Check run-time R_X86_64_32 relocation overflow

Since elf_x86_64_check_relocs is called after opening all input files,
we can detect dynamic R_X86_64_32 relocation overflow there.

bfd/

	PR ld/19969
	* elf64-x86-64.c (check_relocs_failed): New.
	(elf_x86_64_need_pic): Moved before elf_x86_64_check_relocs.
	Support relocation agaist local symbol.  Set check_relocs_failed.
	(elf_x86_64_check_relocs): Use elf_x86_64_need_pic.  Check
	R_X86_64_32 relocation overflow.
	(elf_x86_64_relocate_section): Skip if check_relocs failed.
	Update one elf_x86_64_need_pic and remove one elf_x86_64_need_pic.

ld/

	PR ld/19969
	* testsuite/ld-x86-64/pr19969.d: New file.
	* testsuite/ld-x86-64/pr19969a.S: Likewise.
	* testsuite/ld-x86-64/pr19969b.S: Likewise.
	* testsuite/ld-x86-64/x86-64.exp: Run pr19969 tests.

1 files changed, 71 insertions, 74 deletions

diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 197a1b8..54fc1c8 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1587,7 +1587,57 @@ elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd,
 
 /* Rename some of the generic section flags to better document how they
    are used here.  */
-#define need_convert_load sec_flg0
+#define need_convert_load	sec_flg0
+#define check_relocs_failed	sec_flg1
+
+static bfd_boolean
+elf_x86_64_need_pic (bfd *input_bfd, asection *sec,
+		     struct elf_link_hash_entry *h,
+		     Elf_Internal_Shdr *symtab_hdr,
+		     Elf_Internal_Sym *isym,
+		     reloc_howto_type *howto)
+{
+  const char *v = "";
+  const char *und = "";
+  const char *pic = "";
+
+  const char *name;
+  if (h)
+    {
+      name = h->root.root.string;
+      switch (ELF_ST_VISIBILITY (h->other))
+	{
+	case STV_HIDDEN:
+	  v = _("hidden symbol ");
+	  break;
+	case STV_INTERNAL:
+	  v = _("internal symbol ");
+	  break;
+	case STV_PROTECTED:
+	  v = _("protected symbol ");
+	  break;
+	default:
+	  v = _("symbol ");
+	  pic = _("; recompile with -fPIC");
+	  break;
+	}
+
+      if (!h->def_regular && !h->def_dynamic)
+	und = _("undefined ");
+    }
+  else
+    {
+      name = bfd_elf_sym_name (input_bfd, symtab_hdr, isym, NULL);
+      pic = _("; recompile with -fPIC");
+    }
+
+  (*_bfd_error_handler) (_("%B: relocation %s against %s%s`%s' can "
+			   "not be used when making a shared object%s"),
+			 input_bfd, howto->name, und, v, name, pic);
+  bfd_set_error (bfd_error_bad_value);
+  sec->check_relocs_failed = 1;
+  return FALSE;
+}
 
 /* Look through the relocs for a section during the first phase, and
    calculate needed space in the global offset table, procedure
@@ -1802,19 +1852,8 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
 
 	case R_X86_64_TPOFF32:
 	  if (!bfd_link_executable (info) && ABI_64_P (abfd))
-	    {
-	      if (h)
-		name = h->root.root.string;
-	      else
-		name = bfd_elf_sym_name (abfd, symtab_hdr, isym,
-					 NULL);
-	      (*_bfd_error_handler)
-		(_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
-		 abfd,
-		 x86_64_elf_howto_table[r_type].name, name);
-	      bfd_set_error (bfd_error_bad_value);
-	      return FALSE;
-	    }
+	    return elf_x86_64_need_pic (abfd, sec, h, symtab_hdr, isym,
+					&x86_64_elf_howto_table[r_type]);
 	  if (eh != NULL)
 	    eh->has_got_reloc = 1;
 	  break;
@@ -1973,26 +2012,20 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	case R_X86_64_8:
 	case R_X86_64_16:
 	case R_X86_64_32S:
-	  /* Let's help debug shared library creation.  These relocs
-	     cannot be used in shared libs.  Don't error out for
+	  /* Check relocation overflow as these relocs may lead to
+	     run-time relocation overflow.  Don't error out for
 	     sections we don't care about, such as debug sections or
-	     non-constant sections, or when relocation overflow check
-	     is disabled.  */
+	     when relocation overflow check is disabled.  */
 	  if (!info->no_reloc_overflow_check
-	      && bfd_link_pic (info)
-	      && (sec->flags & SEC_ALLOC) != 0
-	      && (sec->flags & SEC_READONLY) != 0)
-	    {
-	      if (h)
-		name = h->root.root.string;
-	      else
-		name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL);
-	      (*_bfd_error_handler)
-		(_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"),
-		 abfd, x86_64_elf_howto_table[r_type].name, name);
-	      bfd_set_error (bfd_error_bad_value);
-	      return FALSE;
-	    }
+	      && (bfd_link_pic (info)
+		  || (bfd_link_executable (info)
+		      && h != NULL
+		      && !h->def_regular
+		      && h->def_dynamic
+		      && (sec->flags & SEC_READONLY) == 0))
+	      && (sec->flags & SEC_ALLOC) != 0)
+	    return elf_x86_64_need_pic (abfd, sec, h, symtab_hdr, isym,
+					&x86_64_elf_howto_table[r_type]);
 	  /* Fall through.  */
 
 	case R_X86_64_PC8:
@@ -4040,42 +4073,6 @@ is_32bit_relative_branch (bfd_byte *contents, bfd_vma offset)
 	      && (contents [offset - 1] & 0xf0) == 0x80));
 }
 
-static bfd_boolean
-elf_x86_64_need_pic (bfd *input_bfd, struct elf_link_hash_entry *h,
-		     reloc_howto_type *howto)
-{
-  const char *fmt;
-  const char *v;
-  const char *pic = "";
-
-  switch (ELF_ST_VISIBILITY (h->other))
-    {
-    case STV_HIDDEN:
-      v = _("hidden symbol");
-      break;
-    case STV_INTERNAL:
-      v = _("internal symbol");
-      break;
-    case STV_PROTECTED:
-      v = _("protected symbol");
-      break;
-    default:
-      v = _("symbol");
-      pic = _("; recompile with -fPIC");
-      break;
-    }
-
-  if (h->def_regular)
-    fmt = _("%B: relocation %s against %s `%s' can not be used when making a shared object%s");
-  else
-    fmt = _("%B: relocation %s against undefined %s `%s' can not be used when making a shared object%s");
-
-  (*_bfd_error_handler) (fmt, input_bfd, howto->name,
-			 v,  h->root.root.string, pic);
-  bfd_set_error (bfd_error_bad_value);
-  return FALSE;
-}
-
 /* Relocate an x86_64 ELF section.  */
 
 static bfd_boolean
@@ -4100,6 +4097,10 @@ elf_x86_64_relocate_section (bfd *output_bfd,
 
   BFD_ASSERT (is_x86_64_elf (input_bfd));
 
+  /* Skip if check_relocs failed.  */
+  if (input_section->check_relocs_failed)
+    return FALSE;
+
   htab = elf_x86_64_hash_table (info);
   if (htab == NULL)
     return FALSE;
@@ -4756,7 +4757,8 @@ elf_x86_64_relocate_section (bfd *output_bfd,
 		}
 
 	      if (fail)
-		return elf_x86_64_need_pic (input_bfd, h, howto);
+		return elf_x86_64_need_pic (input_bfd, input_section,
+					    h, NULL, NULL, howto);
 	    }
 	  /* Fall through.  */
 
@@ -4838,11 +4840,6 @@ direct:
 				|| SYMBOLIC_BIND (info, h))
 			   || ! h->def_regular))
 		{
-		  if ((r_type != R_X86_64_PC64 && r_type != R_X86_64_64)
-		      && bfd_link_executable (info)
-		      && h->root.type == bfd_link_hash_undefweak
-		      && !resolved_to_zero)
-		    return elf_x86_64_need_pic (input_bfd, h, howto);
 		  outrel.r_info = htab->r_info (h->dynindx, r_type);
 		  outrel.r_addend = rel->r_addend;
 		}