1 files changed, 122 insertions, 0 deletions
diff --git a/elf/dl-libc.c b/elf/dl-libc.c
new file mode 100644
index 0000000000..afb3f2d14e
--- /dev/null
+++ b/elf/dl-libc.c
@@ -0,0 +1,122 @@
+/* Handle loading and unloading shared objects for internal libc purposes.
+   Copyright (C) 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Zack Weinberg <zack@rabi.columbia.edu>, 1999.
+
+   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 <dlfcn.h>
+#include <stdlib.h>
+#include <ldsodefs.h>
+
+/* The purpose of this file is to provide wrappers around the dynamic
+   linker error mechanism (similar to dlopen() et al in libdl) which
+   are usable from within libc.  Generally we want to throw away the
+   string that dlerror() would return and just pass back a null pointer
+   for errors.  This also lets the rest of libc not know about the error
+   handling mechanism.
+
+   Much of this code came from gconv_dl.c with slight modifications. */
+
+static int
+internal_function
+dlerror_run (void (*operate) (void *), void *args)
+{
+  char *last_errstring = NULL;
+  int result;
+
+  (void) _dl_catch_error (&last_errstring, operate, args);
+
+  result = last_errstring != NULL;
+  if (result)
+    free (last_errstring);
+
+  return result;
+}
+
+/* These functions are called by dlerror_run... */
+
+struct do_dlopen_args
+{
+  /* Argument to do_dlopen.  */
+  const char *name;
+
+  /* Return from do_dlopen.  */
+  struct link_map *map;
+};
+
+struct do_dlsym_args
+{
+  /* Arguments to do_dlsym.  */
+  struct link_map *map;
+  const char *name;
+
+  /* Return values of do_dlsym.  */
+  ElfW(Addr) loadbase;
+  const ElfW(Sym) *ref;
+};
+
+static void
+do_dlopen (void *ptr)
+{
+  struct do_dlopen_args *args = (struct do_dlopen_args *) ptr;
+  /* Open and relocate the shared object.  */
+  args->map = _dl_open (args->name, RTLD_LAZY, NULL);
+}
+
+static void
+do_dlsym (void *ptr)
+{
+  struct do_dlsym_args *args = (struct do_dlsym_args *) ptr;
+  args->ref = NULL;
+  args->loadbase = _dl_lookup_symbol (args->name, &args->ref,
+				      args->map->l_local_scope,
+				      args->map->l_name, 0);
+}
+
+static void
+do_dlclose (void *ptr)
+{
+    _dl_close ((struct link_map *) ptr);
+}
+
+/* ... and these functions call dlerror_run. */
+
+void *
+__libc_dlopen (const char *__name)
+{
+  struct do_dlopen_args args;
+  args.name = __name;
+
+  return (dlerror_run (do_dlopen, &args) ? NULL : (void *) args.map);
+}
+
+void *
+__libc_dlsym (void *__map, const char *__name)
+{
+  struct do_dlsym_args args;
+  args.map = __map;
+  args.name = __name;
+
+  return (dlerror_run (do_dlsym, &args) ? NULL
+	  : (void *) (args.loadbase + args.ref->st_value));
+}
+
+int
+__libc_dlclose (void *__map)
+{
+  return dlerror_run (do_dlclose, __map);
+}