/* X86-64 specific support for ELF
- Copyright (C) 2000-2015 Free Software Foundation, Inc.
+ Copyright (C) 2000-2016 Free Software Foundation, Inc.
Contributed by Jan Hubicka <jh@suse.cz>.
This file is part of BFD, the Binary File Descriptor library.
#include "dwarf2.h"
#include "libiberty.h"
+#include "opcode/i386.h"
#include "elf/x86-64.h"
#ifdef CORE_HEADER
HOWTO(R_X86_64_PLT32_BND, 0, 2, 32, TRUE, 0, complain_overflow_signed,
bfd_elf_generic_reloc, "R_X86_64_PLT32_BND", FALSE, 0xffffffff, 0xffffffff,
TRUE),
+ HOWTO(R_X86_64_GOTPCRELX, 0, 2, 32, TRUE, 0, complain_overflow_signed,
+ bfd_elf_generic_reloc, "R_X86_64_GOTPCRELX", FALSE, 0xffffffff,
+ 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, 0xffffffff,
+ 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_PLT32_BND + 1)
+#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. */
{ 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_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, },
};
/* TRUE if symbol has at least one BND relocation. */
unsigned int has_bnd_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;
+
/* Information about the GOT PLT entry. Filled when there are both
GOT and PLT relocations against the same function. */
union gotplt_union plt_got;
eh->tls_type = GOT_UNKNOWN;
eh->needs_copy = 0;
eh->has_bnd_reloc = 0;
+ eh->func_pointer_refcount = 0;
eh->plt_bnd.offset = (bfd_vma) -1;
eh->plt_got.offset = (bfd_vma) -1;
eh->tlsdesc_got = (bfd_vma) -1;
ret->elf.indx = sec->id;
ret->elf.dynstr_index = htab->r_sym (rel->r_info);
ret->elf.dynindx = -1;
+ ret->func_pointer_refcount = 0;
ret->plt_got.offset = (bfd_vma) -1;
*slot = ret;
}
if (!htab->sdynbss)
abort ();
- if (info->executable)
+ if (bfd_link_executable (info))
{
/* Always allow copy relocs for building executables. */
asection *s = bfd_get_linker_section (dynobj, ".rela.bss");
dir->pointer_equality_needed |= ind->pointer_equality_needed;
}
else
- _bfd_elf_link_hash_copy_indirect (info, dir, ind);
+ {
+ if (eind->func_pointer_refcount > 0)
+ {
+ edir->func_pointer_refcount += eind->func_pointer_refcount;
+ eind->func_pointer_refcount = 0;
+ }
+
+ _bfd_elf_link_hash_copy_indirect (info, dir, ind);
+ }
}
static bfd_boolean
case R_X86_64_GOTPC32_TLSDESC:
case R_X86_64_TLSDESC_CALL:
case R_X86_64_GOTTPOFF:
- if (info->executable)
+ if (bfd_link_executable (info))
{
if (h == NULL)
to_type = R_X86_64_TPOFF32;
{
unsigned int new_to_type = to_type;
- if (info->executable
+ if (bfd_link_executable (info)
&& h != NULL
&& h->dynindx == -1
&& tls_type == GOT_TLS_IE)
break;
case R_X86_64_TLSLD:
- if (info->executable)
+ if (bfd_link_executable (info))
to_type = R_X86_64_TPOFF32;
break;
/* Rename some of the generic section flags to better document how they
are used here. */
-#define need_convert_mov_to_lea sec_flg0
+#define need_convert_load sec_flg0
/* Look through the relocs for a section during the first phase, and
calculate needed space in the global offset table, procedure
asection *sreloc;
bfd_boolean use_plt_got;
- if (info->relocatable)
+ if (bfd_link_relocatable (info))
return TRUE;
BFD_ASSERT (is_x86_64_elf (abfd));
case R_X86_64_32S:
case R_X86_64_PC64:
case R_X86_64_GOTPCREL:
+ case R_X86_64_GOTPCRELX:
+ case R_X86_64_REX_GOTPCRELX:
case R_X86_64_GOTPCREL64:
if (htab->elf.dynobj == NULL)
htab->elf.dynobj = abfd;
/* It is referenced by a non-shared object. */
h->ref_regular = 1;
h->root.non_ir_ref = 1;
+
+ if (h->type == STT_GNU_IFUNC)
+ elf_tdata (info->output_bfd)->has_gnu_symbols
+ |= elf_gnu_symbol_ifunc;
}
if (! elf_x86_64_tls_transition (info, abfd, sec, NULL,
goto create_got;
case R_X86_64_TPOFF32:
- if (!info->executable && ABI_64_P (abfd))
+ if (!bfd_link_executable (info) && ABI_64_P (abfd))
{
if (h)
name = h->root.root.string;
break;
case R_X86_64_GOTTPOFF:
- if (!info->executable)
+ 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:
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 (info->shared
+ if (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 && info->executable)
+ if (h != NULL && bfd_link_executable (info))
{
/* If this reloc is in a read-only section, we might
need a copy reloc. We can't check reliably at this
/* We may need a .plt entry if the function this reloc
refers to is in a shared lib. */
h->plt.refcount += 1;
- if (r_type != R_X86_64_PC32
- && r_type != R_X86_64_PC32_BND
- && r_type != R_X86_64_PC64)
- h->pointer_equality_needed = 1;
+ 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;
+ }
+ 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))))
+ {
+ struct elf_x86_64_link_hash_entry *eh
+ = (struct elf_x86_64_link_hash_entry *) h;
+ eh->func_pointer_refcount += 1;
+ }
+ }
}
size_reloc = FALSE;
may need to keep relocations for symbols satisfied by a
dynamic library if we manage to avoid copy relocs for the
symbol. */
- if ((info->shared
+ if ((bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& (! IS_X86_64_PCREL_TYPE (r_type)
|| (h != NULL
|| h->root.type == bfd_link_hash_defweak
|| !h->def_regular))))
|| (ELIMINATE_COPY_RELOCS
- && !info->shared
+ && !bfd_link_pic (info)
&& (sec->flags & SEC_ALLOC) != 0
&& h != NULL
&& (h->root.type == bfd_link_hash_defweak
if (use_plt_got
&& h != NULL
&& h->plt.refcount > 0
- && h->got.refcount > 0
+ && (((info->flags & DF_BIND_NOW) && !h->pointer_equality_needed)
+ || h->got.refcount > 0)
&& htab->plt_got == NULL)
{
/* Create the GOT procedure linkage table. */
return FALSE;
}
- if (r_type == R_X86_64_GOTPCREL
+ 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))
- sec->need_convert_mov_to_lea = 1;
+ sec->need_convert_load = 1;
}
return TRUE;
bfd_signed_vma *local_got_refcounts;
const Elf_Internal_Rela *rel, *relend;
- if (info->relocatable)
+ if (bfd_link_relocatable (info))
return TRUE;
htab = elf_x86_64_hash_table (info);
unsigned long r_symndx;
unsigned int r_type;
struct elf_link_hash_entry *h = NULL;
+ bfd_boolean pointer_reloc;
r_symndx = htab->r_sym (rel->r_info);
if (r_symndx >= symtab_hdr->sh_info)
rel, relend, h, r_symndx))
return FALSE;
+ pointer_reloc = FALSE;
switch (r_type)
{
case R_X86_64_TLSLD:
case R_X86_64_GOTTPOFF:
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_GOT64:
case R_X86_64_GOTPCREL64:
case R_X86_64_GOTPLT64:
}
break;
- case R_X86_64_8:
- case R_X86_64_16:
case R_X86_64_32:
- case R_X86_64_64:
case R_X86_64_32S:
+ pointer_reloc = !ABI_64_P (abfd);
+ goto pointer;
+
+ case R_X86_64_64:
+ pointer_reloc = TRUE;
+ case R_X86_64_8:
+ case R_X86_64_16:
case R_X86_64_PC8:
case R_X86_64_PC16:
case R_X86_64_PC32:
case R_X86_64_PC64:
case R_X86_64_SIZE32:
case R_X86_64_SIZE64:
- if (info->shared
+pointer:
+ if (bfd_link_pic (info)
&& (h == NULL || h->type != STT_GNU_IFUNC))
break;
/* Fall thru */
{
if (h->plt.refcount > 0)
h->plt.refcount -= 1;
+ if (pointer_reloc && (sec->flags & SEC_READONLY) == 0)
+ {
+ struct elf_x86_64_link_hash_entry *eh
+ = (struct elf_x86_64_link_hash_entry *) h;
+ if (eh->func_pointer_refcount > 0)
+ eh->func_pointer_refcount -= 1;
+ }
}
break;
only references to the symbol are via the global offset table.
For such cases we need not do anything here; the relocations will
be handled correctly by relocate_section. */
- if (!info->executable)
+ if (!bfd_link_executable (info))
return TRUE;
/* If there are no references to this symbol that do not use the
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
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 > 0 || eh->plt_got.refcount > 0))
+ && (h->plt.refcount > eh->func_pointer_refcount
+ || eh->plt_got.refcount > 0))
{
- bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
+ bfd_boolean use_plt_got;
+
+ /* Clear the reference count of function pointer relocations
+ if PLT is used. */
+ eh->func_pointer_refcount = 0;
+
+ if ((info->flags & DF_BIND_NOW) && !h->pointer_equality_needed)
+ {
+ /* Don't use the regular PLT for DF_BIND_NOW. */
+ h->plt.offset = (bfd_vma) -1;
+
+ /* Use the GOT PLT. */
+ h->got.refcount = 1;
+ eh->plt_got.refcount = 1;
+ }
+
+ use_plt_got = eh->plt_got.refcount > 0;
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
return FALSE;
}
- if (info->shared
+ if (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
{
asection *s = htab->elf.splt;
asection *bnd_s = htab->plt_bnd;
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 = plt_entry_size;
+
if (use_plt_got)
eh->plt_got.offset = got_s->size;
else
{
- /* If this is the first .plt entry, make room for the
- special first entry. */
- if (s->size == 0)
- s->size = plt_entry_size;
h->plt.offset = s->size;
if (bnd_s)
eh->plt_bnd.offset = bnd_s->size;
location in the .plt. This is required to make function
pointers compare as equal between the normal executable and
the shared library. */
- if (! info->shared
+ if (! bfd_link_pic (info)
&& !h->def_regular)
{
if (use_plt_got)
/* 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
- && info->executable
+ && bfd_link_executable (info)
&& h->dynindx == -1
&& elf_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE)
{
else if (! GOT_TLS_GDESC_P (tls_type)
&& (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak)
- && (info->shared
+ && (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))
space for pc-relative relocs that have become local due to symbol
visibility changes. */
- if (info->shared)
+ 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.
}
/* For PIE, discard space for pc-relative relocs against
symbols which turn out to need copy relocs. */
- else if (info->executable
+ else if (bfd_link_executable (info)
&& (h->needs_copy || eh->needs_copy)
&& h->def_dynamic
&& !h->def_regular)
{
/* For the non-shared case, discard space for relocs against
symbols which turn out to need copy relocs or are not
- dynamic. */
+ dynamic. Keep dynamic relocations for run-time function
+ pointer initialization. */
- if (!h->non_got_ref
+ if ((!h->non_got_ref || eh->func_pointer_refcount > 0)
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
}
eh->dyn_relocs = NULL;
+ eh->func_pointer_refcount = 0;
keep: ;
}
info->flags |= DF_TEXTREL;
- if ((info->warn_shared_textrel && info->shared)
+ if ((info->warn_shared_textrel && bfd_link_pic (info))
|| info->error_textrel)
info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"),
p->sec->owner, h->root.root.string,
return TRUE;
}
-/* Convert
+/* With the local symbol, foo, we convert
mov foo@GOTPCREL(%rip), %reg
to
lea foo(%rip), %reg
- with the local symbol, foo. */
+ 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 bfd_boolean
-elf_x86_64_convert_mov_to_lea (bfd *abfd, asection *sec,
- struct bfd_link_info *link_info)
+elf_x86_64_convert_load (bfd *abfd, asection *sec,
+ struct bfd_link_info *link_info)
{
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Rela *internal_relocs;
bfd_boolean changed_contents;
bfd_boolean changed_relocs;
bfd_signed_vma *local_got_refcounts;
+ bfd_vma maxpagesize;
/* Don't even try to convert non-ELF outputs. */
if (!is_elf_hash_table (link_info->hash))
/* Nothing to do if there is no need or no output. */
if ((sec->flags & (SEC_CODE | SEC_RELOC)) != (SEC_CODE | SEC_RELOC)
- || sec->need_convert_mov_to_lea == 0
+ || sec->need_convert_load == 0
|| bfd_is_abs_section (sec->output_section))
return TRUE;
changed_contents = FALSE;
changed_relocs = FALSE;
local_got_refcounts = elf_local_got_refcounts (abfd);
+ maxpagesize = get_elf_backend_data (abfd)->maxpagesize;
/* Get the section contents. */
if (elf_section_data (sec)->this_hdr.contents != NULL)
unsigned int r_symndx = htab->r_sym (irel->r_info);
unsigned int indx;
struct elf_link_hash_entry *h;
+ asection *tsec;
+ char symtype;
+ bfd_vma toff, roff;
+ bfd_signed_vma raddend;
+ unsigned int opcode;
+ unsigned int modrm;
+
+ if (r_type != R_X86_64_GOTPCREL
+ && r_type != R_X86_64_GOTPCRELX
+ && r_type != R_X86_64_REX_GOTPCRELX)
+ continue;
+
+ roff = irel->r_offset;
+ if (roff < (r_type == R_X86_64_REX_GOTPCRELX ? 3 : 2))
+ continue;
- if (r_type != R_X86_64_GOTPCREL)
+ raddend = irel->r_addend;
+ /* Addend for 32-bit PC-relative relocation must be -4. */
+ if (raddend != -4)
continue;
+ opcode = bfd_get_8 (abfd, contents + roff - 2);
+
+ /* It is OK to convert mov to lea. */
+ 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)
+ 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;
+ }
+ }
+
/* Get the symbol referred to by the reloc. */
if (r_symndx < symtab_hdr->sh_info)
{
isym = bfd_sym_from_r_symndx (&htab->sym_cache,
abfd, r_symndx);
- /* STT_GNU_IFUNC must keep R_X86_64_GOTPCREL relocation. */
- if (ELF_ST_TYPE (isym->st_info) != STT_GNU_IFUNC
- && irel->r_offset >= 2
- && bfd_get_8 (abfd, contents + irel->r_offset - 2) == 0x8b)
+ symtype = ELF_ST_TYPE (isym->st_info);
+
+ /* STT_GNU_IFUNC must keep GOTPCREL relocations and skip
+ relocation against undefined symbols. */
+ if (symtype == STT_GNU_IFUNC || isym->st_shndx == SHN_UNDEF)
+ continue;
+
+ if (isym->st_shndx == SHN_ABS)
+ tsec = bfd_abs_section_ptr;
+ 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);
+
+ h = NULL;
+ toff = isym->st_value;
+ }
+ else
+ {
+ indx = r_symndx - symtab_hdr->sh_info;
+ h = elf_sym_hashes (abfd)[indx];
+ BFD_ASSERT (h != NULL);
+
+ 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;
+
+ /* 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))
{
- bfd_put_8 (abfd, 0x8d, contents + irel->r_offset - 2);
- irel->r_info = htab->r_info (r_symndx, R_X86_64_PC32);
- if (local_got_refcounts != NULL
- && local_got_refcounts[r_symndx] > 0)
- local_got_refcounts[r_symndx] -= 1;
- changed_contents = TRUE;
- changed_relocs = TRUE;
+ /* 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. */
+ if (h->def_regular
+ && (h->root.type == bfd_link_hash_new
+ || h->root.type == bfd_link_hash_undefined))
+ goto convert;
+ tsec = h->root.u.def.section;
+ toff = h->root.u.def.value;
+ symtype = h->type;
}
- continue;
+ else
+ continue;
}
- indx = r_symndx - symtab_hdr->sh_info;
- h = elf_sym_hashes (abfd)[indx];
- BFD_ASSERT (h != NULL);
+ if (tsec->sec_info_type == SEC_INFO_TYPE_MERGE)
+ {
+ /* At this stage in linking, no SEC_MERGE symbol has been
+ adjusted, so all references to such symbols need to be
+ passed through _bfd_merged_section_offset. (Later, in
+ relocate_section, all SEC_MERGE symbols *except* for
+ section symbols have been adjusted.)
+
+ gas may reduce relocations against symbols in SEC_MERGE
+ sections to a relocation against the section symbol when
+ the original addend was zero. When the reloc is against
+ a section symbol we should include the addend in the
+ offset passed to _bfd_merged_section_offset, since the
+ location of interest is the original symbol. On the
+ other hand, an access to "sym+addend" where "sym" is not
+ a section symbol should not include the addend; Such an
+ access is presumed to be an offset from "sym"; The
+ location of interest is just "sym". */
+ if (symtype == STT_SECTION)
+ toff += raddend;
+
+ toff = _bfd_merged_section_offset (abfd, &tsec,
+ elf_section_data (tsec)->sec_info,
+ toff);
+
+ if (symtype != STT_SECTION)
+ toff += raddend;
+ }
+ else
+ toff += raddend;
- 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;
+ /* Don't convert if R_X86_64_PC32 relocation overflows. */
+ if (tsec->output_section == sec->output_section)
+ {
+ if ((toff - roff + 0x80000000) > 0xffffffff)
+ continue;
+ }
+ else
+ {
+ 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. 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 *asect;
+ bfd_size_type size = 0;
+ for (asect = link_info->output_bfd->sections;
+ asect != NULL;
+ asect = asect->next)
+ {
+ 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;
+ }
+ }
- /* STT_GNU_IFUNC must keep R_X86_64_GOTPCREL relocation. We also
- avoid optimizing _DYNAMIC since ld.so may use its link-time
- address. */
- if (h->def_regular
- && h->type != STT_GNU_IFUNC
- && h != htab->elf.hdynamic
- && SYMBOL_REFERENCES_LOCAL (link_info, h)
- && irel->r_offset >= 2
- && bfd_get_8 (abfd, contents + irel->r_offset - 2) == 0x8b)
+ /* Don't convert GOTPCREL relocations if TSEC isn't placed
+ after SEC. */
+ 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 + distance + maxpagesize - roff + 0x80000000)
+ > 0xffffffff)
+ continue;
+ }
+
+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
+ {
+ /* Convert to "nop call foo". ADDR_PREFIX_OPCODE
+ is a nop prefix. */
+ modrm = 0xe8;
+ nop = link_info->call_nop_byte;
+ if (link_info->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
+ {
+ if (opcode == 0x8b)
+ {
+ /* Convert "mov foo@GOTPCREL(%rip), %reg" to
+ "lea foo(%rip), %reg". */
+ opcode = 0x8d;
+ r_type = R_X86_64_PC32;
+ }
+ else
+ {
+ 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;
+ }
+ bfd_put_8 (abfd, modrm, contents + roff - 1);
+
+ if (r_type == R_X86_64_REX_GOTPCRELX)
+ {
+ /* 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;
+ bfd_put_8 (abfd, rex, contents + roff - 3);
+ }
+ /* No addend for R_X86_64_32S relocation. */
+ irel->r_addend = 0;
+ r_type = R_X86_64_32S;
+ }
+
+ bfd_put_8 (abfd, opcode, contents + roff - 2);
+ }
+
+ irel->r_info = htab->r_info (r_symndx, r_type);
+ changed_contents = TRUE;
+ changed_relocs = TRUE;
+
+ if (h)
{
- bfd_put_8 (abfd, 0x8d, contents + irel->r_offset - 2);
- irel->r_info = htab->r_info (r_symndx, R_X86_64_PC32);
if (h->got.refcount > 0)
h->got.refcount -= 1;
- changed_contents = TRUE;
- changed_relocs = TRUE;
+ }
+ else
+ {
+ if (local_got_refcounts != NULL
+ && local_got_refcounts[r_symndx] > 0)
+ local_got_refcounts[r_symndx] -= 1;
}
}
if (htab->elf.dynamic_sections_created)
{
/* Set the contents of the .interp section to the interpreter. */
- if (info->executable)
+ if (bfd_link_executable (info) && !info->nointerp)
{
s = bfd_get_linker_section (dynobj, ".interp");
if (s == NULL)
{
struct elf_dyn_relocs *p;
- if (!elf_x86_64_convert_mov_to_lea (ibfd, s, info))
+ if (!elf_x86_64_convert_load (ibfd, s, info))
return FALSE;
for (p = (struct elf_dyn_relocs *)
&& (info->flags & DF_TEXTREL) == 0)
{
info->flags |= DF_TEXTREL;
- if ((info->warn_shared_textrel && info->shared)
+ if ((info->warn_shared_textrel && bfd_link_pic (info))
|| info->error_textrel)
info->callbacks->einfo (_("%P: %B: warning: relocation in readonly section `%A'\n"),
p->sec->owner, p->sec);
if (GOT_TLS_GD_P (*local_tls_type))
s->size += GOT_ENTRY_SIZE;
}
- if (info->shared
+ if (bfd_link_pic (info)
|| GOT_TLS_GD_ANY_P (*local_tls_type)
|| *local_tls_type == GOT_TLS_IE)
{
#define add_dynamic_entry(TAG, VAL) \
_bfd_elf_add_dynamic_entry (info, TAG, VAL)
- if (info->executable)
+ if (bfd_link_executable (info))
{
if (!add_dynamic_entry (DT_DEBUG, 0))
return FALSE;
if (htab->elf.splt->size != 0)
{
- if (!add_dynamic_entry (DT_PLTGOT, 0)
- || !add_dynamic_entry (DT_PLTRELSZ, 0)
- || !add_dynamic_entry (DT_PLTREL, DT_RELA)
- || !add_dynamic_entry (DT_JMPREL, 0))
+ /* DT_PLTGOT is used by prelink even if there is no PLT
+ relocation. */
+ if (!add_dynamic_entry (DT_PLTGOT, 0))
return FALSE;
+ if (htab->elf.srelplt->size != 0)
+ {
+ if (!add_dynamic_entry (DT_PLTRELSZ, 0)
+ || !add_dynamic_entry (DT_PLTREL, DT_RELA)
+ || !add_dynamic_entry (DT_JMPREL, 0))
+ return FALSE;
+ }
+
if (htab->tlsdesc_plt
&& (!add_dynamic_entry (DT_TLSDESC_PLT, 0)
|| !add_dynamic_entry (DT_TLSDESC_GOT, 0)))
if ((info->flags & DF_TEXTREL) != 0)
{
+ if ((elf_tdata (output_bfd)->has_gnu_symbols
+ & elf_gnu_symbol_ifunc) == elf_gnu_symbol_ifunc)
+ {
+ info->callbacks->einfo
+ (_("%P%X: read-only segment has dynamic IFUNC relocations; recompile with -fPIC\n"));
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+
if (!add_dynamic_entry (DT_TEXTREL, 0))
return FALSE;
}
struct elf_x86_64_link_hash_table *htab;
struct bfd_link_hash_entry *base;
- if (!info->executable)
+ if (!bfd_link_executable (info))
return;
htab = elf_x86_64_hash_table (info);
bfd_vma *local_got_offsets;
bfd_vma *local_tlsdesc_gotents;
Elf_Internal_Rela *rel;
+ Elf_Internal_Rela *wrel;
Elf_Internal_Rela *relend;
const unsigned int plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd);
elf_x86_64_set_tls_module_base (info);
- rel = relocs;
+ rel = wrel = relocs;
relend = relocs + input_section->reloc_count;
- for (; rel < relend; rel++)
+ for (; rel < relend; wrel++, rel++)
{
unsigned int r_type;
reloc_howto_type *howto;
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)
- continue;
+ {
+ if (wrel != rel)
+ *wrel = *rel;
+ continue;
+ }
if (r_type >= (int) R_X86_64_standard)
{
st_size = sym->st_size;
/* Relocate against local STT_GNU_IFUNC symbol. */
- if (!info->relocatable
+ if (!bfd_link_relocatable (info)
&& ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
{
h = elf_x86_64_get_local_sym_hash (htab, input_bfd,
}
if (sec != NULL && discarded_section (sec))
- RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
- rel, 1, relend, howto, 0, contents);
+ {
+ _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--;
- if (info->relocatable)
- continue;
+ continue;
+ }
+
+ if (bfd_link_relocatable (info))
+ {
+ if (wrel != rel)
+ *wrel = *rel;
+ continue;
+ }
if (rel->r_addend == 0 && !ABI_64_P (output_bfd))
{
bfd_vma plt_index;
const char *name;
- if ((input_section->flags & SEC_ALLOC) == 0
- || h->plt.offset == (bfd_vma) -1)
+ if ((input_section->flags & SEC_ALLOC) == 0)
+ {
+ /* 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 ();
+ }
+ else if (h->plt.offset == (bfd_vma) -1)
abort ();
/* STT_GNU_IFUNC symbol must go through PLT. */
return FALSE;
case R_X86_64_32S:
- if (info->shared)
+ if (bfd_link_pic (info))
abort ();
goto do_relocation;
/* Generate dynamic relcoation only when there is a
non-GOT reference in a shared object. */
- if (info->shared && h->non_got_ref)
+ if (bfd_link_pic (info) && h->non_got_ref)
{
Elf_Internal_Rela outrel;
asection *sreloc;
if (h->dynindx == -1
|| h->forced_local
- || info->executable)
+ || bfd_link_executable (info))
{
/* This symbol is resolved locally. */
outrel.r_info = htab->r_info (0, R_X86_64_IRELATIVE);
goto do_relocation;
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;
/* Relocation is to the entry for this symbol in the global
offset table. */
case R_X86_64_GOTPCREL:
+ case R_X86_64_GOTPCRELX:
+ case R_X86_64_REX_GOTPCRELX:
case R_X86_64_GOTPCREL64:
/* Use global offset table entry as symbol value. */
case R_X86_64_GOTPLT64:
dyn = htab->elf.dynamic_sections_created;
- if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h)
- || (info->shared
+ if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info), h)
+ || (bfd_link_pic (info)
&& SYMBOL_REFERENCES_LOCAL (info, h))
|| (ELF_ST_VISIBILITY (h->other)
&& h->root.type == bfd_link_hash_undefweak))
bfd_put_64 (output_bfd, relocation,
base_got->contents + off);
- if (info->shared)
+ if (bfd_link_pic (info))
{
asection *s;
Elf_Internal_Rela outrel;
relocation = base_got->output_section->vma
+ base_got->output_offset + off;
- if (r_type != R_X86_64_GOTPCREL && r_type != R_X86_64_GOTPCREL64)
+ if (r_type != R_X86_64_GOTPCREL
+ && r_type != R_X86_64_GOTPCRELX
+ && r_type != R_X86_64_REX_GOTPCRELX
+ && r_type != R_X86_64_GOTPCREL64)
relocation -= htab->elf.sgotplt->output_section->vma
- htab->elf.sgotplt->output_offset;
symbol for shared library since it may not be local when
used as function address or with copy relocation. We also
need to make sure that a symbol is referenced locally. */
- if (info->shared && h)
+ if (bfd_link_pic (info) && h)
{
if (!h->def_regular)
{
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
- else if (!info->executable
+ else if (!bfd_link_executable (info)
&& !SYMBOL_REFERENCES_LOCAL (info, h)
&& (h->type == STT_FUNC
|| h->type == STT_OBJECT)
case R_X86_64_PC32_BND:
/* Don't complain about -fPIC if the symbol is undefined when
building executable. */
- if (info->shared
+ if (bfd_link_pic (info)
&& (input_section->flags & SEC_ALLOC) != 0
&& (input_section->flags & SEC_READONLY) != 0
&& h != NULL
- && !(info->executable
+ && !(bfd_link_executable (info)
&& h->root.type == bfd_link_hash_undefined))
{
bfd_boolean fail = FALSE;
defined locally or for a branch. */
fail = !h->def_regular && !branch;
}
- else if (!(info->executable
+ else if (!(bfd_link_executable (info)
&& (h->needs_copy || eh->needs_copy)))
{
/* Symbol doesn't need copy reloc and isn't referenced
/* 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. */
- if ((info->shared
- && !(info->executable
+ when building executable. Copy dynamic function pointer
+ relocations. */
+ if ((bfd_link_pic (info)
+ && !(bfd_link_executable (info)
&& h != NULL
&& (h->needs_copy
|| eh->needs_copy
&& r_type != R_X86_64_SIZE64)
|| ! SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
- && !info->shared
+ && !bfd_link_pic (info)
&& h != NULL
&& h->dynindx != -1
- && !h->non_got_ref
+ && (!h->non_got_ref || eh->func_pointer_refcount > 0)
&& ((h->def_dynamic
&& !h->def_regular)
|| h->root.type == bfd_link_hash_undefweak
else if (h != NULL
&& h->dynindx != -1
&& (IS_X86_64_PCREL_TYPE (r_type)
- || ! info->shared
+ || ! bfd_link_pic (info)
|| ! SYMBOLIC_BIND (info, h)
|| ! h->def_regular))
{
contents + roff + 8 + largepic);
/* Skip R_X86_64_PC32/R_X86_64_PLT32/R_X86_64_PLTOFF64. */
rel++;
+ wrel++;
continue;
}
else if (ELF32_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
contents + roff + 8 + largepic);
/* Skip R_X86_64_PLT32/R_X86_64_PLTOFF64. */
rel++;
+ wrel++;
continue;
}
else if (ELF32_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC)
"\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0", 12);
/* Skip R_X86_64_PC32/R_X86_64_PLT32/R_X86_64_PLTOFF64. */
rel++;
+ wrel++;
continue;
}
break;
case R_X86_64_DTPOFF32:
- if (!info->executable|| (input_section->flags & SEC_CODE) == 0)
+ if (!bfd_link_executable (info)
+ || (input_section->flags & SEC_CODE) == 0)
relocation -= elf_x86_64_dtpoff_base (info);
else
relocation = elf_x86_64_tpoff (info, relocation);
case R_X86_64_TPOFF32:
case R_X86_64_TPOFF64:
- BFD_ASSERT (info->executable);
+ BFD_ASSERT (bfd_link_executable (info));
relocation = elf_x86_64_tpoff (info, relocation);
break;
return FALSE;
}
}
+
+ if (wrel != rel)
+ *wrel = *rel;
+ }
+
+ if (wrel != rel)
+ {
+ Elf_Internal_Shdr *rel_hdr;
+ size_t deleted = rel - wrel;
+
+ rel_hdr = _bfd_elf_single_rel_hdr (input_section->output_section);
+ rel_hdr->sh_size -= rel_hdr->sh_entsize * deleted;
+ if (rel_hdr->sh_size == 0)
+ {
+ /* It is too late to remove an empty reloc section. Leave
+ one NONE reloc.
+ ??? What is wrong with an empty section??? */
+ rel_hdr->sh_size = rel_hdr->sh_entsize;
+ deleted -= 1;
+ }
+ rel_hdr = _bfd_elf_single_rel_hdr (input_section);
+ rel_hdr->sh_size -= rel_hdr->sh_entsize * deleted;
+ input_section->reloc_count -= deleted;
}
return TRUE;
/* This symbol has an entry in the procedure linkage table. Set
it up. */
if ((h->dynindx == -1
- && !((h->forced_local || info->executable)
+ && !((h->forced_local || bfd_link_executable (info))
&& h->def_regular
&& h->type == STT_GNU_IFUNC))
|| plt == NULL
+ gotplt->output_offset
+ got_offset);
if (h->dynindx == -1
- || ((info->executable
+ || ((bfd_link_executable (info)
|| ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
&& h->def_regular
&& h->type == STT_GNU_IFUNC))
if (h->def_regular
&& h->type == STT_GNU_IFUNC)
{
- if (info->shared)
+ if (bfd_link_pic (info))
{
/* Generate R_X86_64_GLOB_DAT. */
goto do_glob_dat;
return TRUE;
}
}
- else if (info->shared
+ else if (bfd_link_pic (info)
&& SYMBOL_REFERENCES_LOCAL (info, h))
{
if (!h->def_regular)
dynamic linker, before writing them out. */
static enum elf_reloc_type_class
-elf_x86_64_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED,
+elf_x86_64_reloc_type_class (const struct bfd_link_info *info,
const asection *rel_sec ATTRIBUTE_UNUSED,
const Elf_Internal_Rela *rela)
{
+ bfd *abfd = info->output_bfd;
+ const struct elf_backend_data *bed = get_elf_backend_data (abfd);
+ struct elf_x86_64_link_hash_table *htab = elf_x86_64_hash_table (info);
+
+ if (htab->elf.dynsym != NULL
+ && htab->elf.dynsym->contents != NULL)
+ {
+ /* Check relocation against STT_GNU_IFUNC symbol if there are
+ dynamic symbols. */
+ unsigned long r_symndx = htab->r_sym (rela->r_info);
+ Elf_Internal_Sym sym;
+ if (!bed->s->swap_symbol_in (abfd,
+ (htab->elf.dynsym->contents
+ + r_symndx * bed->s->sizeof_sym),
+ 0, &sym))
+ abort ();
+
+ if (ELF_ST_TYPE (sym.st_info) == STT_GNU_IFUNC)
+ return reloc_class_ifunc;
+ }
+
switch ((int) ELF32_R_TYPE (rela->r_info))
{
case R_X86_64_RELATIVE:
reloc_index = H_GET_32 (abfd, (plt_contents + plt_offset
+ bed->plt_reloc_offset));
- if (reloc_index >= count)
- abort ();
- if (plt_bnd)
+ if (reloc_index < count)
{
- /* This is the index in .plt section. */
- long plt_index = plt_offset / bed->plt_entry_size;
- /* Store VMA + the offset in .plt.bnd section. */
- plt_sym_val[reloc_index] =
- (plt_bnd->vma
- + (plt_index - 1) * sizeof (elf_x86_64_legacy_plt2_entry));
+ if (plt_bnd)
+ {
+ /* This is the index in .plt section. */
+ long plt_index = plt_offset / bed->plt_entry_size;
+ /* Store VMA + the offset in .plt.bnd section. */
+ plt_sym_val[reloc_index] =
+ (plt_bnd->vma
+ + (plt_index - 1) * sizeof (elf_x86_64_legacy_plt2_entry));
+ }
+ else
+ plt_sym_val[reloc_index] = plt->vma + plt_offset;
}
- else
- plt_sym_val[reloc_index] = plt->vma + plt_offset;
plt_offset += bed->plt_entry_size;
+
+ /* PR binutils/18437: Skip extra relocations in the .rela.plt
+ section. */
+ if (plt_offset >= plt->size)
+ break;
}
free (plt_contents);
return TRUE;
}
- if ((ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC
- || ELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE)
+ if (ELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE
&& (abfd->flags & DYNAMIC) == 0
&& bfd_get_flavour (info->output_bfd) == bfd_target_elf_flavour)
- elf_tdata (info->output_bfd)->has_gnu_symbols = TRUE;
+ elf_tdata (info->output_bfd)->has_gnu_symbols
+ |= elf_gnu_symbol_unique;
return TRUE;
}