[BZ #15022] Correct global-scope dlopen issues in static executables.

This change creates a link map in static executables to serve as the
global search list for dlopen.  It fixes a problem with the inability
to access the global symbol object and a crash on an attempt to map a
DSO into the global scope.  Some code that has become dead after the
addition of this link map is removed too and test cases are provided.

1 files changed, 128 insertions, 0 deletions

diff --git a/dlfcn/tststatic3.c b/dlfcn/tststatic3.c
new file mode 100644
index 0000000..8a3421e
--- /dev/null
+++ b/dlfcn/tststatic3.c
@@ -0,0 +1,128 @@
+/* Global-scope DSO mapping test with a static executable (BZ #15022).
+   Copyright (C) 2013 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 <stddef.h>
+#include <stdio.h>
+
+#define MAGIC0 0
+#define MAGIC1 0x5500ffaa
+#define MAGIC2 0xaaff0055
+
+/* Mapping a DSO into the global scope used to crash in static
+   executables.  Check that it succeeds and then that symbols from
+   the DSO can be accessed and operate as expected.  */
+static int
+do_test (void)
+{
+  unsigned int (*getfoo) (void);
+  void (*setfoo) (unsigned int);
+  unsigned int *foop;
+  unsigned int foo;
+  void *handle;
+
+  /* Try to map a module into the global scope.  */
+  handle = dlopen ("modstatic3.so", RTLD_LAZY | RTLD_GLOBAL);
+  if (handle == NULL)
+    {
+      printf ("dlopen (modstatic3.so): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Get at its symbols.  */
+  foop = dlsym (handle, "foo");
+  if (foop == NULL)
+    {
+      printf ("dlsym (foo): %s\n", dlerror ());
+      return 1;
+    }
+
+  getfoo = dlsym (handle, "getfoo");
+  if (getfoo == NULL)
+    {
+      printf ("dlsym (getfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  setfoo = dlsym (handle, "setfoo");
+  if (setfoo == NULL)
+    {
+      printf ("dlsym (setfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Make sure the view of the initial state is consistent.  */
+  foo = *foop;
+  if (foo != MAGIC0)
+    {
+      printf ("*foop: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  foo = getfoo ();
+  if (foo != MAGIC0)
+    {
+      printf ("getfoo: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  /* Likewise with one change to its state.  */
+  setfoo (MAGIC1);
+
+  foo = *foop;
+  if (foo != MAGIC1)
+    {
+      printf ("*foop: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  foo = getfoo ();
+  if (foo != MAGIC1)
+    {
+      printf ("getfoo: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  /* And with another.  */
+  setfoo (MAGIC2);
+
+  foo = *foop;
+  if (foo != MAGIC2)
+    {
+      printf ("*foop: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  foo = getfoo ();
+  if (foo != MAGIC2)
+    {
+      printf ("getfoo: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  /* All done, clean up.  */
+  getfoo = NULL;
+  setfoo = NULL;
+  foop = NULL;
+  dlclose (handle);
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"