Update Crashpad to 8e37886d418dd042c3c7bfadac99214739ee4d98

third_party/crashpad/crashpad/minidump/minidump_file_writer.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 11 matching lines @@
 #include "minidump/minidump_exception_writer.h"
 #include "minidump/minidump_handle_writer.h"
 #include "minidump/minidump_memory_info_writer.h"
 #include "minidump/minidump_memory_writer.h"
 #include "minidump/minidump_misc_info_writer.h"
 #include "minidump/minidump_module_writer.h"
 #include "minidump/minidump_system_info_writer.h"
 #include "minidump/minidump_thread_id_map.h"
 #include "minidump/minidump_thread_writer.h"
 #include "minidump/minidump_unloaded_module_writer.h"
+#include "minidump/minidump_user_extension_stream_data_source.h"
 #include "minidump/minidump_user_stream_writer.h"
 #include "minidump/minidump_writer_util.h"
 #include "snapshot/exception_snapshot.h"
 #include "snapshot/module_snapshot.h"
 #include "snapshot/process_snapshot.h"
 #include "util/file/file_writer.h"
 #include "util/numeric/safe_assignment.h"
 
 namespace crashpad {
 
@@ skipping 25 matching lines @@
   // done by MinidumpMiscInfoWriter::InitializeFromSnapshot(). Handling both
   // timestamps in the same way allows the highest-fidelity computation of
   // process uptime as the difference between the two values.
   timeval snapshot_time;
   process_snapshot->SnapshotTime(&snapshot_time);
   SetTimestamp(snapshot_time.tv_sec);
 
   const SystemSnapshot* system_snapshot = process_snapshot->System();
   auto system_info = base::WrapUnique(new MinidumpSystemInfoWriter());
   system_info->InitializeFromSnapshot(system_snapshot);
-  AddStream(std::move(system_info));
+  bool add_stream_result = AddStream(std::move(system_info));
+  DCHECK(add_stream_result);
 
   auto misc_info = base::WrapUnique(new MinidumpMiscInfoWriter());
   misc_info->InitializeFromSnapshot(process_snapshot);
-  AddStream(std::move(misc_info));
+  add_stream_result = AddStream(std::move(misc_info));
+  DCHECK(add_stream_result);
 
   auto memory_list = base::WrapUnique(new MinidumpMemoryListWriter());
   auto thread_list = base::WrapUnique(new MinidumpThreadListWriter());
   thread_list->SetMemoryListWriter(memory_list.get());
   MinidumpThreadIDMap thread_id_map;
   thread_list->InitializeFromSnapshot(process_snapshot->Threads(),
                                       &thread_id_map);
-  AddStream(std::move(thread_list));
+  add_stream_result = AddStream(std::move(thread_list));
+  DCHECK(add_stream_result);
 
   const ExceptionSnapshot* exception_snapshot = process_snapshot->Exception();
   if (exception_snapshot) {
     auto exception = base::WrapUnique(new MinidumpExceptionWriter());
     exception->InitializeFromSnapshot(exception_snapshot, thread_id_map);
-    AddStream(std::move(exception));
+    add_stream_result = AddStream(std::move(exception));
+    DCHECK(add_stream_result);
   }
 
   auto module_list = base::WrapUnique(new MinidumpModuleListWriter());
   module_list->InitializeFromSnapshot(process_snapshot->Modules());
-  AddStream(std::move(module_list));
-
-  for (const auto& module : process_snapshot->Modules()) {
-    for (const UserMinidumpStream* stream : module->CustomMinidumpStreams()) {
-      auto user_stream = base::WrapUnique(new MinidumpUserStreamWriter());
-      user_stream->InitializeFromSnapshot(stream);
-      AddStream(std::move(user_stream));
-    }
-  }
+  add_stream_result = AddStream(std::move(module_list));
+  DCHECK(add_stream_result);
 
   auto unloaded_modules = process_snapshot->UnloadedModules();
   if (!unloaded_modules.empty()) {
     auto unloaded_module_list =
         base::WrapUnique(new MinidumpUnloadedModuleListWriter());
     unloaded_module_list->InitializeFromSnapshot(unloaded_modules);
-    AddStream(std::move(unloaded_module_list));
+    add_stream_result = AddStream(std::move(unloaded_module_list));
+    DCHECK(add_stream_result);
   }
 
   auto crashpad_info = base::WrapUnique(new MinidumpCrashpadInfoWriter());
   crashpad_info->InitializeFromSnapshot(process_snapshot);
 
   // Since the MinidumpCrashpadInfo stream is an extension, it’s safe to not add
   // it to the minidump file if it wouldn’t carry any useful information.
   if (crashpad_info->IsUseful()) {
-    AddStream(std::move(crashpad_info));
+    add_stream_result = AddStream(std::move(crashpad_info));
+    DCHECK(add_stream_result);
   }
 
   std::vector<const MemoryMapRegionSnapshot*> memory_map_snapshot =
       process_snapshot->MemoryMap();
   if (!memory_map_snapshot.empty()) {
     auto memory_info_list =
         base::WrapUnique(new MinidumpMemoryInfoListWriter());
     memory_info_list->InitializeFromSnapshot(memory_map_snapshot);
-    AddStream(std::move(memory_info_list));
+    add_stream_result = AddStream(std::move(memory_info_list));
+    DCHECK(add_stream_result);
   }
 
   std::vector<HandleSnapshot> handles_snapshot = process_snapshot->Handles();
   if (!handles_snapshot.empty()) {
     auto handle_data_writer = base::WrapUnique(new MinidumpHandleDataWriter());
     handle_data_writer->InitializeFromSnapshot(handles_snapshot);
-    AddStream(std::move(handle_data_writer));
+    add_stream_result = AddStream(std::move(handle_data_writer));
+    DCHECK(add_stream_result);
   }
 
   memory_list->AddFromSnapshot(process_snapshot->ExtraMemory());
-  if (exception_snapshot)
+  if (exception_snapshot) {
     memory_list->AddFromSnapshot(exception_snapshot->ExtraMemory());
+  }
 
-  AddStream(std::move(memory_list));
+  // These user streams must be added last. Otherwise, a user stream with the
+  // same type as a well-known stream could preempt the well-known stream. As it
+  // stands now, earlier-discovered user streams can still preempt
+  // later-discovered ones. The well-known memory list stream is added after
+  // these user streams, but only with a check here to avoid adding a user
+  // stream that would preempt the memory list stream.
+  for (const auto& module : process_snapshot->Modules()) {
+    for (const UserMinidumpStream* stream : module->CustomMinidumpStreams()) {
+      if (stream->stream_type() == kMinidumpStreamTypeMemoryList) {
+        LOG(WARNING) << "discarding duplicate stream of type "
+                     << stream->stream_type();
+        continue;
+      }
+      auto user_stream = base::WrapUnique(new MinidumpUserStreamWriter());
+      user_stream->InitializeFromSnapshot(stream);
+      AddStream(std::move(user_stream));
+    }
+  }
+
+  // The memory list stream should be added last. This keeps the “extra memory”
+  // at the end so that if the minidump file is truncated, other, more critical
+  // data is more likely to be preserved. Note that non-“extra” memory regions
+  // will not have to ride at the end of the file. Thread stack memory, for
+  // example, exists as a children of threads, and appears alongside them in the
+  // file, despite also being mentioned by the memory list stream.
+  add_stream_result = AddStream(std::move(memory_list));
+  DCHECK(add_stream_result);
 }
 
 void MinidumpFileWriter::SetTimestamp(time_t timestamp) {
   DCHECK_EQ(state(), kStateMutable);
 
   internal::MinidumpWriterUtil::AssignTimeT(&header_.TimeDateStamp, timestamp);
 }
 
-void MinidumpFileWriter::AddStream(
+bool MinidumpFileWriter::AddStream(
     std::unique_ptr<internal::MinidumpStreamWriter> stream) {
   DCHECK_EQ(state(), kStateMutable);
 
   MinidumpStreamType stream_type = stream->StreamType();
 
   auto rv = stream_types_.insert(stream_type);
-  CHECK(rv.second) << "stream_type " << stream_type << " already present";
+  if (!rv.second) {
+    LOG(WARNING) << "discarding duplicate stream of type " << stream_type;
+    return false;
+  }
 
   streams_.push_back(stream.release());
 
   DCHECK_EQ(streams_.size(), stream_types_.size());
+  return true;
+}
+
+bool MinidumpFileWriter::AddUserExtensionStream(
+    std::unique_ptr<MinidumpUserExtensionStreamDataSource>
+        user_extension_stream_data) {
+  DCHECK_EQ(state(), kStateMutable);
+
+  auto user_stream = base::WrapUnique(new MinidumpUserStreamWriter());
+  user_stream->InitializeFromBuffer(user_extension_stream_data->stream_type(),
+                                    user_extension_stream_data->buffer(),
+                                    user_extension_stream_data->buffer_size());
+
+  return AddStream(std::move(user_stream));
 }
 
 bool MinidumpFileWriter::WriteEverything(FileWriterInterface* file_writer) {
   DCHECK_EQ(state(), kStateMutable);
 
   FileOffset start_offset = file_writer->Seek(0, SEEK_CUR);
   if (start_offset < 0) {
     return false;
   }
 
@@ skipping 87 matching lines @@
   for (internal::MinidumpStreamWriter* stream : streams_) {
     iov.iov_base = stream->DirectoryListEntry();
     iov.iov_len = sizeof(MINIDUMP_DIRECTORY);
     iovecs.push_back(iov);
   }
 
   return file_writer->WriteIoVec(&iovecs);
 }
 
 }  // namespace crashpad