aarch64: Check UNDEFWEAK_NO_DYNAMIC_RELOC

Don't generate dynamic relocation against weak undefined symbol if it
is resolved to zero.  FIXME: UNDEFWEAK_NO_DYNAMIC_RELOC may need to be
checked in more places.

	PR ld/22269
	* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Don't
	generate dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is
	true.
	(elfNN_aarch64_allocate_dynrelocs): Discard dynamic relocations
	if UNDEFWEAK_NO_DYNAMIC_RELOC is true.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 59bfdf0..70b153b 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,14 @@
 2017-10-14  H.J. Lu  <hongjiu.lu@intel.com>
 
+       PR ld/22269
+       * elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Don't
+       generate dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is
+       true.
+       (elfNN_aarch64_allocate_dynrelocs): Discard dynamic relocations
+       if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
+
+2017-10-14  H.J. Lu  <hongjiu.lu@intel.com>
+
        * elf32-ppc.c (UNDEFWEAK_NO_DYNAMIC_RELOC): Moved to ...
        * elf-bfd.h (UNDEFWEAK_NO_DYNAMIC_RELOC): Here.
        * elf64-ppc.c (UNDEFWEAK_NO_DYNAMIC_RELOC): Removed.

diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 5fd314d..3083f3b 100644 (file)
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -4953,6 +4953,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
   bfd_boolean relative_reloc;
   asection *base_got;
   bfd_vma orig_value = value;
+  bfd_boolean resolved_to_zero;
 
   globals = elf_aarch64_hash_table (info);
 
@@ -5178,6 +5179,9 @@ bad_ifunc_reloc:
        }
     }
 
+  resolved_to_zero = (h != NULL
+                     && UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));
+
   switch (bfd_r_type)
     {
     case BFD_RELOC_AARCH64_NONE:
@@ -5196,7 +5200,8 @@ bad_ifunc_reloc:
            || globals->root.is_relocatable_executable)
           && (input_section->flags & SEC_ALLOC)
           && (h == NULL
-              || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+              || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                  && !resolved_to_zero)
               || h->root.type != bfd_link_hash_undefweak))
          /* Or we are creating an executable, we may need to keep relocations
             for symbols satisfied by a dynamic library if we manage to avoid
@@ -8287,7 +8292,8 @@ elfNN_aarch64_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
          visibility.  */
       if (eh->dyn_relocs != NULL && h->root.type == bfd_link_hash_undefweak)
        {
-         if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
+         if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+             || UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
            eh->dyn_relocs = NULL;
 
          /* Make sure undefined weak symbols are output as a dynamic