1    :  // Copyright 2013 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/common/dbghelp_util.h"
  16    :  
  17    :  #include <dbghelp.h>
  18    :  
  19    :  #include "base/logging.h"
  20    :  #include "syzygy/common/com_utils.h"
  21    :  
  22    :  namespace common {
  23    :  
  24    :  // A wrapper for SymInitialize. It looks like it has an internal race condition
  25    :  // that can occasionally fail, so we wrap it and retry a finite number of times.
  26    :  // Ugly, but necessary.
  27    :  bool SymInitialize(HANDLE process,
  28    :                     const char* user_search_path,
  29  E :                     bool invade_process) {
  30  E :    for (int retry_count = 0; retry_count < 3; ++retry_count) {
  31  E :      BOOL result = ::SymInitialize(process, user_search_path, invade_process);
  32  E :      if (result == TRUE)
  33  E :        return true;
  34    :  
  35  i :      DWORD error = ::GetLastError();
  36    :      // This corresponds to STATUS_INFO_LENGTH_MISMATCH, which is defined in
  37    :      // ntstatus.h. This doesn't like being included alongside windows.h.
  38  i :      if (error == 0xC0000004)
  39  i :        continue;
  40    :  
  41  i :      LOG(ERROR) << "SymInitialize failed: " << common::LogWe(error);
  42  i :      return false;
  43  i :    }
  44    :  
  45  i :    LOG(ERROR) << "SymInitialize failed repeatedly.";
  46  i :    return false;
  47  E :  }
  48    :  
  49    :  }  // namespace common