1    :  // Copyright 2015 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 the data structures that will be injected into images transformed
  16    :  // by hot patching transformations. These data structures contain the necessary
  17    :  // metadata that is required to perform the hot patching of blocks at runtime.
  18    :  
  19    :  #ifndef SYZYGY_BLOCK_GRAPH_HOT_PATCHING_METADATA_H_
  20    :  #define SYZYGY_BLOCK_GRAPH_HOT_PATCHING_METADATA_H_
  21    :  
  22    :  #include <vector>
  23    :  
  24    :  
  25  m :  namespace block_graph {
  26    :  
  27    :  // Ensure there are no padding bytes because these structs are going to be
  28    :  // written to the .syzyhp stream directly.
  29    :  #pragma pack(push, 1)
  30    :  
  31    :  // This data structure describes a single Block in the HotPatchingMetadata.
  32  m :  struct HotPatchingBlockMetadata {
  33    :    // The RVA of the start of the block.
  34  m :    uint32_t relative_address;
  35    :  
  36    :    // The size of the code in the block data.
  37  m :    uint16_t code_size;
  38    :  
  39    :    // The size of the block data.
  40  m :    uint16_t block_size;
  41  m :  };
  42    :  
  43    :  // This struct contains the data that will be injected into images transformed
  44    :  // by hot patching transformations, it contains the necessary metadata that is
  45    :  // required to perform the hot patching of blocks at runtime.
  46  m :  struct HotPatchingMetadataHeader {
  47    :    // Version information.
  48  m :    uint32_t version;
  49    :  
  50    :    // Number of HotPatchingBlockMetadata structures to follow.
  51  m :    uint32_t number_of_blocks;
  52  m :  };
  53    :  
  54    :  #pragma pack(pop)
  55    :  
  56    :  // The current version of the HotPatchingMetadata structure. This needs to
  57    :  // be incremented if any time a non-backwards compatible change is made to the
  58    :  // serialization format.
  59  m :  const uint32_t kHotPatchingMetadataVersion = 1U;
  60    :  
  61  m :  }  // namespace block_graph
  62    :  
  63    :  #endif  // SYZYGY_BLOCK_GRAPH_HOT_PATCHING_METADATA_H_