[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, 363 insertions, 0 deletions

diff --git a/dlfcn/tststatic4.c b/dlfcn/tststatic4.c
new file mode 100644
index 0000000..f6078e0
--- /dev/null
+++ b/dlfcn/tststatic4.c
@@ -0,0 +1,363 @@
+/* Global object symbol access tests 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
+#define MAGIC3 0xff55aa00
+
+/* Check the ability to access the global symbol object and then
+   global-scope symbol access consistency via different mappings
+   requested from a static executable.  */
+static int
+do_test (void)
+{
+  unsigned int (*initial_getfoo) (void);
+  void (*initial_setfoo) (unsigned int);
+  unsigned int (*global_getfoo) (void);
+  void (*global_setfoo) (unsigned int);
+  unsigned int (*local_getfoo) (void);
+  void (*local_setfoo) (unsigned int);
+  unsigned int *initial_foop;
+  unsigned int *global_foop;
+  unsigned int *local_foop;
+  void *initial_handle;
+  void *global_handle;
+  void *local_handle;
+  unsigned int foo;
+
+  /* Try to map self.  */
+  initial_handle = dlopen (NULL, RTLD_LAZY | RTLD_GLOBAL);
+  if (initial_handle == NULL)
+    {
+      printf ("dlopen [initial] (NULL): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Make sure symbol lookups fail gracefully.  */
+  initial_foop = dlsym (initial_handle, "foo");
+  if (initial_foop != NULL)
+    {
+      printf ("dlsym [initial] (foo): got %p, expected NULL\n", initial_foop);
+      return 1;
+    }
+
+  initial_getfoo = dlsym (initial_handle, "getfoo");
+  if (initial_getfoo != NULL)
+    {
+      printf ("dlsym [initial] (getfoo): got %p, expected NULL\n",
+	      initial_getfoo);
+      return 1;
+    }
+
+  initial_setfoo = dlsym (initial_handle, "setfoo");
+  if (initial_setfoo != NULL)
+    {
+      printf ("dlsym [initial] (setfoo): got %p, expected NULL\n",
+	      initial_setfoo);
+      return 1;
+    }
+
+  /* Try to map a module into the global scope.  */
+  global_handle = dlopen ("modstatic3.so", RTLD_LAZY | RTLD_GLOBAL);
+  if (global_handle == NULL)
+    {
+      printf ("dlopen [global] (modstatic3.so): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Get at its symbols.  */
+  global_foop = dlsym (global_handle, "foo");
+  if (global_foop == NULL)
+    {
+      printf ("dlsym [global] (foo): %s\n", dlerror ());
+      return 1;
+    }
+
+  global_getfoo = dlsym (global_handle, "getfoo");
+  if (global_getfoo == NULL)
+    {
+      printf ("dlsym [global] (getfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  global_setfoo = dlsym (global_handle, "setfoo");
+  if (global_setfoo == NULL)
+    {
+      printf ("dlsym [global] (setfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Try to map self again now.  */
+  local_handle = dlopen (NULL, RTLD_LAZY | RTLD_LOCAL);
+  if (local_handle == NULL)
+    {
+      printf ("dlopen [local] (NULL): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Make sure we can get at the previously loaded module's symbols
+     via this handle too.  */
+  local_foop = dlsym (local_handle, "foo");
+  if (local_foop == NULL)
+    {
+      printf ("dlsym [local] (foo): %s\n", dlerror ());
+      return 1;
+    }
+
+  local_getfoo = dlsym (local_handle, "getfoo");
+  if (local_getfoo == NULL)
+    {
+      printf ("dlsym [local] (getfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  local_setfoo = dlsym (local_handle, "setfoo");
+  if (local_setfoo == NULL)
+    {
+      printf ("dlsym [local] (setfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Make sure we can get at the previously loaded module's symbols
+     via a handle that was obtained before the module was loaded too.  */
+  initial_foop = dlsym (initial_handle, "foo");
+  if (initial_foop == NULL)
+    {
+      printf ("dlsym [initial] (foo): %s\n", dlerror ());
+      return 1;
+    }
+
+  initial_getfoo = dlsym (initial_handle, "getfoo");
+  if (initial_getfoo == NULL)
+    {
+      printf ("dlsym [initial] (getfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  initial_setfoo = dlsym (initial_handle, "setfoo");
+  if (initial_setfoo == NULL)
+    {
+      printf ("dlsym [initial] (setfoo): %s\n", dlerror ());
+      return 1;
+    }
+
+  /* Make sure the view of the initial state is consistent.  */
+  foo = *initial_foop;
+  if (foo != MAGIC0)
+    {
+      printf ("*foop [initial]: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  foo = *global_foop;
+  if (foo != MAGIC0)
+    {
+      printf ("*foop [global]: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  foo = *local_foop;
+  if (foo != MAGIC0)
+    {
+      printf ("*foop [local]: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  foo = initial_getfoo ();
+  if (foo != MAGIC0)
+    {
+      printf ("getfoo [initial]: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  foo = global_getfoo ();
+  if (foo != MAGIC0)
+    {
+      printf ("getfoo [global]: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  foo = local_getfoo ();
+  if (foo != MAGIC0)
+    {
+      printf ("getfoo [local]: got %#x, expected %#x\n", foo, MAGIC0);
+      return 1;
+    }
+
+  /* Likewise with a change to its state made through the first handle.  */
+  initial_setfoo (MAGIC1);
+
+  foo = *initial_foop;
+  if (foo != MAGIC1)
+    {
+      printf ("*foop [initial]: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  foo = *global_foop;
+  if (foo != MAGIC1)
+    {
+      printf ("*foop [global]: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  foo = *local_foop;
+  if (foo != MAGIC1)
+    {
+      printf ("*foop [local]: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  foo = initial_getfoo ();
+  if (foo != MAGIC1)
+    {
+      printf ("getfoo [initial]: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  foo = global_getfoo ();
+  if (foo != MAGIC1)
+    {
+      printf ("getfoo [global]: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  foo = local_getfoo ();
+  if (foo != MAGIC1)
+    {
+      printf ("getfoo [local]: got %#x, expected %#x\n", foo, MAGIC1);
+      return 1;
+    }
+
+  /* Likewise with a change to its state made through the second handle.  */
+  global_setfoo (MAGIC2);
+
+  foo = *initial_foop;
+  if (foo != MAGIC2)
+    {
+      printf ("*foop [initial]: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  foo = *global_foop;
+  if (foo != MAGIC2)
+    {
+      printf ("*foop [global]: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  foo = *local_foop;
+  if (foo != MAGIC2)
+    {
+      printf ("*foop [local]: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  foo = initial_getfoo ();
+  if (foo != MAGIC2)
+    {
+      printf ("getfoo [initial]: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  foo = global_getfoo ();
+  if (foo != MAGIC2)
+    {
+      printf ("getfoo [global]: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  foo = local_getfoo ();
+  if (foo != MAGIC2)
+    {
+      printf ("getfoo [local]: got %#x, expected %#x\n", foo, MAGIC2);
+      return 1;
+    }
+
+  /* Likewise with a change to its state made through the third handle.  */
+  local_setfoo (MAGIC3);
+
+  foo = *initial_foop;
+  if (foo != MAGIC3)
+    {
+      printf ("*foop [initial]: got %#x, expected %#x\n", foo, MAGIC3);
+      return 1;
+    }
+
+  foo = *global_foop;
+  if (foo != MAGIC3)
+    {
+      printf ("*foop [global]: got %#x, expected %#x\n", foo, MAGIC3);
+      return 1;
+    }
+
+  foo = *local_foop;
+  if (foo != MAGIC3)
+    {
+      printf ("*foop [local]: got %#x, expected %#x\n", foo, MAGIC3);
+      return 1;
+    }
+
+  foo = initial_getfoo ();
+  if (foo != MAGIC3)
+    {
+      printf ("getfoo [initial]: got %#x, expected %#x\n", foo, MAGIC3);
+      return 1;
+    }
+
+  foo = global_getfoo ();
+  if (foo != MAGIC3)
+    {
+      printf ("getfoo [global]: got %#x, expected %#x\n", foo, MAGIC3);
+      return 1;
+    }
+
+  foo = local_getfoo ();
+  if (foo != MAGIC3)
+    {
+      printf ("getfoo [local]: got %#x, expected %#x\n", foo, MAGIC3);
+      return 1;
+    }
+
+  /* All done, clean up.  */
+  initial_getfoo = NULL;
+  initial_setfoo = NULL;
+  initial_foop = NULL;
+
+  local_getfoo = NULL;
+  local_setfoo = NULL;
+  local_foop = NULL;
+  dlclose (local_handle);
+
+  global_getfoo = NULL;
+  global_setfoo = NULL;
+  global_foop = NULL;
+  dlclose (global_handle);
+
+  dlclose (initial_handle);
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"