diff -r e43050e1b17f -r e704f55561c3 hotspot/src/share/vm/classfile/systemDictionary.cpp --- a/hotspot/src/share/vm/classfile/systemDictionary.cpp Wed Aug 30 15:48:47 2017 +0200 +++ b/hotspot/src/share/vm/classfile/systemDictionary.cpp Wed Aug 30 19:18:22 2017 -0400 @@ -910,12 +910,9 @@ if (protection_domain() == NULL) return k; // Check the protection domain has the right access - { - MutexLocker mu(SystemDictionary_lock, THREAD); - if (dictionary->is_valid_protection_domain(d_index, d_hash, name, - protection_domain)) { - return k; - } + if (dictionary->is_valid_protection_domain(d_index, d_hash, name, + protection_domain)) { + return k; } // Verify protection domain. If it fails an exception is thrown