elf_i386_allocate_local_dynrelocs
	with _bfd_x86_elf_allocate_dynrelocs and
	_bfd_x86_elf_allocate_local_dynrelocs.
	* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Removed.
	(elf_x86_64_allocate_local_dynrelocs): Likewise.
	(elf_x86_64_size_dynamic_sections): Replace
	elf_x86_64_allocate_dynrelocs/elf_x86_64_allocate_local_dynrelocs
	with _bfd_x86_elf_allocate_dynrelocs and
	_bfd_x86_elf_allocate_local_dynrelocs.
	* elfxx-x86.c (_bfd_x86_elf_allocate_dynrelocs): New function.
	(_bfd_x86_elf_allocate_local_dynrelocs): Likewise.
	* elfxx-x86.h (_bfd_x86_elf_allocate_dynrelocs): New prototype.
	(_bfd_x86_elf_allocate_local_dynrelocs): Likewise.
This commit is contained in:
H.J. Lu 2017-09-02 07:26:54 -07:00
parent fe53b4a4c4
commit b9ce864ca8
5 changed files with 502 additions and 862 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
bfd/ChangeLog
View File

@ -1,3 +1,22 @@
2017-09-02 H.J. Lu <hongjiu.lu@intel.com>
* elf32-i386.c (elf_i386_allocate_dynrelocs): Removed.
(elf_i386_allocate_local_dynrelocs): Likewise.
(elf_i386_size_dynamic_sections): Replace
elf_i386_allocate_dynrelocs/elf_i386_allocate_local_dynrelocs
with _bfd_x86_elf_allocate_dynrelocs and
_bfd_x86_elf_allocate_local_dynrelocs.
* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Removed.
(elf_x86_64_allocate_local_dynrelocs): Likewise.
(elf_x86_64_size_dynamic_sections): Replace
elf_x86_64_allocate_dynrelocs/elf_x86_64_allocate_local_dynrelocs
with _bfd_x86_elf_allocate_dynrelocs and
_bfd_x86_elf_allocate_local_dynrelocs.
* elfxx-x86.c (_bfd_x86_elf_allocate_dynrelocs): New function.
(_bfd_x86_elf_allocate_local_dynrelocs): Likewise.
* elfxx-x86.h (_bfd_x86_elf_allocate_dynrelocs): New prototype.
(_bfd_x86_elf_allocate_local_dynrelocs): Likewise.
2017-09-02 H.J. Lu <hongjiu.lu@intel.com>
* elf32-i386.c (is_i386_elf): Removed.

455
bfd/elf32-i386.c
View File

@ -1951,456 +1951,6 @@ error_return:
return FALSE;
}
/* Allocate space in .plt, .got and associated reloc sections for
dynamic relocs. */
static bfd_boolean
elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
{
struct bfd_link_info *info;
struct elf_x86_link_hash_table *htab;
struct elf_x86_link_hash_entry *eh;
struct elf_dyn_relocs *p;
unsigned plt_entry_size;
bfd_boolean resolved_to_zero;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
eh = (struct elf_x86_link_hash_entry *) h;
info = (struct bfd_link_info *) inf;
htab = elf_x86_hash_table (info, I386_ELF_DATA);
if (htab == NULL)
return FALSE;
plt_entry_size = htab->plt.plt_entry_size;
resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info,
I386_ELF_DATA,
eh->has_got_reloc,
eh);
/* Clear the reference count of function pointer relocations if
symbol isn't a normal function. */
if (h->type != STT_FUNC)
eh->func_pointer_refcount = 0;
/* 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
loop at run-time. */
if (htab->plt_got != NULL
&& h->type != STT_GNU_IFUNC
&& !h->pointer_equality_needed
&& h->plt.refcount > 0
&& h->got.refcount > 0)
{
/* Don't use the regular PLT if there are both GOT and GOTPLT
reloctions. */
h->plt.offset = (bfd_vma) -1;
/* Use the GOT PLT. */
eh->plt_got.refcount = 1;
}
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
here if it is defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
&& h->def_regular)
{
if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs,
&htab->readonly_dynrelocs_against_ifunc,
plt_entry_size,
(htab->plt.has_plt0
* plt_entry_size),
4, TRUE))
{
asection *s = htab->plt_second;
if (h->plt.offset != (bfd_vma) -1 && s != NULL)
{
/* Use the second PLT section if it is created. */
eh->plt_second.offset = s->size;
/* Make room for this entry in the second PLT section. */
s->size += htab->non_lazy_plt->plt_entry_size;
}
return TRUE;
}
else
return FALSE;
}
/* Don't create the PLT entry if there are only function pointer
relocations which can be resolved at run-time. */
else if (htab->elf.dynamic_sections_created
&& (h->plt.refcount > eh->func_pointer_refcount
|| eh->plt_got.refcount > 0))
{
bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
/* Clear the reference count of function pointer relocations
if PLT is used. */
eh->func_pointer_refcount = 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
if (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
{
asection *s = htab->elf.splt;
asection *second_s = htab->plt_second;
asection *got_s = htab->plt_got;
/* If this is the first .plt entry, make room for the special
first entry. The .plt section is used by prelink to undo
prelinking for dynamic relocations. */
if (s->size == 0)
s->size = htab->plt.has_plt0 * plt_entry_size;
if (use_plt_got)
eh->plt_got.offset = got_s->size;
else
{
h->plt.offset = s->size;
if (second_s)
eh->plt_second.offset = second_s->size;
}
/* If this symbol is not defined in a regular file, and we are
not generating a shared library, then set the symbol to this
location in the .plt. This is required to make function
pointers compare as equal between the normal executable and
the shared library. */
if (! bfd_link_pic (info)
&& !h->def_regular)
{
if (use_plt_got)
{
/* We need to make a call to the entry of the GOT PLT
instead of regular PLT entry. */
h->root.u.def.section = got_s;
h->root.u.def.value = eh->plt_got.offset;
}
else
{
if (second_s)
{
/* We need to make a call to the entry of the
second PLT instead of regular PLT entry. */
h->root.u.def.section = second_s;
h->root.u.def.value = eh->plt_second.offset;
}
else
{
h->root.u.def.section = s;
h->root.u.def.value = h->plt.offset;
}
}
}
/* Make room for this entry. */
if (use_plt_got)
got_s->size += htab->non_lazy_plt->plt_entry_size;
else
{
s->size += plt_entry_size;
if (second_s)
second_s->size += htab->non_lazy_plt->plt_entry_size;
/* We also need to make an entry in the .got.plt section,
which will be placed in the .got section by the linker
script. */
htab->elf.sgotplt->size += 4;
/* 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 .rel.plt
section. */
htab->elf.srelplt->size += sizeof (Elf32_External_Rel);
htab->elf.srelplt->reloc_count++;
}
}
if (htab->is_vxworks && !bfd_link_pic (info))
{
/* VxWorks has a second set of relocations for each PLT entry
in executables. They go in a separate relocation section,
which is processed by the kernel loader. */
/* There are two relocations for the initial PLT entry: an
R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
asection *srelplt2 = htab->srelplt2;
if (h->plt.offset == plt_entry_size)
srelplt2->size += (sizeof (Elf32_External_Rel) * 2);
/* There are two extra relocations for each subsequent PLT entry:
an R_386_32 relocation for the GOT entry, and an R_386_32
relocation for the PLT entry. */
srelplt2->size += (sizeof (Elf32_External_Rel) * 2);
}
}
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;
}
eh->tlsdesc_got = (bfd_vma) -1;
/* If R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the binary,
make it a R_386_TLS_LE_32 requiring no TLS entry. */
if (h->got.refcount > 0
&& bfd_link_executable (info)
&& h->dynindx == -1
&& (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
h->got.offset = (bfd_vma) -1;
else if (h->got.refcount > 0)
{
asection *s;
bfd_boolean dyn;
int tls_type = elf_x86_hash_entry (h)->tls_type;
/* 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
s = htab->elf.sgot;
if (GOT_TLS_GDESC_P (tls_type))
{
eh->tlsdesc_got = htab->elf.sgotplt->size
- elf_x86_compute_jump_table_size (htab);
htab->elf.sgotplt->size += 8;
h->got.offset = (bfd_vma) -2;
}
if (! GOT_TLS_GDESC_P (tls_type)
|| GOT_TLS_GD_P (tls_type))
{
h->got.offset = s->size;
s->size += 4;
/* R_386_TLS_GD needs 2 consecutive GOT slots. */
if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
s->size += 4;
}
dyn = htab->elf.dynamic_sections_created;
/* R_386_TLS_IE_32 needs one dynamic relocation,
R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
(but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
need two), R_386_TLS_GD needs one if local symbol and two if
global. No dynamic relocation against resolved undefined weak
symbol in executable. */
if (tls_type == GOT_TLS_IE_BOTH)
htab->elf.srelgot->size += 2 * sizeof (Elf32_External_Rel);
else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
|| (tls_type & GOT_TLS_IE))
htab->elf.srelgot->size += sizeof (Elf32_External_Rel);
else if (GOT_TLS_GD_P (tls_type))
htab->elf.srelgot->size += 2 * sizeof (Elf32_External_Rel);
else if (! GOT_TLS_GDESC_P (tls_type)
&& ((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)))
htab->elf.srelgot->size += sizeof (Elf32_External_Rel);
if (GOT_TLS_GDESC_P (tls_type))
htab->elf.srelplt->size += sizeof (Elf32_External_Rel);
}
else
h->got.offset = (bfd_vma) -1;
if (eh->dyn_relocs == NULL)
return TRUE;
/* In the shared -Bsymbolic case, discard space allocated for
dynamic pc-relative relocs against symbols which turn out to be
defined in regular objects. For the normal shared case, discard
space for pc-relative relocs that have become local due to symbol
visibility changes. */
if (bfd_link_pic (info))
{
/* The only reloc that uses pc_count is R_386_PC32, which will
appear on a call or on something like ".long foo - .". We
want calls to protected symbols to resolve directly to the
function rather than going via the plt. If people want
function pointer comparisons to work as expected then they
should avoid writing assembly like ".long foo - .". */
if (SYMBOL_CALLS_LOCAL (info, h))
{
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
p->count -= p->pc_count;
p->pc_count = 0;
if (p->count == 0)
*pp = p->next;
else
pp = &p->next;
}
}
if (htab->is_vxworks)
{
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
*pp = p->next;
else
pp = &p->next;
}
}
/* Also discard relocs on undefined weak syms with non-default
visibility or in PIE. */
if (eh->dyn_relocs != NULL
&& h->root.type == bfd_link_hash_undefweak)
{
/* Undefined weak symbol is never bound locally in shared
library. */
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
|| resolved_to_zero)
{
if (h->non_got_ref)
{
/* Keep dynamic non-GOT/non-PLT relocation so that we
can branch to 0 without PLT. */
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
if (p->pc_count == 0)
*pp = p->next;
else
{
/* Remove non-R_386_PC32 relocation. */
p->count = p->pc_count;
pp = &p->next;
}
if (eh->dyn_relocs != NULL)
{
/* Make sure undefined weak symbols are output
as dynamic symbols in PIEs for dynamic non-GOT
non-PLT reloations. */
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
}
else
eh->dyn_relocs = NULL;
}
else if (h->dynindx == -1
&& !h->forced_local)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
}
}
else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
dynamic. Keep dynamic relocations for run-time function
pointer initialization. */
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
&& (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_undefined))))
{
/* 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
/* If that succeeded, we know we'll be keeping all the
relocs. */
if (h->dynindx != -1)
goto keep;
}
eh->dyn_relocs = NULL;
eh->func_pointer_refcount = 0;
keep: ;
}
/* Finally, allocate space. */
for (p = eh->dyn_relocs; p != NULL; p = p->next)
{
asection *sreloc;
sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
sreloc->size += p->count * sizeof (Elf32_External_Rel);
}
return TRUE;
}
/* Allocate space in .plt, .got and associated reloc sections for
local dynamic relocs. */
static bfd_boolean
elf_i386_allocate_local_dynrelocs (void **slot, void *inf)
{
struct elf_link_hash_entry *h
= (struct elf_link_hash_entry *) *slot;
if (h->type != STT_GNU_IFUNC
|| !h->def_regular
|| !h->ref_regular
|| !h->forced_local
|| h->root.type != bfd_link_hash_defined)
abort ();
return elf_i386_allocate_dynrelocs (h, inf);
}
/* Convert load via the GOT slot to load immediate. */
static bfd_boolean
@ -2673,11 +2223,12 @@ elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info)
/* Allocate global sym .plt and .got entries, and space for global
sym dynamic relocs. */
elf_link_hash_traverse (&htab->elf, elf_i386_allocate_dynrelocs, info);
elf_link_hash_traverse (&htab->elf, _bfd_x86_elf_allocate_dynrelocs,
info);
/* Allocate .plt and .got entries, and space for local symbols. */
htab_traverse (htab->loc_hash_table,
elf_i386_allocate_local_dynrelocs,
_bfd_x86_elf_allocate_local_dynrelocs,
info);
/* For every jump slot reserved in the sgotplt, reloc_count is

412
bfd/elf64-x86-64.c
View File

@ -2394,414 +2394,6 @@ error_return:
return FALSE;
}
/* Allocate space in .plt, .got and associated reloc sections for
dynamic relocs. */
static bfd_boolean
elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
{
struct bfd_link_info *info;
struct elf_x86_link_hash_table *htab;
struct elf_x86_link_hash_entry *eh;
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;
eh = (struct elf_x86_link_hash_entry *) h;
info = (struct bfd_link_info *) inf;
htab = elf_x86_hash_table (info, X86_64_ELF_DATA);
if (htab == NULL)
return FALSE;
bed = get_elf_backend_data (info->output_bfd);
plt_entry_size = htab->plt.plt_entry_size;
resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info,
X86_64_ELF_DATA,
eh->has_got_reloc,
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
loop at run-time. */
if (htab->plt_got != NULL
&& h->type != STT_GNU_IFUNC
&& !h->pointer_equality_needed
&& h->plt.refcount > 0
&& h->got.refcount > 0)
{
/* Don't use the regular PLT if there are both GOT and GOTPLT
reloctions. */
h->plt.offset = (bfd_vma) -1;
/* Use the GOT PLT. */
eh->plt_got.refcount = 1;
}
/* Clear the reference count of function pointer relocations if
symbol isn't a normal function. */
if (h->type != STT_FUNC)
eh->func_pointer_refcount = 0;
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
here if it is defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
&& h->def_regular)
{
if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h,
&eh->dyn_relocs,
&htab->readonly_dynrelocs_against_ifunc,
plt_entry_size,
(htab->plt.has_plt0
* plt_entry_size),
GOT_ENTRY_SIZE, TRUE))
{
asection *s = htab->plt_second;
if (h->plt.offset != (bfd_vma) -1 && s != NULL)
{
/* Use the second PLT section if it is created. */
eh->plt_second.offset = s->size;
/* Make room for this entry in the second PLT section. */
s->size += htab->non_lazy_plt->plt_entry_size;
}
return TRUE;
}
else
return FALSE;
}
/* Don't create the PLT entry if there are only function pointer
relocations which can be resolved at run-time. */
else if (htab->elf.dynamic_sections_created
&& (h->plt.refcount > eh->func_pointer_refcount
|| eh->plt_got.refcount > 0))
{
bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
/* Clear the reference count of function pointer relocations
if PLT is used. */
eh->func_pointer_refcount = 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
if (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
{
asection *s = htab->elf.splt;
asection *second_s = htab->plt_second;
asection *got_s = htab->plt_got;
/* If this is the first .plt entry, make room for the special
first entry. The .plt section is used by prelink to undo
prelinking for dynamic relocations. */
if (s->size == 0)
s->size = htab->plt.has_plt0 * plt_entry_size;
if (use_plt_got)
eh->plt_got.offset = got_s->size;
else
{
h->plt.offset = s->size;
if (second_s)
eh->plt_second.offset = second_s->size;
}
/* If this symbol is not defined in a regular file, and we are
not generating a shared library, then set the symbol to this
location in the .plt. This is required to make function
pointers compare as equal between the normal executable and
the shared library. */
if (! bfd_link_pic (info)
&& !h->def_regular)
{
if (use_plt_got)
{
/* We need to make a call to the entry of the GOT PLT
instead of regular PLT entry. */
h->root.u.def.section = got_s;
h->root.u.def.value = eh->plt_got.offset;
}
else
{
if (second_s)
{
/* We need to make a call to the entry of the
second PLT instead of regular PLT entry. */
h->root.u.def.section = second_s;
h->root.u.def.value = eh->plt_second.offset;
}
else
{
h->root.u.def.section = s;
h->root.u.def.value = h->plt.offset;
}
}
}
/* Make room for this entry. */
if (use_plt_got)
got_s->size += htab->non_lazy_plt->plt_entry_size;
else
{
s->size += plt_entry_size;
if (second_s)
second_s->size += htab->non_lazy_plt->plt_entry_size;
/* We also need to make an entry in the .got.plt section,
which will be placed in the .got section by the linker
script. */
htab->elf.sgotplt->size += GOT_ENTRY_SIZE;
/* 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;
}
eh->tlsdesc_got = (bfd_vma) -1;
/* If R_X86_64_GOTTPOFF symbol is now local to the binary,
make it a R_X86_64_TPOFF32 requiring no GOT entry. */
if (h->got.refcount > 0
&& bfd_link_executable (info)
&& h->dynindx == -1
&& elf_x86_hash_entry (h)->tls_type == GOT_TLS_IE)
{
h->got.offset = (bfd_vma) -1;
}
else if (h->got.refcount > 0)
{
asection *s;
bfd_boolean dyn;
int tls_type = elf_x86_hash_entry (h)->tls_type;
/* 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
if (GOT_TLS_GDESC_P (tls_type))
{
eh->tlsdesc_got = htab->elf.sgotplt->size
- elf_x86_compute_jump_table_size (htab);
htab->elf.sgotplt->size += 2 * GOT_ENTRY_SIZE;
h->got.offset = (bfd_vma) -2;
}
if (! GOT_TLS_GDESC_P (tls_type)
|| GOT_TLS_GD_P (tls_type))
{
s = htab->elf.sgot;
h->got.offset = s->size;
s->size += GOT_ENTRY_SIZE;
if (GOT_TLS_GD_P (tls_type))
s->size += GOT_ENTRY_SIZE;
}
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. 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
&& !resolved_to_zero)
|| h->root.type != bfd_link_hash_undefweak)
&& (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
htab->elf.srelgot->size += bed->s->sizeof_rela;
if (GOT_TLS_GDESC_P (tls_type))
{
htab->elf.srelplt->size += bed->s->sizeof_rela;
htab->tlsdesc_plt = (bfd_vma) -1;
}
}
else
h->got.offset = (bfd_vma) -1;
if (eh->dyn_relocs == NULL)
return TRUE;
/* In the shared -Bsymbolic case, discard space allocated for
dynamic pc-relative relocs against symbols which turn out to be
defined in regular objects. For the normal shared case, discard
space for pc-relative relocs that have become local due to symbol
visibility changes. */
if (bfd_link_pic (info))
{
/* Relocs that use pc_count are those that appear on a call
insn, or certain REL relocs that can generated via assembly.
We want calls to protected symbols to resolve directly to the
function rather than going via the plt. If people want
function pointer comparisons to work as expected then they
should avoid writing weird assembly. */
if (SYMBOL_CALLS_LOCAL (info, h))
{
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
p->count -= p->pc_count;
p->pc_count = 0;
if (p->count == 0)
*pp = p->next;
else
pp = &p->next;
}
}
/* Also discard relocs on undefined weak syms with non-default
visibility or in PIE. */
if (eh->dyn_relocs != NULL)
{
if (h->root.type == bfd_link_hash_undefweak)
{
/* 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;
else if (h->dynindx == -1
&& ! h->forced_local
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
/* For PIE, discard space for pc-relative relocs against
symbols which turn out to need copy relocs. */
else if (bfd_link_executable (info)
&& (h->needs_copy || eh->needs_copy)
&& h->def_dynamic
&& !h->def_regular)
{
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
if (p->pc_count != 0)
*pp = p->next;
else
pp = &p->next;
}
}
}
}
else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
dynamic. Keep dynamic relocations for run-time function
pointer initialization. */
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
&& (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_undefined))))
{
/* 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
&& ! resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
/* If that succeeded, we know we'll be keeping all the
relocs. */
if (h->dynindx != -1)
goto keep;
}
eh->dyn_relocs = NULL;
eh->func_pointer_refcount = 0;
keep: ;
}
/* Finally, allocate space. */
for (p = eh->dyn_relocs; p != NULL; p = p->next)
{
asection * sreloc;
sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
sreloc->size += p->count * bed->s->sizeof_rela;
}
return TRUE;
}
/* Allocate space in .plt, .got and associated reloc sections for
local dynamic relocs. */
static bfd_boolean
elf_x86_64_allocate_local_dynrelocs (void **slot, void *inf)
{
struct elf_link_hash_entry *h
= (struct elf_link_hash_entry *) *slot;
if (h->type != STT_GNU_IFUNC
|| !h->def_regular
|| !h->ref_regular
|| !h->forced_local
|| h->root.type != bfd_link_hash_defined)
abort ();
return elf_x86_64_allocate_dynrelocs (h, inf);
}
/* Convert load via the GOT slot to load immediate. */
static bfd_boolean
@ -3072,12 +2664,12 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd,
/* Allocate global sym .plt and .got entries, and space for global
sym dynamic relocs. */
elf_link_hash_traverse (&htab->elf, elf_x86_64_allocate_dynrelocs,
elf_link_hash_traverse (&htab->elf, _bfd_x86_elf_allocate_dynrelocs,
info);
/* Allocate .plt and .got entries, and space for local symbols. */
htab_traverse (htab->loc_hash_table,
elf_x86_64_allocate_local_dynrelocs,
_bfd_x86_elf_allocate_local_dynrelocs,
info);
/* For every jump slot reserved in the sgotplt, reloc_count is

472
bfd/elfxx-x86.c
View File

@ -79,6 +79,459 @@ _bfd_x86_elf_dtpoff_base (struct bfd_link_info *info)
return elf_hash_table (info)->tls_sec->vma;
}
/* Allocate space in .plt, .got and associated reloc sections for
dynamic relocs. */
bfd_boolean
_bfd_x86_elf_allocate_dynrelocs (struct elf_link_hash_entry *h,
void *inf)
{
struct bfd_link_info *info;
struct elf_x86_link_hash_table *htab;
struct elf_x86_link_hash_entry *eh;
struct elf_dyn_relocs *p;
unsigned int plt_entry_size;
bfd_boolean resolved_to_zero;
const struct elf_backend_data *bed;
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
eh = (struct elf_x86_link_hash_entry *) h;
info = (struct bfd_link_info *) inf;
bed = get_elf_backend_data (info->output_bfd);
htab = elf_x86_hash_table (info, bed->target_id);
if (htab == NULL)
return FALSE;
plt_entry_size = htab->plt.plt_entry_size;
resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info,
bed->target_id,
eh->has_got_reloc,
eh);
/* Clear the reference count of function pointer relocations if
symbol isn't a normal function. */
if (h->type != STT_FUNC)
eh->func_pointer_refcount = 0;
/* 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
loop at run-time. */
if (htab->plt_got != NULL
&& h->type != STT_GNU_IFUNC
&& !h->pointer_equality_needed
&& h->plt.refcount > 0
&& h->got.refcount > 0)
{
/* Don't use the regular PLT if there are both GOT and GOTPLT
reloctions. */
h->plt.offset = (bfd_vma) -1;
/* Use the GOT PLT. */
eh->plt_got.refcount = 1;
}
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle it
here if it is defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
&& h->def_regular)
{
if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs,
&htab->readonly_dynrelocs_against_ifunc,
plt_entry_size,
(htab->plt.has_plt0
* plt_entry_size),
htab->got_entry_size,
TRUE))
{
asection *s = htab->plt_second;
if (h->plt.offset != (bfd_vma) -1 && s != NULL)
{
/* Use the second PLT section if it is created. */
eh->plt_second.offset = s->size;
/* Make room for this entry in the second PLT section. */
s->size += htab->non_lazy_plt->plt_entry_size;
}
return TRUE;
}
else
return FALSE;
}
/* Don't create the PLT entry if there are only function pointer
relocations which can be resolved at run-time. */
else if (htab->elf.dynamic_sections_created
&& (h->plt.refcount > eh->func_pointer_refcount
|| eh->plt_got.refcount > 0))
{
bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
/* Clear the reference count of function pointer relocations
if PLT is used. */
eh->func_pointer_refcount = 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
if (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
{
asection *s = htab->elf.splt;
asection *second_s = htab->plt_second;
asection *got_s = htab->plt_got;
/* If this is the first .plt entry, make room for the special
first entry. The .plt section is used by prelink to undo
prelinking for dynamic relocations. */
if (s->size == 0)
s->size = htab->plt.has_plt0 * plt_entry_size;
if (use_plt_got)
eh->plt_got.offset = got_s->size;
else
{
h->plt.offset = s->size;
if (second_s)
eh->plt_second.offset = second_s->size;
}
/* If this symbol is not defined in a regular file, and we are
not generating a shared library, then set the symbol to this
location in the .plt. This is required to make function
pointers compare as equal between the normal executable and
the shared library. */
if (! bfd_link_pic (info)
&& !h->def_regular)
{
if (use_plt_got)
{
/* We need to make a call to the entry of the GOT PLT
instead of regular PLT entry. */
h->root.u.def.section = got_s;
h->root.u.def.value = eh->plt_got.offset;
}
else
{
if (second_s)
{
/* We need to make a call to the entry of the
second PLT instead of regular PLT entry. */
h->root.u.def.section = second_s;
h->root.u.def.value = eh->plt_second.offset;
}
else
{
h->root.u.def.section = s;
h->root.u.def.value = h->plt.offset;
}
}
}
/* Make room for this entry. */
if (use_plt_got)
got_s->size += htab->non_lazy_plt->plt_entry_size;
else
{
s->size += plt_entry_size;
if (second_s)
second_s->size += htab->non_lazy_plt->plt_entry_size;
/* We also need to make an entry in the .got.plt section,
which will be placed in the .got section by the linker
script. */
htab->elf.sgotplt->size += htab->got_entry_size;
/* 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 .rel.plt
section. */
htab->elf.srelplt->size += htab->sizeof_reloc;
htab->elf.srelplt->reloc_count++;
}
}
if (htab->is_vxworks && !bfd_link_pic (info))
{
/* VxWorks has a second set of relocations for each PLT entry
in executables. They go in a separate relocation section,
which is processed by the kernel loader. */
/* There are two relocations for the initial PLT entry: an
R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an
R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */
asection *srelplt2 = htab->srelplt2;
if (h->plt.offset == plt_entry_size)
srelplt2->size += (htab->sizeof_reloc * 2);
/* There are two extra relocations for each subsequent PLT entry:
an R_386_32 relocation for the GOT entry, and an R_386_32
relocation for the PLT entry. */
srelplt2->size += (htab->sizeof_reloc * 2);
}
}
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;
}
eh->tlsdesc_got = (bfd_vma) -1;
/* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the
binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For
x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary,
make it a R_X86_64_TPOFF32 requiring no GOT entry. */
if (h->got.refcount > 0
&& bfd_link_executable (info)
&& h->dynindx == -1
&& (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE))
h->got.offset = (bfd_vma) -1;
else if (h->got.refcount > 0)
{
asection *s;
bfd_boolean dyn;
int tls_type = elf_x86_hash_entry (h)->tls_type;
/* 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
s = htab->elf.sgot;
if (GOT_TLS_GDESC_P (tls_type))
{
eh->tlsdesc_got = htab->elf.sgotplt->size
- elf_x86_compute_jump_table_size (htab);
htab->elf.sgotplt->size += 2 * htab->got_entry_size;
h->got.offset = (bfd_vma) -2;
}
if (! GOT_TLS_GDESC_P (tls_type)
|| GOT_TLS_GD_P (tls_type))
{
h->got.offset = s->size;
s->size += htab->got_entry_size;
/* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT
slots. */
if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH)
s->size += htab->got_entry_size;
}
dyn = htab->elf.dynamic_sections_created;
/* R_386_TLS_IE_32 needs one dynamic relocation,
R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation,
(but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we
need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local
symbol and two if global. No dynamic relocation against
resolved undefined weak symbol in executable. */
if (tls_type == GOT_TLS_IE_BOTH)
htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1)
|| (tls_type & GOT_TLS_IE))
htab->elf.srelgot->size += htab->sizeof_reloc;
else if (GOT_TLS_GD_P (tls_type))
htab->elf.srelgot->size += 2 * htab->sizeof_reloc;
else if (! GOT_TLS_GDESC_P (tls_type)
&& ((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)))
htab->elf.srelgot->size += htab->sizeof_reloc;
if (GOT_TLS_GDESC_P (tls_type))
htab->elf.srelplt->size += htab->sizeof_reloc;
}
else
h->got.offset = (bfd_vma) -1;
if (eh->dyn_relocs == NULL)
return TRUE;
/* In the shared -Bsymbolic case, discard space allocated for
dynamic pc-relative relocs against symbols which turn out to be
defined in regular objects. For the normal shared case, discard
space for pc-relative relocs that have become local due to symbol
visibility changes. */
if (bfd_link_pic (info))
{
/* Relocs that use pc_count are those that appear on a call
insn, or certain REL relocs that can generated via assembly.
We want calls to protected symbols to resolve directly to the
function rather than going via the plt. If people want
function pointer comparisons to work as expected then they
should avoid writing weird assembly. */
if (SYMBOL_CALLS_LOCAL (info, h))
{
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
p->count -= p->pc_count;
p->pc_count = 0;
if (p->count == 0)
*pp = p->next;
else
pp = &p->next;
}
}
if (htab->is_vxworks)
{
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
if (strcmp (p->sec->output_section->name, ".tls_vars") == 0)
*pp = p->next;
else
pp = &p->next;
}
}
/* Also discard relocs on undefined weak syms with non-default
visibility or in PIE. */
if (eh->dyn_relocs != NULL)
{
if (h->root.type == bfd_link_hash_undefweak)
{
/* Undefined weak symbol is never bound locally in shared
library. */
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
|| resolved_to_zero)
{
if (bed->target_id == I386_ELF_DATA
&& h->non_got_ref)
{
/* Keep dynamic non-GOT/non-PLT relocation so
that we can branch to 0 without PLT. */
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
if (p->pc_count == 0)
*pp = p->next;
else
{
/* Remove non-R_386_PC32 relocation. */
p->count = p->pc_count;
pp = &p->next;
}
/* Make sure undefined weak symbols are output
as dynamic symbols in PIEs for dynamic non-GOT
non-PLT reloations. */
if (eh->dyn_relocs != NULL
&& !bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
else
eh->dyn_relocs = NULL;
}
else if (h->dynindx == -1
&& !h->forced_local
&& !bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
}
else if (bfd_link_executable (info)
&& (h->needs_copy || eh->needs_copy)
&& h->def_dynamic
&& !h->def_regular)
{
/* NB: needs_copy is set only for x86-64. For PIE,
discard space for pc-relative relocs against symbols
which turn out to need copy relocs. */
struct elf_dyn_relocs **pp;
for (pp = &eh->dyn_relocs; (p = *pp) != NULL; )
{
if (p->pc_count != 0)
*pp = p->next;
else
pp = &p->next;
}
}
}
}
else if (ELIMINATE_COPY_RELOCS)
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
dynamic. Keep dynamic relocations for run-time function
pointer initialization. */
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
&& (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_undefined))))
{
/* 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
&& !resolved_to_zero
&& h->root.type == bfd_link_hash_undefweak
&& ! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
/* If that succeeded, we know we'll be keeping all the
relocs. */
if (h->dynindx != -1)
goto keep;
}
eh->dyn_relocs = NULL;
eh->func_pointer_refcount = 0;
keep: ;
}
/* Finally, allocate space. */
for (p = eh->dyn_relocs; p != NULL; p = p->next)
{
asection *sreloc;
sreloc = elf_section_data (p->sec)->sreloc;
BFD_ASSERT (sreloc != NULL);
sreloc->size += p->count * htab->sizeof_reloc;
}
return TRUE;
}
/* Find any dynamic relocs that apply to read-only sections. */
bfd_boolean
@ -117,6 +570,25 @@ _bfd_x86_elf_readonly_dynrelocs (struct elf_link_hash_entry *h,
return TRUE;
}
/* Allocate space in .plt, .got and associated reloc sections for
local dynamic relocs. */
bfd_boolean
_bfd_x86_elf_allocate_local_dynrelocs (void **slot, void *inf)
{
struct elf_link_hash_entry *h
= (struct elf_link_hash_entry *) *slot;
if (h->type != STT_GNU_IFUNC
|| !h->def_regular
|| !h->ref_regular
|| !h->forced_local
|| h->root.type != bfd_link_hash_defined)
abort ();
return _bfd_x86_elf_allocate_dynrelocs (h, inf);
}
/* Find and/or create a hash entry for local symbol. */
struct elf_link_hash_entry *

6
bfd/elfxx-x86.h
View File

@ -401,6 +401,12 @@ extern void _bfd_x86_elf_set_tls_module_base
extern bfd_vma _bfd_x86_elf_dtpoff_base
(struct bfd_link_info *);
extern bfd_boolean _bfd_x86_elf_allocate_dynrelocs
(struct elf_link_hash_entry *, void *);
extern bfd_boolean _bfd_x86_elf_allocate_local_dynrelocs
(void **, void *);
extern bfd_boolean _bfd_x86_elf_readonly_dynrelocs
(struct elf_link_hash_entry *, void *);