Enable elf_backend_rela_normal for AArch64

  If we are generating non-relocatable object and --emit-relocs specified,
  aarch64 ld is actually generating wrong addend for rela entry when
  relocate against local symbol.

  for example, for simple testcase

  foo.c
  ===

  const char * const a = "foo";

  const char *
  foo ()
  {
    return a;
  }

  bar.c
  ===

  const char * const b = "bar";

  const char * bar ()
  {
    return b;
  }

  aarch64-none-linux-gnu-ld --emit-relocs -o x.o  foo.o bar.o
  aarch64-none-linux-gnu-readelf -r x.o

   ... R_AARCH64_ADR_PRE 0000000000400018 .rodata + 0
   ... R_AARCH64_ADD_ABS 0000000000400018 .rodata + 0
   ... R_AARCH64_ADR_PRE 0000000000400018 .rodata + 0
   ... R_AARCH64_ADD_ABS 0000000000400018 .rodata + 0

   while it should be:

   ... R_AARCH64_ADR_PRE 0000000000400018 .rodata + 0
   ... R_AARCH64_ADD_ABS 0000000000400018 .rodata + 0
   ... R_AARCH64_ADR_PRE 0000000000400018 .rodata + 10
   ... R_AARCH64_ADD_ABS 0000000000400018 .rodata + 10

   bfd generic code could actually handle this properly, but only when
   elf_backend_rela_normal set to '1'.

   this patch enable this and remove those target specific hack.

    bfd/
      * elfnn-aarch64.c (elf_backend_rela_normal): Set to 1.
      (elfNN_aarch64_relocate_section): Remove duplicated addend adjustment
      when info->relocatable be true.

    ld/testsuite/
      * ld-aarch64/emit-relocs-local-addend-bar.s: * New source file.
      * ld-aarch64/emit-relocs-local-addend-foo.s: * Likewise.
      * ld-aarch64/emit-relocs-local-addend.d: * New testcase.
      * ld-aarch64/local-addend-r.d: Likewise.

1 files changed, 2 insertions, 9 deletions

diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index a8578da..4dfb604 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -4158,15 +4158,7 @@ elfNN_aarch64_relocate_section (bfd *output_bfd,
 					 rel, 1, relend, howto, 0, contents);
 
       if (info->relocatable)
-	{
-	  /* This is a relocatable link.  We don't have to change
-	     anything, unless the reloc is against a section symbol,
-	     in which case we have to adjust according to where the
-	     section symbol winds up in the output section.  */
-	  if (sym != NULL && ELF_ST_TYPE (sym->st_info) == STT_SECTION)
-	    rel->r_addend += sec->output_offset;
-	  continue;
-	}
+	continue;
 
       if (h != NULL)
 	name = h->root.root.string;
@@ -7288,6 +7280,7 @@ const struct elf_size_info elfNN_aarch64_size_info =
 #define elf_backend_may_use_rel_p      0
 #define elf_backend_may_use_rela_p     1
 #define elf_backend_default_use_rela_p 1
+#define elf_backend_rela_normal        1
 #define elf_backend_got_header_size (GOT_ENTRY_SIZE * 3)
 #define elf_backend_default_execstack  0