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-rw-r--r--elf/dlvsym.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/elf/dlvsym.c b/elf/dlvsym.c
new file mode 100644
index 0000000000..5063b3ba0d
--- /dev/null
+++ b/elf/dlvsym.c
@@ -0,0 +1,72 @@
+/* Look up a symbol in a shared object loaded by `dlopen'.
+   Copyright (C) 1995, 1996, 1997 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <stddef.h>
+#include <link.h>
+#include <dlfcn.h>
+#include <setjmp.h>
+
+
+void *
+__dlvsym (void *handle, const char *name, const char *version)
+{
+  ElfW(Addr) caller = (ElfW(Addr)) __builtin_return_address (0);
+  ElfW(Addr) loadbase;
+  const ElfW(Sym) *ref = NULL;
+  void doit (void)
+    {
+      if (handle == NULL)
+	/* Search the global scope.  */
+	loadbase = _dl_lookup_versioned_symbol
+	  (name, &ref, &(_dl_global_scope ?: _dl_default_scope)[2], NULL,
+	   version, 0);
+      else if (handle == RTLD_NEXT)
+	{
+	  struct link_map *l, *match;
+
+	  /* Find the highest-addressed object that CALLER is not below.  */
+	  match = NULL;
+	  for (l = _dl_loaded; l; l = l->l_next)
+	    if (caller >= l->l_addr && (!match || match->l_addr < l->l_addr))
+	      match = l;
+
+	  if (! match)
+	    _dl_signal_error (0, NULL, _("\
+RTLD_NEXT used in code not dynamically loaded"));
+
+	  l = match;
+	  while (l->l_loader)
+	    l = l->l_loader;
+
+	  loadbase = _dl_lookup_versioned_symbol_skip
+	    (name, &ref, &_dl_loaded, NULL, version, l, 0);
+	}
+      else
+	{
+	  /* Search the scope of the given object.  */
+	  struct link_map *map = handle;
+	  struct link_map *mapscope[2] = { map, NULL };
+	  loadbase = _dl_lookup_versioned_symbol
+	    (name, &ref, mapscope, map->l_name, version, 0);
+	}
+    }
+
+  return _dlerror_run (doit) ? NULL : (void *) (loadbase + ref->st_value);
+}
+weak_alias (__dlvsym, dlvsym)