x86/CET: Add tests with legacy non-CET shared objects

Check binary compatibility of CET-enabled executables:

1. When CET-enabled executable is used with legacy non-CET shared object
at run-time, ld.so should disable SHSTK and put legacy non-CET shared
objects in legacy bitmap.
2. When IBT-enabled executable dlopens legacy non-CET shared object,
ld.so should put legacy shared object in legacy bitmap.
3. Use GLIBC_TUNABLES=glibc.tune.x86_shstk=[on|off|permissive] to
control how SHSTK is enabled.

	* sysdeps/x86/Makefile (tests): Add tst-cet-legacy-1,
	tst-cet-legacy-2, tst-cet-legacy-2a, tst-cet-legacy-3,
	tst-cet-legacy-4, tst-cet-legacy-4a, tst-cet-legacy-4b
	and tst-cet-legacy-4c.
	(modules-names): Add tst-cet-legacy-mod-1, tst-cet-legacy-mod-2
	and tst-cet-legacy-mod-4.
	(CFLAGS-tst-cet-legacy-2.c): New.
	(CFLAGS-tst-cet-legacy-mod-1.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-2.c): Likewise.
	(CFLAGS-tst-cet-legacy-3.c): Likewise.
	(CFLAGS-tst-cet-legacy-4.c): Likewise.
	(CFLAGS-tst-cet-legacy-mod-4.c): Likewise.
	($(objpfx)tst-cet-legacy-1): Likewise.
	($(objpfx)tst-cet-legacy-2): Likewise.
	($(objpfx)tst-cet-legacy-2.out): Likewise.
	($(objpfx)tst-cet-legacy-2a): Likewise.
	($(objpfx)tst-cet-legacy-2a.out): Likewise.
	($(objpfx)tst-cet-legacy-4): Likewise.
	($(objpfx)tst-cet-legacy-4.out): Likewise.
	($(objpfx)tst-cet-legacy-4a): Likewise.
	($(objpfx)tst-cet-legacy-4a.out): Likewise.
	(tst-cet-legacy-4a-ENV): Likewise.
	($(objpfx)tst-cet-legacy-4b): Likewise.
	($(objpfx)tst-cet-legacy-4b.out): Likewise.
	(tst-cet-legacy-4b-ENV): Likewise.
	($(objpfx)tst-cet-legacy-4c): Likewise.
	($(objpfx)tst-cet-legacy-4c.out): Likewise.
	(tst-cet-legacy-4c-ENV): Likewise.
	* sysdeps/x86/tst-cet-legacy-1.c: New file.
	* sysdeps/x86/tst-cet-legacy-2.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-2a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-3.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-4.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-4a.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-4b.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-4c.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-1.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-2.c: Likewise.
	* sysdeps/x86/tst-cet-legacy-mod-4.c: Likewise.

1 files changed, 56 insertions, 0 deletions

diff --git a/sysdeps/x86/tst-cet-legacy-4.c b/sysdeps/x86/tst-cet-legacy-4.c
new file mode 100644
index 0000000000..3ead63dd24
--- /dev/null
+++ b/sysdeps/x86/tst-cet-legacy-4.c
@@ -0,0 +1,56 @@
+/* Check compatibility of CET-enabled executable with dlopened legacy
+   shared object.
+   Copyright (C) 2018 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>
+
+static int
+do_test (void)
+{
+  static const char modname[] = "tst-cet-legacy-mod-4.so";
+  int (*fp) (void);
+  void *h;
+
+  h = dlopen (modname, RTLD_LAZY);
+  if (h == NULL)
+    {
+      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);
+
+  return 0;
+}
+
+#include <support/test-driver.c>