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Diffstat (limited to 'dlfcn/dlvsym.c')
-rw-r--r--dlfcn/dlvsym.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/dlfcn/dlvsym.c b/dlfcn/dlvsym.c
index 62415feaac..24868456e9 100644
--- a/dlfcn/dlvsym.c
+++ b/dlfcn/dlvsym.c
@@ -1,5 +1,5 @@
 /* Look up a versioned symbol in a shared object loaded by `dlopen'.
-   Copyright (C) 1995, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1995-2000, 2004 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
@@ -20,6 +20,8 @@
 #include <dlfcn.h>
 #include <stddef.h>
 
+#include <ldsodefs.h>
+
 struct dlvsym_args
 {
   /* The arguments to dlvsym_doit.  */
@@ -51,6 +53,13 @@ __dlvsym (void *handle, const char *name, const char *version_str)
   args.who = RETURN_ADDRESS (0);
   args.version = version_str;
 
-  return (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);
+  /* Protect against concurrent loads and unloads.  */
+  __rtld_lock_lock_recursive (GL(dl_load_lock));
+
+  void *result = (_dlerror_run (dlvsym_doit, &args) ? NULL : args.sym);
+
+  __rtld_lock_unlock_recursive (GL(dl_load_lock));
+
+  return result;
 }
 weak_alias (__dlvsym, dlvsym)