[08/10] x86: Add DT_RELR support

Message ID 20220107190631.309790-9-hjl.tools@gmail.com (mailing list archive)
State Superseded
Headers
Series ld: Implement DT_RELR for x86 |

Checks

Context Check Description
dj/TryBot-apply_patch fail Patch failed to apply to master at the time it was sent

Commit Message

H.J. Lu Jan. 7, 2022, 7:06 p.m. UTC
  DT_RELR is implemented with linker relaxation:

1. During linker relaxation, we scan input relocations with the same
logic in relocate_section to determine if a relative relocation should
be generated and save the relative relocation candidate information for
sizing the DT_RELR section later after all symbols addresses can be
determined.  For these relative relocations which can't be placed in
the DT_RELR section, they will be placed in the rela.dyn/rel.dyn
section.
2. When DT_RELR is enabled, _bfd_elf_map_sections_to_segments calls a
backend function to size the DT_RELR section which will compute the
DT_RELR section size and tell ldelf_map_segments to layout sections
again when the DT_RELR section size has been increased.
3. After regular symbol processing is finished, bfd_elf_final_link calls
a backend function to finish the DT_RELR section.

	* elf32-i386.c (elf_i386_scan_relocs): Set SEC_ELF_REVERSE_COPY
	on input section for DT_RELR.
	(elf_i386_relocate_section): Don't generate relative relocation
	when DT_RELR is enabled.
	* elf64-x86-64.c (elf_x86_64_scan_relocs): Set
	SEC_ELF_REVERSE_COPY on input section for DT_RELR.
	(elf_x86_64_relocate_section): Don't generate relative relocation
	when DT_RELR is enabled.
	* elfxx-x86.c (_bfd_x86_elf_link_hash_table_create): Initialize
	relative_r_type, relative_r_name, elf_append_reloc,
	elf_write_addend and elf_write_addend_in_got.
	(elf_x86_relative_reloc_record_add): New function.
	(_bfd_x86_elf_link_relax_section): Likewise.
	(elf64_dt_relr_bitmap_add): Likewise.
	(elf32_dt_relr_bitmap_add): Likewise.
	(_bfd_elf32_write_addend): Likewise.
	(_bfd_elf64_write_addend): Likewise.
	(elf_x86_size_or_finish_relative_reloc): Likewise.
	(elf_x86_compute_dl_relr_bitmap): Likewise.
	(elf_x86_write_dl_relr_bitmap): Likewise.
	(elf_x86_relative_reloc_compare ): Likewise.
	(_bfd_elf_x86_size_relative_relocs): Likewise.
	(_bfd_elf_x86_finish_relative_relocs): Likewise.
	(_bfd_x86_elf_size_dynamic_sections): Skip the .relr.dyn section.
	(_bfd_x86_elf_finish_dynamic_sections): Convert 3 spare dynamic
	tags to DT_RELR, DT_RELRSZ and for compact relative relocation.
	* elfxx-x86.h (X86_64_GOT_TYPE_P): New.
	(I386_GOT_TYPE_P): Likewise.
	(X86_GOT_TYPE_P): Likewise.
	(X86_64_RELATIVE_RELOC_TYPE_P): Likewise.
	(I386_RELATIVE_RELOC_TYPE_P): Likewise.
	(X86_RELATIVE_RELOC_TYPE_P): Likewise.
	(X86_LOCAL_GOT_RELATIVE_RELOC_P): Likewise.
	(I386_PCREL_TYPE_P): Likewise.
	(X86_64_PCREL_TYPE_P): Likewise.
	(X86_64_NEED_DYNAMIC_RELOC_TYPE_P): Rewrite.
	(I386_NEED_DYNAMIC_RELOC_TYPE_P): Likewise.
	(GENERATE_DYNAMIC_RELOCATION_P): Also check rel_from_abs.
	(elf_x86_link_hash_entry): Add got_relative_reloc_done.
	(elf_x86_relative_reloc_record): New.
	(elf_x86_relative_reloc_data): Likewise.
	(elf_dt_relr_bitmap): Likewise.
	(elf_x86_link_hash_table): Add dt_relr_bitmap, relative_reloc,
	unaligned_relative_reloc, relative_r_type, relative_r_name,
	elf_append_reloc, elf_write_addend, elf_write_addend_in_got and
	relative_reloc_done.
	(elf_x86_relative_reloc_done): New.
	(relative_reloc_packed): Likewise.
	(_bfd_x86_elf_link_relax_section): Likewise.
	(_bfd_elf_x86_size_relative_relocs): Likewise.
	(_bfd_elf_x86_finish_relative_relocs): Likewise.
	(_bfd_elf32_write_addend): Likewise.
	(_bfd_elf64_write_addend): Likewise.
	(bfd_elf32_bfd_relax_section): Likewise.
	(bfd_elf64_bfd_relax_section): Likewise.
	(elf_backend_size_relative_relocs): Likewise.
	(elf_backend_finish_relative_relocs): Likewise.
	(elf_x86_allocate_local_got_info): Also allocate
	relative_reloc_done.
---
 bfd/elf32-i386.c   |  54 ++-
 bfd/elf64-x86-64.c |  63 ++-
 bfd/elfxx-x86.c    | 937 +++++++++++++++++++++++++++++++++++++++++++++
 bfd/elfxx-x86.h    | 147 ++++++-
 4 files changed, 1161 insertions(+), 40 deletions(-)
  

Patch

diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index d1f61be5044..8e34bf0bcb4 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -1456,6 +1456,7 @@  elf_i386_scan_relocs (bfd *abfd,
 		      asection *sec,
 		      const Elf_Internal_Rela *relocs)
 {
+  const struct elf_backend_data *bed;
   struct elf_x86_link_hash_table *htab;
   Elf_Internal_Shdr *symtab_hdr;
   struct elf_link_hash_entry **sym_hashes;
@@ -1485,6 +1486,14 @@  elf_i386_scan_relocs (bfd *abfd,
       return false;
     }
 
+  bed = get_elf_backend_data (abfd);
+
+  /* Set SEC_ELF_REVERSE_COPY here so that the correct section offset
+     will be used for DT_RELR.  */
+  if (!_bfd_elf_process_reverse_copy (sec, 4,
+				      bed->s->int_rels_per_ext_rel))
+    return false;
+
   symtab_hdr = &elf_symtab_hdr (abfd);
   sym_hashes = elf_sym_hashes (abfd);
 
@@ -2473,8 +2482,10 @@  elf_i386_relocate_section (bfd *output_bfd,
 		      bfd_put_32 (output_bfd, relocation,
 				  htab->elf.sgot->contents + off);
 		      h->got.offset |= 1;
-
-		      if (GENERATE_RELATIVE_RELOC_P (info, h))
+		      /* NB: Don't generate relative relocation here if
+			 it has been generated by DT_RELR.  */
+		      if (!info->enable_dt_relr
+			  && GENERATE_RELATIVE_RELOC_P (info, h))
 			{
 			  /* PR ld/21402: If this symbol isn't dynamic
 			     in PIC, generate R_386_RELATIVE here.  */
@@ -2504,7 +2515,9 @@  elf_i386_relocate_section (bfd *output_bfd,
 			      htab->elf.sgot->contents + off);
 		  local_got_offsets[r_symndx] |= 1;
 
-		  if (bfd_link_pic (info))
+		  /* NB: Don't generate relative relocation here if it
+		     has been generated by DT_RELR.  */
+		  if (!info->enable_dt_relr && bfd_link_pic (info))
 		    relative_reloc = true;
 		}
 	    }
@@ -2707,6 +2720,7 @@  elf_i386_relocate_section (bfd *output_bfd,
 	    {
 	      Elf_Internal_Rela outrel;
 	      bool skip, relocate;
+	      bool generate_dynamic_reloc = true;
 	      asection *sreloc;
 
 	      /* When generating a shared object, these relocations
@@ -2734,23 +2748,33 @@  elf_i386_relocate_section (bfd *output_bfd,
 		{
 		  /* This symbol is local, or marked to become local.  */
 		  relocate = true;
-		  outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
+		  /* NB: Don't generate relative relocation here if it
+		     has been generated by DT_RELR.  */
+		  if (info->enable_dt_relr)
+		    generate_dynamic_reloc = false;
+		  else
+		    {
+		      outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE);
 
-		  if (htab->params->report_relative_reloc)
-		    _bfd_x86_elf_link_report_relative_reloc
-		      (info, input_section, h, sym, "R_386_RELATIVE",
-		       &outrel);
+		      if (htab->params->report_relative_reloc)
+			_bfd_x86_elf_link_report_relative_reloc
+			  (info, input_section, h, sym, "R_386_RELATIVE",
+			   &outrel);
+		    }
 		}
 
-	      sreloc = elf_section_data (input_section)->sreloc;
-
-	      if (sreloc == NULL || sreloc->contents == NULL)
+	      if (generate_dynamic_reloc)
 		{
-		  r = bfd_reloc_notsupported;
-		  goto check_relocation_error;
-		}
+		  sreloc = elf_section_data (input_section)->sreloc;
 
-	      elf_append_rel (output_bfd, sreloc, &outrel);
+		  if (sreloc == NULL || sreloc->contents == NULL)
+		    {
+		      r = bfd_reloc_notsupported;
+		      goto check_relocation_error;
+		    }
+
+		  elf_append_rel (output_bfd, sreloc, &outrel);
+		}
 
 	      /* If this reloc is against an external symbol, we do
 		 not want to fiddle with the addend.  Otherwise, we
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index ad885f89e11..0842df33c75 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1826,6 +1826,7 @@  elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
 			asection *sec,
 			const Elf_Internal_Rela *relocs)
 {
+  const struct elf_backend_data *bed;
   struct elf_x86_link_hash_table *htab;
   Elf_Internal_Shdr *symtab_hdr;
   struct elf_link_hash_entry **sym_hashes;
@@ -1855,6 +1856,14 @@  elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
       return false;
     }
 
+  bed = get_elf_backend_data (abfd);
+
+  /* Set SEC_ELF_REVERSE_COPY here so that the correct section offset
+     will be used for DT_RELR.  */
+  if (!_bfd_elf_process_reverse_copy (sec, ABI_64_P (abfd) ? 8 : 4,
+				      bed->s->int_rels_per_ext_rel))
+    return false;
+
   symtab_hdr = &elf_symtab_hdr (abfd);
   sym_hashes = elf_sym_hashes (abfd);
 
@@ -2867,7 +2876,10 @@  elf_x86_64_relocate_section (bfd *output_bfd,
 			 as -1 | 1 still is -1.  */
 		      h->got.offset |= 1;
 
-		      if (GENERATE_RELATIVE_RELOC_P (info, h))
+		      /* NB: Don't generate relative relocation here if
+			 it has been generated by DT_RELR.  */
+		      if (!info->enable_dt_relr
+			  && GENERATE_RELATIVE_RELOC_P (info, h))
 			{
 			  /* If this symbol isn't dynamic in PIC,
 			     generate R_X86_64_RELATIVE here.  */
@@ -2899,8 +2911,11 @@  elf_x86_64_relocate_section (bfd *output_bfd,
 
 		  /* NB: GOTPCREL relocations against local absolute
 		     symbol store relocation value in the GOT slot
-		     without relative relocation.  */
-		  if (bfd_link_pic (info)
+		     without relative relocation.  Don't generate
+		     relative relocation here if it has been generated
+		     by DT_RELR.  */
+		  if (!info->enable_dt_relr
+		      && bfd_link_pic (info)
 		      && !(sym->st_shndx == SHN_ABS
 			   && (r_type == R_X86_64_GOTPCREL
 			       || r_type == R_X86_64_GOTPCRELX
@@ -3215,6 +3230,7 @@  elf_x86_64_relocate_section (bfd *output_bfd,
 	    {
 	      Elf_Internal_Rela outrel;
 	      bool skip, relocate;
+	      bool generate_dynamic_reloc = true;
 	      asection *sreloc;
 	      const char *relative_reloc_name = NULL;
 
@@ -3253,9 +3269,17 @@  elf_x86_64_relocate_section (bfd *output_bfd,
 			  && htab->params->no_reloc_overflow_check))
 		    {
 		      relocate = true;
-		      outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE);
-		      outrel.r_addend = relocation + rel->r_addend;
-		      relative_reloc_name = "R_X86_64_RELATIVE";
+		      /* NB: Don't generate relative relocation here if
+			 it has been generated by DT_RELR.  */
+		      if (info->enable_dt_relr)
+			generate_dynamic_reloc = false;
+		      else
+			{
+			  outrel.r_info =
+			    htab->r_info (0, R_X86_64_RELATIVE);
+			  outrel.r_addend = relocation + rel->r_addend;
+			  relative_reloc_name = "R_X86_64_RELATIVE";
+			}
 		    }
 		  else if (r_type == R_X86_64_64
 			   && !ABI_64_P (output_bfd))
@@ -3323,21 +3347,24 @@  elf_x86_64_relocate_section (bfd *output_bfd,
 		    }
 		}
 
-	      sreloc = elf_section_data (input_section)->sreloc;
-
-	      if (sreloc == NULL || sreloc->contents == NULL)
+	      if (generate_dynamic_reloc)
 		{
-		  r = bfd_reloc_notsupported;
-		  goto check_relocation_error;
-		}
+		  sreloc = elf_section_data (input_section)->sreloc;
 
-	      if (relative_reloc_name
-		  && htab->params->report_relative_reloc)
-		_bfd_x86_elf_link_report_relative_reloc
-		  (info, input_section, h, sym, relative_reloc_name,
-		   &outrel);
+		  if (sreloc == NULL || sreloc->contents == NULL)
+		    {
+		      r = bfd_reloc_notsupported;
+		      goto check_relocation_error;
+		    }
 
-	      elf_append_rela (output_bfd, sreloc, &outrel);
+		  if (relative_reloc_name
+		      && htab->params->report_relative_reloc)
+		    _bfd_x86_elf_link_report_relative_reloc
+		      (info, input_section, h, sym,
+		       relative_reloc_name, &outrel);
+
+		  elf_append_rela (output_bfd, sreloc, &outrel);
+		}
 
 	      /* If this reloc is against an external symbol, we do
 		 not want to fiddle with the addend.  Otherwise, we
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 25f7717ea88..0f4e6542ef0 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -726,6 +726,10 @@  _bfd_x86_elf_link_hash_table_create (bfd *abfd)
       ret->got_entry_size = 8;
       ret->pcrel_plt = true;
       ret->tls_get_addr = "__tls_get_addr";
+      ret->relative_r_type = R_X86_64_RELATIVE;
+      ret->relative_r_name = "R_X86_64_RELATIVE";
+      ret->elf_append_reloc = elf_append_rela;
+      ret->elf_write_addend_in_got = _bfd_elf64_write_addend;
     }
   if (ABI_64_P (abfd))
     {
@@ -733,6 +737,7 @@  _bfd_x86_elf_link_hash_table_create (bfd *abfd)
       ret->pointer_r_type = R_X86_64_64;
       ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER;
       ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER;
+      ret->elf_write_addend = _bfd_elf64_write_addend;
     }
   else
     {
@@ -743,6 +748,7 @@  _bfd_x86_elf_link_hash_table_create (bfd *abfd)
 	  ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER;
 	  ret->dynamic_interpreter_size
 	    = sizeof ELFX32_DYNAMIC_INTERPRETER;
+	  ret->elf_write_addend = _bfd_elf32_write_addend;
 	}
       else
 	{
@@ -751,6 +757,11 @@  _bfd_x86_elf_link_hash_table_create (bfd *abfd)
 	  ret->got_entry_size = 4;
 	  ret->pcrel_plt = false;
 	  ret->pointer_r_type = R_386_32;
+	  ret->relative_r_type = R_386_RELATIVE;
+	  ret->relative_r_name = "R_386_RELATIVE";
+	  ret->elf_append_reloc = elf_append_rel;
+	  ret->elf_write_addend = _bfd_elf32_write_addend;
+	  ret->elf_write_addend_in_got = _bfd_elf32_write_addend;
 	  ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER;
 	  ret->dynamic_interpreter_size
 	    = sizeof ELF32_DYNAMIC_INTERPRETER;
@@ -977,6 +988,902 @@  _bfd_x86_elf_check_relocs (bfd *abfd,
   return true;
 }
 
+/* Add an entry to the relative reloc record.  */
+
+static bool
+elf_x86_relative_reloc_record_add
+  (struct bfd_link_info *info,
+   struct elf_x86_relative_reloc_data *relative_reloc,
+   Elf_Internal_Rela *rel, asection *sec,
+   asection *sym_sec, struct elf_link_hash_entry *h,
+   Elf_Internal_Sym *sym, bfd_vma offset)
+{
+  bfd_size_type newidx;
+
+  if (relative_reloc->data == NULL)
+    {
+      relative_reloc->data = bfd_malloc
+	(sizeof (struct elf_x86_relative_reloc_record));
+      relative_reloc->count = 0;
+      relative_reloc->size = 1;
+    }
+
+  newidx = relative_reloc->count++;
+
+  if (relative_reloc->count > relative_reloc->size)
+    {
+      relative_reloc->size <<= 1;
+      relative_reloc->data = bfd_realloc
+	(relative_reloc->data,
+	 (relative_reloc->size
+	  * sizeof (struct elf_x86_relative_reloc_record)));
+    }
+
+  if (relative_reloc->data == NULL)
+    {
+      info->callbacks->einfo
+	/* xgettext:c-format */
+	(_("%F%P: %pB: failed to allocate relative reloc record\n"),
+	 info->output_bfd);
+      return false;
+    }
+
+  relative_reloc->data[newidx].rel = *rel;
+  relative_reloc->data[newidx].sec = sec;
+  if (h != NULL)
+    {
+      /* Set SYM to NULL to indicate a global symbol.  */
+      relative_reloc->data[newidx].sym = NULL;
+      relative_reloc->data[newidx].u.h = h;
+    }
+  else
+    {
+      relative_reloc->data[newidx].sym = sym;
+      relative_reloc->data[newidx].u.sym_sec = sym_sec;
+    }
+  relative_reloc->data[newidx].offset = offset;
+  relative_reloc->data[newidx].address = 0;
+  return true;
+}
+
+/* After input sections have been mapped to output sections and
+   addresses of output sections are set initiallly, scan input
+   relocations with the same logic in relocate_section to determine
+   if a relative relocation should be generated.  Save the relative
+   relocation candidate information for sizing the DT_RELR section
+   later after all symbols addresses can be determined.  */
+
+bool
+_bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
+				 asection *input_section,
+				 struct bfd_link_info *info,
+				 bool *again)
+{
+  Elf_Internal_Shdr *symtab_hdr;
+  Elf_Internal_Rela *internal_relocs;
+  Elf_Internal_Rela *irel, *irelend;
+  Elf_Internal_Sym *isymbuf = NULL;
+  struct elf_link_hash_entry **sym_hashes;
+  const struct elf_backend_data *bed;
+  struct elf_x86_link_hash_table *htab;
+  bfd_vma *local_got_offsets;
+  bool is_x86_64;
+  bool unaligned_section;
+
+  if (bfd_link_relocatable (info))
+    return true;
+
+  /* Assume we're not going to change any sizes, and we'll only need
+     one pass.  */
+  *again = false;
+
+  bed = get_elf_backend_data (abfd);
+  htab = elf_x86_hash_table (info, bed->target_id);
+  if (htab == NULL)
+    return true;
+
+  /* Nothing to do if there are no relocations or relative relocations
+     have been packed.  */
+  if (input_section == htab->elf.srelrdyn
+      || input_section->relative_reloc_packed
+      || ((input_section->flags & (SEC_RELOC | SEC_ALLOC))
+	  != (SEC_RELOC | SEC_ALLOC))
+      || (input_section->flags & SEC_DEBUGGING) != 0
+      || input_section->reloc_count == 0)
+    return true;
+
+  /* Skip if the section isn't aligned.  */
+  unaligned_section = input_section->alignment_power == 0;
+
+  is_x86_64 = bed->target_id == X86_64_ELF_DATA;
+
+  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
+  sym_hashes = elf_sym_hashes (abfd);
+  local_got_offsets = elf_local_got_offsets (abfd);
+
+  /* Load the relocations for this section.  */
+  internal_relocs =
+    _bfd_elf_link_read_relocs (abfd, input_section, NULL,
+			       (Elf_Internal_Rela *) NULL,
+			       info->keep_memory);
+  if (internal_relocs == NULL)
+    return false;
+
+  irelend = internal_relocs + input_section->reloc_count;
+  for (irel = internal_relocs; irel < irelend; irel++)
+    {
+      unsigned int r_type;
+      unsigned int r_symndx;
+      Elf_Internal_Sym *isym;
+      struct elf_link_hash_entry *h;
+      struct elf_x86_link_hash_entry *eh;
+      bfd_vma offset;
+      bool resolved_to_zero;
+      bool need_copy_reloc_in_pie;
+      bool pc32_reloc;
+      asection *sec;
+      /* Offset must be a multiple of 2.  */
+      bool unaligned_offset = (irel->r_offset & 1) != 0;
+
+      /* Get the value of the symbol referred to by the reloc.  */
+      r_symndx = htab->r_sym (irel->r_info);
+
+      r_type = ELF32_R_TYPE (irel->r_info);
+      /* Clear the R_X86_64_converted_reloc_bit bit.  */
+      r_type &= ~R_X86_64_converted_reloc_bit;
+
+      sec = NULL;
+      h = NULL;
+
+      if (r_symndx < symtab_hdr->sh_info)
+	{
+	  /* Read this BFD's local symbols.  */
+	  if (isymbuf == NULL)
+	    {
+	      isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
+	      if (isymbuf == NULL)
+		isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
+						symtab_hdr->sh_info, 0,
+						NULL, NULL, NULL);
+	      if (isymbuf == NULL)
+		goto error_return;
+	    }
+
+	  isym = isymbuf + r_symndx;
+	  switch (isym->st_shndx)
+	    {
+	    case SHN_ABS:
+	      sec = bfd_abs_section_ptr;
+	      break;
+	    case SHN_COMMON:
+	      sec = bfd_com_section_ptr;
+	      break;
+	    case SHN_X86_64_LCOMMON:
+	      if (!is_x86_64)
+		abort ();
+	      sec = &_bfd_elf_large_com_section;
+	      break;
+	    default:
+	      sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
+	      break;
+	    }
+
+	  /* Check relocation against local STT_GNU_IFUNC symbol.  */
+	  if (ELF32_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
+	    {
+	      h = _bfd_elf_x86_get_local_sym_hash (htab, abfd, irel,
+						   true);
+	      if (h == NULL)
+		goto error_return;
+	    }
+
+	  resolved_to_zero = false;
+	}
+      else
+	{
+	  /* Get H and SEC for GENERATE_DYNAMIC_RELOCATION_P below.  */
+	  h = sym_hashes[r_symndx - symtab_hdr->sh_info];
+	  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;
+
+	  if (h->root.type == bfd_link_hash_defined
+	      || h->root.type == bfd_link_hash_defweak)
+	    sec = h->root.u.def.section;
+
+	  isym = NULL;
+	}
+
+      eh = (struct elf_x86_link_hash_entry *) h;
+      resolved_to_zero = (eh != NULL
+			  && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh));
+
+      if (X86_GOT_TYPE_P (is_x86_64, r_type))
+	{
+	  /* Pack GOT relative relocations.  There should be only a
+	     single R_*_RELATIVE relocation in GOT.  */
+	  if (eh != NULL)
+	    {
+	      if (eh->got_relative_reloc_done)
+		continue;
+
+	      if (!(h->type != STT_GNU_IFUNC
+		    && RESOLVED_LOCALLY_P (info, h, htab)
+		    && GENERATE_RELATIVE_RELOC_P (info, h)))
+		continue;
+
+	      eh->no_finish_dynamic_symbol = 1;
+	      eh->got_relative_reloc_done = 1;
+	      offset = h->got.offset;
+	    }
+	  else
+	    {
+	      if (elf_x86_relative_reloc_done (abfd)[r_symndx])
+		continue;
+
+	      if (!X86_LOCAL_GOT_RELATIVE_RELOC_P (is_x86_64, info,
+						   isym))
+		continue;
+
+	      elf_x86_relative_reloc_done (abfd)[r_symndx] = 1;
+	      offset = local_got_offsets[r_symndx];
+	    }
+
+	  if (!elf_x86_relative_reloc_record_add (info,
+						  &htab->relative_reloc,
+						  irel, htab->elf.sgot,
+						  sec, h, isym, offset))
+	    goto error_return;
+
+	  continue;
+	}
+
+      if (is_x86_64
+	  && irel->r_addend == 0
+	  && !ABI_64_P (info->output_bfd))
+	{
+	  /* For x32, if addend is zero, treat R_X86_64_64 like
+	     R_X86_64_32 and R_X86_64_SIZE64 like R_X86_64_SIZE32.  */
+	  if (r_type == R_X86_64_64)
+	    r_type = R_X86_64_32;
+	  else if (r_type == R_X86_64_SIZE64)
+	    r_type = R_X86_64_SIZE32;
+	}
+
+      if (!X86_RELATIVE_RELOC_TYPE_P (is_x86_64, r_type)
+	  || (h != NULL && h->type == STT_GNU_IFUNC))
+	continue;
+
+      /* Pack non-GOT relative relocations.  */
+      if (is_x86_64)
+	{
+	  need_copy_reloc_in_pie =
+	    (bfd_link_pie (info)
+	     && h != NULL
+	     && (h->needs_copy
+		 || eh->needs_copy
+		 || (h->root.type == bfd_link_hash_undefined))
+	     && (X86_PCREL_TYPE_P (true, r_type)
+		 || X86_SIZE_TYPE_P (true, r_type)));
+	  pc32_reloc = false;
+	}
+      else
+	{
+	  need_copy_reloc_in_pie = false;
+	  pc32_reloc = r_type == R_386_PC32;
+	}
+
+      if (GENERATE_DYNAMIC_RELOCATION_P (is_x86_64, info, eh, r_type,
+					 sec, need_copy_reloc_in_pie,
+					 resolved_to_zero, pc32_reloc))
+	{
+	  /* When generating a shared object, these relocations
+	     are copied into the output file to be resolved at run
+	     time.	*/
+	  offset = _bfd_elf_section_offset (info->output_bfd, info,
+					    input_section,
+					    irel->r_offset);
+	  if (offset == (bfd_vma) -1
+	      || offset == (bfd_vma) -2
+	      || COPY_INPUT_RELOC_P (is_x86_64, info, h, r_type))
+	    continue;
+
+	  /* This symbol is local, or marked to become local.  When
+	     relocation overflow check is disabled, we convert
+	     R_X86_64_32 to dynamic R_X86_64_RELATIVE.  */
+	  if (is_x86_64
+	      && !(r_type == htab->pointer_r_type
+		   || (r_type == R_X86_64_32
+		       && htab->params->no_reloc_overflow_check)))
+	    continue;
+
+	  if (!elf_x86_relative_reloc_record_add
+	        (info,
+		 ((unaligned_section || unaligned_offset)
+		  ? &htab->unaligned_relative_reloc
+		  : &htab->relative_reloc),
+		 irel, input_section, sec, h, isym, offset))
+	    goto error_return;
+	}
+    }
+
+  input_section->relative_reloc_packed = 1;
+
+  return true;
+
+error_return:
+  if ((unsigned char *) isymbuf != symtab_hdr->contents)
+    free (isymbuf);
+  if (elf_section_data (input_section)->relocs != internal_relocs)
+    free (internal_relocs);
+  return false;
+}
+
+/* Add an entry to the 64-bit DT_RELR bitmap.  */
+
+static void
+elf64_dt_relr_bitmap_add
+  (struct bfd_link_info *info, struct elf_dt_relr_bitmap *bitmap,
+   uint64_t entry)
+{
+  bfd_size_type newidx;
+
+  if (bitmap->u.elf64 == NULL)
+    {
+      bitmap->u.elf64 = bfd_malloc (sizeof (uint64_t));
+      bitmap->count = 0;
+      bitmap->size = 1;
+    }
+
+  newidx = bitmap->count++;
+
+  if (bitmap->count > bitmap->size)
+    {
+      bitmap->size <<= 1;
+      bitmap->u.elf64 = bfd_realloc (bitmap->u.elf64,
+				     (bitmap->size * sizeof (uint64_t)));
+    }
+
+  if (bitmap->u.elf64 == NULL)
+    {
+      info->callbacks->einfo
+	/* xgettext:c-format */
+	(_("%F%P: %pB: failed to allocate 64-bit DT_RELR bitmap\n"),
+	 info->output_bfd);
+    }
+
+  bitmap->u.elf64[newidx] = entry;
+}
+
+/* Add an entry to the 32-bit DT_RELR bitmap.  */
+
+static void
+elf32_dt_relr_bitmap_add
+  (struct bfd_link_info *info, struct elf_dt_relr_bitmap *bitmap,
+   uint32_t entry)
+{
+  bfd_size_type newidx;
+
+  if (bitmap->u.elf32 == NULL)
+    {
+      bitmap->u.elf32 = bfd_malloc (sizeof (uint32_t));
+      bitmap->count = 0;
+      bitmap->size = 1;
+    }
+
+  newidx = bitmap->count++;
+
+  if (bitmap->count > bitmap->size)
+    {
+      bitmap->size <<= 1;
+      bitmap->u.elf32 = bfd_realloc (bitmap->u.elf32,
+				     (bitmap->size * sizeof (uint32_t)));
+    }
+
+  if (bitmap->u.elf32 == NULL)
+    {
+      info->callbacks->einfo
+	/* xgettext:c-format */
+	(_("%F%P: %pB: failed to allocate 32-bit DT_RELR bitmap\n"),
+	 info->output_bfd);
+    }
+
+  bitmap->u.elf32[newidx] = entry;
+}
+
+void
+_bfd_elf32_write_addend (bfd *abfd, uint64_t value, void *addr)
+{
+  bfd_put_32 (abfd, value, addr);
+}
+
+void
+_bfd_elf64_write_addend (bfd *abfd, uint64_t value, void *addr)
+{
+  bfd_put_64 (abfd, value, addr);
+}
+
+/* Size or finish relative relocations to determine the run-time
+   addresses for DT_RELR bitmap computation later.  OUTREL is set
+   to NULL in the sizing phase and non-NULL in the finising phase
+   where the regular relative relocations will be written out.  */
+
+static void
+elf_x86_size_or_finish_relative_reloc
+  (bool is_x86_64, struct bfd_link_info *info,
+   struct elf_x86_link_hash_table *htab, bool unaligned,
+   Elf_Internal_Rela *outrel)
+{
+  unsigned int align_mask;
+  bfd_size_type i, count;
+  asection *sec, *srel;
+  struct elf_link_hash_entry *h;
+  bfd_vma offset;
+  Elf_Internal_Sym *sym;
+  asection *sym_sec;
+  asection *sgot = htab->elf.sgot;
+  asection *srelgot = htab->elf.srelgot;
+  struct elf_x86_relative_reloc_data *relative_reloc;
+
+  if (unaligned)
+    {
+      align_mask = 0;
+      relative_reloc = &htab->unaligned_relative_reloc;
+    }
+  else
+    {
+      align_mask = 1;
+      relative_reloc = &htab->relative_reloc;
+    }
+
+  count = relative_reloc->count;
+  for (i = 0; i < count; i++)
+    {
+      sec = relative_reloc->data[i].sec;
+      sym = relative_reloc->data[i].sym;
+
+      /* If SYM is NULL, it must be a global symbol.  */
+      if (sym == NULL)
+	h = relative_reloc->data[i].u.h;
+      else
+	h = NULL;
+
+      if (is_x86_64)
+	{
+	  bfd_vma relocation;
+	  /* This function may be called more than once and REL may be
+	     updated by _bfd_elf_rela_local_sym below.  */
+	  Elf_Internal_Rela rel = relative_reloc->data[i].rel;
+
+	  if (h != NULL)
+	    {
+	      if (h->root.type == bfd_link_hash_defined
+		  || h->root.type == bfd_link_hash_defweak)
+		{
+		  sym_sec = h->root.u.def.section;
+		  relocation = (h->root.u.def.value
+				+ sym_sec->output_section->vma
+				+ sym_sec->output_offset);
+		}
+	      else
+		{
+		  /* Allow undefined symbol only at the sizing phase.  */
+		  if (outrel == NULL)
+		    relocation = 0;
+		  else
+		    abort ();
+		}
+	    }
+	  else
+	    {
+	      sym_sec = relative_reloc->data[i].u.sym_sec;
+	      relocation = _bfd_elf_rela_local_sym
+		(info->output_bfd, sym, &sym_sec, &rel);
+	    }
+
+	  if (outrel != NULL)
+	    {
+	      outrel->r_addend = relocation;
+	      if (sec == sgot)
+		{
+		  if (h != NULL && h->needs_plt)
+		    abort ();
+		}
+	      else
+		outrel->r_addend += rel.r_addend;
+
+	      /* Write the implicit addend if ALIGN_MASK isn't 0.  */
+	      if (align_mask)
+		{
+		  if (sec == sgot)
+		    {
+		      if (relative_reloc->data[i].offset >= sec->size)
+			abort ();
+		      htab->elf_write_addend_in_got
+			(info->output_bfd, outrel->r_addend,
+			 sec->contents + relative_reloc->data[i].offset);
+		    }
+		  else
+		    {
+		      if (rel.r_offset >= sec->size)
+			abort ();
+		      htab->elf_write_addend
+			(info->output_bfd, outrel->r_addend,
+			 (elf_section_data (sec)->this_hdr.contents
+			  + rel.r_offset));
+		    }
+		}
+	    }
+	}
+
+      if (sec == sgot)
+	srel = srelgot;
+      else
+	srel = elf_section_data (sec)->sreloc;
+      offset = (sec->output_section->vma + sec->output_offset
+		+ relative_reloc->data[i].offset);
+      relative_reloc->data[i].address = offset;
+      if (outrel != NULL)
+	{
+	  outrel->r_offset = offset;
+
+	  if ((outrel->r_offset & align_mask) != 0)
+	    abort ();
+
+	  if (htab->params->report_relative_reloc)
+	    _bfd_x86_elf_link_report_relative_reloc
+	      (info, sec, h, sym, htab->relative_r_name, outrel);
+
+	  /* Generate regular relative relocation if ALIGN_MASK is 0.  */
+	  if (align_mask == 0)
+	    htab->elf_append_reloc (info->output_bfd, srel, outrel);
+	}
+    }
+}
+
+/* Compute the DT_RELR section size.  Set NEED_PLAYOUT to true if
+   the DT_RELR section size has been increased.  */
+
+static void
+elf_x86_compute_dl_relr_bitmap
+  (struct bfd_link_info *info, struct elf_x86_link_hash_table *htab,
+   bool *need_layout)
+{
+  bfd_vma base;
+  bfd_size_type i, count, new_count;
+  struct elf_x86_relative_reloc_data *relative_reloc =
+    &htab->relative_reloc;
+  /* Save the old DT_RELR bitmap count.  Don't shrink the DT_RELR bitmap
+     if the new DT_RELR bitmap count is smaller than the old one.  Pad
+     with trailing 1s which won't be decoded to more relocations.  */
+  bfd_size_type dt_relr_bitmap_count = htab->dt_relr_bitmap.count;
+
+  /* Clear the DT_RELR bitmap count.  */
+  htab->dt_relr_bitmap.count = 0;
+
+  count = relative_reloc->count;
+
+  if (ABI_64_P (info->output_bfd))
+    {
+      /* Compute the 64-bit DT_RELR bitmap.  */
+      i = 0;
+      while (i < count)
+	{
+	  if ((relative_reloc->data[i].address % 1) != 0)
+	    abort ();
+
+	  elf64_dt_relr_bitmap_add (info, &htab->dt_relr_bitmap,
+				    relative_reloc->data[i].address);
+
+	  base = relative_reloc->data[i].address + 8;
+	  i++;
+
+	  while (i < count)
+	    {
+	      uint64_t bitmap = 0;
+	      for (; i < count; i++)
+		{
+		  bfd_vma delta = (relative_reloc->data[i].address
+				   - base);
+		  /* Stop if it is too far from base.  */
+		  if (delta >= 63 * 8)
+		    break;
+		  /* Stop if it isn't a multiple of 8.  */
+		  if ((delta % 8) != 0)
+		    break;
+		  bitmap |= 1ULL << (delta / 8);
+		}
+
+	      if (bitmap == 0)
+		break;
+
+	      elf64_dt_relr_bitmap_add (info, &htab->dt_relr_bitmap,
+					(bitmap << 1) | 1);
+
+	      base += 63 * 8;
+	    }
+	}
+
+      new_count = htab->dt_relr_bitmap.count;
+      if (dt_relr_bitmap_count > new_count)
+	{
+	  /* Don't shrink the DT_RELR section size to avoid section
+	     layout oscillation.  Instead, pad the DT_RELR bitmap with
+	     1s which do not decode to more relocations.  */
+
+	  htab->dt_relr_bitmap.count = dt_relr_bitmap_count;
+	  count = dt_relr_bitmap_count - new_count;
+	  for (i = 0; i < count; i++)
+	    htab->dt_relr_bitmap.u.elf64[new_count + i] = 1;
+	}
+    }
+  else
+    {
+      /* Compute the 32-bit DT_RELR bitmap.  */
+      i = 0;
+      while (i < count)
+	{
+	  if ((relative_reloc->data[i].address % 1) != 0)
+	    abort ();
+
+	  elf32_dt_relr_bitmap_add (info, &htab->dt_relr_bitmap,
+				    relative_reloc->data[i].address);
+
+	  base = relative_reloc->data[i].address + 4;
+	  i++;
+
+	  while (i < count)
+	    {
+	      uint32_t bitmap = 0;
+	      for (; i < count; i++)
+		{
+		  bfd_vma delta = (relative_reloc->data[i].address
+				   - base);
+		  /* Stop if it is too far from base.  */
+		  if (delta >= 31 * 4)
+		    break;
+		  /* Stop if it isn't a multiple of 4.  */
+		  if ((delta % 4) != 0)
+		    break;
+		  bitmap |= 1ULL << (delta / 4);
+		}
+
+	      if (bitmap == 0)
+		break;
+
+	      elf32_dt_relr_bitmap_add (info, &htab->dt_relr_bitmap,
+					(bitmap << 1) | 1);
+
+	      base += 31 * 4;
+	    }
+	}
+
+      new_count = htab->dt_relr_bitmap.count;
+      if (dt_relr_bitmap_count > new_count)
+	{
+	  /* Don't shrink the DT_RELR section size to avoid section
+	     layout oscillation.  Instead, pad the DT_RELR bitmap with
+	     1s which do not decode to more relocations.  */
+
+	  htab->dt_relr_bitmap.count = dt_relr_bitmap_count;
+	  count = dt_relr_bitmap_count - new_count;
+	  for (i = 0; i < count; i++)
+	    htab->dt_relr_bitmap.u.elf32[new_count + i] = 1;
+	}
+    }
+
+  if (htab->dt_relr_bitmap.count != dt_relr_bitmap_count)
+    {
+      if (need_layout)
+	{
+	  /* The .relr.dyn section size is changed.  Update the section
+	     size and tell linker to layout sections again.  */
+	  htab->elf.srelrdyn->size =
+	    (htab->dt_relr_bitmap.count
+	     * (ABI_64_P (info->output_bfd) ? 8 : 4));
+
+	  *need_layout = true;
+	}
+      else
+	info->callbacks->einfo
+	  /* xgettext:c-format */
+	  (_("%F%P: %pB: size of compact relative reloc section is "
+	     "changed: new (%lu) != old (%lu)\n"),
+	   info->output_bfd, htab->dt_relr_bitmap.count,
+	   dt_relr_bitmap_count);
+    }
+}
+
+/* Write out the DT_RELR section.  */
+
+static void
+elf_x86_write_dl_relr_bitmap (struct bfd_link_info *info,
+			      struct elf_x86_link_hash_table *htab)
+{
+  asection *sec = htab->elf.srelrdyn;
+  bfd_size_type size = sec->size;
+  bfd_size_type i;
+  unsigned char *contents;
+
+  contents = (unsigned char *) bfd_alloc (sec->owner, size);
+  if (contents == NULL)
+    info->callbacks->einfo
+      /* xgettext:c-format */
+      (_("%F%P: %pB: failed to allocate compact relative reloc section\n"),
+       info->output_bfd);
+
+  /* Cache the section contents for elf_link_input_bfd.  */
+  sec->contents = contents;
+
+  if (ABI_64_P (info->output_bfd))
+    for (i = 0; i < htab->dt_relr_bitmap.count; i++, contents += 8)
+      bfd_put_64 (info->output_bfd, htab->dt_relr_bitmap.u.elf64[i],
+		  contents);
+  else
+    for (i = 0; i < htab->dt_relr_bitmap.count; i++, contents += 4)
+      bfd_put_32 (info->output_bfd, htab->dt_relr_bitmap.u.elf32[i],
+		  contents);
+}
+
+/* Sort relative relocations by address.  */
+
+static int
+elf_x86_relative_reloc_compare (const void *pa, const void *pb)
+{
+  struct elf_x86_relative_reloc_record *a =
+    (struct elf_x86_relative_reloc_record *) pa;
+  struct elf_x86_relative_reloc_record *b =
+    (struct elf_x86_relative_reloc_record *) pb;
+  if (a->address < b->address)
+    return -1;
+  if (a->address > b->address)
+    return 1;
+  return 0;
+}
+
+bool
+_bfd_elf_x86_size_relative_relocs (struct bfd_link_info *info,
+				   bool *need_layout)
+{
+  struct elf_x86_link_hash_table *htab;
+  const struct elf_backend_data *bed;
+  bool is_x86_64;
+  bfd_size_type i, count, unaligned_count;
+  asection *sec, *srel;
+
+  /* Do nothing for ld -r.  */
+  if (bfd_link_relocatable (info))
+    return true;
+
+  bed = get_elf_backend_data (info->output_bfd);
+  htab = elf_x86_hash_table (info, bed->target_id);
+  if (htab == NULL)
+    return false;
+
+  count = htab->relative_reloc.count;
+  unaligned_count = htab->unaligned_relative_reloc.count;
+  if (count == 0)
+    {
+      if (htab->generate_relative_reloc_pass == 0
+	  && htab->elf.srelrdyn != NULL)
+	{
+	  /* Remove the empty .relr.dyn sections now.  */
+	  if (!bfd_is_abs_section (htab->elf.srelrdyn->output_section))
+	    {
+	      bfd_section_list_remove
+		(info->output_bfd, htab->elf.srelrdyn->output_section);
+	      info->output_bfd->section_count--;
+	    }
+	  bfd_section_list_remove (htab->elf.srelrdyn->owner,
+				   htab->elf.srelrdyn);
+	  htab->elf.srelrdyn->owner->section_count--;
+	}
+      if (unaligned_count == 0)
+	{
+	  htab->generate_relative_reloc_pass++;
+	  return true;
+	}
+    }
+
+  is_x86_64 = bed->target_id == X86_64_ELF_DATA;
+
+  /* Size relative relocations.  */
+  if (htab->generate_relative_reloc_pass)
+    {
+      /* Reset the regular relative relocation count.  */
+      for (i = 0; i < unaligned_count; i++)
+	{
+	  sec = htab->unaligned_relative_reloc.data[i].sec;
+	  srel = elf_section_data (sec)->sreloc;
+	  srel->reloc_count = 0;
+	}
+    }
+  else
+    {
+      /* Remove the reserved space for compact relative relocations.  */
+      if (count)
+	{
+	  asection *sgot = htab->elf.sgot;
+	  asection *srelgot = htab->elf.srelgot;
+
+	  for (i = 0; i < count; i++)
+	    {
+	      sec = htab->relative_reloc.data[i].sec;
+	      if (sec == sgot)
+		srel = srelgot;
+	      else
+		srel = elf_section_data (sec)->sreloc;
+	      srel->size -= htab->sizeof_reloc;
+	    }
+	}
+    }
+
+  /* Size unaligned relative relocations.  */
+  if (unaligned_count)
+    elf_x86_size_or_finish_relative_reloc (is_x86_64, info, htab,
+					   true, NULL);
+
+  if (count)
+    {
+      elf_x86_size_or_finish_relative_reloc (is_x86_64, info, htab,
+					     false, NULL);
+
+      /* Sort relative relocations by addresses.  We only need to
+	 sort them in the first pass since the relative positions
+	 won't change.  */
+      if (htab->generate_relative_reloc_pass == 0)
+	qsort (htab->relative_reloc.data, count,
+	       sizeof (struct elf_x86_relative_reloc_record),
+	       elf_x86_relative_reloc_compare);
+
+      elf_x86_compute_dl_relr_bitmap (info, htab, need_layout);
+    }
+
+  htab->generate_relative_reloc_pass++;
+
+  return true;
+}
+
+bool
+_bfd_elf_x86_finish_relative_relocs (struct bfd_link_info *info)
+{
+  struct elf_x86_link_hash_table *htab;
+  const struct elf_backend_data *bed;
+  Elf_Internal_Rela outrel;
+  bool is_x86_64;
+  bfd_size_type count;
+
+  /* Do nothing for ld -r.  */
+  if (bfd_link_relocatable (info))
+    return true;
+
+  bed = get_elf_backend_data (info->output_bfd);
+  htab = elf_x86_hash_table (info, bed->target_id);
+  if (htab == NULL)
+    return false;
+
+  is_x86_64 = bed->target_id == X86_64_ELF_DATA;
+
+  outrel.r_info = htab->r_info (0, htab->relative_r_type);
+
+  if (htab->unaligned_relative_reloc.count)
+    elf_x86_size_or_finish_relative_reloc (is_x86_64, info, htab,
+					   true, &outrel);
+
+  count = htab->relative_reloc.count;
+  if (count)
+    {
+      elf_x86_size_or_finish_relative_reloc (is_x86_64, info, htab,
+					     false, &outrel);
+
+      elf_x86_compute_dl_relr_bitmap (info, htab, NULL);
+
+      elf_x86_write_dl_relr_bitmap (info, htab);
+    }
+
+  return true;
+}
+
 bool
 _bfd_elf_x86_valid_reloc_p (asection *input_section,
 			    struct bfd_link_info *info,
@@ -1332,6 +2239,11 @@  _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
       if ((s->flags & SEC_LINKER_CREATED) == 0)
 	continue;
 
+      /* The .relr.dyn section for compact relative relocation will
+	 be filled later.  */
+      if (s == htab->elf.srelrdyn)
+	continue;
+
       if (s == htab->elf.splt
 	  || s == htab->elf.sgot)
 	{
@@ -1459,6 +2371,7 @@  _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd,
   asection *sdyn;
   bfd_byte *dyncon, *dynconend;
   bfd_size_type sizeof_dyn;
+  bfd_size_type dt_relr_bitmap_count;
 
   bed = get_elf_backend_data (output_bfd);
   htab = elf_x86_hash_table (info, bed->target_id);
@@ -1517,6 +2430,8 @@  _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd,
   if (sdyn == NULL || htab->elf.sgot == NULL)
     abort ();
 
+  dt_relr_bitmap_count = htab->dt_relr_bitmap.count;
+
   sizeof_dyn = bed->s->sizeof_dyn;
   dyncon = sdyn->contents;
   dynconend = sdyn->contents + sdyn->size;
@@ -1535,6 +2450,28 @@  _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd,
 	    break;
 	  continue;
 
+	case DT_NULL:
+	  if (dt_relr_bitmap_count != 0)
+	    {
+	      /* Convert 3 spare dynamic tags to DT_RELR, DT_RELRSZ and
+		 DT_RELRENT for compact relative relocation.  */
+	      s = htab->elf.srelrdyn;
+	      dyn.d_tag = DT_RELR;
+	      dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
+	      (*bed->s->swap_dyn_out) (output_bfd, &dyn, dyncon);
+	      dyncon += sizeof_dyn;
+	      dyn.d_tag = DT_RELRSZ;
+	      dyn.d_un.d_val = s->size;
+	      (*bed->s->swap_dyn_out) (output_bfd, &dyn, dyncon);
+	      dyncon += sizeof_dyn;
+	      dyn.d_tag = DT_RELRENT;
+	      dyn.d_un.d_val = ABI_64_P (output_bfd) ? 8 : 4;
+	      elf_section_data (s->output_section)->this_hdr.sh_entsize
+		= dyn.d_un.d_val;
+	      dt_relr_bitmap_count = 0;
+	    }
+	  break;
+
 	case DT_PLTGOT:
 	  s = htab->elf.sgotplt;
 	  dyn.d_un.d_ptr = s->output_section->vma + s->output_offset;
diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h
index 1bb80280918..4b5784ca08a 100644
--- a/bfd/elfxx-x86.h
+++ b/bfd/elfxx-x86.h
@@ -47,18 +47,35 @@ 
 #define X86_SIZE_TYPE_P(IS_X86_64, TYPE) \
   ((IS_X86_64) ? X86_64_SIZE_TYPE_P(TYPE) : I386_SIZE_TYPE_P (TYPE))
 
-#define X86_64_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
-  (X86_64_SIZE_TYPE_P (TYPE) \
-   || X86_64_PCREL_TYPE_P (TYPE) \
+#define X86_64_GOT_TYPE_P(TYPE) \
+  ((TYPE) == R_X86_64_GOTPCREL \
+   || (TYPE) == R_X86_64_GOTPCRELX \
+   || (TYPE) == R_X86_64_REX_GOTPCRELX)
+#define I386_GOT_TYPE_P(TYPE) \
+  ((TYPE) == R_386_GOT32 || (TYPE) == R_386_GOT32X)
+#define X86_GOT_TYPE_P(IS_X86_64, TYPE) \
+  ((IS_X86_64) ? X86_64_GOT_TYPE_P (TYPE) : I386_GOT_TYPE_P (TYPE))
+
+#define X86_64_RELATIVE_RELOC_TYPE_P(TYPE) \
+  (X86_64_PCREL_TYPE_P (TYPE) \
    || (TYPE) == R_X86_64_8 \
    || (TYPE) == R_X86_64_16 \
    || (TYPE) == R_X86_64_32 \
    || (TYPE) == R_X86_64_32S \
    || (TYPE) == R_X86_64_64)
+#define I386_RELATIVE_RELOC_TYPE_P(TYPE) \
+  ((TYPE) == R_386_32 || (TYPE) == R_386_PC32)
+#define X86_RELATIVE_RELOC_TYPE_P(IS_X86_64, TYPE) \
+  ((IS_X86_64) \
+   ? X86_64_RELATIVE_RELOC_TYPE_P (TYPE) \
+   : I386_RELATIVE_RELOC_TYPE_P(TYPE))
+
+#define X86_64_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
+  (X86_64_SIZE_TYPE_P (TYPE) \
+   || X86_64_RELATIVE_RELOC_TYPE_P (TYPE))
 #define I386_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
   (I386_SIZE_TYPE_P (TYPE) \
-   || I386_PCREL_TYPE_P (TYPE) \
-   || (TYPE) == R_386_32 \
+   || I386_RELATIVE_RELOC_TYPE_P (TYPE) \
    || (TYPE) == R_386_TLS_LE \
    || (TYPE) == R_386_TLS_LE_32)
 #define X86_NEED_DYNAMIC_RELOC_TYPE_P(IS_X86_64, TYPE) \
@@ -66,11 +83,23 @@ 
    ? X86_64_NEED_DYNAMIC_RELOC_TYPE_P (TYPE) \
    : I386_NEED_DYNAMIC_RELOC_TYPE_P (TYPE))
 
+#define X86_LOCAL_GOT_RELATIVE_RELOC_P(IS_X86_64, INFO, SYM) \
+  (bfd_link_pic (INFO) \
+   && (!(IS_X86_64) || ((SYM) != NULL && (SYM)->st_shndx != SHN_ABS)))
+
 #define PLT_CIE_LENGTH		20
 #define PLT_FDE_LENGTH		36
 #define PLT_FDE_START_OFFSET	4 + PLT_CIE_LENGTH + 8
 #define PLT_FDE_LEN_OFFSET	4 + PLT_CIE_LENGTH + 12
 
+#define I386_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
+#define X86_64_PCREL_TYPE_P(TYPE) \
+  ((TYPE) == R_X86_64_PC8 \
+   || (TYPE) == R_X86_64_PC16 \
+   || (TYPE) == R_X86_64_PC32 \
+   || (TYPE) == R_X86_64_PC32_BND \
+   || (TYPE) == R_X86_64_PC64)
+
 #define ABI_64_P(abfd) \
   (get_elf_backend_data (abfd)->s->elfclass == ELFCLASS64)
 
@@ -160,12 +189,18 @@ 
    relocations against resolved undefined weak symbols in PIE, except
    when PC32_RELOC is TRUE.  Undefined weak symbol is bound locally
    when PIC is false.  Don't generate dynamic relocations against
-   non-preemptible absolute symbol.  */
+   non-preemptible absolute symbol.  NB: rel_from_abs is set on symbols
+   defined by linker scripts from "dot" (also SEGMENT_START or ORIGIN)
+   outside of an output section statement, which will be converted from
+   absolute to section-relative in set_sym_sections called from
+   ldexp_finalize_syms after ldemul_finish.   */
 #define GENERATE_DYNAMIC_RELOCATION_P(IS_X86_64, INFO, EH, R_TYPE, \
 				      SEC, NEED_COPY_RELOC_IN_PIE, \
 				      RESOLVED_TO_ZERO, PC32_RELOC) \
   ((bfd_link_pic (INFO) \
     && !(bfd_is_abs_section (SEC) \
+	 && ((EH) == NULL \
+	     || (EH)->elf.root.rel_from_abs == 0) \
 	 && ((EH) == NULL \
 	     || SYMBOL_REFERENCES_LOCAL (INFO, &(EH)->elf))) \
     && !(NEED_COPY_RELOC_IN_PIE) \
@@ -302,6 +337,10 @@  struct elf_x86_link_hash_entry
   /* Don't call finish_dynamic_symbol on this symbol.  */
   unsigned int no_finish_dynamic_symbol : 1;
 
+  /* R_*_RELATIVE relocation in GOT for this symbol has been
+     processed.  */
+  unsigned int got_relative_reloc_done : 1;
+
   /* TRUE if symbol is __tls_get_addr.  */
   unsigned int tls_get_addr : 1;
 
@@ -481,6 +520,52 @@  struct elf_x86_plt_layout
 #define elf_x86_hash_entry(ent) \
   ((struct elf_x86_link_hash_entry *)(ent))
 
+/* Information of an input relocation used to compute its contribution
+   to the DT_RELR section size.  */
+
+struct elf_x86_relative_reloc_record
+{
+  /* The original relocation info.  */
+  Elf_Internal_Rela rel;
+  /* The input or the GOT section where the relocation is applied.  */
+  asection *sec;
+  /* Local symbol info.  NULL for global symbol.  */
+  Elf_Internal_Sym *sym;
+  union
+    {
+      /* Section where the local symbol is defined.  */
+      asection *sym_sec;
+      /* Global symbol hash.  */
+      struct elf_link_hash_entry *h;
+    } u;
+  /* The offset into the output section where the relative relocation
+     will be applied at run-time.  */
+  bfd_vma offset;
+  /* The run-time address.  */
+  bfd_vma address;
+};
+
+struct elf_x86_relative_reloc_data
+{
+  bfd_size_type count;
+  bfd_size_type size;
+  struct elf_x86_relative_reloc_record *data;
+};
+
+/* DT_RELR bitmap.  */
+struct elf_dt_relr_bitmap
+{
+  bfd_size_type count;
+  bfd_size_type size;
+  union
+    {
+      /* 32-bit bitmap.  */
+      uint32_t *elf32;
+      /* 64-bit bitmap.  */
+      uint64_t *elf64;
+    } u;
+};
+
 /* x86 ELF linker hash table.  */
 
 struct elf_x86_link_hash_table
@@ -533,6 +618,18 @@  struct elf_x86_link_hash_table
      is only used for i386.  */
   bfd_vma next_tls_desc_index;
 
+  /* DT_RELR bitmap.  */
+  struct elf_dt_relr_bitmap dt_relr_bitmap;
+
+  /* Relative relocation data.  */
+  struct elf_x86_relative_reloc_data relative_reloc;
+
+  /* Unaligned relative relocation data.  */
+  struct elf_x86_relative_reloc_data unaligned_relative_reloc;
+
+  /* Number of relative reloc generation pass.  */
+  unsigned int generate_relative_reloc_pass;
+
    /* Value used to fill the unused bytes of the first PLT entry.  This
       is only used for i386.  */
   bfd_byte plt0_pad_byte;
@@ -554,9 +651,14 @@  struct elf_x86_link_hash_table
   unsigned int sizeof_reloc;
   unsigned int got_entry_size;
   unsigned int pointer_r_type;
+  unsigned int relative_r_type;
   int dynamic_interpreter_size;
   const char *dynamic_interpreter;
   const char *tls_get_addr;
+  const char *relative_r_name;
+  void (*elf_append_reloc) (bfd *, asection *, Elf_Internal_Rela *);
+  void (*elf_write_addend) (bfd *, uint64_t, void *);
+  void (*elf_write_addend_in_got) (bfd *, uint64_t, void *);
 
   /* Options passed from the linker.  */
   struct elf_linker_x86_params *params;
@@ -591,6 +693,10 @@  struct elf_x86_obj_tdata
 
   /* GOTPLT entries for TLS descriptors.  */
   bfd_vma *local_tlsdesc_gotent;
+
+  /* R_*_RELATIVE relocation in GOT for this local symbol has been
+     processed.  */
+  char *relative_reloc_done;
 };
 
 enum elf_x86_plt_type
@@ -626,6 +732,9 @@  struct elf_x86_plt
 #define elf_x86_local_tlsdesc_gotent(abfd) \
   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 
+#define elf_x86_relative_reloc_done(abfd) \
+  (elf_x86_tdata (abfd)->relative_reloc_done)
+
 #define elf_x86_compute_jump_table_size(htab) \
   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 
@@ -637,6 +746,7 @@  struct elf_x86_plt
 /* Rename some of the generic section flags to better document how they
    are used here.  */
 #define check_relocs_failed	sec_flg0
+#define relative_reloc_packed	sec_flg1
 
 extern bool _bfd_x86_elf_mkobject
   (bfd *);
@@ -676,6 +786,18 @@  extern bool _bfd_x86_elf_check_relocs
   (bfd *, struct bfd_link_info *, asection *,
    const Elf_Internal_Rela *);
 
+extern bool _bfd_x86_elf_link_relax_section
+  (bfd *, asection *, struct bfd_link_info *, bool *);
+
+extern bool _bfd_elf_x86_size_relative_relocs
+  (struct bfd_link_info *, bool *);
+
+extern bool _bfd_elf_x86_finish_relative_relocs
+  (struct bfd_link_info *);
+
+extern void _bfd_elf32_write_addend (bfd *, uint64_t, void *);
+extern void _bfd_elf64_write_addend (bfd *, uint64_t, void *);
+
 extern bool _bfd_elf_x86_valid_reloc_p
   (asection *, struct bfd_link_info *, struct elf_x86_link_hash_table *,
    const Elf_Internal_Rela *, struct elf_link_hash_entry *,
@@ -752,6 +874,10 @@  extern void _bfd_x86_elf_link_report_relative_reloc
   _bfd_x86_elf_link_check_relocs
 #define bfd_elf32_bfd_link_check_relocs \
   _bfd_x86_elf_link_check_relocs
+#define bfd_elf32_bfd_relax_section \
+  _bfd_x86_elf_link_relax_section
+#define bfd_elf64_bfd_relax_section \
+  _bfd_x86_elf_link_relax_section
 
 #define elf_backend_check_relocs \
   _bfd_x86_elf_check_relocs
@@ -777,6 +903,10 @@  extern void _bfd_x86_elf_link_report_relative_reloc
   _bfd_x86_elf_merge_gnu_properties
 #define elf_backend_fixup_gnu_properties \
   _bfd_x86_elf_link_fixup_gnu_properties
+#define elf_backend_size_relative_relocs \
+  _bfd_elf_x86_size_relative_relocs
+#define elf_backend_finish_relative_relocs \
+  _bfd_elf_x86_finish_relative_relocs
 
 #define ELF_P_ALIGN ELF_MINPAGESIZE
 
@@ -789,7 +919,8 @@  elf_x86_allocate_local_got_info (bfd *abfd, bfd_size_type count)
   if (local_got_refcounts == NULL)
     {
       bfd_size_type size = count * (sizeof (bfd_signed_vma)
-				    + sizeof (bfd_vma) + sizeof(char));
+				    + sizeof (bfd_vma)
+				    + 2 * sizeof(char));
       local_got_refcounts = (bfd_signed_vma *) bfd_zalloc (abfd, size);
       if (local_got_refcounts == NULL)
 	return false;
@@ -798,6 +929,8 @@  elf_x86_allocate_local_got_info (bfd *abfd, bfd_size_type count)
 	(bfd_vma *) (local_got_refcounts + count);
       elf_x86_local_got_tls_type (abfd) =
 	(char *) (local_got_refcounts + 2 * count);
+      elf_x86_relative_reloc_done (abfd) =
+	((char *) (local_got_refcounts + 2 * count)) + count;
     }
   return true;
 }