1    :  // Copyright 2014 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // Declares HeapChecker, a class that checks a heap for corruption.
  16    :  
  17    :  #ifndef SYZYGY_AGENT_ASAN_HEAP_CHECKER_H_
  18    :  #define SYZYGY_AGENT_ASAN_HEAP_CHECKER_H_
  19    :  
  20    :  #include <vector>
  21    :  
  22    :  #include "base/logging.h"
  23    :  #include "syzygy/agent/asan/error_info.h"
  24    :  #include "syzygy/agent/common/stack_capture.h"
  25    :  
  26  m :  namespace agent {
  27  m :  namespace asan {
  28    :  
  29    :  // Forward declarations.
  30  m :  class AsanRuntime;
  31  m :  class Shadow;
  32    :  
  33    :  // A class to analyze the heap and to check if it's corrupt.
  34  m :  class HeapChecker {
  35  m :   public:
  36  m :    typedef std::vector<AsanCorruptBlockRange> CorruptRangesVector;
  37    :  
  38    :    // Constructor.
  39    :    // @param shadow The shadow memory to query.
  40  m :    explicit HeapChecker(Shadow* shadow);
  41    :  
  42    :    // Checks if the heap is corrupt and returns the information about the
  43    :    // corrupt ranges. This permanently removes all page protections as it
  44    :    // walks through memory.
  45    :    // @param corrupt_ranges Will receive the information about the corrupt
  46    :    //     ranges.
  47    :    // @returns true if the heap is corrupt, false otherwise.
  48  m :    bool IsHeapCorrupt(CorruptRangesVector* corrupt_ranges);
  49    :  
  50    :    // TODO(sebmarchand): Add a testing seam that controls the range of memory
  51    :    //     that is walked by HeapChecker to keep unittest times to something
  52    :    //     reasonable.
  53    :  
  54  m :   private:
  55    :    // Get the information about the corrupt ranges in a heap slab.
  56    :    // @param lower_bound The lower bound for this slab.
  57    :    // @param length The length of this slab.
  58    :    // @param corrupt_ranges Will receive the information about the corrupt ranges
  59    :    //     in this slab.
  60  m :    void GetCorruptRangesInSlab(const uint8_t* lower_bound,
  61  m :                                size_t length,
  62  m :                                CorruptRangesVector* corrupt_ranges);
  63    :  
  64    :    // The shadow memory that will be analyzed.
  65  m :    Shadow* shadow_;
  66    :  
  67  m :    DISALLOW_COPY_AND_ASSIGN(HeapChecker);
  68  m :  };
  69    :  
  70  m :  }  // namespace asan
  71  m :  }  // namespace agent
  72    :  
  73    :  #endif  // SYZYGY_AGENT_ASAN_HEAP_CHECKER_H_