Update year range in copyright notice of binutils files
[deliverable/binutils-gdb.git] / bfd / elfxx-x86.c
index 6c1f4c32fcffe132fee35bc7021f072c575393be..d6b851ce780d5a6a157cea587e746d46eddb9b48 100644 (file)
@@ -1,5 +1,5 @@
 /* x86 specific support for ELF
-   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   Copyright (C) 2017-2019 Free Software Foundation, Inc.
 
    This file is part of BFD, the Binary File Descriptor library.
 
@@ -876,6 +876,27 @@ elf_x86_linker_defined (struct bfd_link_info *info, const char *name)
     }
 }
 
+/* Hide a linker-defined symbol, NAME, with hidden visibility.  */
+
+static void
+elf_x86_hide_linker_defined (struct bfd_link_info *info,
+                            const char *name)
+{
+  struct elf_link_hash_entry *h;
+
+  h = elf_link_hash_lookup (elf_hash_table (info), name,
+                           FALSE, FALSE, FALSE);
+  if (h == NULL)
+    return;
+
+  while (h->root.type == bfd_link_hash_indirect)
+    h = (struct elf_link_hash_entry *) h->root.u.i.link;
+
+  if (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
+      || ELF_ST_VISIBILITY (h->other) == STV_HIDDEN)
+    _bfd_elf_link_hash_hide_symbol (info, h, TRUE);
+}
+
 bfd_boolean
 _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
 {
@@ -916,6 +937,14 @@ _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
              elf_x86_linker_defined (info, "_end");
              elf_x86_linker_defined (info, "_edata");
            }
+         else
+           {
+             /* Hide hidden __bss_start, _end and _edata in shared
+                libraries.  */
+             elf_x86_hide_linker_defined (info, "__bss_start");
+             elf_x86_hide_linker_defined (info, "_end");
+             elf_x86_hide_linker_defined (info, "_edata");
+           }
        }
     }
 
@@ -1246,6 +1275,14 @@ _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
       if ((s->flags & SEC_HAS_CONTENTS) == 0)
        continue;
 
+      /* NB: Initially, the iplt section has minimal alignment to
+        avoid moving dot of the following section backwards when
+        it is empty.  Update its section alignment now since it
+        is non-empty.  */
+      if (s == htab->elf.iplt)
+       bfd_set_section_alignment (s->owner, s,
+                                  htab->plt.iplt_alignment);
+
       /* Allocate memory for the section contents.  We use bfd_zalloc
         here in case unused entries are not reclaimed before the
         section's contents are written out.  This should not happen,
@@ -1730,6 +1767,52 @@ _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info,
   return TRUE;
 }
 
+/* Change the STT_GNU_IFUNC symbol defined in position-dependent
+   executable into the normal function symbol and set its address
+   to its PLT entry, which should be resolved by R_*_IRELATIVE at
+   run-time.  */
+
+void
+_bfd_x86_elf_link_fixup_ifunc_symbol (struct bfd_link_info *info,
+                                     struct elf_x86_link_hash_table *htab,
+                                     struct elf_link_hash_entry *h,
+                                     Elf_Internal_Sym *sym)
+{
+  if (bfd_link_pde (info)
+      && h->def_regular
+      && h->dynindx != -1
+      && h->plt.offset != (bfd_vma) -1
+      && h->type == STT_GNU_IFUNC
+      && h->pointer_equality_needed)
+    {
+      asection *plt_s;
+      bfd_vma plt_offset;
+      bfd *output_bfd = info->output_bfd;
+
+      if (htab->plt_second)
+       {
+         struct elf_x86_link_hash_entry *eh
+           = (struct elf_x86_link_hash_entry *) h;
+
+         plt_s = htab->plt_second;
+         plt_offset = eh->plt_second.offset;
+       }
+      else
+       {
+         plt_s = htab->elf.splt;
+         plt_offset = h->plt.offset;
+       }
+
+      sym->st_size = 0;
+      sym->st_info = ELF_ST_INFO (ELF_ST_BIND (sym->st_info), STT_FUNC);
+      sym->st_shndx
+       = _bfd_elf_section_from_bfd_section (output_bfd,
+                                            plt_s->output_section);
+      sym->st_value = (plt_s->output_section->vma
+                      + plt_s->output_offset + plt_offset);
+    }
+}
+
 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section.  */
 
 bfd_boolean
@@ -1992,10 +2075,8 @@ _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
                  && htab->interp == NULL)
              || info->dynamic_undefined_weak == 0))
       || ((h->def_regular || ELF_COMMON_DEF_P (h))
-         && h->versioned == unversioned
          && info->version_info != NULL
-         && bfd_hide_sym_by_version (info->version_info,
-                                     h->root.root.string)))
+         && _bfd_elf_link_hide_sym_by_version (info, h)))
     {
       eh->local_ref = 2;
       return TRUE;
@@ -2288,33 +2369,29 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
 {
   elf_property *prop;
 
-  switch (type)
+  if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
+      || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
+      || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
+         && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
+      || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
+         && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
+      || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
+         && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
     {
-    case GNU_PROPERTY_X86_ISA_1_USED:
-    case GNU_PROPERTY_X86_ISA_1_NEEDED:
-    case GNU_PROPERTY_X86_FEATURE_1_AND:
       if (datasz != 4)
        {
          _bfd_error_handler
-           ((type == GNU_PROPERTY_X86_ISA_1_USED
-             ? _("error: %pB: <corrupt x86 ISA used size: 0x%x>")
-             : (type == GNU_PROPERTY_X86_ISA_1_NEEDED
-                ? _("error: %pB: <corrupt x86 ISA needed size: 0x%x>")
-                : _("error: %pB: <corrupt x86 feature size: 0x%x>"))),
-            abfd, datasz);
+           (_("error: %pB: <corrupt x86 property (0x%x) size: 0x%x>"),
+            abfd, type, datasz);
          return property_corrupt;
        }
       prop = _bfd_elf_get_property (abfd, type, datasz);
-      /* Combine properties of the same type.  */
       prop->u.number |= bfd_h_get_32 (abfd, ptr);
       prop->pr_kind = property_number;
-      break;
-
-    default:
-      return property_ignored;
+      return property_number;
     }
 
-  return property_number;
+  return property_ignored;
 }
 
 /* Merge x86 GNU property BPROP with APROP.  If APROP isn't NULL,
@@ -2331,25 +2408,71 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
   bfd_boolean updated = FALSE;
   unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
 
-  switch (pr_type)
+  if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
+      || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
+         && pr_type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
     {
-    case GNU_PROPERTY_X86_ISA_1_USED:
-    case GNU_PROPERTY_X86_ISA_1_NEEDED:
-      if (aprop != NULL && bprop != NULL)
+      if (aprop == NULL || bprop == NULL)
+       {
+         /* Only one of APROP and BPROP can be NULL.  */
+         if (aprop != NULL)
+           {
+             /* Remove this property since the other input file doesn't
+                have it.  */
+             aprop->pr_kind = property_remove;
+             updated = TRUE;
+           }
+       }
+      else
        {
          number = aprop->u.number;
          aprop->u.number = number | bprop->u.number;
          updated = number != (unsigned int) aprop->u.number;
        }
+      return updated;
+    }
+  else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
+          || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_LO
+              && pr_type <= GNU_PROPERTY_X86_UINT32_OR_HI))
+    {
+      if (aprop != NULL && bprop != NULL)
+       {
+         number = aprop->u.number;
+         aprop->u.number = number | bprop->u.number;
+         /* Remove the property if all bits are empty.  */
+         if (aprop->u.number == 0)
+           {
+             aprop->pr_kind = property_remove;
+             updated = TRUE;
+           }
+         else
+           updated = number != (unsigned int) aprop->u.number;
+       }
       else
        {
-         /* Return TRUE if APROP is NULL to indicate that BPROP should
-            be added to ABFD.  */
-         updated = aprop == NULL;
+         /* Only one of APROP and BPROP can be NULL.  */
+         if (aprop != NULL)
+           {
+             if (aprop->u.number == 0)
+               {
+                 /* Remove APROP if all bits are empty.  */
+                 aprop->pr_kind = property_remove;
+                 updated = TRUE;
+               }
+           }
+         else
+           {
+             /* Return TRUE if APROP is NULL and all bits of BPROP
+                aren't empty to indicate that BPROP should be added
+                to ABFD.  */
+             updated = bprop->u.number != 0;
+           }
        }
-      break;
-
-    case GNU_PROPERTY_X86_FEATURE_1_AND:
+      return updated;
+    }
+  else if (pr_type >= GNU_PROPERTY_X86_UINT32_AND_LO
+          && pr_type <= GNU_PROPERTY_X86_UINT32_AND_HI)
+    {
       /* Only one of APROP and BPROP can be NULL:
         1. APROP & BPROP when both APROP and BPROP aren't NULL.
         2. If APROP is NULL, remove x86 feature.
@@ -2400,9 +2523,10 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
              updated = TRUE;
            }
        }
-      break;
-
-    default:
+      return updated;
+    }
+  else
+    {
       /* Never should happen.  */
       abort ();
     }
@@ -2450,18 +2574,28 @@ _bfd_x86_elf_link_setup_gnu_properties
          break;
       }
 
-  if (ebfd != NULL && features)
+  bed = get_elf_backend_data (info->output_bfd);
+
+  htab = elf_x86_hash_table (info, bed->target_id);
+  if (htab == NULL)
+    return pbfd;
+
+  if (ebfd != NULL)
     {
-      /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
-        GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */
-      prop = _bfd_elf_get_property (ebfd,
-                                   GNU_PROPERTY_X86_FEATURE_1_AND,
-                                   4);
-      prop->u.number |= features;
-      prop->pr_kind = property_number;
+      prop = NULL;
+      if (features)
+       {
+         /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and
+            GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */
+         prop = _bfd_elf_get_property (ebfd,
+                                       GNU_PROPERTY_X86_FEATURE_1_AND,
+                                       4);
+         prop->u.number |= features;
+         prop->pr_kind = property_number;
+       }
 
       /* Create the GNU property note section if needed.  */
-      if (pbfd == NULL)
+      if (prop != NULL && pbfd == NULL)
        {
          sec = bfd_make_section_with_flags (ebfd,
                                             NOTE_GNU_PROPERTY_SECTION_NAME,
@@ -2487,12 +2621,6 @@ error_alignment:
 
   pbfd = _bfd_elf_link_setup_gnu_properties (info);
 
-  bed = get_elf_backend_data (info->output_bfd);
-
-  htab = elf_x86_hash_table (info, bed->target_id);
-  if (htab == NULL)
-    return pbfd;
-
   htab->r_info = init_table->r_info;
   htab->r_sym = init_table->r_sym;
 
@@ -2791,16 +2919,67 @@ error_alignment:
        }
     }
 
-  if (normal_target)
+  /* The .iplt section is used for IFUNC symbols in static
+     executables.  */
+  sec = htab->elf.iplt;
+  if (sec != NULL)
     {
-      /* The .iplt section is used for IFUNC symbols in static
-        executables.  */
-      sec = htab->elf.iplt;
-      if (sec != NULL
-         && !bfd_set_section_alignment (sec->owner, sec,
-                                        plt_alignment))
+      /* NB: Delay setting its alignment until we know it is non-empty.
+        Otherwise an empty iplt section may change vma and lma of the
+        following sections, which triggers moving dot of the following
+        section backwards, resulting in a warning and section lma not
+        being set properly.  It later leads to a "File truncated"
+        error.  */
+      if (!bfd_set_section_alignment (sec->owner, sec, 0))
        goto error_alignment;
+
+      htab->plt.iplt_alignment = (normal_target
+                                 ? plt_alignment
+                                 : bed->plt_alignment);
     }
 
   return pbfd;
 }
+
+/* Fix up x86 GNU properties.  */
+
+void
+_bfd_x86_elf_link_fixup_gnu_properties
+  (struct bfd_link_info *info ATTRIBUTE_UNUSED,
+   elf_property_list **listp)
+{
+  elf_property_list *p;
+
+  for (p = *listp; p; p = p->next)
+    {
+      unsigned int type = p->property.pr_type;
+      if (type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
+         || type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
+         || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
+             && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
+         || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
+             && type <= GNU_PROPERTY_X86_UINT32_OR_HI)
+         || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
+             && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
+       {
+         if (p->property.u.number == 0
+             && (type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
+                 || (type >= GNU_PROPERTY_X86_UINT32_AND_LO
+                     && type <= GNU_PROPERTY_X86_UINT32_AND_HI)
+                 || (type >= GNU_PROPERTY_X86_UINT32_OR_LO
+                     && type <= GNU_PROPERTY_X86_UINT32_OR_HI)))
+           {
+             /* Remove empty property.  */
+             *listp = p->next;
+             continue;
+           }
+
+         listp = &p->next;
+       }
+      else if (type > GNU_PROPERTY_HIPROC)
+       {
+         /* The property list is sorted in order of type.  */
+         break;
+       }
+    }
+}
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