Work around sparc glibc bug

	* elfxx-sparc.c (_bfd_sparc_elf_relocate_section): When emitting
	dynamic R_SPARC_RELATIVE for GOT entries, ensure the section
	contents are zeroed.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 7f59fa0..69ca494 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2017-12-09  Alan Modra  <amodra@gmail.com>
+
+       * elfxx-sparc.c (_bfd_sparc_elf_relocate_section): When emitting
+       dynamic R_SPARC_RELATIVE for GOT entries, ensure the section
+       contents are zeroed.
+
 2017-12-08  Nick Clifton  <nickc@redhat.com>
 
        * elfcode.h (elf_write_relocs): Check for an empty howto field.

diff --git a/bfd/elfxx-sparc.c b/bfd/elfxx-sparc.c
index adc9ed3..9885059 100644 (file)
--- a/bfd/elfxx-sparc.c
+++ b/bfd/elfxx-sparc.c
@@ -3212,10 +3212,6 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
                    off &= ~1;
                  else
                    {
-                     SPARC_ELF_PUT_WORD (htab, output_bfd, relocation,
-                                         htab->elf.sgot->contents + off);
-                     h->got.offset |= 1;
-
                      if (h->dynindx == -1
                          && !h->forced_local
                          && h->root.type != bfd_link_hash_undefweak
@@ -3225,6 +3221,10 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
                             generate R_SPARC_RELATIVE here.  */
                          relative_reloc = TRUE;
                        }
+                     else
+                       SPARC_ELF_PUT_WORD (htab, output_bfd, relocation,
+                                           htab->elf.sgot->contents + off);
+                     h->got.offset |= 1;
                    }
                }
              else
@@ -3245,12 +3245,10 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
              else
                {
                  if (bfd_link_pic (info))
-                   {
-                     relative_reloc = TRUE;
-                   }
-
-                 SPARC_ELF_PUT_WORD (htab, output_bfd, relocation,
-                                     htab->elf.sgot->contents + off);
+                   relative_reloc = TRUE;
+                 else
+                   SPARC_ELF_PUT_WORD (htab, output_bfd, relocation,
+                                       htab->elf.sgot->contents + off);
                  local_got_offsets[r_symndx] |= 1;
                }
            }
@@ -3271,8 +3269,14 @@ _bfd_sparc_elf_relocate_section (bfd *output_bfd,
              outrel.r_info = SPARC_ELF_R_INFO (htab, NULL,
                                                0, R_SPARC_RELATIVE);
              outrel.r_addend = relocation;
-             relocation = 0;
              sparc_elf_append_rela (output_bfd, s, &outrel);
+             /* Versions of glibc ld.so at least up to 2.26 wrongly
+                add the section contents to the value calculated for
+                a RELATIVE reloc.  Zero the contents to work around
+                this bug.  */
+             relocation = 0;
+             SPARC_ELF_PUT_WORD (htab, output_bfd, relocation,
+                                 htab->elf.sgot->contents + off);
            }
 
          relocation = htab->elf.sgot->output_offset + off - got_base;