1  /*
 2   * Copyright (C) 2019 Apple Inc. All rights reserved.
 3   *
 4   * Redistribution and use in source and binary forms, with or without
 5   * modification, are permitted provided that the following conditions
 6   * are met:
 7   * 1. Redistributions of source code must retain the above copyright
 8   *    notice, this list of conditions and the following disclaimer.
 9   * 2. Redistributions in binary form must reproduce the above copyright
10   *    notice, this list of conditions and the following disclaimer in the
11   *    documentation and/or other materials provided with the distribution.
12   *
13   * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24   */
25  
26  #include "config.h"
27  #include "RandomizingFuzzerAgent.h"
28  
29  #include "CodeBlock.h"
30  #include <wtf/Locker.h>
31  
32  namespace JSC {
33  
34  RandomizingFuzzerAgent::RandomizingFuzzerAgent(VM&)
35      : m_random(Options::seedOfRandomizingFuzzerAgent())
36  {
37  }
38  
39  SpeculatedType RandomizingFuzzerAgent::getPrediction(CodeBlock* codeBlock, const CodeOrigin& codeOrigin, SpeculatedType original)
40  {
41      auto locker = holdLock(m_lock);
42      uint32_t high = m_random.getUint32();
43      uint32_t low = m_random.getUint32();
44      SpeculatedType generated = static_cast<SpeculatedType>((static_cast<uint64_t>(high) << 32) | low) & SpecFullTop;
45      if (Options::dumpFuzzerAgentPredictions())
46          dataLogLn("getPrediction name:(", codeBlock->inferredName(), "#", codeBlock->hashAsStringIfPossible(), "),bytecodeIndex:(", codeOrigin.bytecodeIndex(), "),original:(", SpeculationDump(original), "),generated:(", SpeculationDump(generated), ")");
47      return generated;
48  }
49  
50  } // namespace JSC