[binutils-gdb/binutils-2_26-branch] Fix powerpc64 segfault caused by zero r_symndx relocs.

[Alan Modra <amodra at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=3c2d791fbf1b16ad661d2f2d4917166ea900a0e6

commit 3c2d791fbf1b16ad661d2f2d4917166ea900a0e6
Author: Alan Modra <amodra@gmail.com>
Date:   Wed Dec 2 18:49:53 2015 +1030

    Fix powerpc64 segfault caused by zero r_symndx relocs.
    
    Fixes a segfault in ppc64_elf_tls_optimize found when testing
    R_PPC64_ENTRY, and potential for trouble in other places found by
    code inspection.
    
    	* elf64-ppc.c (ppc64_elf_tls_optimize): Don't segfault on NULL
    	symbol section or output section.
    	(ppc64_elf_edit_toc): Similarly for ld -R objects.
    	(ppc64_elf_size_stubs): Likewise.

Diff:
---
 bfd/ChangeLog   | 6 ++++++
 bfd/elf64-ppc.c | 8 ++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 3194cc3..d3a75f5 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,6 +1,12 @@
 2015-12-10  Alan Modra  <amodra@gmail.com>
 
 	Apply from master.
+	2015-12-02  Alan Modra  <amodra@gmail.com>
+	* elf64-ppc.c (ppc64_elf_tls_optimize): Don't segfault on NULL
+	symbol section or output section.
+	(ppc64_elf_edit_toc): Similarly for ld -R objects.
+	(ppc64_elf_size_stubs): Likewise.
+
 	2015-11-20  Stefan Teleman  <stefan.teleman@oracle.com>
 	PR ld/19260
 	* cache.c (bfd_cache_max_open): Avoid using getrlimit on 32-bit
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 42356d8..9b5ebcd 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -8391,7 +8391,8 @@ ppc64_elf_tls_optimize (struct bfd_link_info *info)
 		      if (h != NULL
 			  && h->root.type == bfd_link_hash_undefweak)
 			ok_tprel = TRUE;
-		      else
+		      else if (sym_sec != NULL
+			       && sym_sec->output_section != NULL)
 			{
 			  value += sym_sec->output_offset;
 			  value += sym_sec->output_section->vma;
@@ -8952,6 +8953,7 @@ ppc64_elf_edit_toc (struct bfd_link_info *info)
 		goto error_ret;
 
 	      if (sym_sec == NULL
+		  || sym_sec->output_section == NULL
 		  || discarded_section (sym_sec))
 		continue;
 
@@ -12275,7 +12277,9 @@ ppc64_elf_size_stubs (struct bfd_link_info *info)
 		  if (hash == NULL)
 		    {
 		      sym_value = sym->st_value;
-		      ok_dest = TRUE;
+		      if (sym_sec != NULL
+			  && sym_sec->output_section != NULL)
+			ok_dest = TRUE;
 		    }
 		  else if (hash->elf.root.type == bfd_link_hash_defined
 			   || hash->elf.root.type == bfd_link_hash_defweak)