Remove all loaded objects if dlopen fails, ignoring NODELETE [BZ #20839]

This introduces a “pending NODELETE” state in the link map, which is
flipped to the persistent NODELETE state late in dlopen, via
activate_nodelete.    During initial relocation, symbol binding
records pending NODELETE state only.  dlclose ignores pending NODELETE
state.  Taken together, this results that a partially completed dlopen
is rolled back completely because new NODELETE mappings are unloaded.

Tested on x86_64-linux-gnu and i386-linux-gnu.

Change-Id: Ib2a3d86af6f92d75baca65431d74783ee0dbc292

1 files changed, 36 insertions, 0 deletions

diff --git a/elf/tst-dlopenfailmod1.c b/elf/tst-dlopenfailmod1.c
new file mode 100644
index 0000000..6ef4882
--- /dev/null
+++ b/elf/tst-dlopenfailmod1.c
@@ -0,0 +1,36 @@
+/* Module which depends on two modules: one NODELETE, one missing.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Note: Due to the missing second module, this object cannot be
+   loaded at run time.  */
+
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+
+/* Force linking against libpthread.  */
+void *pthread_create_reference = pthread_create;
+
+/* The constructor will never be executed because the module cannot be
+   loaded.  */
+static void __attribute__ ((constructor))
+init (void)
+{
+  puts ("tst-dlopenfailmod1 constructor executed");
+  _exit (1);
+}