Fix GOT address computations in initial PLT entries for nios2.

2015-12-09  Sandra Loosemore  <sandra@codesourcery.com>

	bfd/
	* elf32-nios2.c (nios2_elf32_finish_dynamic_sections): Correct
	%hiadj/%lo computations for _GLOBAL_OFFSET_TABLE_ in initial
	PLT entries.  Assert alignment requirements.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 2473d6e..a306cca 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2015-12-09  Sandra Loosemore  <sandra@codesourcery.com>
+
+       * elf32-nios2.c (nios2_elf32_finish_dynamic_sections): Correct
+       %hiadj/%lo computations for _GLOBAL_OFFSET_TABLE_ in initial
+       PLT entries.  Assert alignment requirements.
+
 2015-12-08  DJ Delorie  <dj@redhat.com>
 
        * elf32-rl78.c (rl78_offset_for_reloc): Add more relocs.

diff --git a/bfd/elf32-nios2.c b/bfd/elf32-nios2.c
index 6b29d8b..1c54320 100644 (file)
--- a/bfd/elf32-nios2.c
+++ b/bfd/elf32-nios2.c
@@ -5383,12 +5383,17 @@ nios2_elf32_finish_dynamic_sections (bfd *output_bfd,
                                 + sgotplt->output_offset);
          if (bfd_link_pic (info))
            {
-             bfd_vma corrected = got_address - (splt->output_section->vma
-                                                + splt->output_offset + 4);
+             bfd_vma got_pcrel = got_address - (splt->output_section->vma
+                                                + splt->output_offset);
+             /* Both GOT and PLT must be aligned to a 16-byte boundary
+                for the two loads to share the %hiadj part.  The 4-byte
+                offset for nextpc is accounted for in the %lo offsets
+                on the loads.  */
+             BFD_ASSERT ((got_pcrel & 0xf) == 0);
              nios2_elf32_install_data (splt, nios2_so_plt0_entry, 0, 6);
-             nios2_elf32_install_imm16 (splt, 4, hiadj (corrected));
-             nios2_elf32_install_imm16 (splt, 12, (corrected & 0xffff) + 4);
-             nios2_elf32_install_imm16 (splt, 16, (corrected & 0xffff) + 8);
+             nios2_elf32_install_imm16 (splt, 4, hiadj (got_pcrel));
+             nios2_elf32_install_imm16 (splt, 12, got_pcrel & 0xffff);
+             nios2_elf32_install_imm16 (splt, 16, (got_pcrel + 4) & 0xffff);
            }
          else
            {
@@ -5404,6 +5409,10 @@ nios2_elf32_finish_dynamic_sections (bfd *output_bfd,
                            6 | ((res_size - (res_offset + 4)) << 6),
                            splt->contents + res_offset);
 
+             /* The GOT must be aligned to a 16-byte boundary for the
+                two loads to share the same %hiadj part.  */
+             BFD_ASSERT ((got_address & 0xf) == 0);
+
              nios2_elf32_install_data (splt, nios2_plt0_entry, res_size, 7);
              nios2_elf32_install_imm16 (splt, res_size, hiadj (res_start));
              nios2_elf32_install_imm16 (splt, res_size + 4,
@@ -5411,9 +5420,9 @@ nios2_elf32_finish_dynamic_sections (bfd *output_bfd,
              nios2_elf32_install_imm16 (splt, res_size + 12,
                                         hiadj (got_address));
              nios2_elf32_install_imm16 (splt, res_size + 16,
-                                        (got_address & 0xffff) + 4);
+                                        (got_address + 4) & 0xffff);
              nios2_elf32_install_imm16 (splt, res_size + 20,
-                                        (got_address & 0xffff) + 8);
+                                        (got_address + 8) & 0xffff);
            }
        }
     }