ld -r abort in _bfd_elf_write_section_eh_frame

[Alan Modra]

Turning on .eh_frame processing for ld -r resulted in systemtap
tickling a ld bug.  Triggered by the zero terminator not being added
to .eh_frame in a separate file as it usually is (crtend.o), but
instead being present in the last .eh_frame section along with CIEs
and FDEs.  The 4-byte terminator makes the section size check fail
on 64-bit targets.

	* elf-eh-frame (_bfd_elf_write_section_eh_frame): Adjust section
	size check to account for possible zero terminator.

diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c
index e481f34..002932d 100644
--- a/bfd/elf-eh-frame.c
+++ b/bfd/elf-eh-frame.c
@@ -1398,6 +1398,7 @@ _bfd_elf_write_section_eh_frame (bfd *abfd,
   struct eh_frame_hdr_info *hdr_info;
   unsigned int ptr_size;
   struct eh_cie_fde *ent;
+  bfd_size_type sec_size;
 
   if (sec->sec_info_type != SEC_INFO_TYPE_EH_FRAME)
     /* FIXME: octets_per_byte.  */
@@ -1723,7 +1724,11 @@ _bfd_elf_write_section_eh_frame (bfd *abfd,
      the pointer size. _bfd_elf_discard_section_eh_frame should
      have padded CIE/FDE records to multiple of pointer size with
      size_of_output_cie_fde.  */
-  if ((sec->size % ptr_size) != 0)
+  sec_size = sec->size;
+  if (sec_info->count != 0
+      && sec_info->entry[sec_info->count - 1].size == 4)
+    sec_size -= 4;
+  if ((sec_size % ptr_size) != 0)
     abort ();
 
   /* FIXME: octets_per_byte.  */

-- 
Alan Modra
Australia Development Lab, IBM