1    :  // Copyright 2012 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    :  #include "syzygy/simulate/page_fault_simulation.h"
  16    :  
  17    :  #include "syzygy/core/json_file_writer.h"
  18    :  
  19    :  namespace simulate {
  20    :  
  21    :  PageFaultSimulation::PageFaultSimulation()
  22    :      : fault_count_(0),
  23    :        page_size_(0),
  24  E :        pages_per_code_fault_(kDefaultPagesPerCodeFault) {
  25  E :  }
  26    :  
  27    :  void PageFaultSimulation::OnProcessStarted(base::Time /*time*/,
  28  E :                                             size_t default_page_size) {
  29    :    // Set the page size if it wasn't set by the user yet.
  30  E :    if (page_size_ != 0)
  31  i :      return;
  32    :  
  33  E :    if (default_page_size != 0)
  34  E :      page_size_ = default_page_size;
  35  E :    else
  36  i :      page_size_ = kDefaultPageSize;
  37    :  
  38  E :    LOG(INFO) << "Page size set to " << page_size_;
  39  E :  }
  40    :  
  41    :  bool PageFaultSimulation::SerializeToJSON(FILE* output,
  42  E :                                            bool pretty_print) {
  43  E :    DCHECK(output != NULL);
  44  E :    core::JSONFileWriter json_file(output, pretty_print);
  45    :  
  46    :    // TODO(fixman): Report faulting addresses and times.
  47    :    if (!json_file.OpenDict() ||
  48    :        !json_file.OutputKey("page_size") ||
  49    :        !json_file.OutputInteger(page_size_) ||
  50    :        !json_file.OutputKey("pages_per_code_fault") ||
  51    :        !json_file.OutputInteger(pages_per_code_fault_) ||
  52    :        !json_file.OutputKey("fault_count") ||
  53    :        !json_file.OutputInteger(fault_count_) ||
  54    :        !json_file.OutputKey("loaded_pages") ||
  55  E :        !json_file.OpenList()) {
  56  i :      return false;
  57    :    }
  58    :  
  59  E :    PageSet::const_iterator i = pages_.begin();
  60  E :    for (; i != pages_.end(); i++) {
  61  E :      if (!json_file.OutputInteger(*i)) {
  62  i :        return false;
  63    :      }
  64  E :    }
  65    :  
  66    :    if (!json_file.CloseList() ||
  67  E :        !json_file.CloseDict()) {
  68  i :      return false;
  69    :    }
  70    :  
  71  E :    DCHECK(json_file.Finished());
  72  E :    return true;
  73  E :  }
  74    :  
  75    :  void PageFaultSimulation::OnFunctionEntry(base::Time /*time*/,
  76  E :                                            const Block* block) {
  77  E :    DCHECK(block != NULL);
  78  E :    DCHECK(page_size_ != 0);
  79    :  
  80  E :    const uint32 block_start = block->addr().value();
  81  E :    const uint32 block_size = block->size();
  82  E :    const size_t kStartIndex = block_start / page_size_;
  83    :    const size_t kEndIndex = (block_start + block_size +
  84  E :        page_size_ - 1) / page_size_;
  85    :  
  86    :    // Loop through all the pages in the block, and if it isn't already in memory
  87    :    // then simulate a code fault and load all the faulting pages in memory.
  88  E :    for (size_t i = kStartIndex; i < kEndIndex; i++) {
  89  E :      if (pages_.find(i) == pages_.end()) {
  90  E :        fault_count_++;
  91  E :        for (size_t j = 0; j < pages_per_code_fault_; j++) {
  92  E :          pages_.insert(i + j);
  93  E :        }
  94    :      }
  95  E :    }
  96  E :  }
  97    :  
  98    :  } // namespace simulate