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    :  // Utility functions for working with Asan Blocks.
  16    :  
  17    :  #ifndef SYZYGY_AGENT_ASAN_BLOCK_UTILS_H_
  18    :  #define SYZYGY_AGENT_ASAN_BLOCK_UTILS_H_
  19    :  
  20    :  #include "base/logging.h"
  21    :  #include "syzygy/agent/asan/block.h"
  22    :  #include "syzygy/agent/asan/shadow.h"
  23    :  
  24    :  namespace agent {
  25    :  namespace asan {
  26    :  
  27    :  // A functor that retrieves the total size of an Asan allocation.
  28    :  struct GetTotalBlockSizeFunctor {
  29  E :    size_t operator()(const CompactBlockInfo& info) {
  30  E :      DCHECK_NE(static_cast<uint8*>(nullptr), info.block);
  31  E :      return info.block_size;
  32  E :    }
  33    :  };
  34    :  
  35    :  // A functor for calculating a hash value associated with a block. This is used
  36    :  // by the sharded quarantine.
  37    :  struct GetBlockHashFunctor {
  38  E :    size_t operator()(const CompactBlockInfo& info) {
  39  E :      DCHECK_NE(static_cast<uint8*>(nullptr), info.block);
  40    :      const BlockTrailer* trailer = reinterpret_cast<const BlockTrailer*>(
  41  E :          info.block + info.block_size) - 1;
  42  E :      return trailer->alloc_ticks + reinterpret_cast<size_t>(info.block);
  43  E :    }
  44    :  };
  45    :  
  46    :  // Checks if a block is corrupt. This checks the block's metadata and its
  47    :  // checksum.
  48    :  // @param block_header A pointer to the block header of the block.
  49    :  // @param block_info Will be filled in with pointers to the various portions
  50    :  //     of the block if this function succeeds. May be NULL.
  51    :  // @returns true if the block is corrupt, false otherwise.
  52    :  // @note The pages containing the block redzones must be readable.
  53    :  bool IsBlockCorrupt(const uint8* block_header, BlockInfo* block_info);
  54    :  
  55    :  }  // namespace asan
  56    :  }  // namespace agent
  57    :  
  58    :  #endif  // SYZYGY_AGENT_ASAN_BLOCK_UTILS_H_