bfd/
[deliverable/binutils-gdb.git] / bfd / elf-eh-frame.c
index 37c92553ce352e90ab452a22a084a177c85f6959..832a99192deb6a0d172837a1804e116b32c0c3f2 100644 (file)
@@ -1,6 +1,6 @@
 /* .eh_frame section optimization.
-   Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
-   Free Software Foundation, Inc.
+   Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
+   2012 Free Software Foundation, Inc.
    Written by Jakub Jelinek <jakub@redhat.com>.
 
    This file is part of BFD, the Binary File Descriptor library.
@@ -490,7 +490,8 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
   if (hdr_info->parsed_eh_frames)
     return;
 
-  if (sec->size == 0)
+  if (sec->size == 0
+      || sec->sec_info_type != SEC_INFO_TYPE_NONE)
     {
       /* This file does not contain .eh_frame information.  */
       return;
@@ -636,7 +637,9 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
          REQUIRE (read_byte (&buf, end, &cie->version));
 
          /* Cannot handle unknown versions.  */
-         REQUIRE (cie->version == 1 || cie->version == 3);
+         REQUIRE (cie->version == 1
+                  || cie->version == 3
+                  || cie->version == 4);
          REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation));
 
          strcpy (cie->augmentation, (char *) buf);
@@ -651,6 +654,13 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
              REQUIRE (skip_bytes (&buf, end, ptr_size));
              SKIP_RELOCS (buf);
            }
+         if (cie->version >= 4)
+           {
+             REQUIRE (buf + 1 < end);
+             REQUIRE (buf[0] == ptr_size);
+             REQUIRE (buf[1] == 0);
+             buf += 2;
+           }
          REQUIRE (read_uleb128 (&buf, end, &cie->code_align));
          REQUIRE (read_sleb128 (&buf, end, &cie->data_align));
          if (cie->version == 1)
@@ -768,8 +778,6 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
        }
       else
        {
-         asection *rsec;
-
          /* Find the corresponding CIE.  */
          unsigned int cie_offset = this_inf->offset + 4 - hdr_id;
          for (cie = local_cies; cie < local_cies + cie_count; cie++)
@@ -785,17 +793,22 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
            = cie->cie_inf->add_augmentation_size;
 
          ENSURE_NO_RELOCS (buf);
-         REQUIRE (GET_RELOC (buf));
-
-         /* Chain together the FDEs for each section.  */
-         rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook, cookie);
-         /* RSEC will be NULL if FDE was cleared out as it was belonging to
-            a discarded SHT_GROUP.  */
-         if (rsec)
+         if ((sec->flags & SEC_LINKER_CREATED) == 0 || cookie->rels != NULL)
            {
-             REQUIRE (rsec->owner == abfd);
-             this_inf->u.fde.next_for_section = elf_fde_list (rsec);
-             elf_fde_list (rsec) = this_inf;
+             asection *rsec;
+
+             REQUIRE (GET_RELOC (buf));
+
+             /* Chain together the FDEs for each section.  */
+             rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook, cookie);
+             /* RSEC will be NULL if FDE was cleared out as it was belonging to
+                a discarded SHT_GROUP.  */
+             if (rsec)
+               {
+                 REQUIRE (rsec->owner == abfd);
+                 this_inf->u.fde.next_for_section = elf_fde_list (rsec);
+                 elf_fde_list (rsec) = this_inf;
+               }
            }
 
          /* Skip the initial location and address range.  */
@@ -891,7 +904,7 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
   BFD_ASSERT (cie_count == num_cies);
 
   elf_section_data (sec)->sec_info = sec_info;
-  sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME;
+  sec->sec_info_type = SEC_INFO_TYPE_EH_FRAME;
   if (hdr_info->merge_cies)
     {
       sec_info->cies = local_cies;
@@ -1124,10 +1137,16 @@ _bfd_elf_discard_section_eh_frame
   struct eh_frame_hdr_info *hdr_info;
   unsigned int ptr_size, offset;
 
+  if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
+    return FALSE;
+
   sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
   if (sec_info == NULL)
     return FALSE;
 
+  ptr_size = (get_elf_backend_data (sec->owner)
+             ->elf_backend_eh_frame_address_size (sec->owner, sec));
+
   hdr_info = &elf_hash_table (info)->eh_info;
   for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
     if (ent->size == 4)
@@ -1136,11 +1155,25 @@ _bfd_elf_discard_section_eh_frame
       ent->removed = sec->map_head.s != NULL;
     else if (!ent->cie)
       {
-       cookie->rel = cookie->rels + ent->reloc_index;
-       /* FIXME: octets_per_byte.  */
-       BFD_ASSERT (cookie->rel < cookie->relend
-                   && cookie->rel->r_offset == ent->offset + 8);
-       if (!(*reloc_symbol_deleted_p) (ent->offset + 8, cookie))
+       bfd_boolean keep;
+       if ((sec->flags & SEC_LINKER_CREATED) != 0 && cookie->rels == NULL)
+         {
+           unsigned int width
+             = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
+           bfd_vma value
+             = read_value (abfd, sec->contents + ent->offset + 8 + width,
+                           width, get_DW_EH_PE_signed (ent->fde_encoding));
+           keep = value != 0;
+         }
+       else
+         {
+           cookie->rel = cookie->rels + ent->reloc_index;
+           /* FIXME: octets_per_byte.  */
+           BFD_ASSERT (cookie->rel < cookie->relend
+                       && cookie->rel->r_offset == ent->offset + 8);
+           keep = !(*reloc_symbol_deleted_p) (ent->offset + 8, cookie);
+         }
+       if (keep)
          {
            if (info->shared
                && (((ent->fde_encoding & 0x70) == DW_EH_PE_absptr
@@ -1169,8 +1202,6 @@ _bfd_elf_discard_section_eh_frame
       sec_info->cies = NULL;
     }
 
-  ptr_size = (get_elf_backend_data (sec->owner)
-             ->elf_backend_eh_frame_address_size (sec->owner, sec));
   offset = 0;
   for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
     if (!ent->removed)
@@ -1212,10 +1243,30 @@ _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
   if (hdr_info->table)
     sec->size += 4 + hdr_info->fde_count * 8;
 
-  elf_tdata (abfd)->eh_frame_hdr = sec;
+  elf_eh_frame_hdr (abfd) = sec;
   return TRUE;
 }
 
+/* Return true if there is at least one non-empty .eh_frame section in
+   input files.  Can only be called after ld has mapped input to
+   output sections, and before sections are stripped.  */
+bfd_boolean
+_bfd_elf_eh_frame_present (struct bfd_link_info *info)
+{
+  asection *eh = bfd_get_section_by_name (info->output_bfd, ".eh_frame");
+
+  if (eh == NULL)
+    return FALSE;
+
+  /* Count only sections which have at least a single CIE or FDE.
+     There cannot be any CIE or FDE <= 8 bytes.  */
+  for (eh = eh->map_head.s; eh != NULL; eh = eh->map_head.s)
+    if (eh->size > 8)
+      return TRUE;
+
+  return FALSE;
+}
+
 /* This function is called from size_dynamic_sections.
    It needs to decide whether .eh_frame_hdr should be output or not,
    because when the dynamic symbol table has been sized it is too late
@@ -1224,8 +1275,6 @@ _bfd_elf_discard_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
 bfd_boolean
 _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info)
 {
-  asection *o;
-  bfd *abfd;
   struct elf_link_hash_table *htab;
   struct eh_frame_hdr_info *hdr_info;
 
@@ -1234,24 +1283,9 @@ _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info)
   if (hdr_info->hdr_sec == NULL)
     return TRUE;
 
-  if (bfd_is_abs_section (hdr_info->hdr_sec->output_section))
-    {
-      hdr_info->hdr_sec = NULL;
-      return TRUE;
-    }
-
-  abfd = NULL;
-  if (info->eh_frame_hdr)
-    for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next)
-      {
-       /* Count only sections which have at least a single CIE or FDE.
-          There cannot be any CIE or FDE <= 8 bytes.  */
-       o = bfd_get_section_by_name (abfd, ".eh_frame");
-       if (o && o->size > 8 && !bfd_is_abs_section (o->output_section))
-         break;
-      }
-
-  if (abfd == NULL)
+  if (bfd_is_abs_section (hdr_info->hdr_sec->output_section)
+      || !info->eh_frame_hdr
+      || !_bfd_elf_eh_frame_present (info))
     {
       hdr_info->hdr_sec->flags |= SEC_EXCLUDE;
       hdr_info->hdr_sec = NULL;
@@ -1269,25 +1303,20 @@ _bfd_elf_maybe_strip_eh_frame_hdr (struct bfd_link_info *info)
 
 bfd_vma
 _bfd_elf_eh_frame_section_offset (bfd *output_bfd ATTRIBUTE_UNUSED,
-                                 struct bfd_link_info *info,
+                                 struct bfd_link_info *info ATTRIBUTE_UNUSED,
                                  asection *sec,
                                  bfd_vma offset)
 {
   struct eh_frame_sec_info *sec_info;
-  struct elf_link_hash_table *htab;
-  struct eh_frame_hdr_info *hdr_info;
   unsigned int lo, hi, mid;
 
-  if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME)
+  if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
     return offset;
   sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
 
   if (offset >= sec->rawsize)
     return offset - sec->rawsize + sec->size;
 
-  htab = elf_hash_table (info);
-  hdr_info = &htab->eh_info;
-
   lo = 0;
   hi = sec_info->count;
   mid = 0;
@@ -1369,7 +1398,7 @@ _bfd_elf_write_section_eh_frame (bfd *abfd,
   unsigned int ptr_size;
   struct eh_cie_fde *ent;
 
-  if (sec->sec_info_type != ELF_INFO_TYPE_EH_FRAME)
+  if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
     /* FIXME: octets_per_byte.  */
     return bfd_set_section_contents (abfd, sec->output_section, contents,
                                     sec->output_offset, sec->size);
@@ -1568,10 +1597,31 @@ _bfd_elf_write_section_eh_frame (bfd *abfd,
                  break;
                case DW_EH_PE_datarel:
                  {
-                   asection *got = bfd_get_section_by_name (abfd, ".got");
-
-                   BFD_ASSERT (got != NULL);
-                   address += got->vma;
+                   switch (abfd->arch_info->arch)
+                     {
+                     case bfd_arch_ia64:
+                       BFD_ASSERT (elf_gp (abfd) != 0);
+                       address += elf_gp (abfd);
+                       break;
+                     default:
+                       (*info->callbacks->einfo)
+                         (_("%P: DW_EH_PE_datarel unspecified"
+                            " for this architecture.\n"));
+                       /* Fall thru */
+                     case bfd_arch_frv:
+                     case bfd_arch_i386:
+                       BFD_ASSERT (htab->hgot != NULL
+                                   && ((htab->hgot->root.type
+                                        == bfd_link_hash_defined)
+                                       || (htab->hgot->root.type
+                                           == bfd_link_hash_defweak)));
+                       address
+                         += (htab->hgot->root.u.def.value
+                             + htab->hgot->root.u.def.section->output_offset
+                             + (htab->hgot->root.u.def.section->output_section
+                                ->vma));
+                       break;
+                     }
                  }
                  break;
                case DW_EH_PE_pcrel:
@@ -1592,6 +1642,11 @@ _bfd_elf_write_section_eh_frame (bfd *abfd,
 
          if (hdr_info)
            {
+             /* The address calculation may overflow, giving us a
+                value greater than 4G on a 32-bit target when
+                dwarf_vma is 64-bit.  */
+             if (sizeof (address) > 4 && ptr_size == 4)
+               address &= 0xffffffff;
              hdr_info->array[hdr_info->array_count].initial_loc = address;
              hdr_info->array[hdr_info->array_count++].fde
                = (sec->output_section->vma
@@ -1715,74 +1770,81 @@ _bfd_elf_write_section_eh_frame_hdr (bfd *abfd, struct bfd_link_info *info)
   struct elf_link_hash_table *htab;
   struct eh_frame_hdr_info *hdr_info;
   asection *sec;
-  bfd_byte *contents;
-  asection *eh_frame_sec;
-  bfd_size_type size;
-  bfd_boolean retval;
-  bfd_vma encoded_eh_frame;
+  bfd_boolean retval = TRUE;
 
   htab = elf_hash_table (info);
   hdr_info = &htab->eh_info;
   sec = hdr_info->hdr_sec;
-  if (sec == NULL)
-    return TRUE;
-
-  size = EH_FRAME_HDR_SIZE;
-  if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count)
-    size += 4 + hdr_info->fde_count * 8;
-  contents = (bfd_byte *) bfd_malloc (size);
-  if (contents == NULL)
-    return FALSE;
 
-  eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame");
-  if (eh_frame_sec == NULL)
+  if (info->eh_frame_hdr && sec != NULL)
     {
-      free (contents);
-      return FALSE;
-    }
+      bfd_byte *contents;
+      asection *eh_frame_sec;
+      bfd_size_type size;
+      bfd_vma encoded_eh_frame;
+
+      size = EH_FRAME_HDR_SIZE;
+      if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count)
+       size += 4 + hdr_info->fde_count * 8;
+      contents = (bfd_byte *) bfd_malloc (size);
+      if (contents == NULL)
+       return FALSE;
 
-  memset (contents, 0, EH_FRAME_HDR_SIZE);
-  contents[0] = 1;                             /* Version.  */
-  contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address
-    (abfd, info, eh_frame_sec, 0, sec, 4,
-     &encoded_eh_frame);                       /* .eh_frame offset.  */
+      eh_frame_sec = bfd_get_section_by_name (abfd, ".eh_frame");
+      if (eh_frame_sec == NULL)
+       {
+         free (contents);
+         return FALSE;
+       }
 
-  if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count)
-    {
-      contents[2] = DW_EH_PE_udata4;           /* FDE count encoding.  */
-      contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; /* Search table enc.  */
-    }
-  else
-    {
-      contents[2] = DW_EH_PE_omit;
-      contents[3] = DW_EH_PE_omit;
-    }
-  bfd_put_32 (abfd, encoded_eh_frame, contents + 4);
+      memset (contents, 0, EH_FRAME_HDR_SIZE);
+      /* Version.  */
+      contents[0] = 1;
+      /* .eh_frame offset.  */
+      contents[1] = get_elf_backend_data (abfd)->elf_backend_encode_eh_address
+       (abfd, info, eh_frame_sec, 0, sec, 4, &encoded_eh_frame);
 
-  if (contents[2] != DW_EH_PE_omit)
-    {
-      unsigned int i;
+      if (hdr_info->array && hdr_info->array_count == hdr_info->fde_count)
+       {
+         /* FDE count encoding.  */
+         contents[2] = DW_EH_PE_udata4;
+         /* Search table encoding.  */
+         contents[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4;
+       }
+      else
+       {
+         contents[2] = DW_EH_PE_omit;
+         contents[3] = DW_EH_PE_omit;
+       }
+      bfd_put_32 (abfd, encoded_eh_frame, contents + 4);
 
-      bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE);
-      qsort (hdr_info->array, hdr_info->fde_count, sizeof (*hdr_info->array),
-            vma_compare);
-      for (i = 0; i < hdr_info->fde_count; i++)
+      if (contents[2] != DW_EH_PE_omit)
        {
-         bfd_put_32 (abfd,
-                     hdr_info->array[i].initial_loc
-                     - sec->output_section->vma,
-                     contents + EH_FRAME_HDR_SIZE + i * 8 + 4);
-         bfd_put_32 (abfd,
-                     hdr_info->array[i].fde - sec->output_section->vma,
-                     contents + EH_FRAME_HDR_SIZE + i * 8 + 8);
+         unsigned int i;
+
+         bfd_put_32 (abfd, hdr_info->fde_count, contents + EH_FRAME_HDR_SIZE);
+         qsort (hdr_info->array, hdr_info->fde_count,
+                sizeof (*hdr_info->array), vma_compare);
+         for (i = 0; i < hdr_info->fde_count; i++)
+           {
+             bfd_put_32 (abfd,
+                         hdr_info->array[i].initial_loc
+                         - sec->output_section->vma,
+                         contents + EH_FRAME_HDR_SIZE + i * 8 + 4);
+             bfd_put_32 (abfd,
+                         hdr_info->array[i].fde - sec->output_section->vma,
+                         contents + EH_FRAME_HDR_SIZE + i * 8 + 8);
+           }
        }
-    }
 
-  /* FIXME: octets_per_byte.  */
-  retval = bfd_set_section_contents (abfd, sec->output_section,
-                                    contents, (file_ptr) sec->output_offset,
-                                    sec->size);
-  free (contents);
+      /* FIXME: octets_per_byte.  */
+      retval = bfd_set_section_contents (abfd, sec->output_section, contents,
+                                        (file_ptr) sec->output_offset,
+                                        sec->size);
+      free (contents);
+    }
+  if (hdr_info->array != NULL)
+    free (hdr_info->array);
   return retval;
 }
 
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