/* Intel 80386/80486-specific support for 32-bit ELF
- Copyright (C) 1993-2015 Free Software Foundation, Inc.
+ Copyright (C) 1993-2016 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
#include "objalloc.h"
#include "hashtab.h"
#include "dwarf2.h"
+#include "opcode/i386.h"
/* 386 uses REL relocations instead of RELA. */
#define USE_REL 1
HOWTO(R_386_IRELATIVE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield,
bfd_elf_generic_reloc, "R_386_IRELATIVE",
TRUE, 0xffffffff, 0xffffffff, FALSE),
+ HOWTO(R_386_GOT32X, 0, 2, 32, FALSE, 0, complain_overflow_bitfield,
+ bfd_elf_generic_reloc, "R_386_GOT32X",
+ TRUE, 0xffffffff, 0xffffffff, FALSE),
/* Another gap. */
-#define R_386_ext2 (R_386_IRELATIVE + 1 - R_386_tls_offset)
+#define R_386_ext2 (R_386_GOT32X + 1 - R_386_tls_offset)
#define R_386_vt_offset (R_386_GNU_VTINHERIT - R_386_ext2)
/* GNU extension to record C++ vtable hierarchy. */
TRACE ("BFD_RELOC_386_IRELATIVE");
return &elf_howto_table[R_386_IRELATIVE - R_386_tls_offset];
+ case BFD_RELOC_386_GOT32X:
+ TRACE ("BFD_RELOC_386_GOT32X");
+ return &elf_howto_table[R_386_GOT32X - R_386_tls_offset];
+
case BFD_RELOC_VTABLE_INHERIT:
TRACE ("BFD_RELOC_VTABLE_INHERIT");
return &elf_howto_table[R_386_GNU_VTINHERIT - R_386_vt_offset];
#define elf_backend_arch_data &elf_i386_arch_bed
+/* Is a undefined weak symbol which is resolved to 0. Reference to an
+ undefined weak symbol is resolved to 0 when building executable if
+ it isn't dynamic and
+ 1. Has non-GOT/non-PLT relocations in text section. Or
+ 2. Has no GOT/PLT relocation.
+ */
+#define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
+ ((EH)->elf.root.type == bfd_link_hash_undefweak \
+ && bfd_link_executable (INFO) \
+ && (elf_i386_hash_table (INFO)->interp == NULL \
+ || !(EH)->has_got_reloc \
+ || (EH)->has_non_got_reloc \
+ || !(INFO)->dynamic_undefined_weak))
+
/* i386 ELF linker hash entry. */
struct elf_i386_link_hash_entry
/* Symbol is referenced by R_386_GOTOFF relocation. */
unsigned int gotoff_ref : 1;
+ /* Symbol has GOT or PLT relocations. */
+ unsigned int has_got_reloc : 1;
+
+ /* Symbol has non-GOT/non-PLT relocations in text sections. */
+ unsigned int has_non_got_reloc : 1;
+
/* Reference count of C/C++ function pointer relocations in read-write
section which can be resolved at run-time. */
bfd_signed_vma func_pointer_refcount;
struct elf_link_hash_table elf;
/* Short-cuts to get to dynamic linker sections. */
+ asection *interp;
asection *sdynbss;
asection *srelbss;
asection *plt_eh_frame;
eh->dyn_relocs = NULL;
eh->tls_type = GOT_UNKNOWN;
eh->gotoff_ref = 0;
+ eh->has_got_reloc = 0;
+ eh->has_non_got_reloc = 0;
eh->func_pointer_refcount = 0;
eh->plt_got.offset = (bfd_vma) -1;
eh->tlsdesc_got = (bfd_vma) -1;
generate a R_386_COPY reloc. */
edir->gotoff_ref |= eind->gotoff_ref;
+ edir->has_got_reloc |= eind->has_got_reloc;
+ edir->has_non_got_reloc |= eind->has_non_got_reloc;
+
if (ELIMINATE_COPY_RELOCS
&& ind->root.type != bfd_link_hash_indirect
&& dir->dynamic_adjusted)
/* 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 linkage
case R_386_PC32:
case R_386_PLT32:
case R_386_GOT32:
+ case R_386_GOT32X:
if (htab->elf.dynobj == NULL)
htab->elf.dynobj = abfd;
if (!_bfd_elf_create_ifunc_sections (htab->elf.dynobj, info))
if (h == NULL)
continue;
+ eh->has_got_reloc = 1;
h->needs_plt = 1;
h->plt.refcount += 1;
break;
/* Fall through */
case R_386_GOT32:
+ case R_386_GOT32X:
case R_386_TLS_GD:
case R_386_TLS_GOTDESC:
case R_386_TLS_DESC_CALL:
switch (r_type)
{
default:
- case R_386_GOT32: tls_type = GOT_NORMAL; break;
+ case R_386_GOT32:
+ case R_386_GOT32X:
+ tls_type = GOT_NORMAL;
+ break;
case R_386_TLS_GD: tls_type = GOT_TLS_GD; break;
case R_386_TLS_GOTDESC:
case R_386_TLS_DESC_CALL:
return FALSE;
}
if (r_type != R_386_TLS_IE)
- break;
+ {
+ if (eh != NULL)
+ eh->has_got_reloc = 1;
+ break;
+ }
/* Fall through */
case R_386_TLS_LE_32:
case R_386_TLS_LE:
+ if (eh != NULL)
+ eh->has_got_reloc = 1;
if (bfd_link_executable (info))
break;
info->flags |= DF_STATIC_TLS;
- /* Fall through */
+ goto do_relocation;
case R_386_32:
case R_386_PC32:
- if (h != NULL && bfd_link_executable (info))
+ if (eh != NULL && (sec->flags & SEC_CODE) != 0)
+ eh->has_non_got_reloc = 1;
+do_relocation:
+ /* STT_GNU_IFUNC symbol must go through PLT even if it is
+ locally defined and undefined symbol may turn out to be
+ a STT_GNU_IFUNC symbol later. */
+ if (h != NULL
+ && (bfd_link_executable (info)
+ || ((h->type == STT_GNU_IFUNC
+ || h->root.type == bfd_link_hash_undefweak
+ || h->root.type == bfd_link_hash_undefined)
+ && SYMBOLIC_BIND (info, h))))
{
/* If this reloc is in a read-only section, we might
need a copy reloc. We can't check reliably at this
/* 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_386_PC32)
+ if (r_type == R_386_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
{
h->pointer_equality_needed = 1;
/* R_386_32 can be resolved at run-time. */
return FALSE;
}
- if (r_type == R_386_GOT32
+ if ((r_type == R_386_GOT32 || r_type == R_386_GOT32X)
&& (h == NULL || h->type != STT_GNU_IFUNC))
- sec->need_convert_mov_to_lea = 1;
+ sec->need_convert_load = 1;
}
return TRUE;
case R_386_TLS_IE:
case R_386_TLS_GOTIE:
case R_386_GOT32:
+ case R_386_GOT32X:
if (h != NULL)
{
if (h->got.refcount > 0)
return TRUE;
}
+/* Remove undefined weak symbol from the dynamic symbol table if it
+ is resolved to 0. */
+
+static bfd_boolean
+elf_i386_fixup_symbol (struct bfd_link_info *info,
+ struct elf_link_hash_entry *h)
+{
+ if (h->dynindx != -1
+ && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info,
+ elf_i386_hash_entry (h)))
+ {
+ h->dynindx = -1;
+ _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
+ h->dynstr_index);
+ }
+ return TRUE;
+}
+
/* Adjust a symbol defined by a dynamic object and referenced by a
regular object. The current definition is in some section of the
dynamic object, but we're not including those sections. We have to
struct elf_i386_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;
plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd);
+ resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
+
/* Clear the reference count of function pointer relocations if
symbol isn't a normal function. */
if (h->type != STT_FUNC)
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
- && !h->forced_local)
+ && !h->forced_local
+ && !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
script. */
htab->elf.sgotplt->size += 4;
- /* 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++;
+ /* 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 (get_elf_i386_backend_data (info->output_bfd)->is_vxworks
}
else
{
+ eh->plt_got.offset = (bfd_vma) -1;
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
}
else
{
+ eh->plt_got.offset = (bfd_vma) -1;
h->plt.offset = (bfd_vma) -1;
h->needs_plt = 0;
}
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
- && !h->forced_local)
+ && !h->forced_local
+ && !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
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. */
+ 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)
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
+ && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+ && !resolved_to_zero)
|| h->root.type != bfd_link_hash_undefweak)
&& (bfd_link_pic (info)
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h)))
}
/* Also discard relocs on undefined weak syms with non-default
- visibility. */
+ visibility or in PIE. */
if (eh->dyn_relocs != NULL
&& h->root.type == bfd_link_hash_undefweak)
{
- if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
- eh->dyn_relocs = NULL;
+ /* 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;
- /* Make sure undefined weak symbols are output as a dynamic
- symbol in PIEs. */
+ 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)
{
dynamic. Keep dynamic relocations for run-time function
pointer initialization. */
- if ((!h->non_got_ref || eh->func_pointer_refcount > 0)
+ if ((!h->non_got_ref
+ || eh->func_pointer_refcount > 0
+ || (h->root.type == bfd_link_hash_undefweak
+ && !resolved_to_zero))
&& ((h->def_dynamic
&& !h->def_regular)
|| (htab->elf.dynamic_sections_created
/* Make sure this symbol is output as a dynamic symbol.
Undefined weak syms won't yet be marked as dynamic. */
if (h->dynindx == -1
- && !h->forced_local)
+ && !h->forced_local
+ && !resolved_to_zero)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
return TRUE;
}
-/* Convert
- mov foo@GOT(%reg), %reg
+/* With the local symbol, foo, we convert
+ mov foo@GOT[(%reg1)], %reg2
+ to
+ lea foo[@GOTOFF(%reg1)], %reg2
+ and convert
+ call/jmp *foo@GOT[(%reg)]
to
- lea foo@GOTOFF(%reg), %reg
- with the local symbol, foo. */
+ nop call foo/jmp foo nop
+ When PIC is false, convert
+ test %reg1, foo@GOT[(%reg2)]
+ to
+ test $foo, %reg1
+ and convert
+ binop foo@GOT[(%reg1)], %reg2
+ to
+ binop $foo, %reg2
+ where binop is one of adc, add, and, cmp, or, sbb, sub, xor
+ instructions. */
static bfd_boolean
-elf_i386_convert_mov_to_lea (bfd *abfd, asection *sec,
- struct bfd_link_info *link_info)
+elf_i386_convert_load (bfd *abfd, asection *sec,
+ struct bfd_link_info *link_info)
{
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Rela *internal_relocs;
struct elf_i386_link_hash_table *htab;
bfd_boolean changed_contents;
bfd_boolean changed_relocs;
+ bfd_boolean is_pic;
bfd_signed_vma *local_got_refcounts;
/* Don't even try to convert non-ELF outputs. */
/* 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_relocs = FALSE;
local_got_refcounts = elf_local_got_refcounts (abfd);
+ is_pic = bfd_link_pic (link_info);
+
/* Get the section contents. */
if (elf_section_data (sec)->this_hdr.contents != NULL)
contents = elf_section_data (sec)->this_hdr.contents;
unsigned int r_symndx = ELF32_R_SYM (irel->r_info);
unsigned int indx;
struct elf_link_hash_entry *h;
+ unsigned int opcode;
+ unsigned int modrm;
+ bfd_vma roff;
+ bfd_boolean baseless;
+ Elf_Internal_Sym *isym;
+ unsigned int addend;
+ unsigned int nop;
+ bfd_vma nop_offset;
+ bfd_boolean to_reloc_32;
- if (r_type != R_386_GOT32)
+ if (r_type != R_386_GOT32 && r_type != R_386_GOT32X)
continue;
- /* Get the symbol referred to by the reloc. */
- if (r_symndx < symtab_hdr->sh_info)
+ roff = irel->r_offset;
+ if (roff < 2)
+ continue;
+
+ /* Addend for R_386_GOT32 and R_386_GOT32X relocations must be 0. */
+ addend = bfd_get_32 (abfd, contents + roff);
+ if (addend != 0)
+ continue;
+
+ modrm = bfd_get_8 (abfd, contents + roff - 1);
+ baseless = (modrm & 0xc7) == 0x5;
+
+ if (r_type == R_386_GOT32X && baseless && is_pic)
{
- Elf_Internal_Sym *isym;
+ /* For PIC, disallow R_386_GOT32X without a base register
+ since we don't know what the GOT base is. Allow
+ R_386_GOT32 for existing object files. */
+ const char *name;
+ if (r_symndx < symtab_hdr->sh_info)
+ {
+ isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd,
+ r_symndx);
+ name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL);
+ }
+ else
+ {
+ indx = r_symndx - symtab_hdr->sh_info;
+ h = elf_sym_hashes (abfd)[indx];
+ BFD_ASSERT (h != NULL);
+ name = h->root.root.string;
+ }
+
+ (*_bfd_error_handler)
+ (_("%B: direct GOT relocation R_386_GOT32X against `%s' without base register can not be used when making a shared object"),
+ abfd, name);
+ goto error_return;
+ }
+
+ opcode = bfd_get_8 (abfd, contents + roff - 2);
+
+ /* Convert mov to lea since it has been done for a while. */
+ if (opcode != 0x8b)
+ {
+ /* Only convert R_386_GOT32X relocation for call, jmp or
+ one of adc, add, and, cmp, or, sbb, sub, test, xor
+ instructions. */
+ if (r_type != R_386_GOT32X)
+ continue;
+ }
+
+ /* Convert to R_386_32 if PIC is false or there is no base
+ register. */
+ to_reloc_32 = !is_pic || baseless;
+
+ /* Try to convert R_386_GOT32 and R_386_GOT32X. 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_386_GOT32 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)
- {
- bfd_put_8 (abfd, 0x8d, contents + irel->r_offset - 2);
- irel->r_info = ELF32_R_INFO (r_symndx, R_386_GOTOFF);
- if (local_got_refcounts != NULL
- && local_got_refcounts[r_symndx] > 0)
- local_got_refcounts[r_symndx] -= 1;
- changed_contents = TRUE;
- changed_relocs = TRUE;
- }
- continue;
+ /* STT_GNU_IFUNC must keep GOT32 relocations. */
+ if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
+ continue;
+
+ h = NULL;
+ if (opcode == 0x0ff)
+ /* Convert "call/jmp *foo@GOT[(%reg)]". */
+ goto convert_branch;
+ else
+ /* Convert "mov foo@GOT[(%reg1)], %reg2",
+ "test %reg1, foo@GOT(%reg2)" and
+ "binop foo@GOT[(%reg1)], %reg2". */
+ goto convert_load;
}
indx = r_symndx - symtab_hdr->sh_info;
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
- /* STT_GNU_IFUNC must keep R_386_GOT32 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)
+ /* STT_GNU_IFUNC must keep GOT32 relocations. */
+ if (h->type == STT_GNU_IFUNC)
+ continue;
+
+ /* Undefined weak symbol is only bound locally in executable
+ and its reference is resolved as 0. */
+ if (UNDEFINED_WEAK_RESOLVED_TO_ZERO (link_info,
+ elf_i386_hash_entry (h)))
+ {
+ if (opcode == 0xff)
+ {
+ /* No direct branch to 0 for PIC. */
+ if (is_pic)
+ continue;
+ else
+ goto convert_branch;
+ }
+ else
+ {
+ /* We can convert load of address 0 to R_386_32. */
+ to_reloc_32 = TRUE;
+ goto convert_load;
+ }
+ }
+
+ if (opcode == 0xff)
+ {
+ /* We have "call/jmp *foo@GOT[(%reg)]". */
+ if ((h->root.type == bfd_link_hash_defined
+ || h->root.type == bfd_link_hash_defweak)
+ && SYMBOL_REFERENCES_LOCAL (link_info, h))
+ {
+ /* The function is locally defined. */
+convert_branch:
+ /* Convert R_386_GOT32X to R_386_PC32. */
+ if (modrm == 0x15 || (modrm & 0xf8) == 0x90)
+ {
+ /* 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 = roff + 3;
+ irel->r_offset -= 1;
+ }
+ else
+ nop_offset = roff - 2;
+ }
+ else
+ {
+ /* Convert to "jmp foo nop". */
+ modrm = 0xe9;
+ nop = NOP_OPCODE;
+ nop_offset = roff + 3;
+ irel->r_offset -= 1;
+ }
+
+ bfd_put_8 (abfd, nop, contents + nop_offset);
+ bfd_put_8 (abfd, modrm, contents + irel->r_offset - 1);
+ /* When converting to PC-relative relocation, we
+ need to adjust addend by -4. */
+ bfd_put_32 (abfd, -4, contents + irel->r_offset);
+ irel->r_info = ELF32_R_INFO (r_symndx, R_386_PC32);
+
+ if (h)
+ {
+ if (h->got.refcount > 0)
+ h->got.refcount -= 1;
+ }
+ else
+ {
+ if (local_got_refcounts != NULL
+ && local_got_refcounts[r_symndx] > 0)
+ local_got_refcounts[r_symndx] -= 1;
+ }
+
+ changed_contents = TRUE;
+ changed_relocs = TRUE;
+ }
+ }
+ else
{
- bfd_put_8 (abfd, 0x8d, contents + irel->r_offset - 2);
- irel->r_info = ELF32_R_INFO (r_symndx, R_386_GOTOFF);
- if (h->got.refcount > 0)
- h->got.refcount -= 1;
- changed_contents = TRUE;
- changed_relocs = TRUE;
+ /* We have "mov foo@GOT[(%re1g)], %reg2",
+ "test %reg1, foo@GOT(%reg2)" and
+ "binop foo@GOT[(%reg1)], %reg2".
+
+ Avoid optimizing _DYNAMIC since ld.so may use its
+ link-time address. */
+ if (h == htab->elf.hdynamic)
+ continue;
+
+ /* def_regular is set by an assignment in a linker script in
+ bfd_elf_record_link_assignment. */
+ if ((h->def_regular
+ || h->root.type == bfd_link_hash_defined
+ || h->root.type == bfd_link_hash_defweak)
+ && SYMBOL_REFERENCES_LOCAL (link_info, h))
+ {
+convert_load:
+ if (opcode == 0x8b)
+ {
+ if (to_reloc_32)
+ {
+ /* Convert "mov foo@GOT[(%reg1)], %reg2" to
+ "mov $foo, %reg2" with R_386_32. */
+ r_type = R_386_32;
+ modrm = 0xc0 | (modrm & 0x38) >> 3;
+ bfd_put_8 (abfd, modrm, contents + roff - 1);
+ opcode = 0xc7;
+ }
+ else
+ {
+ /* Convert "mov foo@GOT(%reg1), %reg2" to
+ "lea foo@GOTOFF(%reg1), %reg2". */
+ r_type = R_386_GOTOFF;
+ opcode = 0x8d;
+ }
+ }
+ else
+ {
+ /* Only R_386_32 is supported. */
+ if (!to_reloc_32)
+ continue;
+
+ if (opcode == 0x85)
+ {
+ /* Convert "test %reg1, foo@GOT(%reg2)" to
+ "test $foo, %reg1". */
+ modrm = 0xc0 | (modrm & 0x38) >> 3;
+ opcode = 0xf7;
+ }
+ else
+ {
+ /* Convert "binop foo@GOT(%reg1), %reg2" to
+ "binop $foo, %reg2". */
+ modrm = (0xc0
+ | (modrm & 0x38) >> 3
+ | (opcode & 0x3c));
+ opcode = 0x81;
+ }
+ bfd_put_8 (abfd, modrm, contents + roff - 1);
+ r_type = R_386_32;
+ }
+
+ bfd_put_8 (abfd, opcode, contents + roff - 2);
+ irel->r_info = ELF32_R_INFO (r_symndx, r_type);
+
+ if (h)
+ {
+ if (h->got.refcount > 0)
+ h->got.refcount -= 1;
+ }
+ else
+ {
+ if (local_got_refcounts != NULL
+ && local_got_refcounts[r_symndx] > 0)
+ local_got_refcounts[r_symndx] -= 1;
+ }
+
+ changed_contents = TRUE;
+ changed_relocs = TRUE;
+ }
}
}
abort ();
s->size = sizeof ELF_DYNAMIC_INTERPRETER;
s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
+ htab->interp = s;
}
}
{
struct elf_dyn_relocs *p;
- if (!elf_i386_convert_mov_to_lea (ibfd, s, info))
+ if (!elf_i386_convert_load (ibfd, s, info))
return FALSE;
for (p = ((struct elf_dyn_relocs *)
bfd_vma *local_got_offsets;
bfd_vma *local_tlsdesc_gotents;
Elf_Internal_Rela *rel;
+ Elf_Internal_Rela *wrel;
Elf_Internal_Rela *relend;
bfd_boolean is_vxworks_tls;
unsigned plt_entry_size;
plt_entry_size = GET_PLT_ENTRY_SIZE (output_bfd);
- 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;
int tls_type;
bfd_vma st_size;
asection *resolved_plt;
+ bfd_boolean resolved_to_zero;
r_type = ELF32_R_TYPE (rel->r_info);
if (r_type == R_386_GNU_VTINHERIT
|| r_type == R_386_GNU_VTENTRY)
- continue;
+ {
+ if (wrel != rel)
+ *wrel = *rel;
+ continue;
+ }
if ((indx = r_type) >= R_386_standard
&& ((indx = r_type - R_386_ext_offset) - R_386_standard
}
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--;
+
+ continue;
+ }
if (bfd_link_relocatable (info))
- continue;
+ {
+ if (wrel != rel)
+ *wrel = *rel;
+ continue;
+ }
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle
it here if it is defined in a non-shared object. */
goto do_relocation;
case R_386_GOT32:
+ case R_386_GOT32X:
base_got = htab->elf.sgot;
off = h->got.offset;
}
eh = (struct elf_i386_link_hash_entry *) h;
+ resolved_to_zero = (eh != NULL
+ && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh));
+
switch (r_type)
{
+ case R_386_GOT32X:
+ /* Avoid optimizing _DYNAMIC since ld.so may use its
+ link-time address. */
+ if (h == htab->elf.hdynamic)
+ goto r_386_got32;
+
+ if (bfd_link_pic (info))
+ {
+ /* It is OK to convert mov to lea and convert indirect
+ branch to direct branch. It is OK to convert adc,
+ add, and, cmp, or, sbb, sub, test, xor only when PIC
+ is false. */
+ unsigned int opcode, addend;
+ addend = bfd_get_32 (input_bfd, contents + rel->r_offset);
+ if (addend != 0)
+ goto r_386_got32;
+ opcode = bfd_get_8 (input_bfd, contents + rel->r_offset - 2);
+ if (opcode != 0x8b && opcode != 0xff)
+ goto r_386_got32;
+ }
+
+ /* Resolve "mov GOT[(%reg)], %reg",
+ "call/jmp *GOT[(%reg)]", "test %reg, foo@GOT[(%reg)]"
+ and "binop foo@GOT[(%reg)], %reg". */
+ if (h == NULL
+ || (h->plt.offset == (bfd_vma) -1
+ && h->got.offset == (bfd_vma) -1)
+ || htab->elf.sgotplt == NULL)
+ abort ();
+
+ offplt = (htab->elf.sgotplt->output_section->vma
+ + htab->elf.sgotplt->output_offset);
+
+ /* It is relative to .got.plt section. */
+ if (h->got.offset != (bfd_vma) -1)
+ /* Use GOT entry. Mask off the least significant bit in
+ GOT offset which may be set by R_386_GOT32 processing
+ below. */
+ relocation = (htab->elf.sgot->output_section->vma
+ + htab->elf.sgot->output_offset
+ + (h->got.offset & ~1) - offplt);
+ else
+ /* Use GOTPLT entry. */
+ relocation = (h->plt.offset / plt_entry_size - 1 + 3) * 4;
+
+ if (!bfd_link_pic (info))
+ {
+ /* If not PIC, add the .got.plt section address for
+ baseless addressing. */
+ unsigned int modrm;
+ modrm = bfd_get_8 (input_bfd, contents + rel->r_offset - 1);
+ if ((modrm & 0xc7) == 0x5)
+ relocation += offplt;
+ }
+
+ unresolved_reloc = FALSE;
+ break;
+
case R_386_GOT32:
+r_386_got32:
/* Relocation is to the entry for this symbol in the global
offset table. */
if (htab->elf.sgot == NULL)
|| is_vxworks_tls)
break;
- /* Copy dynamic function pointer relocations. */
+ /* Copy dynamic function pointer relocations. Don't generate
+ dynamic relocations against resolved undefined weak symbols
+ in PIE, except for R_386_PC32. */
if ((bfd_link_pic (info)
&& (h == NULL
- || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
- || h->root.type != bfd_link_hash_undefweak)
+ || ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+ && (!resolved_to_zero
+ || r_type == R_386_PC32))
+ || h->root.type != bfd_link_hash_undefweak))
&& ((r_type != R_386_PC32 && r_type != R_386_SIZE32)
|| !SYMBOL_CALLS_LOCAL (info, h)))
|| (ELIMINATE_COPY_RELOCS
&& !bfd_link_pic (info)
&& h != NULL
&& h->dynindx != -1
- && (!h->non_got_ref || eh->func_pointer_refcount > 0)
- && ((h->def_dynamic
- && !h->def_regular)
- || h->root.type == bfd_link_hash_undefweak
- || h->root.type == bfd_link_hash_undefined)))
+ && (!h->non_got_ref
+ || eh->func_pointer_refcount > 0
+ || (h->root.type == bfd_link_hash_undefweak
+ && !resolved_to_zero))
+ && ((h->def_dynamic && !h->def_regular)
+ /* Undefined weak symbol is bound locally when
+ PIC is false. */
+ || h->root.type == bfd_link_hash_undefweak)))
{
Elf_Internal_Rela outrel;
bfd_boolean skip, relocate;
contents + roff);
/* Skip R_386_PC32/R_386_PLT32. */
rel++;
+ wrel++;
continue;
}
else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GOTDESC)
contents + roff + 8);
/* Skip R_386_PLT32. */
rel++;
+ wrel++;
continue;
}
else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GOTDESC)
"\x65\xa1\0\0\0\0\x90\x8d\x74\x26", 11);
/* Skip R_386_PC32/R_386_PLT32. */
rel++;
+ wrel++;
continue;
}
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;
unsigned plt_entry_size;
const struct elf_i386_backend_data *abed;
struct elf_i386_link_hash_entry *eh;
+ bfd_boolean local_undefweak;
htab = elf_i386_hash_table (info);
if (htab == NULL)
eh = (struct elf_i386_link_hash_entry *) h;
+ /* We keep PLT/GOT entries without dynamic PLT/GOT relocations for
+ resolved undefined weak symbols in executable so that their
+ references have value 0 at run-time. */
+ local_undefweak = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
+
if (h->plt.offset != (bfd_vma) -1)
{
bfd_vma plt_index;
it up. */
if ((h->dynindx == -1
+ && !local_undefweak
&& !((h->forced_local || bfd_link_executable (info))
&& h->def_regular
&& h->type == STT_GNU_IFUNC))
+ abed->plt->plt_got_offset);
}
- /* Fill in the entry in the global offset table. */
- bfd_put_32 (output_bfd,
- (plt->output_section->vma
- + plt->output_offset
- + h->plt.offset
- + abed->plt->plt_lazy_offset),
- gotplt->contents + got_offset);
-
- /* Fill in the entry in the .rel.plt section. */
- rel.r_offset = (gotplt->output_section->vma
- + gotplt->output_offset
- + got_offset);
- if (h->dynindx == -1
- || ((bfd_link_executable (info)
- || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
- && h->def_regular
- && h->type == STT_GNU_IFUNC))
+ /* Fill in the entry in the global offset table. Leave the entry
+ as zero for undefined weak symbol in PIE. No PLT relocation
+ against undefined weak symbol in PIE. */
+ if (!local_undefweak)
{
- /* If an STT_GNU_IFUNC symbol is locally defined, generate
- R_386_IRELATIVE instead of R_386_JUMP_SLOT. Store addend
- in the .got.plt section. */
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),
+ (plt->output_section->vma
+ + plt->output_offset
+ + h->plt.offset
+ + abed->plt->plt_lazy_offset),
gotplt->contents + got_offset);
- rel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE);
- /* R_386_IRELATIVE comes last. */
- plt_index = htab->next_irelative_index--;
- }
- else
- {
- rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
- plt_index = htab->next_jump_slot_index++;
- }
- loc = relplt->contents + plt_index * sizeof (Elf32_External_Rel);
- bfd_elf32_swap_reloc_out (output_bfd, &rel, loc);
- /* Don't fill PLT entry for static executables. */
- if (plt == htab->elf.splt)
- {
- bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel),
- plt->contents + h->plt.offset
- + abed->plt->plt_reloc_offset);
- bfd_put_32 (output_bfd, - (h->plt.offset
- + abed->plt->plt_plt_offset + 4),
- plt->contents + h->plt.offset
- + abed->plt->plt_plt_offset);
+ /* Fill in the entry in the .rel.plt section. */
+ rel.r_offset = (gotplt->output_section->vma
+ + gotplt->output_offset
+ + got_offset);
+ if (h->dynindx == -1
+ || ((bfd_link_executable (info)
+ || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
+ && h->def_regular
+ && h->type == STT_GNU_IFUNC))
+ {
+ /* If an STT_GNU_IFUNC symbol is locally defined, generate
+ R_386_IRELATIVE instead of R_386_JUMP_SLOT. Store addend
+ in the .got.plt section. */
+ 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),
+ gotplt->contents + got_offset);
+ rel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE);
+ /* R_386_IRELATIVE comes last. */
+ plt_index = htab->next_irelative_index--;
+ }
+ else
+ {
+ rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT);
+ plt_index = htab->next_jump_slot_index++;
+ }
+
+ loc = relplt->contents + plt_index * sizeof (Elf32_External_Rel);
+ bfd_elf32_swap_reloc_out (output_bfd, &rel, loc);
+
+ /* Don't fill PLT entry for static executables. */
+ if (plt == htab->elf.splt)
+ {
+ bfd_put_32 (output_bfd,
+ plt_index * sizeof (Elf32_External_Rel),
+ plt->contents + h->plt.offset
+ + abed->plt->plt_reloc_offset);
+ bfd_put_32 (output_bfd, - (h->plt.offset
+ + abed->plt->plt_plt_offset + 4),
+ plt->contents + h->plt.offset
+ + abed->plt->plt_plt_offset);
+ }
}
}
else if (eh->plt_got.offset != (bfd_vma) -1)
plt->contents + plt_offset + plt_got_offset);
}
- if (!h->def_regular
+ if (!local_undefweak
+ && !h->def_regular
&& (h->plt.offset != (bfd_vma) -1
|| eh->plt_got.offset != (bfd_vma) -1))
{
sym->st_value = 0;
}
+ /* Don't generate dynamic GOT relocation against undefined weak
+ symbol in executable. */
if (h->got.offset != (bfd_vma) -1
&& ! GOT_TLS_GD_ANY_P (elf_i386_hash_entry(h)->tls_type)
- && (elf_i386_hash_entry(h)->tls_type & GOT_TLS_IE) == 0)
+ && (elf_i386_hash_entry(h)->tls_type & GOT_TLS_IE) == 0
+ && !local_undefweak)
{
Elf_Internal_Rela rel;
h, NULL);
}
+/* Finish up undefined weak symbol handling in PIE. Fill its PLT entry
+ here since undefined weak symbol may not be dynamic and may not be
+ called for elf_i386_finish_dynamic_symbol. */
+
+static bfd_boolean
+elf_i386_pie_finish_undefweak_symbol (struct bfd_hash_entry *bh,
+ void *inf)
+{
+ struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) bh;
+ struct bfd_link_info *info = (struct bfd_link_info *) inf;
+
+ if (h->root.type != bfd_link_hash_undefweak
+ || h->dynindx != -1)
+ return TRUE;
+
+ return elf_i386_finish_dynamic_symbol (info->output_bfd,
+ info, h, NULL);
+}
+
/* Used to decide how to sort relocs in an optimal manner for the
dynamic linker, before writing them out. */
bfd *abfd = info->output_bfd;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
struct elf_link_hash_table *htab = elf_hash_table (info);
- unsigned long r_symndx = ELF32_R_SYM (rela->r_info);
- Elf_Internal_Sym sym;
-
- if (htab->dynsym == NULL
- || !bed->s->swap_symbol_in (abfd,
- (htab->dynsym->contents
- + r_symndx * sizeof (Elf32_External_Sym)),
- 0, &sym))
- abort ();
- /* Check relocation against STT_GNU_IFUNC symbol. */
- if (ELF32_ST_TYPE (sym.st_info) == STT_GNU_IFUNC)
- return reloc_class_ifunc;
+ if (htab->dynsym != NULL
+ && htab->dynsym->contents != NULL)
+ {
+ /* Check relocation against STT_GNU_IFUNC symbol if there are
+ dynamic symbols. */
+ unsigned long r_symndx = ELF32_R_SYM (rela->r_info);
+ Elf_Internal_Sym sym;
+ if (!bed->s->swap_symbol_in (abfd,
+ (htab->dynsym->contents
+ + r_symndx * sizeof (Elf32_External_Sym)),
+ 0, &sym))
+ abort ();
+
+ if (ELF32_ST_TYPE (sym.st_info) == STT_GNU_IFUNC)
+ return reloc_class_ifunc;
+ }
switch (ELF32_R_TYPE (rela->r_info))
{
elf_i386_finish_local_dynamic_symbol,
info);
+ /* Fill PLT entries for undefined weak symbols in PIE. */
+ if (bfd_link_pie (info))
+ bfd_hash_traverse (&info->hash->table,
+ elf_i386_pie_finish_undefweak_symbol,
+ info);
+
return TRUE;
}
reloc_index = H_GET_32 (abfd, (plt_contents + plt_offset
+ bed->plt->plt_reloc_offset));
reloc_index /= sizeof (Elf32_External_Rel);
- if (reloc_index >= count)
- abort ();
- plt_sym_val[reloc_index] = plt->vma + plt_offset;
+ if (reloc_index < count)
+ plt_sym_val[reloc_index] = plt->vma + plt_offset;
+
plt_offset += bed->plt->plt_entry_size;
/* PR binutils/18437: Skip extra relocations in the .rel.plt
((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true)
#define elf_backend_hash_symbol elf_i386_hash_symbol
#define elf_backend_add_symbol_hook elf_i386_add_symbol_hook
+#define elf_backend_fixup_symbol elf_i386_fixup_symbol
#include "elf32-target.h"
projects / deliverable / binutils-gdb.git / blobdiff