Call _dl_open_check after relocation [BZ #24259]

This is a workaround for [BZ #20839] which doesn't remove the NODELETE
object when _dl_open_check throws an exception.  Move it after relocation
in dl_open_worker to avoid leaving the NODELETE object mapped without
relocation.

	[BZ #24259]
	* elf/dl-open.c (dl_open_worker): Call _dl_open_check after
	relocation.
	* sysdeps/x86/Makefile (tests): Add tst-cet-legacy-5a,
	tst-cet-legacy-5b, tst-cet-legacy-6a and tst-cet-legacy-6b.
	(modules-names): Add tst-cet-legacy-mod-5a, tst-cet-legacy-mod-5b,
	tst-cet-legacy-mod-5c, tst-cet-legacy-mod-6a, tst-cet-legacy-mod-6b
	and tst-cet-legacy-mod-6c.
	(CFLAGS-tst-cet-legacy-5a.c): New.
	(CFLAGS-tst-cet-legacy-5b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-5a.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-5b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-5c.c): Likewise.
	(CFLAGS-tst-cet-legacy-6a.c): Likewise.
	(CFLAGS-tst-cet-legacy-6b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-6a.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-6b.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-6c.c): Likewise.
	($(objpfx)tst-cet-legacy-5a): Likewise.
	($(objpfx)tst-cet-legacy-5a.out): Likewise.
	($(objpfx)tst-cet-legacy-mod-5a.so): Likewise.
	($(objpfx)tst-cet-legacy-mod-5b.so): Likewise.
	($(objpfx)tst-cet-legacy-5b): Likewise.
	($(objpfx)tst-cet-legacy-5b.out): Likewise.
	(tst-cet-legacy-5b-ENV): Likewise.
	($(objpfx)tst-cet-legacy-6a): Likewise.
	($(objpfx)tst-cet-legacy-6a.out): Likewise.
	($(objpfx)tst-cet-legacy-mod-6a.so): Likewise.
	($(objpfx)tst-cet-legacy-mod-6b.so): Likewise.
	($(objpfx)tst-cet-legacy-6b): Likewise.
	($(objpfx)tst-cet-legacy-6b.out): Likewise.
	(tst-cet-legacy-6b-ENV): Likewise.
	* sysdeps/x86/tst-cet-legacy-5.c: New file.
	* sysdeps/x86/tst-cet-legacy-5a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-5b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-6.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-6a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-6b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-5c.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-6c.c: Likewise.

1 files changed, 76 insertions, 0 deletions

diff --git a/sysdeps/x86/tst-cet-legacy-6.c b/sysdeps/x86/tst-cet-legacy-6.c
new file mode 100644
index 0000000000..9151225264
--- /dev/null
+++ b/sysdeps/x86/tst-cet-legacy-6.c
@@ -0,0 +1,76 @@
+/* Check compatibility of CET-enabled executable with dlopened legacy
+   shared object.
+   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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+static void
+do_test_1 (const char *modname, bool fail)
+{
+  int (*fp) (void);
+  void *h;
+
+  h = dlopen (modname, RTLD_LAZY);
+  if (h == NULL)
+    {
+      if (fail)
+	{
+	  const char *err = dlerror ();
+	  if (strstr (err, "shadow stack isn't enabled") == NULL)
+	    {
+	      printf ("incorrect dlopen '%s' error: %s\n", modname,
+		      dlerror ());
+	      exit (1);
+	    }
+
+	  return;
+	}
+
+      printf ("cannot open '%s': %s\n", modname, dlerror ());
+      exit (1);
+    }
+
+  fp = dlsym (h, "test");
+  if (fp == NULL)
+    {
+      printf ("cannot get symbol 'test': %s\n", dlerror ());
+      exit (1);
+    }
+
+  if (fp () != 0)
+    {
+      puts ("test () != 0");
+      exit (1);
+    }
+
+  dlclose (h);
+}
+
+static int
+do_test (void)
+{
+  do_test_1 ("tst-cet-legacy-mod-6a.so", true);
+  do_test_1 ("tst-cet-legacy-mod-6b.so", false);
+  return 0;
+}
+
+#include <support/test-driver.c>