Add R_X86_64_GPRELusers/hjl/gprel/master

"%seg:foo@GPREL" is used to address symbol, foo, relative to __gp. foo is
addressed by %seg + offset of foo relative to __gp.  Linker sets __gp to
the middle of GP section which contains definitions of symbols with GPREL
relocations.  Run-time should load address of __gp into segment register,
%seg before accessing foo via "%seg:foo@GPREL".

20 files changed, 509 insertions, 11 deletions

diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 448599eb9b3..320c6983220 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -183,12 +183,15 @@ static reloc_howto_type x86_64_elf_howto_table[] =
   HOWTO(R_X86_64_REX_GOTPCRELX, 0, 2, 32, TRUE, 0, complain_overflow_signed,
 	bfd_elf_generic_reloc, "R_X86_64_REX_GOTPCRELX", FALSE, 0xffffffff,
 	0xffffffff, TRUE),
+  HOWTO(R_X86_64_GPREL, 0, 2, 32, FALSE, 0, complain_overflow_signed,
+	bfd_elf_generic_reloc, "R_X86_64_GPREL",
+	FALSE, MINUS_ONE, MINUS_ONE, FALSE),
 
   /* We have a gap in the reloc numbers here.
      R_X86_64_standard counts the number up to this point, and
      R_X86_64_vt_offset is the value to subtract from a reloc type of
      R_X86_64_GNU_VT* to form an index into this table.  */
-#define R_X86_64_standard (R_X86_64_REX_GOTPCRELX + 1)
+#define R_X86_64_standard (R_X86_64_GPREL + 1)
 #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard)
 
 /* GNU extension to record C++ vtable hierarchy.  */
@@ -264,6 +267,7 @@ static const struct elf_reloc_map x86_64_reloc_map[] =
   { BFD_RELOC_X86_64_PLT32_BND,	R_X86_64_PLT32_BND, },
   { BFD_RELOC_X86_64_GOTPCRELX, R_X86_64_GOTPCRELX, },
   { BFD_RELOC_X86_64_REX_GOTPCRELX, R_X86_64_REX_GOTPCRELX, },
+  { BFD_RELOC_GPREL32,		R_X86_64_GPREL, },
   { BFD_RELOC_VTABLE_INHERIT,	R_X86_64_GNU_VTINHERIT, },
   { BFD_RELOC_VTABLE_ENTRY,	R_X86_64_GNU_VTENTRY, },
 };
@@ -1092,6 +1096,12 @@ struct elf_x86_64_link_hash_entry
      real definition and check it when allowing copy reloc in PIE.  */
   unsigned int needs_copy : 1;
 
+  /* TRUE if symbol is __gp.  */
+  unsigned int is_gp : 1;
+
+  /* TRUE if symbol has GPREL relocations.  */
+  unsigned int has_gprel_reloc : 1;
+
   /* TRUE if symbol has GOT or PLT relocations.  */
   unsigned int has_got_reloc : 1;
 
@@ -1171,6 +1181,8 @@ struct elf_x86_64_link_hash_table
   asection *plt_got;
   asection *plt_got_eh_frame;
 
+  struct elf_link_hash_entry *gp;
+
   /* Parameters describing PLT generation, lazy or non-lazy.  */
   struct elf_x86_64_plt_layout plt;
 
@@ -1261,6 +1273,8 @@ elf_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry,
       eh->dyn_relocs = NULL;
       eh->tls_type = GOT_UNKNOWN;
       eh->needs_copy = 0;
+      eh->is_gp = 0;
+      eh->has_gprel_reloc = 0;
       eh->has_got_reloc = 0;
       eh->has_non_got_reloc = 0;
       eh->no_finish_dynamic_symbol = 0;
@@ -1423,6 +1437,7 @@ elf_x86_64_copy_indirect_symbol (struct bfd_link_info *info,
   edir = (struct elf_x86_64_link_hash_entry *) dir;
   eind = (struct elf_x86_64_link_hash_entry *) ind;
 
+  edir->has_gprel_reloc |= eind->has_gprel_reloc;
   edir->has_got_reloc |= eind->has_got_reloc;
   edir->has_non_got_reloc |= eind->has_non_got_reloc;
 
@@ -2098,6 +2113,7 @@ elf_x86_64_convert_load_reloc (bfd *abfd, asection *sec,
       /* Avoid optimizing GOTPCREL relocations againt _DYNAMIC since
 	 ld.so may use its link-time address.  */
       else if (h->start_stop
+	       || ((struct elf_x86_64_link_hash_entry *) h)->is_gp
 	       || ((h->def_regular
 		    || h->root.type == bfd_link_hash_defined
 		    || h->root.type == bfd_link_hash_defweak)
@@ -2108,8 +2124,10 @@ elf_x86_64_convert_load_reloc (bfd *abfd, asection *sec,
 	     set by an assignment in a linker script in
 	     bfd_elf_record_link_assignment.  start_stop is set
 	     on __start_SECNAME/__stop_SECNAME which mark section
-	     SECNAME.  */
+	     SECNAME.  is_gp is set on __gp symbol which will be
+	     resolved to GP section and marked as hidden.  */
 	  if (h->start_stop
+	      || ((struct elf_x86_64_link_hash_entry *) h)->is_gp
 	      || (h->def_regular
 		  && (h->root.type == bfd_link_hash_new
 		      || h->root.type == bfd_link_hash_undefined
@@ -2453,18 +2471,26 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	  if (isym == NULL)
 	    goto error_return;
 
-	  /* Check relocation against local STT_GNU_IFUNC symbol.  */
-	  if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
+	  /* Check relocation against local STT_GNU_IFUNC symbol and
+	     GPREL relocation.  */
+	  if (r_type == R_X86_64_GPREL
+	      || ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC)
 	    {
 	      h = elf_x86_64_get_local_sym_hash (htab, abfd, rel,
 						 TRUE);
 	      if (h == NULL)
 		goto error_return;
 
-	      /* Fake a STT_GNU_IFUNC symbol.  */
-	      h->root.root.string = bfd_elf_sym_name (abfd, symtab_hdr,
-						      isym, NULL);
-	      h->type = STT_GNU_IFUNC;
+	      if (r_type == R_X86_64_GPREL)
+		/* Prepare for GP section.  */
+		h->root.u.def.section
+		  = bfd_section_from_elf_index (abfd, isym->st_shndx);
+	      else
+		/* Fake a STT_GNU_IFUNC symbol.  */
+		h->root.root.string = bfd_elf_sym_name (abfd, symtab_hdr,
+							isym, NULL);
+
+	      h->type = ELF_ST_TYPE (isym->st_info);
 	      h->def_regular = 1;
 	      h->ref_regular = 1;
 	      h->forced_local = 1;
@@ -2891,6 +2917,11 @@ do_size:
 	    goto error_return;
 	  break;
 
+	case R_X86_64_GPREL:
+	  if (eh != NULL)
+	    eh->has_gprel_reloc = 1;
+	  break;
+
 	default:
 	  break;
 	}
@@ -3548,6 +3579,10 @@ elf_x86_64_allocate_local_dynrelocs (void **slot, void *inf)
   struct elf_link_hash_entry *h
     = (struct elf_link_hash_entry *) *slot;
 
+  /* Skip local symbol with GPREL relocation.  */
+  if (((struct elf_x86_64_link_hash_entry *) h)->has_gprel_reloc)
+    return TRUE;
+
   if (h->type != STT_GNU_IFUNC
       || !h->def_regular
       || !h->ref_regular
@@ -5716,6 +5751,41 @@ direct:
 	  relocation -= elf_x86_64_dtpoff_base (info);
 	  break;
 
+	case R_X86_64_GPREL:
+	  if (h == NULL || h->def_regular)
+	    {
+	      asection *def_sec;
+
+	      if (h != NULL)
+		def_sec = h->root.u.def.section;
+	      else
+		def_sec = local_sections[r_symndx];
+
+	      if (htab->gp->root.u.def.section
+		  != def_sec->output_section)
+		{
+		  if (h != NULL && h->root.root.string != NULL)
+		    _bfd_error_handler
+		      /* xgettext:c-format */
+		      (_("%B: symbol `%s' with GPREL relocation "
+			 "defined in %B(%A) isn't in GP section `%A'"),
+		       input_bfd, h->root.root.string, def_sec->owner,
+		       def_sec, htab->gp->root.u.def.section);
+		  else
+		    _bfd_error_handler
+		      /* xgettext:c-format */
+		      (_("%B: GPREL relocation at %#Lx in section "
+			 "`%A' must be against symbol defined in GP "
+			 "section `%A'"),
+		       input_bfd, rel->r_offset, input_section,
+		       htab->gp->root.u.def.section);
+		  return FALSE;
+		}
+	      relocation -= (htab->gp->root.u.def.section->vma
+			     + htab->gp->root.u.def.value);
+	    }
+	  break;
+
 	default:
 	  break;
 	}
@@ -6225,8 +6295,12 @@ elf_x86_64_finish_local_dynamic_symbol (void **slot, void *inf)
   struct bfd_link_info *info
     = (struct bfd_link_info *) inf;
 
+  /* Skip local symbol with GPREL relocation.  */
+  if (((struct elf_x86_64_link_hash_entry *) h)->has_gprel_reloc)
+    return TRUE;
+
   return elf_x86_64_finish_dynamic_symbol (info->output_bfd,
-					     info, h, NULL);
+					   info, h, NULL);
 }
 
 /* Finish up undefined weak symbol handling in PIE.  Fill its PLT entry
@@ -7332,6 +7406,7 @@ elf_x86_64_link_setup_gnu_properties (struct bfd_link_info *info)
   bfd_boolean use_ibt_plt;
   unsigned int plt_alignment, features;
   struct elf_x86_64_link_hash_table *htab;
+  struct elf_link_hash_entry *gp;
   bfd *pbfd;
 
   features = 0;
@@ -7712,9 +7787,137 @@ error_alignment:
 	goto error_alignment;
     }
 
+  /* Set is_gp for __gp symbol.  */
+  gp = elf_link_hash_lookup (elf_hash_table (info), "__gp", FALSE,
+			     FALSE, FALSE);
+  if (gp != NULL)
+    {
+      ((struct elf_x86_64_link_hash_entry *) gp)->is_gp = 1;
+      htab->gp = gp;
+    }
+
   return pbfd;
 }
 
+/* Set up GP section from symbols with GPREL relocations.  */
+
+static bfd_boolean
+elf_x86_64_setup_gp (struct elf_link_hash_entry *h, void * inf)
+{
+  struct bfd_link_info *info;
+  struct elf_x86_64_link_hash_table *htab;
+  struct elf_x86_64_link_hash_entry *eh;
+  struct elf_link_hash_entry *gp;
+  const struct elf_backend_data *bed;
+  asection *gpsection;
+  bfd_size_type gpsection_size;
+
+  eh = (struct elf_x86_64_link_hash_entry *) h;
+
+  /* Skip if there is no GPREL relocation or symbol is undefined.  */
+  if (!eh->has_gprel_reloc
+      || (h->root.type != bfd_link_hash_defined
+	  && h->root.type != bfd_link_hash_defweak))
+    return TRUE;
+
+  info = (struct bfd_link_info *) inf;
+  htab = elf_x86_64_hash_table (info);
+  if (htab == NULL)
+    return FALSE;
+
+  gpsection = h->root.u.def.section->output_section;
+  gpsection_size = bfd_get_section_size (gpsection);
+  if (gpsection_size > 0xffffffff)
+    {
+      info->callbacks->einfo (_("%F%B: GP section `%A' size overflow\n"),
+			      info->output_bfd, gpsection);
+      return FALSE;
+    }
+
+  gp = htab->gp;
+  gp->def_regular = 1;
+  gp->root.type = bfd_link_hash_defined;
+  gp->root.u.def.value = gpsection_size / 2;
+  gp->root.u.def.section = gpsection;
+  gp->root.linker_def = 1;
+  gp->other = STV_HIDDEN;
+  bed = get_elf_backend_data (info->output_bfd);
+  bed->elf_backend_hide_symbol (info, gp, TRUE);
+
+  return FALSE;
+}
+
+/* Set up GP section from local symbols with GPREL relocations.  */
+
+static bfd_boolean
+elf_x86_64_setup_gp_from_local_symbol (void **slot, void *inf)
+{
+  struct elf_link_hash_entry *h
+    = (struct elf_link_hash_entry *) *slot;
+  struct bfd_link_info *info
+    = (struct bfd_link_info *) inf;
+
+  return elf_x86_64_setup_gp (h, info);
+}
+
+/* Set up GP section for __gp symbol.  */
+
+static bfd_boolean
+elf_x86_64_final_link (bfd *abfd, struct bfd_link_info *info)
+{
+  if (!bfd_link_relocatable (info))
+    {
+      struct elf_link_hash_entry *gp;
+      struct elf_x86_64_link_hash_table *htab;
+
+      htab = elf_x86_64_hash_table (info);
+      if (htab == NULL)
+	return FALSE;
+
+      gp = htab->gp;
+      if (gp != NULL)
+	{
+	  if (gp->root.type == bfd_link_hash_defined
+	      || gp->root.type == bfd_link_hash_defweak)
+	    {
+	      /* Hide __gp.  */
+	      const struct elf_backend_data *bed
+		= get_elf_backend_data (abfd);
+	      gp->other = STV_HIDDEN;
+	      bed->elf_backend_hide_symbol (info, gp, TRUE);
+	    }
+	  else
+	    {
+	      /* Set up __gp from a symbol with GPREL relocations.  */
+	      elf_link_hash_traverse (&htab->elf,
+				      elf_x86_64_setup_gp,
+				      info);
+
+	      if (gp->root.type != bfd_link_hash_defined
+		  && gp->root.type != bfd_link_hash_defweak)
+		{
+		  /* Set up __gp from a local symbol with GPREL
+		     relocations.  */
+		  htab_traverse (htab->loc_hash_table,
+				 elf_x86_64_setup_gp_from_local_symbol,
+				 info);
+		}
+
+	      if (gp->root.type != bfd_link_hash_defined
+		  && gp->root.type != bfd_link_hash_defweak)
+		{
+		  info->callbacks->einfo (_("%F%B: undefined __gp symbol\n"),
+					  info->output_bfd);
+		  return FALSE;
+		}
+	    }
+	}
+    }
+
+  /* Invoke the regular ELF backend linker to do all the work.  */
+  return bfd_elf_final_link (abfd, info);
+}
+
 static const struct bfd_elf_special_section
 elf_x86_64_special_sections[]=
 {
@@ -7779,6 +7982,7 @@ elf_x86_64_special_sections[]=
 #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 bfd_elf64_bfd_final_link	    elf_x86_64_final_link
 
 #define elf_backend_section_from_shdr \
 	elf_x86_64_section_from_shdr
@@ -8078,6 +8282,8 @@ elf32_x86_64_nacl_elf_object_p (bfd *abfd)
   elf_x86_64_mkobject
 #define bfd_elf32_get_synthetic_symtab \
   elf_x86_64_get_synthetic_symtab
+#define bfd_elf32_bfd_final_link \
+  elf_x86_64_final_link
 
 #undef elf_backend_object_p
 #define elf_backend_object_p \
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 456be9e07cf..c15742b1c12 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -672,6 +672,9 @@ static enum rc_type evexrcig = rne;
 /* Pre-defined "_GLOBAL_OFFSET_TABLE_".  */
 static symbolS *GOT_symbol;
 
+/* Pre-defined "__gp".  */
+static symbolS *GP_symbol;
+
 /* The dwarf2 return column, adjusted for 32 or 64 bit.  */
 unsigned int x86_dwarf2_return_column;
 
@@ -7776,6 +7779,9 @@ lex_got (enum bfd_reloc_code_real *rel,
     { STRING_COMMA_LEN ("GOTPCREL"), { _dummy_first_bfd_reloc_code_real,
 				       BFD_RELOC_X86_64_GOTPCREL },
       OPERAND_TYPE_IMM32_32S_DISP32 },
+    { STRING_COMMA_LEN ("GPREL"),    { _dummy_first_bfd_reloc_code_real,
+				       BFD_RELOC_GPREL32 },
+      OPERAND_TYPE_IMM32_32S_DISP32 },
     { STRING_COMMA_LEN ("TLSGD"),    { BFD_RELOC_386_TLS_GD,
 				       BFD_RELOC_X86_64_TLSGD    },
       OPERAND_TYPE_IMM32_32S_DISP32 },
@@ -7848,8 +7854,19 @@ lex_got (enum bfd_reloc_code_real *rel,
 		    *types = gotrel[j].types64;
 		}
 
-	      if (j != 0 && GOT_symbol == NULL)
-		GOT_symbol = symbol_find_or_make (GLOBAL_OFFSET_TABLE_NAME);
+	      if (j != 0)
+		{
+		  if (gotrel[j].rel[1] == BFD_RELOC_GPREL32)
+		    {
+		      if (GP_symbol == NULL)
+			GP_symbol = symbol_find_or_make (GLOBAL_POINTER_NAME);
+		    }
+		  else
+		    {
+		      if (GOT_symbol == NULL)
+			GOT_symbol = symbol_find_or_make (GLOBAL_OFFSET_TABLE_NAME);
+		    }
+		}
 
 	      /* The length of the first part of our input line.  */
 	      first = cp - input_line_pointer;
@@ -8506,6 +8523,11 @@ i386_displacement (char *disp_start, char *disp_end)
   if (gotfree_input_line)
     input_line_pointer = gotfree_input_line;
 
+  if (i.reloc[this_operand] == BFD_RELOC_GPREL32
+      && (i.seg[0] == NULL
+	  ||  i.types[this_operand].bitfield.baseindex))
+    as_bad (_("invalid GP relocation"));
+
   exp_seg = expression (exp);
 
   SKIP_WHITESPACE ();
@@ -10740,6 +10762,21 @@ md_undefined_symbol (char *name)
 	};
       return GOT_symbol;
     }
+  else if (name[0] == GLOBAL_POINTER_NAME[0]
+	   && name[1] == GLOBAL_POINTER_NAME[1]
+	   && name[2] == GLOBAL_POINTER_NAME[2]
+	   && name[3] == GLOBAL_POINTER_NAME[3]
+	   && strcmp (name, GLOBAL_POINTER_NAME) == 0)
+    {
+      if (!GP_symbol)
+	{
+	  if (symbol_find (name))
+	    as_bad (_("GP already in symbol table"));
+	  GP_symbol = symbol_new (name, undefined_section,
+				  (valueT) 0, &zero_address_frag);
+	};
+      return GP_symbol;
+    }
   return 0;
 }
 
@@ -10899,6 +10936,7 @@ tc_gen_reloc (asection *section ATTRIBUTE_UNUSED, fixS *fixp)
     case BFD_RELOC_X86_64_PLTOFF64:
     case BFD_RELOC_X86_64_GOTPC32_TLSDESC:
     case BFD_RELOC_X86_64_TLSDESC_CALL:
+    case BFD_RELOC_GPREL32:
     case BFD_RELOC_RVA:
     case BFD_RELOC_VTABLE_ENTRY:
     case BFD_RELOC_VTABLE_INHERIT:
diff --git a/gas/config/tc-i386.h b/gas/config/tc-i386.h
index f54924c4382..beaa4614ddc 100644
--- a/gas/config/tc-i386.h
+++ b/gas/config/tc-i386.h
@@ -128,6 +128,12 @@ extern const char *i386_comment_chars;
 #define GLOBAL_OFFSET_TABLE_NAME "_GLOBAL_OFFSET_TABLE_"
 #endif
 
+/* The name of the global pointer.  Allow this to be overridden if need
+   be.  */
+#ifndef GLOBAL_POINTER_NAME
+#define GLOBAL_POINTER_NAME "__gp"
+#endif
+
 #if (defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)) && !defined (LEX_AT)
 #define TC_PARSE_CONS_EXPRESSION(EXP, NBYTES) x86_cons (EXP, NBYTES)
 #endif
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 67a7a13b259..427a758b35a 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -868,6 +868,9 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check]] t
 	run_dump_test "x86-64-gotpcrel-no-relax"
 
 	run_dump_test "x86-64-addend"
+
+	run_dump_test "x86-64-gprel"
+	run_list_test "x86-64-inval-gprel" "-al"
     }
 
     set ASFLAGS "$old_ASFLAGS"
diff --git a/gas/testsuite/gas/i386/x86-64-gprel.d b/gas/testsuite/gas/i386/x86-64-gprel.d
new file mode 100644
index 00000000000..f70624ab42e
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-gprel.d
@@ -0,0 +1,10 @@
+#objdump: -drw
+#name: x86-64 gprel
+
+.*: +file format .*
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	65 8b 04 25 00 00 00 00 	mov    %gs:0x0,%eax	4: R_X86_64_GPREL	foo
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-gprel.s b/gas/testsuite/gas/i386/x86-64-gprel.s
new file mode 100644
index 00000000000..96b3ce90444
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-gprel.s
@@ -0,0 +1,3 @@
+	.text
+_start:
+	movl	%gs:foo@GPREL, %eax
diff --git a/gas/testsuite/gas/i386/x86-64-inval-gprel.l b/gas/testsuite/gas/i386/x86-64-inval-gprel.l
new file mode 100644
index 00000000000..b6683b036d1
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-inval-gprel.l
@@ -0,0 +1,34 @@
+.*: Assembler messages:
+.*:3: Error: invalid GP relocation
+.*:3: Error: non-pc-relative relocation for pc-relative field
+.*:4: Error: invalid GP relocation
+.*:5: Error: invalid GP relocation
+.*:6: Error: invalid GP relocation
+.*:6: Error: non-pc-relative relocation for pc-relative field
+.*:7: Error: invalid GP relocation
+.*:8: Error: invalid GP relocation
+GAS LISTING .*
+
+
+[ 	]*1[ 	]+\.text
+[ 	]*2[ 	]+_start:
+[ 	]*3[ 	]+\?\?\?\? 648B0500 		movl	%fs:foo@GPREL\(%rip\), %eax
+\*\*\*\*  Error: invalid GP relocation
+\*\*\*\*  Error: non-pc-relative relocation for pc-relative field
+[ 	]*3[ 	]+000000
+[ 	]*4[ 	]+\?\?\?\? 648B8000 		movl	%fs:foo@GPREL\(%rax\), %eax
+\*\*\*\*  Error: invalid GP relocation
+[ 	]*4[ 	]+000000
+[ 	]*5[ 	]+\?\?\?\? 8B844800 		movl	%ds:foo@GPREL\(%rax, %rcx, 2\), %eax
+\*\*\*\*  Error: invalid GP relocation
+[ 	]*5[ 	]+000000
+[ 	]*6[ 	]+\?\?\?\? 8B050000 		movl	foo@GPREL\(%rip\), %eax
+\*\*\*\*  Error: invalid GP relocation
+\*\*\*\*  Error: non-pc-relative relocation for pc-relative field
+[ 	]*6[ 	]+0000
+[ 	]*7[ 	]+\?\?\?\? 8B800000 		movl	foo@GPREL\(%rax\), %eax
+\*\*\*\*  Error: invalid GP relocation
+[ 	]*7[ 	]+0000
+[ 	]*8[ 	]+\?\?\?\? 8B042500 		movl	foo@GPREL, %eax
+\*\*\*\*  Error: invalid GP relocation
+[ 	]*8[ 	]+000000
diff --git a/gas/testsuite/gas/i386/x86-64-inval-gprel.s b/gas/testsuite/gas/i386/x86-64-inval-gprel.s
new file mode 100644
index 00000000000..8507926860d
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-inval-gprel.s
@@ -0,0 +1,8 @@
+	.text
+_start:
+	movl	%fs:foo@GPREL(%rip), %eax
+	movl	%fs:foo@GPREL(%rax), %eax
+	movl	%ds:foo@GPREL(%rax, %rcx, 2), %eax
+	movl	foo@GPREL(%rip), %eax
+	movl	foo@GPREL(%rax), %eax
+	movl	foo@GPREL, %eax
diff --git a/include/elf/x86-64.h b/include/elf/x86-64.h
index 976f4fe347b..f9697ebd009 100644
--- a/include/elf/x86-64.h
+++ b/include/elf/x86-64.h
@@ -82,6 +82,8 @@ START_RELOC_NUMBERS (elf_x86_64_reloc_type)
      /* Load from 32 bit signed pc relative offset to GOT entry with
 	REX prefix, relaxable.  */
      RELOC_NUMBER (R_X86_64_REX_GOTPCRELX, 42)
+     RELOC_NUMBER (R_X86_64_GPREL, 43)        /* 32 bit signed pc relative
+                                                 offset to GP  */
      RELOC_NUMBER (R_X86_64_GNU_VTINHERIT, 250)       /* GNU C++ hack  */
      RELOC_NUMBER (R_X86_64_GNU_VTENTRY, 251)         /* GNU C++ hack  */
 END_RELOC_NUMBERS (R_X86_64_max)
diff --git a/ld/testsuite/ld-x86-64/gprel-1a.S b/ld/testsuite/ld-x86-64/gprel-1a.S
new file mode 100644
index 00000000000..db099abb6a7
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-1a.S
@@ -0,0 +1,15 @@
+	.text
+	.globl get_foo
+get_foo:
+	movl	%gs:foo@GPREL, %eax
+	ret
+
+	.data
+	.globl foo_gprel
+foo_gprel:
+	.long foo@GPREL
+
+	.data
+	.globl foo
+foo:
+	.long 0x12345678
diff --git a/ld/testsuite/ld-x86-64/gprel-1b.c b/ld/testsuite/ld-x86-64/gprel-1b.c
new file mode 100644
index 00000000000..97d3b553b95
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-1b.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <syscall.h>
+#include <asm/prctl.h>
+
+extern int foo;
+extern int __gp;
+extern int foo_gprel;
+extern int get_foo (void);
+
+int
+setup_gp (void *p)
+{
+  int result;
+  asm volatile ("syscall"
+		: "=a" (result)
+		: "0" ((unsigned long int) SYS_arch_prctl),
+		  "D" ((unsigned long int) ARCH_SET_GS),
+		  "S" (p)
+		: "memory", "cc", "r11", "cx");
+  return result;
+}
+
+int
+main ()
+{
+  setup_gp (&__gp);
+  if (foo == 0x12345678
+      && *(int *) ((char *) &__gp + foo_gprel) == 0x12345678
+      && get_foo () == 0x12345678)
+    printf ("PASS\n");
+  return 0;
+}
diff --git a/ld/testsuite/ld-x86-64/gprel-2a.S b/ld/testsuite/ld-x86-64/gprel-2a.S
new file mode 100644
index 00000000000..99165e5b6a4
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-2a.S
@@ -0,0 +1,14 @@
+	.text
+	.globl get_foo
+get_foo:
+	movl	%gs:foo@GPREL, %eax
+	ret
+
+	.data
+	.globl foo_gprel
+foo_gprel:
+	.long foo@GPREL
+
+	.data
+foo:
+	.long 0x12345678
diff --git a/ld/testsuite/ld-x86-64/gprel-2b.c b/ld/testsuite/ld-x86-64/gprel-2b.c
new file mode 100644
index 00000000000..3b53fad432c
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-2b.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <syscall.h>
+#include <asm/prctl.h>
+
+extern int __gp;
+extern int foo_gprel;
+extern int get_foo (void);
+
+int
+setup_gp (void *p)
+{
+  int result;
+  asm volatile ("syscall"
+		: "=a" (result)
+		: "0" ((unsigned long int) SYS_arch_prctl),
+		  "D" ((unsigned long int) ARCH_SET_GS),
+		  "S" (p)
+		: "memory", "cc", "r11", "cx");
+  return result;
+}
+
+int
+main ()
+{
+  setup_gp (&__gp);
+  if (*(int *) ((char *) &__gp + foo_gprel) == 0x12345678
+      && get_foo () == 0x12345678)
+    printf ("PASS\n");
+  return 0;
+}
diff --git a/ld/testsuite/ld-x86-64/gprel-3.d b/ld/testsuite/ld-x86-64/gprel-3.d
new file mode 100644
index 00000000000..c870a95ad7f
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-3.d
@@ -0,0 +1,3 @@
+#as: --64
+#ld: -melf_x86_64
+#error: undefined __gp symbol
diff --git a/ld/testsuite/ld-x86-64/gprel-3.s b/ld/testsuite/ld-x86-64/gprel-3.s
new file mode 100644
index 00000000000..ba79246fda8
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-3.s
@@ -0,0 +1,4 @@
+	.text
+	.globl _start
+_start:
+	movl	%gs:foo@GPREL, %eax
diff --git a/ld/testsuite/ld-x86-64/gprel-4.d b/ld/testsuite/ld-x86-64/gprel-4.d
new file mode 100644
index 00000000000..024e06634e1
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-4.d
@@ -0,0 +1,3 @@
+#as: --64
+#ld: -melf_x86_64
+#error: GPREL relocation at 0x4 in section `\.text' must be against symbol defined in GP section `\.rodata'
diff --git a/ld/testsuite/ld-x86-64/gprel-4.s b/ld/testsuite/ld-x86-64/gprel-4.s
new file mode 100644
index 00000000000..a0a89ba0cd9
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-4.s
@@ -0,0 +1,17 @@
+	.text
+	.globl _start
+_start:
+	movl	%gs:foo@GPREL, %eax
+
+	.data
+	.globl bar_gprel
+bar_gprel:
+	.long bar@GPREL
+
+foo:
+	.long 0x12345678
+
+	.section .rodata,"a",@progbits
+bar:
+	.long 0x12345678
+
diff --git a/ld/testsuite/ld-x86-64/gprel-5.d b/ld/testsuite/ld-x86-64/gprel-5.d
new file mode 100644
index 00000000000..3186c346b4e
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-5.d
@@ -0,0 +1,3 @@
+#as: --64
+#ld: -melf_x86_64
+#error: symbol `bar' with GPREL relocation defined in .*\.o\(\.rodata\) isn't in GP section `\.data'
diff --git a/ld/testsuite/ld-x86-64/gprel-5.s b/ld/testsuite/ld-x86-64/gprel-5.s
new file mode 100644
index 00000000000..a49adec8dab
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gprel-5.s
@@ -0,0 +1,19 @@
+	.text
+	.globl _start
+_start:
+	movl	%gs:foo@GPREL, %eax
+
+	.data
+	.globl bar_gprel
+bar_gprel:
+	.long bar@GPREL
+
+	.globl foo
+foo:
+	.long 0x12345678
+
+	.section .rodata,"a",@progbits
+	.globl bar
+bar:
+	.long 0x12345678
+
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index c5825822978..8f6f0a40384 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -567,6 +567,9 @@ run_dump_test "pr20253-4f"
 run_dump_test "pr20253-5a"
 run_dump_test "pr20253-5b"
 run_dump_test "tlsdesc2"
+run_dump_test "gprel-3"
+run_dump_test "gprel-4"
+run_dump_test "gprel-5"
 
 proc undefined_weak {cflags ldflags} {
     set testname "Undefined weak symbol"
@@ -1571,6 +1574,51 @@ run_ld_link_tests [list \
     ] \
 ]
 
+run_ld_link_exec_tests [list \
+    [list \
+	"Run GPREL 1" \
+	"" \
+	"" \
+	{gprel-1a.S gprel-1b.c} \
+	"gprel-1" "pass.out" \
+    ] \
+    [list \
+	"Run GPREL 1 (PIE)" \
+	"-pie" \
+	"" \
+	{gprel-1a.S gprel-1b.c} \
+	"gprel-1-pie" "pass.out" "-fPIE" \
+    ] \
+    [list \
+	"Run GPREL 1 (static)" \
+	"-static" \
+	"" \
+	{gprel-1a.S gprel-1b.c} \
+	"gprel-1-static" "pass.out" \
+    ] \
+    [list \
+	"Run GPREL 2" \
+	"" \
+	"" \
+	{gprel-2a.S gprel-2b.c} \
+	"gprel-2" "pass.out" \
+    ] \
+    [list \
+	"Run GPREL 2 (PIE)" \
+	"-pie" \
+	"" \
+	{gprel-2a.S gprel-2b.c} \
+	"gprel-2-pie" "pass.out" "-fPIE" \
+    ] \
+    [list \
+	"Run GPREL 2 (static)" \
+	"-static" \
+	"" \
+	{gprel-2a.S gprel-2b.c} \
+	"gprel-2-static" "pass.out" \
+    ] \
+]
+
 # Linux only tests
 run_dump_test "pr17618"
 run_dump_test "pltgot-1"