hppa-linux TLS relocs
authorAlan Modra <amodra@gmail.com>
Thu, 2 Nov 2017 01:39:34 +0000 (12:09 +1030)
committerAlan Modra <amodra@gmail.com>
Sat, 4 Nov 2017 23:07:33 +0000 (09:37 +1030)
This patch fixes various problems with TLS relocations.

1) Report an error if a symbol has both TLS and normal GOT entries.
2) The GOT entry size calculation was obscure and made use of the fact
   that a symbol shouldn't have both normal and TLS GOT entries.
3) The second word of a GD GOT entry sometimes omitted a dynamic
   reloc, which was fine except that doing so makes it impossible for
   ld.so to differentiate GD and LD entries.  Also, a NONE reloc was
   emitted.
4) Unnecessary relocs were emitted for GOT entries.
5) GOT relocs didn't take note of UNDEFWEAK_NO_DYNAMIC_RELOC.

* elf32-hppa.c (enum _tls_type): Move.
(struct elf32_hppa_link_hash_entry): Make tls_type a bitfield.
(elf32_hppa_check_relocs): Set DF_STATIC_TLS only for shared libraries.
Tidy tls_type handling.  Set symbol tls_type for GOT_TLS_LDM too.
(got_entries_needed, got_relocs_needed): New functions.
(allocate_dynrelocs): Use them.
(elf32_hppa_size_dynamic_sections): Likewise.
(elf32_hppa_relocate_section): Delete bogus FIXME.  Formatting.
Correct code emitting relocs on GD/IE got entries.  Report an
error when a symbol has both normal and TLS GOT relocs.

bfd/ChangeLog
bfd/elf32-hppa.c

index 9bdc0f0abf816358accd22561c0bfef7f7f785fc..640130150fbbc8d01fd7714e7335e0bd2a298739 100644 (file)
@@ -1,3 +1,16 @@
+2017-11-04  Alan Modra  <amodra@gmail.com>
+
+       * elf32-hppa.c (enum _tls_type): Move.
+       (struct elf32_hppa_link_hash_entry): Make tls_type a bitfield.
+       (elf32_hppa_check_relocs): Set DF_STATIC_TLS only for shared libraries.
+       Tidy tls_type handling.  Set symbol tls_type for GOT_TLS_LDM too.
+       (got_entries_needed, got_relocs_needed): New functions.
+       (allocate_dynrelocs): Use them.
+       (elf32_hppa_size_dynamic_sections): Likewise.
+       (elf32_hppa_relocate_section): Delete bogus FIXME.  Formatting.
+       Correct code emitting relocs on GD/IE got entries.  Report an
+       error when a symbol has both normal and TLS GOT relocs.
+
 2017-11-04  Alan Modra  <amodra@gmail.com>
 
        PR 22394
index acc96afe078b738083ebe1eb5b6c4e945640c6b7..f9629e4b119d370f13b2d5e21bbea1663f127d30 100644 (file)
@@ -206,6 +206,15 @@ struct elf32_hppa_stub_hash_entry
   asection *id_sec;
 };
 
+enum _tls_type
+  {
+    GOT_UNKNOWN = 0,
+    GOT_NORMAL = 1,
+    GOT_TLS_GD = 2,
+    GOT_TLS_LDM = 4,
+    GOT_TLS_IE = 8
+  };
+
 struct elf32_hppa_link_hash_entry
 {
   struct elf_link_hash_entry eh;
@@ -233,10 +242,7 @@ struct elf32_hppa_link_hash_entry
 #endif
   } *dyn_relocs;
 
-  enum
-  {
-    GOT_UNKNOWN = 0, GOT_NORMAL = 1, GOT_TLS_GD = 2, GOT_TLS_LDM = 4, GOT_TLS_IE = 8
-  } tls_type;
+  ENUM_BITFIELD (_tls_type) tls_type : 8;
 
   /* Set if this symbol is used by a plabel reloc.  */
   unsigned int plabel:1;
@@ -1132,7 +1138,6 @@ elf32_hppa_check_relocs (bfd *abfd,
   const Elf_Internal_Rela *rela_end;
   struct elf32_hppa_link_hash_table *htab;
   asection *sreloc;
-  int tls_type = GOT_UNKNOWN, old_tls_type = GOT_UNKNOWN;
 
   if (bfd_link_relocatable (info))
     return TRUE;
@@ -1312,7 +1317,7 @@ elf32_hppa_check_relocs (bfd *abfd,
 
        case R_PARISC_TLS_IE21L:
        case R_PARISC_TLS_IE14R:
-         if (bfd_link_pic (info))
+         if (bfd_link_dll (info))
             info->flags |= DF_STATIC_TLS;
          need_entry = NEED_GOT;
          break;
@@ -1324,22 +1329,23 @@ elf32_hppa_check_relocs (bfd *abfd,
       /* Now carry out our orders.  */
       if (need_entry & NEED_GOT)
        {
+         int tls_type = GOT_NORMAL;
+
          switch (r_type)
            {
            default:
-             tls_type = GOT_NORMAL;
              break;
            case R_PARISC_TLS_GD21L:
            case R_PARISC_TLS_GD14R:
-             tls_type |= GOT_TLS_GD;
+             tls_type = GOT_TLS_GD;
              break;
            case R_PARISC_TLS_LDM21L:
            case R_PARISC_TLS_LDM14R:
-             tls_type |= GOT_TLS_LDM;
+             tls_type = GOT_TLS_LDM;
              break;
            case R_PARISC_TLS_IE21L:
            case R_PARISC_TLS_IE14R:
-             tls_type |= GOT_TLS_IE;
+             tls_type = GOT_TLS_IE;
              break;
            }
 
@@ -1351,39 +1357,28 @@ elf32_hppa_check_relocs (bfd *abfd,
                return FALSE;
            }
 
-         if (r_type == R_PARISC_TLS_LDM21L
-             || r_type == R_PARISC_TLS_LDM14R)
-           htab->tls_ldm_got.refcount += 1;
-         else
+         if (hh != NULL)
            {
-             if (hh != NULL)
-               {
-                 hh->eh.got.refcount += 1;
-                 old_tls_type = hh->tls_type;
-               }
+             if (tls_type == GOT_TLS_LDM)
+               htab->tls_ldm_got.refcount += 1;
              else
-               {
-                 bfd_signed_vma *local_got_refcounts;
-
-                 /* This is a global offset table entry for a local symbol.  */
-                 local_got_refcounts = hppa32_elf_local_refcounts (abfd);
-                 if (local_got_refcounts == NULL)
-                   return FALSE;
-                 local_got_refcounts[r_symndx] += 1;
-
-                 old_tls_type = hppa_elf_local_got_tls_type (abfd) [r_symndx];
-               }
-
-             tls_type |= old_tls_type;
+               hh->eh.got.refcount += 1;
+             hh->tls_type |= tls_type;
+           }
+         else
+           {
+             bfd_signed_vma *local_got_refcounts;
 
-             if (old_tls_type != tls_type)
-               {
-                 if (hh != NULL)
-                   hh->tls_type = tls_type;
-                 else
-                   hppa_elf_local_got_tls_type (abfd) [r_symndx] = tls_type;
-               }
+             /* This is a global offset table entry for a local symbol.  */
+             local_got_refcounts = hppa32_elf_local_refcounts (abfd);
+             if (local_got_refcounts == NULL)
+               return FALSE;
+             if (tls_type == GOT_TLS_LDM)
+               htab->tls_ldm_got.refcount += 1;
+             else
+               local_got_refcounts[r_symndx] += 1;
 
+             hppa_elf_local_got_tls_type (abfd) [r_symndx] |= tls_type;
            }
        }
 
@@ -1916,6 +1911,39 @@ allocate_plt_static (struct elf_link_hash_entry *eh, void *inf)
   return TRUE;
 }
 
+/* Calculate size of GOT entries for symbol given its TLS_TYPE.  */
+
+static inline unsigned int
+got_entries_needed (int tls_type)
+{
+  unsigned int need = 0;
+
+  if ((tls_type & GOT_NORMAL) != 0)
+    need += GOT_ENTRY_SIZE;
+  if ((tls_type & GOT_TLS_GD) != 0)
+    need += GOT_ENTRY_SIZE * 2;
+  if ((tls_type & GOT_TLS_IE) != 0)
+    need += GOT_ENTRY_SIZE;
+  return need;
+}
+
+/* Calculate size of relocs needed for symbol given its TLS_TYPE and
+   NEEDed GOT entries.  KNOWN says a TPREL offset can be calculated
+   at link time.  */
+
+static inline unsigned int
+got_relocs_needed (int tls_type, unsigned int need, bfd_boolean known)
+{
+  /* All the entries we allocated need relocs.
+     Except IE in executable with a local symbol.  We could also omit
+     the DTPOFF reloc on the second word of a GD entry under the same
+     condition as that for IE, but ld.so might want to differentiate
+     LD and GD entries at some stage.  */
+  if ((tls_type & GOT_TLS_IE) != 0 && known)
+    need -= GOT_ENTRY_SIZE;
+  return need * sizeof (Elf32_External_Rela) / GOT_ENTRY_SIZE;
+}
+
 /* Allocate space in .plt, .got and associated reloc sections for
    global syms.  */
 
@@ -1955,28 +1983,25 @@ allocate_dynrelocs (struct elf_link_hash_entry *eh, void *inf)
 
   if (eh->got.refcount > 0)
     {
+      unsigned int need;
+
       if (!ensure_undef_dynamic (info, eh))
        return FALSE;
 
       sec = htab->etab.sgot;
       eh->got.offset = sec->size;
-      sec->size += GOT_ENTRY_SIZE;
-      /* R_PARISC_TLS_GD* needs two GOT entries */
-      if ((hh->tls_type & (GOT_TLS_GD | GOT_TLS_IE)) == (GOT_TLS_GD | GOT_TLS_IE))
-       sec->size += GOT_ENTRY_SIZE * 2;
-      else if ((hh->tls_type & GOT_TLS_GD) == GOT_TLS_GD)
-       sec->size += GOT_ENTRY_SIZE;
+      need = got_entries_needed (hh->tls_type);
+      sec->size += need;
       if (htab->etab.dynamic_sections_created
          && (bfd_link_pic (info)
              || (eh->dynindx != -1
                  && !SYMBOL_REFERENCES_LOCAL (info, eh)))
          && !UNDEFWEAK_NO_DYNAMIC_RELOC (info, eh))
        {
-         htab->etab.srelgot->size += sizeof (Elf32_External_Rela);
-         if ((hh->tls_type & (GOT_TLS_GD | GOT_TLS_IE)) == (GOT_TLS_GD | GOT_TLS_IE))
-           htab->etab.srelgot->size += 2 * sizeof (Elf32_External_Rela);
-         else if ((hh->tls_type & GOT_TLS_GD) == GOT_TLS_GD)
-           htab->etab.srelgot->size += sizeof (Elf32_External_Rela);
+         bfd_boolean tprel_known = (bfd_link_executable (info)
+                                    && SYMBOL_REFERENCES_LOCAL (info, eh));
+         htab->etab.srelgot->size
+           += got_relocs_needed (hh->tls_type, need, tprel_known);
        }
     }
   else
@@ -2195,20 +2220,17 @@ elf32_hppa_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED,
        {
          if (*local_got > 0)
            {
+             unsigned int need;
+
              *local_got = sec->size;
-             sec->size += GOT_ENTRY_SIZE;
-             if ((*local_tls_type & (GOT_TLS_GD | GOT_TLS_IE)) == (GOT_TLS_GD | GOT_TLS_IE))
-               sec->size += 2 * GOT_ENTRY_SIZE;
-             else if ((*local_tls_type & GOT_TLS_GD) == GOT_TLS_GD)
-               sec->size += GOT_ENTRY_SIZE;
+             need = got_entries_needed (*local_tls_type);
+             sec->size += need;
              if (bfd_link_pic (info))
-               {
-                 srel->size += sizeof (Elf32_External_Rela);
-                 if ((*local_tls_type & (GOT_TLS_GD | GOT_TLS_IE)) == (GOT_TLS_GD | GOT_TLS_IE))
-                   srel->size += 2 * sizeof (Elf32_External_Rela);
-                 else if ((*local_tls_type & GOT_TLS_GD) == GOT_TLS_GD)
-                   srel->size += sizeof (Elf32_External_Rela);
-               }
+               {
+                 bfd_boolean tprel_known = bfd_link_executable (info);
+                 htab->etab.srelgot->size
+                   += got_relocs_needed (*local_tls_type, need, tprel_known);
+               }
            }
          else
            *local_got = (bfd_vma) -1;
@@ -4025,17 +4047,17 @@ elf32_hppa_relocate_section (bfd *output_bfd,
            indx = 0;
            if (hh != NULL)
              {
-               bfd_boolean dyn;
-               dyn = htab->etab.dynamic_sections_created;
-
-               if (WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn,
-                                                    bfd_link_pic (info),
-                                                    &hh->eh)
-                   && (!bfd_link_pic (info)
-                       || !SYMBOL_REFERENCES_LOCAL (info, &hh->eh)))
-                 {
-                   indx = hh->eh.dynindx;
-                 }
+               if (!htab->etab.dynamic_sections_created
+                   || hh->eh.dynindx == -1
+                   || SYMBOL_REFERENCES_LOCAL (info, &hh->eh)
+                   || UNDEFWEAK_NO_DYNAMIC_RELOC (info, &hh->eh))
+                 /* This is actually a static link, or it is a
+                    -Bsymbolic link and the symbol is defined
+                    locally, or the symbol was forced to be local
+                    because of a version file.  */
+                 ;
+               else
+                 indx = hh->eh.dynindx;
                off = hh->eh.got.offset;
                tls_type = hh->tls_type;
              }
@@ -4061,44 +4083,41 @@ elf32_hppa_relocate_section (bfd *output_bfd,
                   now, and emit any relocations.  If both an IE GOT and a
                   GD GOT are necessary, we emit the GD first.  */
 
-               if ((bfd_link_pic (info) || indx != 0)
-                   && (hh == NULL
-                       || ELF_ST_VISIBILITY (hh->eh.other) == STV_DEFAULT
-                       || hh->eh.root.type != bfd_link_hash_undefweak))
+               if (indx != 0
+                   || (bfd_link_pic (info)
+                       && (hh == NULL
+                           || !UNDEFWEAK_NO_DYNAMIC_RELOC (info, &hh->eh))))
                  {
                    need_relocs = TRUE;
                    loc = htab->etab.srelgot->contents;
-                   /* FIXME (CAO): Should this be reloc_count++ ? */
-                   loc += htab->etab.srelgot->reloc_count * sizeof (Elf32_External_Rela);
+                   loc += (htab->etab.srelgot->reloc_count
+                           * sizeof (Elf32_External_Rela));
                  }
 
                if (tls_type & GOT_TLS_GD)
                  {
                    if (need_relocs)
                      {
-                       outrel.r_offset = (cur_off
-                                          + htab->etab.sgot->output_section->vma
-                                          + htab->etab.sgot->output_offset);
-                       outrel.r_info = ELF32_R_INFO (indx,R_PARISC_TLS_DTPMOD32);
+                       outrel.r_offset
+                         = (cur_off
+                            + htab->etab.sgot->output_section->vma
+                            + htab->etab.sgot->output_offset);
+                       outrel.r_info
+                         = ELF32_R_INFO (indx, R_PARISC_TLS_DTPMOD32);
                        outrel.r_addend = 0;
-                       bfd_put_32 (output_bfd, 0, htab->etab.sgot->contents + cur_off);
                        bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc);
                        htab->etab.srelgot->reloc_count++;
                        loc += sizeof (Elf32_External_Rela);
-
-                       if (indx == 0)
-                         bfd_put_32 (output_bfd, relocation - dtpoff_base (info),
-                                     htab->etab.sgot->contents + cur_off + 4);
-                       else
-                         {
-                           bfd_put_32 (output_bfd, 0,
-                                       htab->etab.sgot->contents + cur_off + 4);
-                           outrel.r_info = ELF32_R_INFO (indx, R_PARISC_TLS_DTPOFF32);
-                           outrel.r_offset += 4;
-                           bfd_elf32_swap_reloca_out (output_bfd, &outrel,loc);
-                           htab->etab.srelgot->reloc_count++;
-                           loc += sizeof (Elf32_External_Rela);
-                         }
+                       outrel.r_info
+                         = ELF32_R_INFO (indx, R_PARISC_TLS_DTPOFF32);
+                       outrel.r_offset += 4;
+                       bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc);
+                       htab->etab.srelgot->reloc_count++;
+                       loc += sizeof (Elf32_External_Rela);
+                       bfd_put_32 (output_bfd, 0,
+                                   htab->etab.sgot->contents + cur_off);
+                       bfd_put_32 (output_bfd, 0,
+                                   htab->etab.sgot->contents + cur_off + 4);
                      }
                    else
                      {
@@ -4109,28 +4128,28 @@ elf32_hppa_relocate_section (bfd *output_bfd,
                           to module 1, the executable.  */
                        bfd_put_32 (output_bfd, 1,
                                    htab->etab.sgot->contents + cur_off);
-                       bfd_put_32 (output_bfd, relocation - dtpoff_base (info),
+                       bfd_put_32 (output_bfd, relocation - dtpoff_base (info),
                                    htab->etab.sgot->contents + cur_off + 4);
                      }
-
-
                    cur_off += 8;
                  }
 
                if (tls_type & GOT_TLS_IE)
                  {
-                   if (need_relocs)
+                   if (need_relocs
+                       && !(bfd_link_executable (info)
+                            && SYMBOL_REFERENCES_LOCAL (info, &hh->eh)))
                      {
-                       outrel.r_offset = (cur_off
-                                          + htab->etab.sgot->output_section->vma
-                                          + htab->etab.sgot->output_offset);
-                       outrel.r_info = ELF32_R_INFO (indx, R_PARISC_TLS_TPREL32);
-
+                       outrel.r_offset
+                         = (cur_off
+                            + htab->etab.sgot->output_section->vma
+                            + htab->etab.sgot->output_offset);
+                       outrel.r_info = ELF32_R_INFO (indx,
+                                                     R_PARISC_TLS_TPREL32);
                        if (indx == 0)
                          outrel.r_addend = relocation - dtpoff_base (info);
                        else
                          outrel.r_addend = 0;
-
                        bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc);
                        htab->etab.srelgot->reloc_count++;
                        loc += sizeof (Elf32_External_Rela);
@@ -4138,7 +4157,6 @@ elf32_hppa_relocate_section (bfd *output_bfd,
                    else
                      bfd_put_32 (output_bfd, tpoff (info, relocation),
                                  htab->etab.sgot->contents + cur_off);
-
                    cur_off += 4;
                  }
 
@@ -4148,6 +4166,35 @@ elf32_hppa_relocate_section (bfd *output_bfd,
                  local_got_offsets[r_symndx] |= 1;
              }
 
+           if ((tls_type & GOT_NORMAL) != 0
+               && (tls_type & (GOT_TLS_GD | GOT_TLS_LDM | GOT_TLS_IE)) != 0)
+             {
+               if (hh != NULL)
+                 _bfd_error_handler (_("%s has both normal and TLS relocs"),
+                                     hh_name (hh));
+               else
+                 {
+                   Elf_Internal_Sym *isym
+                     = bfd_sym_from_r_symndx (&htab->sym_cache,
+                                              input_bfd, r_symndx);
+                   if (isym == NULL)
+                     return FALSE;
+                   sym_name
+                     = bfd_elf_string_from_elf_section (input_bfd,
+                                                        symtab_hdr->sh_link,
+                                                        isym->st_name);
+                   if (sym_name == NULL)
+                     return FALSE;
+                   if (*sym_name == '\0')
+                     sym_name = bfd_section_name (input_bfd, sym_sec);
+                   _bfd_error_handler
+                     (_("%B:%s has both normal and TLS relocs"),
+                      input_bfd, sym_name);
+                 }
+               bfd_set_error (bfd_error_bad_value);
+               return FALSE;
+             }
+
            if ((tls_type & GOT_TLS_GD)
                && r_type != R_PARISC_TLS_GD21L
                && r_type != R_PARISC_TLS_GD14R)
@@ -4290,8 +4337,7 @@ elf32_hppa_finish_dynamic_symbol (bfd *output_bfd,
     }
 
   if (eh->got.offset != (bfd_vma) -1
-      && (hppa_elf_hash_entry (eh)->tls_type & GOT_TLS_GD) == 0
-      && (hppa_elf_hash_entry (eh)->tls_type & GOT_TLS_IE) == 0
+      && (hppa_elf_hash_entry (eh)->tls_type & GOT_NORMAL) != 0
       && !UNDEFWEAK_NO_DYNAMIC_RELOC (info, eh))
     {
       bfd_boolean is_dyn = (eh->dynindx != -1