0, 0, 0, 0 /* replaced with offset to start of .plt0. */
};
+/* The first entry in a procedure linkage table with BND relocations
+ like this. */
+
+static const bfd_byte elf_x86_64_bnd_plt0_entry[PLT_ENTRY_SIZE] =
+{
+ 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */
+ 0xf2, 0xff, 0x25, 16, 0, 0, 0, /* bnd jmpq *GOT+16(%rip) */
+ 0x0f, 0x1f, 0 /* nopl (%rax) */
+};
+
+/* Subsequent entries for legacy branches in a procedure linkage table
+ with BND relocations look like this. */
+
+static const bfd_byte elf_x86_64_legacy_plt_entry[PLT_ENTRY_SIZE] =
+{
+ 0x68, 0, 0, 0, 0, /* pushq immediate */
+ 0xe9, 0, 0, 0, 0, /* jmpq relative */
+ 0x66, 0x0f, 0x1f, 0x44, 0, 0 /* nopw (%rax,%rax,1) */
+};
+
+/* Subsequent entries for branches with BND prefx in a procedure linkage
+ table with BND relocations look like this. */
+
+static const bfd_byte elf_x86_64_bnd_plt_entry[PLT_ENTRY_SIZE] =
+{
+ 0x68, 0, 0, 0, 0, /* pushq immediate */
+ 0xf2, 0xe9, 0, 0, 0, 0, /* bnd jmpq relative */
+ 0x0f, 0x1f, 0x44, 0, 0 /* nopl 0(%rax,%rax,1) */
+};
+
+/* Entries for legacy branches in the second procedure linkage table
+ look like this. */
+
+static const bfd_byte elf_x86_64_legacy_plt2_entry[8] =
+{
+ 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */
+ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
+ 0x66, 0x90 /* xchg %ax,%ax */
+};
+
+/* Entries for branches with BND prefix in the second procedure linkage
+ table look like this. */
+
+static const bfd_byte elf_x86_64_bnd_plt2_entry[8] =
+{
+ 0xf2, 0xff, 0x25, /* bnd jmpq *name@GOTPC(%rip) */
+ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */
+ 0x90 /* nop */
+};
+
/* .eh_frame covering the .plt section. */
static const bfd_byte elf_x86_64_eh_frame_plt[] =
sizeof (elf_x86_64_eh_frame_plt), /* eh_frame_plt_size */
};
+static const struct elf_x86_64_backend_data elf_x86_64_bnd_arch_bed =
+ {
+ elf_x86_64_bnd_plt0_entry, /* plt0_entry */
+ elf_x86_64_bnd_plt_entry, /* plt_entry */
+ sizeof (elf_x86_64_bnd_plt_entry), /* plt_entry_size */
+ 2, /* plt0_got1_offset */
+ 1+8, /* plt0_got2_offset */
+ 1+12, /* plt0_got2_insn_end */
+ 1+2, /* plt_got_offset */
+ 1, /* plt_reloc_offset */
+ 7, /* plt_plt_offset */
+ 1+6, /* plt_got_insn_size */
+ 11, /* plt_plt_insn_end */
+ 0, /* plt_lazy_offset */
+ elf_x86_64_eh_frame_plt, /* eh_frame_plt */
+ sizeof (elf_x86_64_eh_frame_plt), /* eh_frame_plt_size */
+ };
+
#define elf_backend_arch_data &elf_x86_64_arch_bed
/* x86-64 ELF linker hash entry. */
(GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
unsigned char tls_type;
+ /* TRUE if symbol has at least one BND relocation. */
+ bfd_boolean has_bnd_reloc;
+
+ /* Information about the second PLT entry. Filled when has_bnd_reloc is
+ set. */
+ union gotplt_union plt_bnd;
+
/* Offset of the GOTPLT entry reserved for the TLS descriptor,
starting at the end of the jump table. */
bfd_vma tlsdesc_got;
asection *sdynbss;
asection *srelbss;
asection *plt_eh_frame;
+ asection *plt_bnd;
union
{
eh = (struct elf_x86_64_link_hash_entry *) entry;
eh->dyn_relocs = NULL;
eh->tls_type = GOT_UNKNOWN;
+ eh->has_bnd_reloc = FALSE;
+ eh->plt_bnd.offset = (bfd_vma) -1;
eh->tlsdesc_got = (bfd_vma) -1;
}
edir = (struct elf_x86_64_link_hash_entry *) dir;
eind = (struct elf_x86_64_link_hash_entry *) ind;
+ if (!edir->has_bnd_reloc)
+ edir->has_bnd_reloc = eind->has_bnd_reloc;
+
if (eind->dyn_relocs != NULL)
{
if (edir->dyn_relocs != NULL)
default:
break;
+ case R_X86_64_PC32_BND:
+ case R_X86_64_PLT32_BND:
+ /* MPX PLT is supported only if elf_x86_64_arch_bed
+ is used in 64-bit mode. */
+ if (ABI_64_P (abfd)
+ && (get_elf_x86_64_backend_data (abfd)
+ == &elf_x86_64_arch_bed))
+ {
+ elf_x86_64_hash_entry (h)->has_bnd_reloc = TRUE;
+
+ /* Create the second PLT for Intel MPX support. */
+ if (htab->plt_bnd == NULL)
+ {
+ unsigned int plt_bnd_align;
+ const struct elf_backend_data *bed;
+
+ bed = get_elf_backend_data (info->output_bfd);
+ switch (sizeof (elf_x86_64_bnd_plt2_entry))
+ {
+ case 8:
+ plt_bnd_align = 3;
+ break;
+ case 16:
+ plt_bnd_align = 4;
+ break;
+ default:
+ abort ();
+ }
+
+ if (htab->elf.dynobj == NULL)
+ htab->elf.dynobj = abfd;
+ htab->plt_bnd
+ = bfd_make_section_anyway_with_flags (htab->elf.dynobj,
+ ".plt.bnd",
+ (bed->dynamic_sec_flags
+ | SEC_ALLOC
+ | SEC_CODE
+ | SEC_LOAD
+ | SEC_READONLY));
+ if (htab->plt_bnd == NULL
+ || !bfd_set_section_alignment (htab->elf.dynobj,
+ htab->plt_bnd,
+ plt_bnd_align))
+ return FALSE;
+ }
+ }
+
case R_X86_64_32S:
case R_X86_64_32:
case R_X86_64_64:
case R_X86_64_PC32:
- case R_X86_64_PC32_BND:
case R_X86_64_PC64:
case R_X86_64_PLT32:
- case R_X86_64_PLT32_BND:
case R_X86_64_GOTPCREL:
case R_X86_64_GOTPCREL64:
if (htab->elf.dynobj == NULL)
here if it is defined and referenced in a non-shared object. */
if (h->type == STT_GNU_IFUNC
&& h->def_regular)
- return _bfd_elf_allocate_ifunc_dyn_relocs (info, h,
- &eh->dyn_relocs,
- plt_entry_size,
- plt_entry_size,
- GOT_ENTRY_SIZE);
+ {
+ if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h,
+ &eh->dyn_relocs,
+ plt_entry_size,
+ plt_entry_size,
+ GOT_ENTRY_SIZE))
+ {
+ asection *s = htab->plt_bnd;
+ if (h->plt.offset != (bfd_vma) -1 && s != NULL)
+ {
+ /* Use the .plt.bnd section if it is created. */
+ eh->plt_bnd.offset = s->size;
+
+ /* Make room for this entry in the .plt.bnd section. */
+ s->size += sizeof (elf_x86_64_legacy_plt2_entry);
+ }
+
+ return TRUE;
+ }
+ else
+ return FALSE;
+ }
else if (htab->elf.dynamic_sections_created
&& h->plt.refcount > 0)
{
|| WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h))
{
asection *s = htab->elf.splt;
+ asection *bnd_s = htab->plt_bnd;
/* If this is the first .plt entry, make room for the special
first entry. */
s->size = plt_entry_size;
h->plt.offset = s->size;
+ if (bnd_s)
+ eh->plt_bnd.offset = bnd_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
if (! info->shared
&& !h->def_regular)
{
- h->root.u.def.section = s;
- h->root.u.def.value = h->plt.offset;
+ if (bnd_s)
+ {
+ /* We need to make a call to the entry of the second
+ PLT instead of regular PLT entry. */
+ h->root.u.def.section = bnd_s;
+ h->root.u.def.value = eh->plt_bnd.offset;
+ }
+ else
+ {
+ h->root.u.def.section = s;
+ h->root.u.def.value = h->plt.offset;
+ }
}
/* Make room for this entry. */
s->size += plt_entry_size;
+ if (bnd_s)
+ {
+ BFD_ASSERT (sizeof (elf_x86_64_bnd_plt2_entry)
+ == sizeof (elf_x86_64_legacy_plt2_entry));
+ bnd_s->size += sizeof (elf_x86_64_legacy_plt2_entry);
+ }
/* We also need to make an entry in the .got.plt section, which
will be placed in the .got section by the linker script. */
|| s == htab->elf.sgotplt
|| s == htab->elf.iplt
|| s == htab->elf.igotplt
+ || s == htab->plt_bnd
|| s == htab->plt_eh_frame
|| s == htab->sdynbss)
{
reloc_howto_type *howto;
unsigned long r_symndx;
struct elf_link_hash_entry *h;
+ struct elf_x86_64_link_hash_entry *eh;
Elf_Internal_Sym *sym;
asection *sec;
- bfd_vma off, offplt;
+ bfd_vma off, offplt, plt_offset;
bfd_vma relocation;
bfd_boolean unresolved_reloc;
bfd_reloc_status_type r;
int tls_type;
- asection *base_got;
+ asection *base_got, *resolved_plt;
bfd_vma st_size;
r_type = ELF32_R_TYPE (rel->r_info);
}
}
+ eh = (struct elf_x86_64_link_hash_entry *) h;
+
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle
it here if it is defined in a non-shared object. */
if (h != NULL
&& h->type == STT_GNU_IFUNC
&& h->def_regular)
{
- asection *plt;
bfd_vma plt_index;
const char *name;
abort ();
/* STT_GNU_IFUNC symbol must go through PLT. */
- plt = htab->elf.splt ? htab->elf.splt : htab->elf.iplt;
- relocation = (plt->output_section->vma
- + plt->output_offset + h->plt.offset);
+ if (htab->elf.splt != NULL)
+ {
+ if (htab->plt_bnd != NULL)
+ {
+ resolved_plt = htab->plt_bnd;
+ plt_offset = eh->plt_bnd.offset;
+ }
+ else
+ {
+ resolved_plt = htab->elf.splt;
+ plt_offset = h->plt.offset;
+ }
+ }
+ else
+ {
+ resolved_plt = htab->elf.iplt;
+ plt_offset = h->plt.offset;
+ }
+
+ relocation = (resolved_plt->output_section->vma
+ + resolved_plt->output_offset + plt_offset);
switch (r_type)
{
&& h->plt.offset != (bfd_vma) -1
&& htab->elf.splt != NULL)
{
- relocation = (htab->elf.splt->output_section->vma
- + htab->elf.splt->output_offset
- + h->plt.offset);
+ if (htab->plt_bnd != NULL)
+ {
+ resolved_plt = htab->plt_bnd;
+ plt_offset = eh->plt_bnd.offset;
+ }
+ else
+ {
+ resolved_plt = htab->elf.splt;
+ plt_offset = h->plt.offset;
+ }
+
+ relocation = (resolved_plt->output_section->vma
+ + resolved_plt->output_offset
+ + plt_offset);
unresolved_reloc = FALSE;
}
break;
}
- relocation = (htab->elf.splt->output_section->vma
- + htab->elf.splt->output_offset
- + h->plt.offset);
+ if (htab->plt_bnd != NULL)
+ {
+ resolved_plt = htab->plt_bnd;
+ plt_offset = eh->plt_bnd.offset;
+ }
+ else
+ {
+ resolved_plt = htab->elf.splt;
+ plt_offset = h->plt.offset;
+ }
+
+ relocation = (resolved_plt->output_section->vma
+ + resolved_plt->output_offset
+ + plt_offset);
unresolved_reloc = FALSE;
break;
Elf_Internal_Sym *sym ATTRIBUTE_UNUSED)
{
struct elf_x86_64_link_hash_table *htab;
- const struct elf_x86_64_backend_data *const abed
- = get_elf_x86_64_backend_data (output_bfd);
+ const struct elf_x86_64_backend_data *abed;
+ bfd_boolean use_plt_bnd;
htab = elf_x86_64_hash_table (info);
if (htab == NULL)
return FALSE;
+ /* Use MPX backend data in case of BND relocation. Use .plt_bnd
+ section only if there is .plt section. */
+ use_plt_bnd = htab->elf.splt != NULL && htab->plt_bnd != NULL;
+ abed = (use_plt_bnd
+ ? &elf_x86_64_bnd_arch_bed
+ : get_elf_x86_64_backend_data (output_bfd));
+
if (h->plt.offset != (bfd_vma) -1)
{
bfd_vma plt_index;
- bfd_vma got_offset;
+ bfd_vma got_offset, plt_offset, plt_plt_offset, plt_got_offset;
+ bfd_vma plt_plt_insn_end, plt_got_insn_size;
Elf_Internal_Rela rela;
bfd_byte *loc;
- asection *plt, *gotplt, *relplt;
+ asection *plt, *gotplt, *relplt, *resolved_plt;
const struct elf_backend_data *bed;
/* When building a static executable, use .iplt, .igot.plt and
got_offset = got_offset * GOT_ENTRY_SIZE;
}
- /* Fill in the entry in the procedure linkage table. */
- memcpy (plt->contents + h->plt.offset, abed->plt_entry,
- abed->plt_entry_size);
+ plt_plt_insn_end = abed->plt_plt_insn_end;
+ plt_plt_offset = abed->plt_plt_offset;
+ plt_got_insn_size = abed->plt_got_insn_size;
+ plt_got_offset = abed->plt_got_offset;
+ if (use_plt_bnd)
+ {
+ /* Use the second PLT with BND relocations. */
+ const bfd_byte *plt_entry, *plt2_entry;
+ struct elf_x86_64_link_hash_entry *eh
+ = (struct elf_x86_64_link_hash_entry *) h;
+
+ if (eh->has_bnd_reloc)
+ {
+ plt_entry = elf_x86_64_bnd_plt_entry;
+ plt2_entry = elf_x86_64_bnd_plt2_entry;
+ }
+ else
+ {
+ plt_entry = elf_x86_64_legacy_plt_entry;
+ plt2_entry = elf_x86_64_legacy_plt2_entry;
+
+ /* Subtract 1 since there is no BND prefix. */
+ plt_plt_insn_end -= 1;
+ plt_plt_offset -= 1;
+ plt_got_insn_size -= 1;
+ plt_got_offset -= 1;
+ }
+
+ BFD_ASSERT (sizeof (elf_x86_64_bnd_plt_entry)
+ == sizeof (elf_x86_64_legacy_plt_entry));
+
+ /* Fill in the entry in the procedure linkage table. */
+ memcpy (plt->contents + h->plt.offset,
+ plt_entry, sizeof (elf_x86_64_legacy_plt_entry));
+ /* Fill in the entry in the second PLT. */
+ memcpy (htab->plt_bnd->contents + eh->plt_bnd.offset,
+ plt2_entry, sizeof (elf_x86_64_legacy_plt2_entry));
+
+ resolved_plt = htab->plt_bnd;
+ plt_offset = eh->plt_bnd.offset;
+ }
+ else
+ {
+ /* Fill in the entry in the procedure linkage table. */
+ memcpy (plt->contents + h->plt.offset, abed->plt_entry,
+ abed->plt_entry_size);
+
+ resolved_plt = plt;
+ plt_offset = h->plt.offset;
+ }
/* Insert the relocation positions of the plt section. */
(gotplt->output_section->vma
+ gotplt->output_offset
+ got_offset
- - plt->output_section->vma
- - plt->output_offset
- - h->plt.offset
- - abed->plt_got_insn_size),
- plt->contents + h->plt.offset + abed->plt_got_offset);
+ - resolved_plt->output_section->vma
+ - resolved_plt->output_offset
+ - plt_offset
+ - plt_got_insn_size),
+ resolved_plt->contents + plt_offset + plt_got_offset);
/* Fill in the entry in the global offset table, initially this
points to the second part of the PLT entry. */
bfd_put_32 (output_bfd, plt_index,
plt->contents + h->plt.offset + abed->plt_reloc_offset);
/* Put offset for jmp .PLT0. */
- bfd_put_32 (output_bfd, - (h->plt.offset + abed->plt_plt_insn_end),
- plt->contents + h->plt.offset + abed->plt_plt_offset);
+ bfd_put_32 (output_bfd, - (h->plt.offset + plt_plt_insn_end),
+ plt->contents + h->plt.offset + plt_plt_offset);
}
bed = get_elf_backend_data (output_bfd);
struct elf_x86_64_link_hash_table *htab;
bfd *dynobj;
asection *sdyn;
- const struct elf_x86_64_backend_data *const abed
- = get_elf_x86_64_backend_data (output_bfd);
+ const struct elf_x86_64_backend_data *abed;
htab = elf_x86_64_hash_table (info);
if (htab == NULL)
return FALSE;
+ /* Use MPX backend data in case of BND relocation. Use .plt_bnd
+ section only if there is .plt section. */
+ abed = (htab->elf.splt != NULL && htab->plt_bnd != NULL
+ ? &elf_x86_64_bnd_arch_bed
+ : get_elf_x86_64_backend_data (output_bfd));
+
dynobj = htab->elf.dynobj;
sdyn = bfd_get_linker_section (dynobj, ".dynamic");
}
}
+ if (htab->plt_bnd != NULL)
+ elf_section_data (htab->plt_bnd->output_section)
+ ->this_hdr.sh_entsize = sizeof (elf_x86_64_bnd_plt2_entry);
+
if (htab->elf.sgotplt)
{
if (bfd_is_abs_section (htab->elf.sgotplt->output_section))
return plt->vma + (i + 1) * GET_PLT_ENTRY_SIZE (plt->owner);
}
+/* Similar to _bfd_elf_get_synthetic_symtab, with .plt.bnd section
+ support. */
+
+static long
+elf_x86_64_get_synthetic_symtab (bfd *abfd,
+ long symcount,
+ asymbol **syms,
+ long dynsymcount,
+ asymbol **dynsyms,
+ asymbol **ret)
+{
+ const struct elf_backend_data *bed = get_elf_backend_data (abfd);
+ asection *relplt;
+ asymbol *s;
+ bfd_boolean (*slurp_relocs) (bfd *, asection *, asymbol **, bfd_boolean);
+ arelent *p;
+ long count, i, n;
+ size_t size;
+ Elf_Internal_Shdr *hdr;
+ char *names;
+ asection *plt;
+ bfd_vma addr;
+
+ plt = bfd_get_section_by_name (abfd, ".plt.bnd");
+ /* Use the generic ELF version if there is no .plt.bnd section. */
+ if (plt == NULL)
+ return _bfd_elf_get_synthetic_symtab (abfd, symcount, syms,
+ dynsymcount, dynsyms, ret);
+
+ *ret = NULL;
+
+ if ((abfd->flags & (DYNAMIC | EXEC_P)) == 0)
+ return 0;
+
+ if (dynsymcount <= 0)
+ return 0;
+
+ relplt = bfd_get_section_by_name (abfd, ".rela.plt");
+ if (relplt == NULL)
+ return 0;
+
+ hdr = &elf_section_data (relplt)->this_hdr;
+ if (hdr->sh_link != elf_dynsymtab (abfd)
+ || (hdr->sh_type != SHT_REL && hdr->sh_type != SHT_RELA))
+ return 0;
+
+ slurp_relocs = get_elf_backend_data (abfd)->s->slurp_reloc_table;
+ if (! (*slurp_relocs) (abfd, relplt, dynsyms, TRUE))
+ return -1;
+
+ count = relplt->size / hdr->sh_entsize;
+ size = count * sizeof (asymbol);
+ p = relplt->relocation;
+ for (i = 0; i < count; i++, p += bed->s->int_rels_per_ext_rel)
+ {
+ size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt");
+ if (p->addend != 0)
+ size += sizeof ("+0x") - 1 + 8 + 8;
+ }
+
+ s = *ret = (asymbol *) bfd_malloc (size);
+ if (s == NULL)
+ return -1;
+
+ names = (char *) (s + count);
+ p = relplt->relocation;
+ n = 0;
+ addr = 0;
+ for (i = 0; i < count; i++, p++)
+ {
+ size_t len;
+
+ *s = **p->sym_ptr_ptr;
+ /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL set. Since
+ we are defining a symbol, ensure one of them is set. */
+ if ((s->flags & BSF_LOCAL) == 0)
+ s->flags |= BSF_GLOBAL;
+ s->flags |= BSF_SYNTHETIC;
+ s->section = plt;
+ s->value = addr;
+ s->name = names;
+ s->udata.p = NULL;
+ len = strlen ((*p->sym_ptr_ptr)->name);
+ memcpy (names, (*p->sym_ptr_ptr)->name, len);
+ names += len;
+ if (p->addend != 0)
+ {
+ char buf[30], *a;
+
+ memcpy (names, "+0x", sizeof ("+0x") - 1);
+ names += sizeof ("+0x") - 1;
+ bfd_sprintf_vma (abfd, buf, p->addend);
+ for (a = buf; *a == '0'; ++a)
+ ;
+ len = strlen (a);
+ memcpy (names, a, len);
+ names += len;
+ }
+ memcpy (names, "@plt", sizeof ("@plt"));
+ names += sizeof ("@plt");
+ ++s, ++n;
+ addr += sizeof (elf_x86_64_legacy_plt2_entry);
+ }
+
+ return n;
+}
+
/* Handle an x86-64 specific section when reading an object file. This
is called when elfcode.h finds a section with an unknown type. */
#define elf_backend_plt_sym_val elf_x86_64_plt_sym_val
#define elf_backend_object_p elf64_x86_64_elf_object_p
#define bfd_elf64_mkobject elf_x86_64_mkobject
+#define bfd_elf64_get_synthetic_symtab elf_x86_64_get_synthetic_symtab
#define elf_backend_section_from_shdr \
elf_x86_64_section_from_shdr
#include "elf64-target.h"
+#undef bfd_elf64_get_synthetic_symtab
+
/* Native Client support. */
static bfd_boolean
projects / binutils-gdb.git / commitdiff