PowerPC dynamic relocations
authorAlan Modra <amodra@gmail.com>
Mon, 23 Jan 2017 22:13:01 +0000 (08:43 +1030)
committerAlan Modra <amodra@gmail.com>
Tue, 24 Jan 2017 01:45:54 +0000 (12:15 +1030)
This patch fixes a number of issues with powerpc dynamic relocations.

1) Both ppc and ppc64 were emitting more dynamic symbols and
relocations than necessary, due to not supporting static linker
resolution of tls_index entries for __tls_get_addr_opt.  This meant
that any @got@tlsgd or @got@tlsld reloc needed to make their symbols
dynamic and generate dptmod and dtprel relocs for the dynamic linker.
That would have been passable, but what happened was that practically
all @got relocations resulted in their symbols being made dynamic and
dynamic relocations emitted against the GOT entries.  (Mostly visible
on ppc32 executables since ppc64 gcc really only uses @got style
relocs for TLS.)

2) The PowerOpen syntax was not supported with __tls_get_addr_opt.
DTPMOD/DTPREL relocs on tls_index TOC entries did not use the trick of
forcing dynamic symbols and relocations so those entries always
resulted in the full __tls_get_addr processing.  gcc doesn't use the
PowerOpen syntax for TLS, and normally such code would be optimized to
TLS IE or LE so the impact of missing this support was minimal.

3) In an executable, relocations against GNU indirect functions always
used the value of their PLT stub.   While this is correct, it is
better in some cases to use a dynamic relocation.  An extra dynamic
relocation can mean that calls via function pointers need not bounce
through the PLT stub at runtime.

The patch also tidies the PLT handling code in ppc32
allocate_dynrelocs.  Allocating PLT entries after other dynamic relocs
allows the PLT loop to omit special handling for undefined weak
symbols, and that in turn allows the loop to be simplified.

bfd/
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Merge two cases
where dynamic relocs are preferable.  Allow ifunc too.
(ensure_undefweak_dynamic): New function.
(allocate_dynrelocs): Use it here.  Move plt handling last and
don't make symbols dynamic, simplifying loop.  Only make undef
weak symbols with GOT entries dynamic.  Correct condition
for GOT relocs.  Handle dynamic relocs on ifuncs.  Correct
comments.  Remove goto.
(ppc_elf_relocate_section): Correct test for using dynamic
symbol on GOT relocs.  Rearrange test for emitting GOT relocs
to suit.  Set up explicit tls_index entries and implicit GOT
tls_index entries resolvable at link time for
__tls_get_addr_opt.  Simplify test to clear mem for prelink.
* elf64-ppc.c (allocate_got): Correct condition for GOT relocs.
(ensure_undefweak_dynamic): New function.
(allocate_dynrelocs): Use it here.  Only make undef weak symbols
with GOT entries dynamic.  Remove unnecessary test of
WILL_CALL_FINISH_DYNAMIC_SYMBOL in PLT handling.
(ppc64_elf_relocate_section): Correct test for using dynamic
symbol on GOT relocs.  Rearrange test for emitting GOT relocs
to suit.  Set up explicit tls_index entries and implicit GOT
tls_index entries resolvable at link time for __tls_get_addr_opt.
Simplify expression to clear mem for prelink.
ld/
* testsuite/ld-powerpc/tlsexe.r: Update for fewer dynamic relocs
and symbols.
* testsuite/ld-powerpc/tlsexe.d: Likewise.
* testsuite/ld-powerpc/tlsexe.g: Likewise.

bfd/ChangeLog
bfd/elf32-ppc.c
bfd/elf64-ppc.c
ld/ChangeLog
ld/testsuite/ld-powerpc/tlsexe.d
ld/testsuite/ld-powerpc/tlsexe.g
ld/testsuite/ld-powerpc/tlsexe.r

index 857f57a..5102221 100644 (file)
@@ -1,3 +1,29 @@
+2017-01-24  Alan Modra  <amodra@gmail.com>
+
+       * elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Merge two cases
+       where dynamic relocs are preferable.  Allow ifunc too.
+       (ensure_undefweak_dynamic): New function.
+       (allocate_dynrelocs): Use it here.  Move plt handling last and
+       don't make symbols dynamic, simplifying loop.  Only make undef
+       weak symbols with GOT entries dynamic.  Correct condition
+       for GOT relocs.  Handle dynamic relocs on ifuncs.  Correct
+       comments.  Remove goto.
+       (ppc_elf_relocate_section): Correct test for using dynamic
+       symbol on GOT relocs.  Rearrange test for emitting GOT relocs
+       to suit.  Set up explicit tls_index entries and implicit GOT
+       tls_index entries resolvable at link time for
+       __tls_get_addr_opt.  Simplify test to clear mem for prelink.
+       * elf64-ppc.c (allocate_got): Correct condition for GOT relocs.
+       (ensure_undefweak_dynamic): New function.
+       (allocate_dynrelocs): Use it here.  Only make undef weak symbols
+       with GOT entries dynamic.  Remove unnecessary test of
+       WILL_CALL_FINISH_DYNAMIC_SYMBOL in PLT handling.
+       (ppc64_elf_relocate_section): Correct test for using dynamic
+       symbol on GOT relocs.  Rearrange test for emitting GOT relocs
+       to suit.  Set up explicit tls_index entries and implicit GOT
+       tls_index entries resolvable at link time for __tls_get_addr_opt.
+       Simplify expression to clear mem for prelink.
+
 2017-01-23  Yury Norov  <ynorov@caviumnetworks.com>
 
        * elfnn-aarch64.c: Fix relaxations for ILP32 mode.
index 989f785..7d69ea0 100644 (file)
@@ -5684,33 +5684,24 @@ ppc_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
          /* Taking a function's address in a read/write section
             doesn't require us to define the function symbol in the
             executable on a plt call stub.  A dynamic reloc can
-            be used instead.  */
-         if (h->pointer_equality_needed
-             && h->type != STT_GNU_IFUNC
+            be used instead, giving better runtime performance.
+            (Calls via that function pointer don't need to bounce
+            through the plt call stub.)  Similarly, use a dynamic
+            reloc for a weak reference when possible, allowing the
+            resolution of the symbol to be set at load time rather
+            than link time.  */
+         if ((h->pointer_equality_needed
+              || (!h->ref_regular_nonweak && h->non_got_ref))
              && !htab->is_vxworks
              && !ppc_elf_hash_entry (h)->has_sda_refs
              && !readonly_dynrelocs (h))
            {
              h->pointer_equality_needed = 0;
+             /* After adjust_dynamic_symbol, non_got_ref set in the
+                non-pic case means that dyn_relocs for this symbol
+                should be discarded.  */
              h->non_got_ref = 0;
            }
-
-         /* After adjust_dynamic_symbol, non_got_ref set in the
-            non-shared case means that we have allocated space in
-            .dynbss for the symbol and thus dyn_relocs for this
-            symbol should be discarded.
-            If we get here we know we are making a PLT entry for this
-            symbol, and in an executable we'd normally resolve
-            relocations against this symbol to the PLT entry.  Allow
-            dynamic relocs if the reference is weak, and the dynamic
-            relocs will not cause text relocation.  */
-         else if (!h->ref_regular_nonweak
-                  && h->non_got_ref
-                  && h->type != STT_GNU_IFUNC
-                  && !htab->is_vxworks
-                  && !ppc_elf_hash_entry (h)->has_sda_refs
-                  && !readonly_dynrelocs (h))
-           h->non_got_ref = 0;
        }
       h->protected_def = 0;
       return TRUE;
@@ -5925,6 +5916,23 @@ allocate_got (struct ppc_elf_link_hash_table *htab, unsigned int need)
   return where;
 }
 
+/* If H is undefined weak, make it dynamic if that makes sense.  */
+
+static bfd_boolean
+ensure_undefweak_dynamic (struct bfd_link_info *info,
+                         struct elf_link_hash_entry *h)
+{
+  struct elf_link_hash_table *htab = elf_hash_table (info);
+
+  if (htab->dynamic_sections_created
+      && h->root.type == bfd_link_hash_undefweak
+      && h->dynindx == -1
+      && !h->forced_local
+      && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
+    return bfd_elf_link_record_dynamic_symbol (info, h);
+  return TRUE;
+}
+
 /* Allocate space in associated reloc sections for dynamic relocs.  */
 
 static bfd_boolean
@@ -5934,175 +5942,12 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
   struct ppc_elf_link_hash_entry *eh;
   struct ppc_elf_link_hash_table *htab;
   struct elf_dyn_relocs *p;
+  bfd_boolean dyn;
 
   if (h->root.type == bfd_link_hash_indirect)
     return TRUE;
 
   htab = ppc_elf_hash_table (info);
-  if (htab->elf.dynamic_sections_created
-      || h->type == STT_GNU_IFUNC)
-    {
-      struct plt_entry *ent;
-      bfd_boolean doneone = FALSE;
-      bfd_vma plt_offset = 0, glink_offset = 0;
-      bfd_boolean dyn;
-
-      for (ent = h->plt.plist; ent != NULL; ent = ent->next)
-       if (ent->plt.refcount > 0)
-         {
-           /* Make sure this symbol is output as a dynamic symbol.  */
-           if (h->dynindx == -1
-               && !h->forced_local
-               && !h->def_regular
-               && htab->elf.dynamic_sections_created)
-             {
-               if (! bfd_elf_link_record_dynamic_symbol (info, h))
-                 return FALSE;
-             }
-
-           dyn = htab->elf.dynamic_sections_created;
-           if (bfd_link_pic (info)
-               || h->type == STT_GNU_IFUNC
-               || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))
-             {
-               asection *s = htab->elf.splt;
-               if (!dyn || h->dynindx == -1)
-                 s = htab->elf.iplt;
-
-               if (htab->plt_type == PLT_NEW || !dyn || h->dynindx == -1)
-                 {
-                   if (!doneone)
-                     {
-                       plt_offset = s->size;
-                       s->size += 4;
-                     }
-                   ent->plt.offset = plt_offset;
-
-                   s = htab->glink;
-                   if (!doneone || bfd_link_pic (info))
-                     {
-                       glink_offset = s->size;
-                       s->size += GLINK_ENTRY_SIZE;
-                       if (h == htab->tls_get_addr
-                           && !htab->params->no_tls_get_addr_opt)
-                         s->size += TLS_GET_ADDR_GLINK_SIZE - GLINK_ENTRY_SIZE;
-                     }
-                   if (!doneone
-                       && !bfd_link_pic (info)
-                       && h->def_dynamic
-                       && !h->def_regular)
-                     {
-                       h->root.u.def.section = s;
-                       h->root.u.def.value = glink_offset;
-                     }
-                   ent->glink_offset = glink_offset;
-
-                   if (htab->params->emit_stub_syms
-                       && !add_stub_sym (ent, h, info))
-                     return FALSE;
-                 }
-               else
-                 {
-                   if (!doneone)
-                     {
-                       /* If this is the first .plt entry, make room
-                          for the special first entry.  */
-                       if (s->size == 0)
-                         s->size += htab->plt_initial_entry_size;
-
-                       /* The PowerPC PLT is actually composed of two
-                          parts, the first part is 2 words (for a load
-                          and a jump), and then there is a remaining
-                          word available at the end.  */
-                       plt_offset = (htab->plt_initial_entry_size
-                                     + (htab->plt_slot_size
-                                        * ((s->size
-                                            - htab->plt_initial_entry_size)
-                                           / htab->plt_entry_size)));
-
-                       /* If this symbol is not defined in a regular
-                          file, and we are not generating a shared
-                          library, then set the symbol to this location
-                          in the .plt.  This is to avoid text
-                          relocations, and is required to make
-                          function pointers compare as equal between
-                          the normal executable and the shared library.  */
-                       if (! bfd_link_pic (info)
-                           && h->def_dynamic
-                           && !h->def_regular)
-                         {
-                           h->root.u.def.section = s;
-                           h->root.u.def.value = plt_offset;
-                         }
-
-                       /* Make room for this entry.  */
-                       s->size += htab->plt_entry_size;
-                       /* After the 8192nd entry, room for two entries
-                          is allocated.  */
-                       if (htab->plt_type == PLT_OLD
-                           && (s->size - htab->plt_initial_entry_size)
-                               / htab->plt_entry_size
-                              > PLT_NUM_SINGLE_ENTRIES)
-                         s->size += htab->plt_entry_size;
-                     }
-                   ent->plt.offset = plt_offset;
-                 }
-
-               /* We also need to make an entry in the .rela.plt section.  */
-               if (!doneone)
-                 {
-                   if (!htab->elf.dynamic_sections_created
-                       || h->dynindx == -1)
-                     htab->elf.irelplt->size += sizeof (Elf32_External_Rela);
-                   else
-                     {
-                       htab->elf.srelplt->size += sizeof (Elf32_External_Rela);
-
-                       if (htab->plt_type == PLT_VXWORKS)
-                         {
-                           /* Allocate space for the unloaded relocations.  */
-                           if (!bfd_link_pic (info)
-                               && htab->elf.dynamic_sections_created)
-                             {
-                               if (ent->plt.offset
-                                   == (bfd_vma) htab->plt_initial_entry_size)
-                                 {
-                                   htab->srelplt2->size
-                                     += (sizeof (Elf32_External_Rela)
-                                         * VXWORKS_PLTRESOLVE_RELOCS);
-                                 }
-
-                               htab->srelplt2->size
-                                 += (sizeof (Elf32_External_Rela)
-                                     * VXWORKS_PLT_NON_JMP_SLOT_RELOCS);
-                             }
-
-                           /* Every PLT entry has an associated GOT entry in
-                              .got.plt.  */
-                           htab->elf.sgotplt->size += 4;
-                         }
-                     }
-                   doneone = TRUE;
-                 }
-             }
-           else
-             ent->plt.offset = (bfd_vma) -1;
-         }
-       else
-         ent->plt.offset = (bfd_vma) -1;
-
-      if (!doneone)
-       {
-         h->plt.plist = NULL;
-         h->needs_plt = 0;
-       }
-    }
-  else
-    {
-      h->plt.plist = NULL;
-      h->needs_plt = 0;
-    }
-
   eh = (struct ppc_elf_link_hash_entry *) h;
   if (eh->elf.got.refcount > 0
       || (ELIMINATE_COPY_RELOCS
@@ -6112,18 +5957,12 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
          && eh->has_addr16_lo
          && htab->params->pic_fixup > 0))
     {
-      bfd_boolean dyn;
       unsigned int need;
 
-      /* Make sure this symbol is output as a dynamic symbol.  */
-      if (eh->elf.dynindx == -1
-         && !eh->elf.forced_local
-         && eh->elf.type != STT_GNU_IFUNC
-         && htab->elf.dynamic_sections_created)
-       {
-         if (!bfd_elf_link_record_dynamic_symbol (info, &eh->elf))
-           return FALSE;
-       }
+      /* Make sure this symbol is output as a dynamic symbol.
+        Undefined weak syms won't yet be marked as dynamic.  */
+      if (!ensure_undefweak_dynamic (info, &eh->elf))
+       return FALSE;
 
       need = 0;
       if ((eh->tls_mask & TLS_TLS) != 0)
@@ -6152,9 +5991,10 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
       else
        {
          eh->elf.got.offset = allocate_got (htab, need);
-         dyn = htab->elf.dynamic_sections_created;
          if ((bfd_link_pic (info)
-              || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, &eh->elf))
+              || (htab->elf.dynamic_sections_created
+                  && eh->elf.dynindx != -1
+                  && !SYMBOL_REFERENCES_LOCAL (info, &eh->elf)))
              && (ELF_ST_VISIBILITY (eh->elf.other) == STV_DEFAULT
                  || eh->elf.root.type != bfd_link_hash_undefweak))
            {
@@ -6174,17 +6014,19 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
   else
     eh->elf.got.offset = (bfd_vma) -1;
 
-  if (eh->dyn_relocs == NULL
-      || !htab->elf.dynamic_sections_created)
-    return TRUE;
+  if (!htab->elf.dynamic_sections_created
+      && h->type != STT_GNU_IFUNC)
+    eh->dyn_relocs = NULL;
+
+  if (eh->dyn_relocs == NULL)
+    ;
 
   /* In the shared -Bsymbolic case, discard space allocated for
      dynamic pc-relative relocs against symbols which turn out to be
      defined in regular objects.  For the normal shared case, discard
      space for relocs that have become local due to symbol visibility
      changes.  */
-
-  if (bfd_link_pic (info))
+  else if (bfd_link_pic (info))
     {
       /* Relocs that use pc_count are those that appear on a call insn,
         or certain REL relocs (see must_be_dyn_reloc) that can be
@@ -6237,21 +6079,15 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 
          /* Make sure undefined weak symbols are output as a dynamic
             symbol in PIEs.  */
-         else if (h->dynindx == -1
-                  && !h->forced_local
-                  && !h->def_regular)
-           {
-             if (! bfd_elf_link_record_dynamic_symbol (info, h))
-               return FALSE;
-           }
+         else if (!ensure_undefweak_dynamic (info, h))
+           return FALSE;
        }
     }
   else if (ELIMINATE_COPY_RELOCS)
     {
-      /* For the non-shared case, discard space for relocs against
+      /* For the non-pic case, discard space for relocs against
         symbols which turn out to need copy relocs or are not
         dynamic.  */
-
       if (!h->non_got_ref
          && !h->def_regular
          && !(h->protected_def
@@ -6261,25 +6097,17 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
        {
          /* Make sure this symbol is output as a dynamic symbol.
             Undefined weak syms won't yet be marked as dynamic.  */
-         if (h->dynindx == -1
-             && !h->forced_local)
-           {
-             if (! bfd_elf_link_record_dynamic_symbol (info, h))
-               return FALSE;
-           }
+         if (!ensure_undefweak_dynamic (info, h))
+           return FALSE;
 
-         /* If that succeeded, we know we'll be keeping all the
-            relocs.  */
-         if (h->dynindx != -1)
-           goto keep;
+         if (h->dynindx == -1)
+           eh->dyn_relocs = NULL;
        }
-
-      eh->dyn_relocs = NULL;
-
-    keep: ;
+      else
+       eh->dyn_relocs = NULL;
     }
 
-  /* Finally, allocate space.  */
+  /* Allocate space.  */
   for (p = eh->dyn_relocs; p != NULL; p = p->next)
     {
       asection *sreloc = elf_section_data (p->sec)->sreloc;
@@ -6288,6 +6116,152 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
       sreloc->size += p->count * sizeof (Elf32_External_Rela);
     }
 
+  /* Handle PLT relocs.  Done last, after dynindx has settled.  */
+  dyn = htab->elf.dynamic_sections_created && h->dynindx != -1;
+  if (dyn || h->type == STT_GNU_IFUNC)
+    {
+      struct plt_entry *ent;
+      bfd_boolean doneone = FALSE;
+      bfd_vma plt_offset = 0, glink_offset = 0;
+
+      for (ent = h->plt.plist; ent != NULL; ent = ent->next)
+       if (ent->plt.refcount > 0)
+         {
+           asection *s = htab->elf.splt;
+
+           if (!dyn)
+             s = htab->elf.iplt;
+
+           if (htab->plt_type == PLT_NEW || !dyn)
+             {
+               if (!doneone)
+                 {
+                   plt_offset = s->size;
+                   s->size += 4;
+                 }
+               ent->plt.offset = plt_offset;
+
+               s = htab->glink;
+               if (!doneone || bfd_link_pic (info))
+                 {
+                   glink_offset = s->size;
+                   s->size += GLINK_ENTRY_SIZE;
+                   if (h == htab->tls_get_addr
+                       && !htab->params->no_tls_get_addr_opt)
+                     s->size += TLS_GET_ADDR_GLINK_SIZE - GLINK_ENTRY_SIZE;
+                 }
+               if (!doneone
+                   && !bfd_link_pic (info)
+                   && h->def_dynamic
+                   && !h->def_regular)
+                 {
+                   h->root.u.def.section = s;
+                   h->root.u.def.value = glink_offset;
+                 }
+               ent->glink_offset = glink_offset;
+
+               if (htab->params->emit_stub_syms
+                   && !add_stub_sym (ent, h, info))
+                 return FALSE;
+             }
+           else
+             {
+               if (!doneone)
+                 {
+                   /* If this is the first .plt entry, make room
+                      for the special first entry.  */
+                   if (s->size == 0)
+                     s->size += htab->plt_initial_entry_size;
+
+                   /* The PowerPC PLT is actually composed of two
+                      parts, the first part is 2 words (for a load
+                      and a jump), and then there is a remaining
+                      word available at the end.  */
+                   plt_offset = (htab->plt_initial_entry_size
+                                 + (htab->plt_slot_size
+                                    * ((s->size
+                                        - htab->plt_initial_entry_size)
+                                       / htab->plt_entry_size)));
+
+                   /* If this symbol is not defined in a regular
+                      file, and we are not generating a shared
+                      library, then set the symbol to this location
+                      in the .plt.  This is to avoid text
+                      relocations, and is required to make
+                      function pointers compare as equal between
+                      the normal executable and the shared library.  */
+                   if (! bfd_link_pic (info)
+                       && h->def_dynamic
+                       && !h->def_regular)
+                     {
+                       h->root.u.def.section = s;
+                       h->root.u.def.value = plt_offset;
+                     }
+
+                   /* Make room for this entry.  */
+                   s->size += htab->plt_entry_size;
+                   /* After the 8192nd entry, room for two entries
+                      is allocated.  */
+                   if (htab->plt_type == PLT_OLD
+                       && (s->size - htab->plt_initial_entry_size)
+                       / htab->plt_entry_size
+                       > PLT_NUM_SINGLE_ENTRIES)
+                     s->size += htab->plt_entry_size;
+                 }
+               ent->plt.offset = plt_offset;
+             }
+
+           /* We also need to make an entry in the .rela.plt section.  */
+           if (!doneone)
+             {
+               if (!dyn)
+                 htab->elf.irelplt->size += sizeof (Elf32_External_Rela);
+               else
+                 {
+                   htab->elf.srelplt->size += sizeof (Elf32_External_Rela);
+
+                   if (htab->plt_type == PLT_VXWORKS)
+                     {
+                       /* Allocate space for the unloaded relocations.  */
+                       if (!bfd_link_pic (info)
+                           && htab->elf.dynamic_sections_created)
+                         {
+                           if (ent->plt.offset
+                               == (bfd_vma) htab->plt_initial_entry_size)
+                             {
+                               htab->srelplt2->size
+                                 += (sizeof (Elf32_External_Rela)
+                                     * VXWORKS_PLTRESOLVE_RELOCS);
+                             }
+
+                           htab->srelplt2->size
+                             += (sizeof (Elf32_External_Rela)
+                                 * VXWORKS_PLT_NON_JMP_SLOT_RELOCS);
+                         }
+
+                       /* Every PLT entry has an associated GOT entry in
+                          .got.plt.  */
+                       htab->elf.sgotplt->size += 4;
+                     }
+                 }
+               doneone = TRUE;
+             }
+         }
+       else
+         ent->plt.offset = (bfd_vma) -1;
+
+      if (!doneone)
+       {
+         h->plt.plist = NULL;
+         h->needs_plt = 0;
+       }
+    }
+  else
+    {
+      h->plt.plist = NULL;
+      h->needs_plt = 0;
+    }
+
   return TRUE;
 }
 
@@ -8502,11 +8476,11 @@ ppc_elf_relocate_section (bfd *output_bfd,
              offp = &htab->tlsld_got.offset;
            else if (h != NULL)
              {
-               bfd_boolean dyn;
-               dyn = htab->elf.dynamic_sections_created;
-               if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info), h)
-                   || (bfd_link_pic (info)
-                       && SYMBOL_REFERENCES_LOCAL (info, h)))
+               if (!htab->elf.dynamic_sections_created
+                   || h->dynindx == -1
+                   || SYMBOL_REFERENCES_LOCAL (info, h)
+                   || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+                       && h->root.type == bfd_link_hash_undefweak))
                  /* 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
@@ -8514,7 +8488,6 @@ ppc_elf_relocate_section (bfd *output_bfd,
                  ;
                else
                  {
-                   BFD_ASSERT (h->dynindx != -1);
                    indx = h->dynindx;
                    unresolved_reloc = FALSE;
                  }
@@ -8573,11 +8546,12 @@ ppc_elf_relocate_section (bfd *output_bfd,
                      }
 
                    /* Generate relocs for the dynamic linker.  */
-                   if ((bfd_link_pic (info) || indx != 0)
-                       && (offp == &htab->tlsld_got.offset
-                           || h == NULL
-                           || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
-                           || h->root.type != bfd_link_hash_undefweak))
+                   if (indx != 0
+                       || (bfd_link_pic (info)
+                           && (h == NULL
+                               || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                               || h->root.type != bfd_link_hash_undefweak
+                               || offp == &htab->tlsld_got.offset)))
                      {
                        asection *rsec = htab->elf.srelgot;
                        bfd_byte * loc;
@@ -8635,25 +8609,31 @@ ppc_elf_relocate_section (bfd *output_bfd,
                    else
                      {
                        bfd_vma value = relocation;
+                       int tlsopt = (htab->plt_type == PLT_NEW
+                                     && !htab->params->no_tls_get_addr_opt
+                                     && htab->tls_get_addr != NULL
+                                     && htab->tls_get_addr->plt.plist != NULL);
 
-                       if (tls_ty == (TLS_TLS | TLS_LD))
-                         value = 1;
-                       else if (tls_ty != 0)
+                       if (tls_ty != 0)
                          {
                            if (htab->elf.tls_sec == NULL)
                              value = 0;
                            else
                              {
-                               value -= htab->elf.tls_sec->vma + DTP_OFFSET;
-                               if (tls_ty == (TLS_TLS | TLS_TPREL))
+                               if (tls_ty & TLS_LD)
+                                 value = 0;
+                               else
+                                 value -= htab->elf.tls_sec->vma + DTP_OFFSET;
+                               if ((tls_ty & TLS_TPREL)
+                                   || (tlsopt && !(tls_ty & TLS_DTPREL)))
                                  value += DTP_OFFSET - TP_OFFSET;
                              }
 
-                           if (tls_ty == (TLS_TLS | TLS_GD))
+                           if (tls_ty & (TLS_LD | TLS_GD))
                              {
                                bfd_put_32 (input_bfd, value,
                                            htab->elf.sgot->contents + off + 4);
-                               value = 1;
+                               value = !tlsopt;
                              }
                          }
                        bfd_put_32 (input_bfd, value,
@@ -8987,17 +8967,43 @@ ppc_elf_relocate_section (bfd *output_bfd,
              if (skip == -1)
                goto copy_reloc;
 
-             /* This reloc will be computed at runtime.  We clear the memory
-                so that it contains predictable value.  */
-             if (! skip
-                 && ((input_section->flags & SEC_ALLOC) != 0
-                     || ELF32_R_TYPE (outrel.r_info) != R_PPC_RELATIVE))
+             /* This reloc will be computed at runtime.  Clear the memory
+                so that it contains a predictable value for prelink.  */
+             if (!skip)
                {
                  relocation = howto->pc_relative ? outrel.r_offset : 0;
                  addend = 0;
                  break;
                }
            }
+         else if (r_type == R_PPC_DTPMOD32
+                  && htab->plt_type == PLT_NEW
+                  && !htab->params->no_tls_get_addr_opt
+                  && htab->tls_get_addr != NULL
+                  && htab->tls_get_addr->plt.plist != NULL)
+           {
+             /* Set up for __tls_get_addr_opt stub when this entry
+                does not have dynamic relocs.  */
+             relocation = 0;
+             /* Set up the next word for local dynamic.  If it turns
+                out to be global dynamic, the reloc will overwrite
+                this value.  */
+             if (rel->r_offset + 8 <= input_section->size)
+               bfd_put_32 (input_bfd, DTP_OFFSET - TP_OFFSET,
+                           contents + rel->r_offset + 4);
+           }
+         else if (r_type == R_PPC_DTPREL32
+                  && htab->plt_type == PLT_NEW
+                  && !htab->params->no_tls_get_addr_opt
+                  && htab->tls_get_addr != NULL
+                  && htab->tls_get_addr->plt.plist != NULL
+                  && rel > relocs
+                  && rel[-1].r_info == ELF32_R_INFO (r_symndx, R_PPC_DTPMOD32)
+                  && rel[-1].r_offset + 4 == rel->r_offset)
+           {
+             /* __tls_get_addr_opt stub value.  */
+             addend += DTP_OFFSET - TP_OFFSET;
+           }
          break;
 
        case R_PPC_RELAX_PLT:
index e038bbf..1e9429c 100644 (file)
@@ -9597,7 +9597,6 @@ allocate_got (struct elf_link_hash_entry *h,
              struct got_entry *gent)
 {
   struct ppc_link_hash_table *htab = ppc_hash_table (info);
-  bfd_boolean dyn;
   struct ppc_link_hash_entry *eh = (struct ppc_link_hash_entry *) h;
   int entsize = (gent->tls_type & eh->tls_mask & (TLS_GD | TLS_LD)
                 ? 16 : 8);
@@ -9608,14 +9607,15 @@ allocate_got (struct elf_link_hash_entry *h,
   gent->got.offset = got->size;
   got->size += entsize;
 
-  dyn = htab->elf.dynamic_sections_created;
   if (h->type == STT_GNU_IFUNC)
     {
       htab->elf.irelplt->size += rentsize;
       htab->got_reli_size += rentsize;
     }
   else if ((bfd_link_pic (info)
-           || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))
+           || (htab->elf.dynamic_sections_created
+               && h->dynindx != -1
+               && !SYMBOL_REFERENCES_LOCAL (info, h)))
           && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
               || h->root.type != bfd_link_hash_undefweak))
     {
@@ -9644,6 +9644,23 @@ merge_got_entries (struct got_entry **pent)
          }
 }
 
+/* If H is undefined weak, make it dynamic if that makes sense.  */
+
+static bfd_boolean
+ensure_undefweak_dynamic (struct bfd_link_info *info,
+                         struct elf_link_hash_entry *h)
+{
+  struct elf_link_hash_table *htab = elf_hash_table (info);
+
+  if (htab->dynamic_sections_created
+      && h->root.type == bfd_link_hash_undefweak
+      && h->dynindx == -1
+      && !h->forced_local
+      && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
+    return bfd_elf_link_record_dynamic_symbol (info, h);
+  return TRUE;
+}
+
 /* Allocate space in .plt, .got and associated reloc sections for
    dynamic relocs.  */
 
@@ -9716,16 +9733,9 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
     if (!gent->is_indirect)
       {
        /* Make sure this symbol is output as a dynamic symbol.
-          Undefined weak syms won't yet be marked as dynamic,
-          nor will all TLS symbols.  */
-       if (h->dynindx == -1
-           && !h->forced_local
-           && h->type != STT_GNU_IFUNC
-           && htab->elf.dynamic_sections_created)
-         {
-           if (! bfd_elf_link_record_dynamic_symbol (info, h))
-             return FALSE;
-         }
+          Undefined weak syms won't yet be marked as dynamic.  */
+       if (!ensure_undefweak_dynamic (info, h))
+         return FALSE;
 
        if (!is_ppc64_elf (gent->owner))
          abort ();
@@ -9779,12 +9789,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 
              /* Make sure this symbol is output as a dynamic symbol.
                 Undefined weak syms won't yet be marked as dynamic.  */
-             else if (h->dynindx == -1
-                      && !h->forced_local)
-               {
-                 if (! bfd_elf_link_record_dynamic_symbol (info, h))
-                   return FALSE;
-               }
+             else if (!ensure_undefweak_dynamic (info, h))
+               return FALSE;
            }
        }
       else if (h->type == STT_GNU_IFUNC)
@@ -9815,20 +9821,18 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
          /* For the non-pic case, discard space for relocs against
             symbols which turn out to need copy relocs or are not
             dynamic.  */
+         if (!h->non_got_ref
+             && !h->def_regular)
+           {
+             /* Make sure this symbol is output as a dynamic symbol.
+                Undefined weak syms won't yet be marked as dynamic.  */
+             if (!ensure_undefweak_dynamic (info, h))
+               return FALSE;
 
-         /* First make sure this symbol is output as a dynamic symbol.
-            Undefined weak syms won't yet be marked as dynamic.  */
-         if (h->root.type == bfd_link_hash_undefweak
-             && !h->non_got_ref
-             && !h->def_regular
-             && h->dynindx == -1
-             && !h->forced_local
-             && !bfd_elf_link_record_dynamic_symbol (info, h))
-           return FALSE;
-
-         if (h->non_got_ref
-             || h->def_regular
-             || h->dynindx == -1)
+             if (h->dynindx == -1)
+               eh->dyn_relocs = NULL;
+           }
+         else
            eh->dyn_relocs = NULL;
        }
 
@@ -9843,8 +9847,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
     }
 
   if ((htab->elf.dynamic_sections_created
-       && h->dynindx != -1
-       && WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, bfd_link_pic (info), h))
+       && h->dynindx != -1)
       || h->type == STT_GNU_IFUNC)
     {
       struct plt_entry *pent;
@@ -14405,14 +14408,13 @@ ppc64_elf_relocate_section (bfd *output_bfd,
              ent = ppc64_tlsld_got (input_bfd);
            else
              {
-
                if (h != NULL)
                  {
-                   bfd_boolean dyn = htab->elf.dynamic_sections_created;
-                   if (!WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info),
-                                                         &h->elf)
-                       || (bfd_link_pic (info)
-                           && SYMBOL_REFERENCES_LOCAL (info, &h->elf)))
+                   if (!htab->elf.dynamic_sections_created
+                       || h->elf.dynindx == -1
+                       || SYMBOL_REFERENCES_LOCAL (info, &h->elf)
+                       || (ELF_ST_VISIBILITY (h->elf.other) != STV_DEFAULT
+                           && h->elf.root.type == bfd_link_hash_undefweak))
                      /* 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
@@ -14420,7 +14422,6 @@ ppc64_elf_relocate_section (bfd *output_bfd,
                      ;
                    else
                      {
-                       BFD_ASSERT (h->elf.dynindx != -1);
                        indx = h->elf.dynindx;
                        unresolved_reloc = FALSE;
                      }
@@ -14470,12 +14471,14 @@ ppc64_elf_relocate_section (bfd *output_bfd,
                         : ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC);
                if (ifunc)
                  relgot = htab->elf.irelplt;
-               else if ((bfd_link_pic (info) || indx != 0)
-                        && (h == NULL
-                            || (tls_type == (TLS_TLS | TLS_LD)
-                                && !h->elf.def_dynamic)
-                            || ELF_ST_VISIBILITY (h->elf.other) == STV_DEFAULT
-                            || h->elf.root.type != bfd_link_hash_undefweak))
+               else if (indx != 0
+                        || (bfd_link_pic (info)
+                            && (h == NULL
+                                || (ELF_ST_VISIBILITY (h->elf.other)
+                                    == STV_DEFAULT)
+                                || h->elf.root.type != bfd_link_hash_undefweak
+                                || (tls_type == (TLS_TLS | TLS_LD)
+                                    && !h->elf.def_dynamic))))
                  relgot = ppc64_elf_tdata (ent->owner)->relgot;
                if (relgot != NULL)
                  {
@@ -14541,28 +14544,34 @@ ppc64_elf_relocate_section (bfd *output_bfd,
                   emitting a reloc.  */
                else
                  {
+                   int tlsopt
+                     = (htab->params->tls_get_addr_opt
+                        && htab->tls_get_addr_fd != NULL
+                        && htab->tls_get_addr_fd->elf.plt.plist != NULL);
+
                    relocation += addend;
-                   if (tls_type == (TLS_TLS | TLS_LD))
-                     relocation = 1;
-                   else if (tls_type != 0)
+                   if (tls_type != 0)
                      {
                        if (htab->elf.tls_sec == NULL)
                          relocation = 0;
                        else
                          {
-                           relocation -= htab->elf.tls_sec->vma + DTP_OFFSET;
-                           if (tls_type == (TLS_TLS | TLS_TPREL))
+                           if (tls_type & TLS_LD)
+                             relocation = 0;
+                           else
+                             relocation -= htab->elf.tls_sec->vma + DTP_OFFSET;
+                           if ((tls_type & TLS_TPREL)
+                               || (tlsopt && !(tls_type & TLS_DTPREL)))
                              relocation += DTP_OFFSET - TP_OFFSET;
                          }
 
-                       if (tls_type == (TLS_TLS | TLS_GD))
+                       if (tls_type & (TLS_GD | TLS_LD))
                          {
                            bfd_put_64 (output_bfd, relocation,
                                        got->contents + off + 8);
-                           relocation = 1;
+                           relocation = !tlsopt;
                          }
                      }
-
                    bfd_put_64 (output_bfd, relocation,
                                got->contents + off);
                  }
@@ -14957,11 +14966,35 @@ ppc64_elf_relocate_section (bfd *output_bfd,
                    addend = outrel.r_addend;
                  /* Adjust pc_relative relocs to have zero in *r_offset.  */
                  else if (ppc64_elf_howto_table[r_type]->pc_relative)
-                   addend = (input_section->output_section->vma
-                             + input_section->output_offset
-                             + rel->r_offset);
+                   addend = outrel.r_offset;
                }
            }
+         else if (r_type == R_PPC64_DTPMOD64
+                  && htab->params->tls_get_addr_opt
+                  && htab->tls_get_addr_fd != NULL
+                  && htab->tls_get_addr_fd->elf.plt.plist != NULL)
+           {
+             /* Set up for __tls_get_addr_opt stub, when this entry
+                does not have dynamic relocs.  */
+             relocation = 0;
+             /* Set up the next word for local dynamic.  If it turns
+                out to be global dynamic, the reloc will overwrite
+                this value.  */
+             if (rel->r_offset + 16 <= input_section->size)
+               bfd_put_64 (input_bfd, DTP_OFFSET - TP_OFFSET,
+                           contents + rel->r_offset + 8);
+           }
+         else if (r_type == R_PPC64_DTPREL64
+                  && htab->params->tls_get_addr_opt
+                  && htab->tls_get_addr_fd != NULL
+                  && htab->tls_get_addr_fd->elf.plt.plist != NULL
+                  && rel > relocs
+                  && rel[-1].r_info == ELF64_R_INFO (r_symndx, R_PPC64_DTPMOD64)
+                  && rel[-1].r_offset + 8 == rel->r_offset)
+           {
+             /* __tls_get_addr_opt stub value.  */
+             addend += DTP_OFFSET - TP_OFFSET;
+           }
          break;
 
        case R_PPC64_COPY:
index cf1d670..f2566a2 100644 (file)
@@ -1,3 +1,10 @@
+2017-01-24  Alan Modra  <amodra@gmail.com>
+
+       * testsuite/ld-powerpc/tlsexe.r: Update for fewer dynamic relocs
+       and symbols.
+       * testsuite/ld-powerpc/tlsexe.d: Likewise.
+       * testsuite/ld-powerpc/tlsexe.g: Likewise.
+
 2017-01-23  Yury Norov  <ynorov@caviumnetworks.com>
 
        * testsuite/ld-aarch64/aarch64-elf.exp: Run new tests.
index 5a449f7..b536622 100644 (file)
@@ -67,8 +67,8 @@ Disassembly of section \.text:
 .*     (e9 4d 90 2a|2a 90 4d e9)       lwa     r10,-28632\(r13\)
 .*     (3d 2d 00 00|00 00 2d 3d)       addis   r9,r13,0
 .*     (a9 49 90 30|30 90 49 a9)       lha     r10,-28624\(r9\)
-.*     (00 00 00 00|e0 02 01 00) .*
-.*     (00 01 02 e0|00 00 00 00) .*
+.*     (00 00 00 00|20 02 01 00) .*
+.*     (00 01 02 20|00 00 00 00) .*
 .* <__glink_PLTresolve>:
 .*     (7d 88 02 a6|a6 02 88 7d)       mflr    r12
 .*     (42 9f 00 05|05 00 9f 42)       bcl     20,4\*cr7\+so,.*
index 8c15244..8bb3dea 100644 (file)
@@ -7,6 +7,6 @@
 .*
 
 Contents of section \.got:
- 10010700 (00000000|00870110) (10018700|00000000) (ffffffff|1880ffff) (ffff8018|ffffffff)  .*
-.* 00000000 00000000 00000000 00000000  .*
+ 10010600 (00000000|00860110) (10018600|00000000) (ffffffff|1880ffff) (ffff8018|ffffffff)  .*
 .* 00000000 00000000 00000000 00000000  .*
+.* 00000000 00000000 (ffffffff|5080ffff) (ffff8050|ffffffff)  .*
index 11da4a8..f51b17e 100644 (file)
@@ -51,11 +51,10 @@ Program Headers:
  +04 +\.dynamic *
  +05 +\.tdata \.tbss *
 
-Relocation section '\.rela\.dyn' at offset .* contains 3 entries:
+Relocation section '\.rela\.dyn' at offset .* contains 2 entries:
  +Offset +Info +Type +Symbol's Value +Symbol's Name \+ Addend
 [0-9a-f ]+R_PPC64_TPREL64 +0+ gd \+ 0
 [0-9a-f ]+R_PPC64_DTPMOD64 +0+ ld \+ 0
-[0-9a-f ]+R_PPC64_DTPREL64 +0+50 ld2 \+ 0
 
 Relocation section '\.rela\.plt' at offset .* contains 1 entries:
  +Offset +Info +Type +Symbol's Value +Symbol's Name \+ Addend
@@ -66,7 +65,6 @@ Symbol table '\.dynsym' contains [0-9]+ entries:
 .* NOTYPE +LOCAL +DEFAULT +UND *
 .* TLS +GLOBAL +DEFAULT +UND gd
 .* TLS +GLOBAL +DEFAULT +UND ld
-.* TLS +GLOBAL +DEFAULT +9 ld2
 .* NOTYPE +GLOBAL +DEFAULT +13 __bss_start
 .* FUNC +GLOBAL +DEFAULT +UND __tls_get_addr_opt
 .* NOTYPE +GLOBAL +DEFAULT +13 _edata