x86: Add -z cet-report=[none|warning|error]
[deliverable/binutils-gdb.git] / bfd / elfxx-x86.c
index 3a7573f7a2605ca53bda910a701974bc5d36c8f0..e661ad30c121ce32a7c13d917d5091d38093ddad 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,
@@ -2332,33 +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,
@@ -2368,6 +2401,7 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
 bfd_boolean
 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
                                   bfd *abfd ATTRIBUTE_UNUSED,
+                                  bfd *bbfd ATTRIBUTE_UNUSED,
                                   elf_property *aprop,
                                   elf_property *bprop)
 {
@@ -2375,36 +2409,88 @@ _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.
         3. Otherwise, do nothing.
        */
+      const struct elf_backend_data *bed
+       = get_elf_backend_data (info->output_bfd);
+      struct elf_x86_link_hash_table *htab
+       = elf_x86_hash_table (info, bed->target_id);
+      if (!htab)
+       abort ();
       if (aprop != NULL && bprop != NULL)
        {
          features = 0;
-         if (info->ibt)
+         if (htab->params->ibt)
            features = GNU_PROPERTY_X86_FEATURE_1_IBT;
-         if (info->shstk)
+         if (htab->params->shstk)
            features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
          number = aprop->u.number;
          /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
@@ -2417,25 +2503,25 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
        }
       else
        {
+         /* There should be no AND properties since some input doesn't
+            have them.  Set IBT and SHSTK properties for -z ibt and -z
+            shstk if needed.  */
          features = 0;
-         if (info->ibt)
+         if (htab->params->ibt)
            features = GNU_PROPERTY_X86_FEATURE_1_IBT;
-         if (info->shstk)
+         if (htab->params->shstk)
            features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
          if (features)
            {
-             /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and
-                GNU_PROPERTY_X86_FEATURE_1_SHSTK.  */
              if (aprop != NULL)
                {
-                 number = aprop->u.number;
-                 aprop->u.number = number | features;
-                 updated = number != (unsigned int) aprop->u.number;
+                 updated = features != (unsigned int) aprop->u.number;
+                 aprop->u.number = features;
                }
              else
                {
-                 bprop->u.number |= features;
                  updated = TRUE;
+                 bprop->u.number = features;
                }
            }
          else if (aprop != NULL)
@@ -2444,9 +2530,10 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
              updated = TRUE;
            }
        }
-      break;
-
-    default:
+      return updated;
+    }
+  else
+    {
       /* Never should happen.  */
       abort ();
     }
@@ -2475,12 +2562,6 @@ _bfd_x86_elf_link_setup_gnu_properties
   unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2;
   unsigned int got_align;
 
-  features = 0;
-  if (info->ibt)
-    features = GNU_PROPERTY_X86_FEATURE_1_IBT;
-  if (info->shstk)
-    features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
-
   /* Find a normal input file with GNU property note.  */
   for (pbfd = info->input_bfds;
        pbfd != NULL;
@@ -2494,18 +2575,42 @@ _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;
+
+  features = 0;
+  if (htab->params->ibt)
     {
-      /* 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;
+      features = GNU_PROPERTY_X86_FEATURE_1_IBT;
+      htab->params->cet_report &= ~cet_report_ibt;
+    }
+  if (htab->params->shstk)
+    {
+      features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK;
+      htab->params->cet_report &= ~cet_report_shstk;
+    }
+  if (!(htab->params->cet_report & (cet_report_ibt | cet_report_shstk)))
+    htab->params->cet_report = cet_report_none;
+
+  if (ebfd != NULL)
+    {
+      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,
@@ -2529,13 +2634,55 @@ error_alignment:
        }
     }
 
-  pbfd = _bfd_elf_link_setup_gnu_properties (info);
+  if (htab->params->cet_report)
+    {
+      /* Report missing IBT and SHSTK properties.  */
+      bfd *abfd;
+      const char *msg;
+      elf_property_list *p;
+      bfd_boolean missing_ibt, missing_shstk;
+      bfd_boolean check_ibt
+       = !!(htab->params->cet_report & cet_report_ibt);
+      bfd_boolean check_shstk
+       = !!(htab->params->cet_report & cet_report_shstk);
+
+      if ((htab->params->cet_report & cet_report_warning))
+       msg = _("%P: %pB: warning: missing %s\n");
+      else
+       msg = _("%X%P: %pB: error: missing %s\n");
 
-  bed = get_elf_backend_data (info->output_bfd);
+      for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
+       if (!(abfd->flags & (DYNAMIC | BFD_PLUGIN | BFD_LINKER_CREATED))
+           && bfd_get_flavour (abfd) == bfd_target_elf_flavour)
+         {
+           for (p = elf_properties (abfd); p; p = p->next)
+             if (p->property.pr_type == GNU_PROPERTY_X86_FEATURE_1_AND)
+               break;
 
-  htab = elf_x86_hash_table (info, bed->target_id);
-  if (htab == NULL)
-    return pbfd;
+           missing_ibt = check_ibt;
+           missing_shstk = check_shstk;
+           if (p)
+             {
+               missing_ibt &= !(p->property.u.number
+                                & GNU_PROPERTY_X86_FEATURE_1_IBT);
+               missing_shstk &= !(p->property.u.number
+                                  & GNU_PROPERTY_X86_FEATURE_1_SHSTK);
+             }
+           if (missing_ibt || missing_shstk)
+             {
+               const char *missing;
+               if (missing_ibt && missing_shstk)
+                 missing = _("IBT and SHSTK properties");
+               else if (missing_ibt)
+                 missing = _("IBT property");
+               else
+                 missing = _("SHSTK property");
+               info->callbacks->einfo (msg, abfd, missing);
+             }
+         }
+    }
+
+  pbfd = _bfd_elf_link_setup_gnu_properties (info);
 
   htab->r_info = init_table->r_info;
   htab->r_sym = init_table->r_sym;
@@ -2545,7 +2692,7 @@ error_alignment:
 
   htab->plt0_pad_byte = init_table->plt0_pad_byte;
 
-  use_ibt_plt = info->ibtplt || info->ibt;
+  use_ibt_plt = htab->params->ibtplt || htab->params->ibt;
   if (!use_ibt_plt && pbfd != NULL)
     {
       /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on.  */
@@ -2768,7 +2915,7 @@ error_alignment:
                                                  plt_alignment))
                    goto error_alignment;
                }
-             else if (info->bndplt && ABI_64_P (dynobj))
+             else if (htab->params->bndplt && ABI_64_P (dynobj))
                {
                  /* Create the second PLT for Intel MPX support.  MPX
                     PLT is supported only for non-NaCl target in 64-bit
@@ -2835,16 +2982,79 @@ 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;
+       }
+    }
+}
+
+void
+_bfd_elf_linker_x86_set_options (struct bfd_link_info * info,
+                                struct elf_linker_x86_params *params)
+{
+  const struct elf_backend_data *bed
+    = get_elf_backend_data (info->output_bfd);
+  struct elf_x86_link_hash_table *htab
+    = elf_x86_hash_table (info, bed->target_id);
+  if (htab != NULL)
+    htab->params = params;
+}
This page took 0.030472 seconds and 4 git commands to generate.