dlopen: Fix issues related to NODELETE handling and relocations

The assumption behind the assert in activate_nodelete was wrong:

Inconsistency detected by ld.so: dl-open.c: 459: activate_nodelete:
Assertion `!imap->l_init_called || imap->l_type != lt_loaded' failed! (edit)

It can happen that an already-loaded object that is in the local
scope is promoted to NODELETE status, via binding to a unique
symbol.

Similarly, it is possible that such NODELETE promotion occurs to
an already-loaded object from the global scope.  This is why the
loop in activate_nodelete has to cover all objects in the namespace
of the new object.

In do_lookup_unique, it could happen that the NODELETE status of
an already-loaded object was overwritten with a pending NODELETE
status.  As a result, if dlopen fails, this could cause a loss of
the NODELETE status of the affected object, eventually resulting
in an incorrect unload.

Fixes commit f63b73814f74032c0e5d0a83300e3d864ef905e5 ("Remove all
loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]").

1 files changed, 3 insertions, 3 deletions

diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c
index a2e85a5568..99846918c3 100644
--- a/elf/dl-lookup.c
+++ b/elf/dl-lookup.c
@@ -311,12 +311,12 @@ do_lookup_unique (const char *undef_name, uint_fast32_t new_hash,
       enter_unique_sym (entries, size,
                         new_hash, strtab + sym->st_name, sym, map);
 
-      if (map->l_type == lt_loaded)
+      if (map->l_type == lt_loaded
+	  && map->l_nodelete == link_map_nodelete_inactive)
 	{
 	  /* Make sure we don't unload this object by
 	     setting the appropriate flag.  */
-	  if (__glibc_unlikely (GLRO (dl_debug_mask) & DL_DEBUG_BINDINGS)
-	      && map->l_nodelete == link_map_nodelete_inactive)
+	  if (__glibc_unlikely (GLRO (dl_debug_mask) & DL_DEBUG_BINDINGS))
 	    _dl_debug_printf ("\
 marking %s [%lu] as NODELETE due to unique symbol\n",
 			      map->l_name, map->l_ns);