PATCH: ld/2008: Segfault on IA64, something to do with Unwind and section ordering

[H. J. Lu]

On Mon, Dec 12, 2005 at 06:59:56AM -0800, H. J. Lu wrote:
> PR 1991 may leave bogus valus in the sh_link field, which leads to
> PR 2008 where linker will segfault. This patch bails out if the section
> which the sh_link field points to doesn't have an output section.
> 
> 

Here is an update. I moved the check from elf_get_linked_section_vma
to _bfd_elf_setup_sections.

Does anyone know why bfd_check_format_matches checks the default
target twice? This patch also removed the duplicate.



H.J.
----
2005-12-12  H.J. Lu  <hongjiu.lu@intel.com>

	PR ld/2008
	* elf.c (_bfd_elf_setup_sections): Return FALSE if
	elf_linked_to_section will be set to NULL.

	* format.c (bfd_check_format_matches): Don't check the default
	target twice.

--- bfd/elf.c.bad	2005-12-08 07:06:37.000000000 -0800
+++ bfd/elf.c	2005-12-12 11:04:26.000000000 -0800
@@ -654,8 +654,23 @@ _bfd_elf_setup_sections (bfd *abfd)
 	    }
 	  else
 	    {
+	      asection *link;
+
 	      this_hdr = elf_elfsections (abfd)[elfsec];
-	      elf_linked_to_section (s) = this_hdr->bfd_section;
+
+	      /* PR 1991, 2008:
+		 Some strip/objcopy may leave an incorrect value in
+		 sh_link.  We don't want to proceed.  */
+	      link = this_hdr->bfd_section;
+	      if (link == NULL)
+		{
+		  (*_bfd_error_handler)
+		    (_("%B: sh_link [%d] in section `%A' is incorrect"),
+		     s->owner, s, elfsec);
+		  result = FALSE;
+		}
+
+	      elf_linked_to_section (s) = link;
 	    }
 	}
     }
--- bfd/format.c.bad	2005-10-07 13:47:31.000000000 -0700
+++ bfd/format.c	2005-12-12 11:14:20.000000000 -0800
@@ -217,7 +217,9 @@ bfd_check_format_matches (bfd *abfd, bfd
       const bfd_target *temp;
       bfd_error_type err;
 
-      if (*target == &binary_vec)
+      /* Don't check the default target twice.  */
+      if (*target == &binary_vec
+	  || (!abfd->target_defaulted && *target == save_targ))
 	continue;
 
       abfd->xvec = *target;	/* Change BFD's target temporarily.  */