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    :  namespace agent {
  27    :  namespace asan {
  28    :  
  29    :  // Forward declaration.
  30    :  class AsanRuntime;
  31    :  
  32    :  // A class to analyze the heap and to check if it's corrupt.
  33    :  class HeapChecker {
  34    :   public:
  35    :    typedef std::vector<AsanCorruptBlockRange> CorruptRangesVector;
  36    :  
  37    :    // Constructor.
  38  E :    HeapChecker() { }
  39    :  
  40    :    // Checks if the heap is corrupt and returns the information about the
  41    :    // corrupt ranges. This permanently removes all page protections as it
  42    :    // walks through memory.
  43    :    // @param corrupt_ranges Will receive the information about the corrupt
  44    :    //     ranges.
  45    :    // @returns true if the heap is corrupt, false otherwise.
  46    :    bool IsHeapCorrupt(CorruptRangesVector* corrupt_ranges);
  47    :  
  48    :    // TODO(sebmarchand): Add a testing seam that controls the range of memory
  49    :    //     that is walked by HeapChecker to keep unittest times to something
  50    :    //     reasonable.
  51    :  
  52    :   private:
  53    :    // Get the information about the corrupt ranges in a heap slab.
  54    :    // @param lower_bound The lower bound for this slab.
  55    :    // @param length The length of this slab.
  56    :    // @param corrupt_ranges Will receive the information about the corrupt ranges
  57    :    //     in this slab.
  58    :    void GetCorruptRangesInSlab(const uint8* lower_bound,
  59    :                                size_t length,
  60    :                                CorruptRangesVector* corrupt_ranges);
  61    :  };
  62    :  
  63    :  }  // namespace asan
  64    :  }  // namespace agent
  65    :  
  66    :  #endif  // SYZYGY_AGENT_ASAN_HEAP_CHECKER_H_