x86: Add _bfd_x86_elf_link_setup_gnu_properties
[deliverable/binutils-gdb.git] / bfd / elfxx-x86.c
index eb02ed24bcca21dcf74d7f62090abe8f1e99ac40..d43fe31ede64e907b1224849cd83e81c6986e8dd 100644 (file)
@@ -19,6 +19,7 @@
    MA 02110-1301, USA.  */
 
 #include "elfxx-x86.h"
+#include "elf-vxworks.h"
 #include "objalloc.h"
 #include "elf/i386.h"
 #include "elf/x86-64.h"
@@ -900,3 +901,392 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
 
   return updated;
 }
+
+/* Set up x86 GNU properties.  Return the first relocatable ELF input
+   with GNU properties if found.  Otherwise, return NULL.  */
+
+bfd *
+_bfd_x86_elf_link_setup_gnu_properties
+  (struct bfd_link_info *info,
+   struct elf_x86_plt_layout_table *plt_layout)
+{
+  bfd_boolean normal_target;
+  bfd_boolean lazy_plt;
+  asection *sec, *pltsec;
+  bfd *dynobj;
+  bfd_boolean use_ibt_plt;
+  unsigned int plt_alignment, features;
+  struct elf_x86_link_hash_table *htab;
+  bfd *pbfd;
+  bfd *ebfd = NULL;
+  elf_property *prop;
+  const struct elf_backend_data *bed;
+  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;
+       pbfd = pbfd->link.next)
+    if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour
+       && bfd_count_sections (pbfd) != 0)
+      {
+       ebfd = pbfd;
+
+       if (elf_properties (pbfd) != NULL)
+         break;
+      }
+
+  if (ebfd != NULL && 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)
+       {
+         sec = bfd_make_section_with_flags (ebfd,
+                                            NOTE_GNU_PROPERTY_SECTION_NAME,
+                                            (SEC_ALLOC
+                                             | SEC_LOAD
+                                             | SEC_IN_MEMORY
+                                             | SEC_READONLY
+                                             | SEC_HAS_CONTENTS
+                                             | SEC_DATA));
+         if (sec == NULL)
+           info->callbacks->einfo (_("%F: failed to create GNU property section\n"));
+
+         if (!bfd_set_section_alignment (ebfd, sec, class_align))
+           {
+error_alignment:
+             info->callbacks->einfo (_("%F%A: failed to align section\n"),
+                                     sec);
+           }
+
+         elf_section_type (sec) = SHT_NOTE;
+       }
+    }
+
+  pbfd = _bfd_elf_link_setup_gnu_properties (info);
+
+  if (bfd_link_relocatable (info))
+    return pbfd;
+
+  bed = get_elf_backend_data (info->output_bfd);
+
+  htab = elf_x86_hash_table (info, bed->target_id);
+  if (htab == NULL)
+    return pbfd;
+
+  use_ibt_plt = info->ibtplt || info->ibt;
+  if (!use_ibt_plt && pbfd != NULL)
+    {
+      /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on.  */
+      elf_property_list *p;
+
+      /* The property list is sorted in order of type.  */
+      for (p = elf_properties (pbfd); p; p = p->next)
+       {
+         if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type)
+           {
+             use_ibt_plt = !!(p->property.u.number
+                              & GNU_PROPERTY_X86_FEATURE_1_IBT);
+             break;
+           }
+         else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type)
+           break;
+       }
+    }
+
+  dynobj = htab->elf.dynobj;
+
+  /* Set htab->elf.dynobj here so that there is no need to check and
+     set it in check_relocs.  */
+  if (dynobj == NULL)
+    {
+      if (pbfd != NULL)
+       {
+         htab->elf.dynobj = pbfd;
+         dynobj = pbfd;
+       }
+      else
+       {
+         bfd *abfd;
+
+         /* Find a normal input file to hold linker created
+            sections.  */
+         for (abfd = info->input_bfds;
+              abfd != NULL;
+              abfd = abfd->link.next)
+           if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
+               && (abfd->flags
+                   & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0)
+             {
+               htab->elf.dynobj = abfd;
+               dynobj = abfd;
+               break;
+             }
+       }
+    }
+
+  /* Even when lazy binding is disabled by "-z now", the PLT0 entry may
+     still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for
+     canonical function address.  */
+  htab->plt.has_plt0 = 1;
+  normal_target = plt_layout->normal_target;
+
+  if (normal_target)
+    {
+      if (use_ibt_plt)
+       {
+         htab->lazy_plt = plt_layout->lazy_ibt_plt;
+         htab->non_lazy_plt = plt_layout->non_lazy_ibt_plt;
+       }
+      else
+       {
+         htab->lazy_plt = plt_layout->lazy_plt;
+         htab->non_lazy_plt = plt_layout->non_lazy_plt;
+       }
+    }
+  else
+    {
+      htab->lazy_plt = plt_layout->lazy_plt;
+      htab->non_lazy_plt = NULL;
+    }
+
+  pltsec = htab->elf.splt;
+
+  /* If the non-lazy PLT is available, use it for all PLT entries if
+     there are no PLT0 or no .plt section.  */
+  if (htab->non_lazy_plt != NULL
+      && (!htab->plt.has_plt0 || pltsec == NULL))
+    {
+      lazy_plt = FALSE;
+      if (bfd_link_pic (info))
+       htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry;
+      else
+       htab->plt.plt_entry = htab->non_lazy_plt->plt_entry;
+      htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size;
+      htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset;
+      htab->plt.plt_got_insn_size
+       = htab->non_lazy_plt->plt_got_insn_size;
+      htab->plt.eh_frame_plt_size
+       = htab->non_lazy_plt->eh_frame_plt_size;
+      htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt;
+    }
+  else
+    {
+      lazy_plt = TRUE;
+      if (bfd_link_pic (info))
+       {
+         htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry;
+         htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry;
+       }
+      else
+       {
+         htab->plt.plt0_entry = htab->lazy_plt->plt0_entry;
+         htab->plt.plt_entry = htab->lazy_plt->plt_entry;
+       }
+      htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size;
+      htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset;
+      htab->plt.plt_got_insn_size
+       = htab->lazy_plt->plt_got_insn_size;
+      htab->plt.eh_frame_plt_size
+       = htab->lazy_plt->eh_frame_plt_size;
+      htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt;
+    }
+
+  /* Return if there are no normal input files.  */
+  if (dynobj == NULL)
+    return pbfd;
+
+  if (plt_layout->is_vxworks
+      && !elf_vxworks_create_dynamic_sections (dynobj, info,
+                                              &htab->srelplt2))
+    {
+      info->callbacks->einfo (_("%F: failed to create VxWorks dynamic sections\n"));
+      return pbfd;
+    }
+
+  /* Since create_dynamic_sections isn't always called, but GOT
+     relocations need GOT relocations, create them here so that we
+     don't need to do it in check_relocs.  */
+  if (htab->elf.sgot == NULL
+      && !_bfd_elf_create_got_section (dynobj, info))
+    info->callbacks->einfo (_("%F: failed to create GOT sections\n"));
+
+  got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2;
+
+  /* Align .got and .got.plt sections to their entry size.  Do it here
+     instead of in create_dynamic_sections so that they are always
+     properly aligned even if create_dynamic_sections isn't called.  */
+  sec = htab->elf.sgot;
+  if (!bfd_set_section_alignment (dynobj, sec, got_align))
+    goto error_alignment;
+
+  sec = htab->elf.sgotplt;
+  if (!bfd_set_section_alignment (dynobj, sec, got_align))
+    goto error_alignment;
+
+  /* Create the ifunc sections here so that check_relocs can be
+     simplified.  */
+  if (!_bfd_elf_create_ifunc_sections (dynobj, info))
+    info->callbacks->einfo (_("%F: failed to create ifunc sections\n"));
+
+  plt_alignment = bfd_log2 (htab->plt.plt_entry_size);
+
+  if (pltsec != NULL)
+    {
+      /* Whe creating executable, set the contents of the .interp
+        section to the interpreter.  */
+      if (bfd_link_executable (info) && !info->nointerp)
+       {
+         asection *s = bfd_get_linker_section (dynobj, ".interp");
+         if (s == NULL)
+           abort ();
+         s->size = htab->dynamic_interpreter_size;
+         s->contents = (unsigned char *) htab->dynamic_interpreter;
+         htab->interp = s;
+       }
+
+      /* Don't change PLT section alignment for NaCl since it uses
+        64-byte PLT entry and sets PLT section alignment to 32
+        bytes.  Don't create additional PLT sections for NaCl.  */
+      if (normal_target)
+       {
+         flagword pltflags = (bed->dynamic_sec_flags
+                              | SEC_ALLOC
+                              | SEC_CODE
+                              | SEC_LOAD
+                              | SEC_READONLY);
+         unsigned int non_lazy_plt_alignment
+           = bfd_log2 (htab->non_lazy_plt->plt_entry_size);
+
+         sec = pltsec;
+         if (!bfd_set_section_alignment (sec->owner, sec,
+                                         plt_alignment))
+           goto error_alignment;
+
+         /* Create the GOT procedure linkage table.  */
+         sec = bfd_make_section_anyway_with_flags (dynobj,
+                                                   ".plt.got",
+                                                   pltflags);
+         if (sec == NULL)
+           info->callbacks->einfo (_("%F: failed to create GOT PLT section\n"));
+
+         if (!bfd_set_section_alignment (dynobj, sec,
+                                         non_lazy_plt_alignment))
+           goto error_alignment;
+
+         htab->plt_got = sec;
+
+         if (lazy_plt)
+           {
+             sec = NULL;
+
+             if (use_ibt_plt)
+               {
+                 /* Create the second PLT for Intel IBT support.  IBT
+                    PLT is supported only for non-NaCl target and is
+                    is needed only for lazy binding.  */
+                 sec = bfd_make_section_anyway_with_flags (dynobj,
+                                                           ".plt.sec",
+                                                           pltflags);
+                 if (sec == NULL)
+                   info->callbacks->einfo (_("%F: failed to create IBT-enabled PLT section\n"));
+
+                 if (!bfd_set_section_alignment (dynobj, sec,
+                                                 plt_alignment))
+                   goto error_alignment;
+               }
+             else if (info->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
+                    mode and is needed only for lazy binding.  */
+                 sec = bfd_make_section_anyway_with_flags (dynobj,
+                                                           ".plt.sec",
+                                                           pltflags);
+                 if (sec == NULL)
+                   info->callbacks->einfo (_("%F: failed to create BND PLT section\n"));
+
+                 if (!bfd_set_section_alignment (dynobj, sec,
+                                                 non_lazy_plt_alignment))
+                   goto error_alignment;
+               }
+
+             htab->plt_second = sec;
+           }
+       }
+
+      if (!info->no_ld_generated_unwind_info)
+       {
+         flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY
+                           | SEC_HAS_CONTENTS | SEC_IN_MEMORY
+                           | SEC_LINKER_CREATED);
+
+         sec = bfd_make_section_anyway_with_flags (dynobj,
+                                                   ".eh_frame",
+                                                   flags);
+         if (sec == NULL)
+           info->callbacks->einfo (_("%F: failed to create PLT .eh_frame section\n"));
+
+         if (!bfd_set_section_alignment (dynobj, sec, class_align))
+           goto error_alignment;
+
+         htab->plt_eh_frame = sec;
+
+         if (htab->plt_got != NULL)
+           {
+             sec = bfd_make_section_anyway_with_flags (dynobj,
+                                                       ".eh_frame",
+                                                       flags);
+             if (sec == NULL)
+               info->callbacks->einfo (_("%F: failed to create GOT PLT .eh_frame section\n"));
+
+             if (!bfd_set_section_alignment (dynobj, sec, class_align))
+               goto error_alignment;
+
+             htab->plt_got_eh_frame = sec;
+           }
+
+         if (htab->plt_second != NULL)
+           {
+             sec = bfd_make_section_anyway_with_flags (dynobj,
+                                                       ".eh_frame",
+                                                       flags);
+             if (sec == NULL)
+               info->callbacks->einfo (_("%F: failed to create the second PLT .eh_frame section\n"));
+
+             if (!bfd_set_section_alignment (dynobj, sec, class_align))
+               goto error_alignment;
+
+             htab->plt_second_eh_frame = sec;
+           }
+       }
+    }
+
+  if (normal_target)
+    {
+      /* 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))
+       goto error_alignment;
+    }
+
+  return pbfd;
+}
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