PR26655, Power10 libstdc++.so R_PPC64_NONE dynamic relocs

Some of the powerpc64 code editing functions are better run after
dynamic symbols have stabilised in order to make proper decisions
based on SYMBOL_REFERENCES_LOCAL.  The dynamic symbols are processed
early in bfd_elf_size_dynamic_sections, before the backend
always_size_sections function is called.

One function, ppc64_elf_tls_setup must run before
bfd_elf_size_dynamic_sections because it changes dynamic symbols.
ppc64_elf_edit_opd and ppc64_elf_inline_plt can run early or late, I
think.  ppc64_elf_tls_optimize and ppc64_elf_edit_toc are better run
later.

So this patch arranges to call some edit functions later via
always_size_sections.

	PR 26655
bfd/
	* elf64-ppc.c (ppc64_elf_func_desc_adjust): Rename to..
	(ppc64_elf_edit): Call params->edit.
	(ppc64_elf_tls_setup): Don't call _bfd_elf_tls_setup.  Return a
	bfd_boolean.
	* elf64-ppc.h (struct ppc64_elf_params): Add "edit".
	(ppc64_elf_tls_setup): Update declaration.
ld/
	* emultempl/ppc64elf.em (params): Add ppc_edit.
	(ppc_before_allocation): Split off some edit functions to..
	(ppc_edit): ..this, new function.

3 files changed, 28 insertions, 12 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 608e3c7..39e5ead 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,13 @@
+2020-09-24  Alan Modra  <amodra@gmail.com>
+
+	PR 26655
+	* elf64-ppc.c (ppc64_elf_func_desc_adjust): Rename to..
+	(ppc64_elf_edit): Call params->edit.
+	(ppc64_elf_tls_setup): Don't call _bfd_elf_tls_setup.  Return a
+	bfd_boolean.
+	* elf64-ppc.h (struct ppc64_elf_params): Add "edit".
+	(ppc64_elf_tls_setup): Update declaration.
+
 2020-09-21  Alan Modra  <amodra@gmail.com>
 
 	PR 26569
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 06202c9..4d16dc3 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -114,7 +114,7 @@ static bfd_vma opd_entry_value
 #define elf_backend_adjust_dynamic_symbol     ppc64_elf_adjust_dynamic_symbol
 #define elf_backend_hide_symbol		      ppc64_elf_hide_symbol
 #define elf_backend_maybe_function_sym	      ppc64_elf_maybe_function_sym
-#define elf_backend_always_size_sections      ppc64_elf_func_desc_adjust
+#define elf_backend_always_size_sections      ppc64_elf_edit
 #define elf_backend_size_dynamic_sections     ppc64_elf_size_dynamic_sections
 #define elf_backend_hash_symbol		      ppc64_elf_hash_symbol
 #define elf_backend_init_index_section	      _bfd_elf_init_2_index_sections
@@ -6341,13 +6341,13 @@ static const struct sfpr_def_parms save_res_funcs[] =
   };
 
 /* Called near the start of bfd_elf_size_dynamic_sections.  We use
-   this hook to a) provide some gcc support functions, and b) transfer
-   dynamic linking information gathered so far on function code symbol
-   entries, to their corresponding function descriptor symbol entries.  */
+   this hook to a) run the edit functions in this file, b) provide
+   some gcc support functions, and c) transfer dynamic linking
+   information gathered so far on function code symbol entries, to
+   their corresponding function descriptor symbol entries.  */
 
 static bfd_boolean
-ppc64_elf_func_desc_adjust (bfd *obfd ATTRIBUTE_UNUSED,
-			    struct bfd_link_info *info)
+ppc64_elf_edit (bfd *obfd ATTRIBUTE_UNUSED, struct bfd_link_info *info)
 {
   struct ppc_link_hash_table *htab;
 
@@ -6355,6 +6355,9 @@ ppc64_elf_func_desc_adjust (bfd *obfd ATTRIBUTE_UNUSED,
   if (htab == NULL)
     return FALSE;
 
+  /* Call back into the linker, which then runs the edit functions.  */
+  htab->params->edit ();
+
   /* Provide any missing _save* and _rest* functions.  */
   if (htab->sfpr != NULL)
     {
@@ -7695,9 +7698,11 @@ ppc64_elf_inline_plt (struct bfd_link_info *info)
   return TRUE;
 }
 
-/* Set htab->tls_get_addr and call the generic ELF tls_setup function.  */
+/* Set htab->tls_get_addr and various other info specific to TLS.
+   This needs to run before dynamic symbols are processed in
+   bfd_elf_size_dynamic_sections.  */
 
-asection *
+bfd_boolean
 ppc64_elf_tls_setup (struct bfd_link_info *info)
 {
   struct ppc_link_hash_table *htab;
@@ -7705,7 +7710,7 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
 
   htab = ppc_hash_table (info);
   if (htab == NULL)
-    return NULL;
+    return FALSE;
 
   if (abiversion (info->output_bfd) == 1)
     htab->opd_abi = 1;
@@ -7827,7 +7832,7 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
 		      _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr,
 					      opt_fd->dynstr_index);
 		      if (!bfd_elf_link_record_dynamic_symbol (info, opt_fd))
-			return NULL;
+			return FALSE;
 		    }
 		  if (tga_fd != NULL)
 		    {
@@ -7886,7 +7891,7 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
       && htab->params->no_tls_get_addr_regsave == -1)
     htab->params->no_tls_get_addr_regsave = 0;
 
-  return _bfd_elf_tls_setup (info->output_bfd, info);
+  return TRUE;
 }
 
 /* Return TRUE iff REL is a branch reloc with a global symbol matching
diff --git a/bfd/elf64-ppc.h b/bfd/elf64-ppc.h
index a7230de..0492fd7 100644
--- a/bfd/elf64-ppc.h
+++ b/bfd/elf64-ppc.h
@@ -27,6 +27,7 @@ struct ppc64_elf_params
   /* Linker call-backs.  */
   asection * (*add_stub_section) (const char *, asection *);
   void (*layout_sections_again) (void);
+  void (*edit) (void);
 
   /* Maximum size of a group of input sections that can be handled by
      one stub section.  A value of +/-1 indicates the bfd back-end
@@ -80,7 +81,7 @@ bfd_boolean ppc64_elf_edit_opd
   (struct bfd_link_info *);
 bfd_boolean ppc64_elf_inline_plt
   (struct bfd_link_info *);
-asection *ppc64_elf_tls_setup
+bfd_boolean ppc64_elf_tls_setup
   (struct bfd_link_info *);
 bfd_boolean ppc64_elf_tls_optimize
   (struct bfd_link_info *);