x86: Remove func_pointer_refcount

Since check_reloc is running after gc_sections, there is no need for
reference count.  If a function pointer relocation can be resolved at
run-time, there is no need for PLT and it doesn't count as non-GOT/PLT
relocation.  func_pointer_refcount can be removed.

	* elf32-i386.c (elf_i386_check_relocs): Set plt.refcount to 1.
	Don't use func_pointer_refcount.  Don't set plt.refcount nor
	non_got_ref for function pointer reference.
	* elf64-x86-64.c (elf_x86_64_check_relocs): Likewise.
	* elfxx-x86.c (elf_x86_allocate_dynrelocs): Don't use
	func_pointer_refcount.
	(_bfd_x86_elf_copy_indirect_symbol): Don't copy
	func_pointer_refcount.
	(_bfd_x86_elf_hide_symbol): Don't use func_pointer_refcount.
	* elfxx-x86.h (GENERATE_DYNAMIC_RELOCATION_P): Likewise.
	(elf_x86_link_hash_entry): Remove func_pointer_refcount.

bfd/ChangeLog

@@ -1,3 +1,17 @@
+2017-11-03  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* elf32-i386.c (elf_i386_check_relocs): Set plt.refcount to 1.
+	Don't use func_pointer_refcount.  Don't set plt.refcount nor
+	non_got_ref for function pointer reference.
+	* elf64-x86-64.c (elf_x86_64_check_relocs): Likewise.
+	* elfxx-x86.c (elf_x86_allocate_dynrelocs): Don't use
+	func_pointer_refcount.
+	(_bfd_x86_elf_copy_indirect_symbol): Don't copy
+	func_pointer_refcount.
+	(_bfd_x86_elf_hide_symbol): Don't use func_pointer_refcount.
+	* elfxx-x86.h (GENERATE_DYNAMIC_RELOCATION_P): Likewise.
+	(elf_x86_link_hash_entry): Remove func_pointer_refcount.
+
 2017-11-03  Mingi Cho  <mgcho.minic@gmail.com>
 	    Nick Clifton  <nickc@redhat.com>
 

bfd/elf32-i386.c

@@ -1600,7 +1600,7 @@ elf_i386_check_relocs (bfd *abfd,
 
 	  eh->zero_undefweak &= 0x2;
 	  h->needs_plt = 1;
-	  h->plt.refcount += 1;
+	  h->plt.refcount = 1;
 	  break;
 
 	case R_386_SIZE32:
@@ -1751,20 +1751,7 @@ do_relocation:
 	      && (bfd_link_executable (info)
 		  || h->type == STT_GNU_IFUNC))
 	    {
-	      /* If this reloc is in a read-only section, we might
+	      bfd_boolean func_pointer_ref = FALSE;
-		 need a copy reloc.  We can't check reliably at this
-		 stage whether the section is read-only, as input
-		 sections have not yet been mapped to output sections.
-		 Tentatively set the flag for now, and correct in
-		 adjust_dynamic_symbol.  */
-	      h->non_got_ref = 1;
-
-	      /* We may need a .plt entry if the symbol is a function
-		 defined in a shared lib or is a STT_GNU_IFUNC function
-		 referenced from the code or read-only section.  */
-	      if (!h->def_regular
-		  || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
-		h->plt.refcount += 1;
 
 	      if (r_type == R_386_PC32)
 		{
@@ -1790,7 +1777,25 @@ do_relocation:
 		  /* R_386_32 can be resolved at run-time.  */
 		  if (r_type == R_386_32
 		      && (sec->flags & SEC_READONLY) == 0)
-		    eh->func_pointer_refcount += 1;
+		    func_pointer_ref = TRUE;
+		}
+
+	      if (!func_pointer_ref)
+		{
+		  /* If this reloc is in a read-only section, we might
+		     need a copy reloc.  We can't check reliably at this
+		     stage whether the section is read-only, as input
+		     sections have not yet been mapped to output sections.
+		     Tentatively set the flag for now, and correct in
+		     adjust_dynamic_symbol.  */
+		  h->non_got_ref = 1;
+
+		  /* We may need a .plt entry if the symbol is a function
+		     defined in a shared lib or is a function referenced
+		     from the code or read-only section.  */
+		  if (!h->def_regular
+		      || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
+		    h->plt.refcount = 1;
 		}
 	    }
 

bfd/elf64-x86-64.c

@@ -2067,7 +2067,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
 
 	  eh->zero_undefweak &= 0x2;
 	  h->needs_plt = 1;
-	  h->plt.refcount += 1;
+	  h->plt.refcount = 1;
 	  break;
 
 	case R_X86_64_PLTOFF64:
@@ -2076,7 +2076,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	  if (h != NULL)
 	    {
 	      h->needs_plt = 1;
-	      h->plt.refcount += 1;
+	      h->plt.refcount = 1;
 	    }
 	  goto create_got;
 
@@ -2124,20 +2124,7 @@ pointer:
 	      && (bfd_link_executable (info)
 		  || h->type == STT_GNU_IFUNC))
 	    {
-	      /* If this reloc is in a read-only section, we might
+	      bfd_boolean func_pointer_ref = FALSE;
-		 need a copy reloc.  We can't check reliably at this
-		 stage whether the section is read-only, as input
-		 sections have not yet been mapped to output sections.
-		 Tentatively set the flag for now, and correct in
-		 adjust_dynamic_symbol.  */
-	      h->non_got_ref = 1;
-
-	      /* We may need a .plt entry if the symbol is a function
-		 defined in a shared lib or is a STT_GNU_IFUNC function
-		 referenced from the code or read-only section.  */
-	      if (!h->def_regular
-		  || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
-		h->plt.refcount += 1;
 
 	      if (r_type == R_X86_64_PC32)
 		{
@@ -2159,7 +2146,25 @@ pointer:
 			  || (!ABI_64_P (abfd)
 			      && (r_type == R_X86_64_32
 				  || r_type == R_X86_64_32S))))
-		    eh->func_pointer_refcount += 1;
+		    func_pointer_ref = TRUE;
+		}
+
+	      if (!func_pointer_ref)
+		{
+		  /* If this reloc is in a read-only section, we might
+		     need a copy reloc.  We can't check reliably at this
+		     stage whether the section is read-only, as input
+		     sections have not yet been mapped to output sections.
+		     Tentatively set the flag for now, and correct in
+		     adjust_dynamic_symbol.  */
+		  h->non_got_ref = 1;
+
+		  /* We may need a .plt entry if the symbol is a function
+		     defined in a shared lib or is a function referenced
+		     from the code or read-only section.  */
+		  if (!h->def_regular
+		      || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0)
+		    h->plt.refcount = 1;
 		}
 	    }
 

bfd/elfxx-x86.c

@@ -108,11 +108,6 @@ elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 
   resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh);
 
-  /* Clear the reference count of function pointer relocations if
-     symbol isn't a normal function.  */
-  if (h->type != STT_FUNC)
-    eh->func_pointer_refcount = 0;
-
   /* We can't use the GOT PLT if pointer equality is needed since
      finish_dynamic_symbol won't clear symbol value and the dynamic
      linker won't update the GOT slot.  We will get into an infinite
@@ -162,15 +157,11 @@ elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
   /* Don't create the PLT entry if there are only function pointer
      relocations which can be resolved at run-time.  */
   else if (htab->elf.dynamic_sections_created
-	   && (h->plt.refcount > eh->func_pointer_refcount
+	   && (h->plt.refcount > 0
 	       || eh->plt_got.refcount > 0))
     {
       bfd_boolean use_plt_got = eh->plt_got.refcount > 0;
 
-      /* Clear the reference count of function pointer relocations
-	 if PLT is used.  */
-      eh->func_pointer_refcount = 0;
-
       /* Make sure this symbol is output as a dynamic symbol.
 	 Undefined weak syms won't yet be marked as dynamic.  */
       if (h->dynindx == -1
@@ -488,7 +479,6 @@ elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 	 pointer initialization.  */
 
       if ((!h->non_got_ref
-	   || eh->func_pointer_refcount > 0
 	   || (h->root.type == bfd_link_hash_undefweak
 	       && !resolved_to_zero))
 	  && ((h->def_dynamic
@@ -513,7 +503,6 @@ elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 	}
 
       eh->dyn_relocs = NULL;
-      eh->func_pointer_refcount = 0;
 
     keep: ;
     }
@@ -1643,15 +1632,7 @@ _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info,
       dir->pointer_equality_needed |= ind->pointer_equality_needed;
     }
   else
-    {
+    _bfd_elf_link_hash_copy_indirect (info, dir, ind);
-      if (eind->func_pointer_refcount > 0)
-	{
-	  edir->func_pointer_refcount += eind->func_pointer_refcount;
-	  eind->func_pointer_refcount = 0;
-	}
-
-      _bfd_elf_link_hash_copy_indirect (info, dir, ind);
-    }
 }
 
 /* Remove undefined weak symbol from the dynamic symbol table if it
@@ -1900,7 +1881,7 @@ _bfd_x86_elf_hide_symbol (struct bfd_link_info *info,
 	 weak symbol dynamic so that PC relative branch to the undefined
 	 weak symbol will land to address 0.  */
       struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h);
-      if (h->plt.refcount > eh->func_pointer_refcount
+      if (h->plt.refcount > 0
 	  || eh->plt_got.refcount > 0)
 	return;
     }

bfd/elfxx-x86.h

@@ -133,7 +133,6 @@
        && (EH) != NULL \
        && (EH)->elf.dynindx != -1 \
        && (!(EH)->elf.non_got_ref \
-	   || (EH)->func_pointer_refcount > 0 \
 	   || ((EH)->elf.root.type == bfd_link_hash_undefweak \
 	       && !(RESOLVED_TO_ZERO))) \
 	       && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \
@@ -268,10 +267,6 @@ struct elf_x86_link_hash_entry
      is only used by x86-64.  */
   unsigned int needs_copy : 1;
 
-  /* Reference count of C/C++ function pointer relocations in read-write
-     section which can be resolved at run-time.  */
-  bfd_signed_vma func_pointer_refcount;
-
   /* Information about the GOT PLT entry. Filled when there are both
      GOT and PLT relocations against the same function.  */
   union gotplt_union plt_got;