Avoid confusing compiler with dynamically impossible statically invalid dereference in _dl_close_worker.

1 files changed, 13 insertions, 3 deletions

diff --git a/elf/dl-close.c b/elf/dl-close.c
index cf8f9e0..412f71d 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -641,9 +641,16 @@ _dl_close_worker (struct link_map *map)
 	  DL_UNMAP (imap);
 
 	  /* Finally, unlink the data structure and free it.  */
-	  if (imap->l_prev != NULL)
-	    imap->l_prev->l_next = imap->l_next;
-	  else
+#if DL_NNS == 1
+	  /* The assert in the (imap->l_prev == NULL) case gives
+	     the compiler license to warn that NS points outside
+	     the dl_ns array bounds in that case (as nsid != LM_ID_BASE
+	     is tantamount to nsid >= DL_NNS).  That should be impossible
+	     in this configuration, so just assert about it instead.  */
+	  assert (nsid == LM_ID_BASE);
+	  assert (imap->l_prev != NULL);
+#else
+	  if (imap->l_prev == NULL)
 	    {
 	      assert (nsid != LM_ID_BASE);
 	      ns->_ns_loaded = imap->l_next;
@@ -652,6 +659,9 @@ _dl_close_worker (struct link_map *map)
 		 we leave for debuggers to examine.  */
 	      r->r_map = (void *) ns->_ns_loaded;
 	    }
+	  else
+#endif
+	    imap->l_prev->l_next = imap->l_next;
 
 	  --ns->_ns_nloaded;
 	  if (imap->l_next != NULL)