Added a trace option for whitewashing trace args against a known-PII-less list.

base/trace_event/trace_event_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/trace_event/trace_event_impl.h"
 
 #include <algorithm>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
@@ skipping 48 matching lines @@
 // trace.
 const int kOverheadReportThresholdInMicroseconds = 50;
 
 // String options that can be used to initialize TraceOptions.
 const char kRecordUntilFull[] = "record-until-full";
 const char kRecordContinuously[] = "record-continuously";
 const char kRecordAsMuchAsPossible[] = "record-as-much-as-possible";
 const char kTraceToConsole[] = "trace-to-console";
 const char kEnableSampling[] = "enable-sampling";
 const char kEnableSystrace[] = "enable-systrace";
+const char kEnableArgsWhitelist[] = "enable-args-whitelist";
 
 // Controls the number of trace events we will buffer in-memory
 // before throwing them away.
 const size_t kTraceBufferChunkSize = TraceBufferChunk::kTraceBufferChunkSize;
 const size_t kTraceEventVectorBigBufferChunks =
     512000000 / kTraceBufferChunkSize;
 const size_t kTraceEventVectorBufferChunks = 256000 / kTraceBufferChunkSize;
 const size_t kTraceEventRingBufferChunks = kTraceEventVectorBufferChunks / 4;
 const size_t kTraceEventBufferSizeInBytes = 100 * 1024;
 // Can store results for 30 seconds with 1 ms sampling interval.
@@ skipping 607 matching lines @@
     case TRACE_VALUE_TYPE_STRING:
     case TRACE_VALUE_TYPE_COPY_STRING:
       EscapeJSONString(value.as_string ? value.as_string : "NULL", true, out);
       break;
     default:
       NOTREACHED() << "Don't know how to print this value";
       break;
   }
 }
 
-void TraceEvent::AppendAsJSON(std::string* out) const {
+bool TraceEvent::IsPIIWhitelisted() const {
+  const char* category_group_name =
+      TraceLog::GetCategoryGroupName(category_group_enabled_);
+  CStringTokenizer category_group_tokens(
+      category_group_name, category_group_name + strlen(category_group_name),
+      ",");
+  while (category_group_tokens.GetNext()) {
+    const std::string& category_group_token = category_group_tokens.token();
+    for (int i = 0; kEventArgsWhitelist[i][0] != NULL; ++i) {
+      DCHECK(kEventArgsWhitelist[i][1]);
+
+      if (MatchPattern(category_group_token.c_str(),
+                       kEventArgsWhitelist[i][0]) &&
+          MatchPattern(name_, kEventArgsWhitelist[i][1])) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+void TraceEvent::AppendAsJSON(std::string* out,
+                              bool enable_args_whitelist) const {
   int64 time_int64 = timestamp_.ToInternalValue();
   int process_id = TraceLog::GetInstance()->process_id();
   // Category group checked at category creation time.
   DCHECK(!strchr(name_, '"'));
   StringAppendF(out,
       "{\"pid\":%i,\"tid\":%i,\"ts\":%" PRId64 ","
       "\"ph\":\"%c\",\"cat\":\"%s\",\"name\":\"%s\",\"args\":{",
       process_id,
       thread_id_,
       time_int64,
       phase_,
       TraceLog::GetCategoryGroupName(category_group_enabled_),
       name_);
 
   // Output argument names and values, stop at first NULL argument name.
-  for (int i = 0; i < kTraceMaxNumArgs && arg_names_[i]; ++i) {
-    if (i > 0)
-      *out += ",";
-    *out += "\"";
-    *out += arg_names_[i];
-    *out += "\":";
+  if (arg_names_[0]) {
+    bool allow_args = !enable_args_whitelist || IsPIIWhitelisted();
 
-    if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE)
-      convertable_values_[i]->AppendAsTraceFormat(out);
-    else
-      AppendValueAsJSON(arg_types_[i], arg_values_[i], out);
+    if (allow_args) {
+      for (int i = 0; i < kTraceMaxNumArgs && arg_names_[i]; ++i) {
+        if (i > 0)
+          *out += ",";
+        *out += "\"";
+        *out += arg_names_[i];
+        *out += "\":";
+
+        if (arg_types_[i] == TRACE_VALUE_TYPE_CONVERTABLE)
+          convertable_values_[i]->AppendAsTraceFormat(out);
+        else
+          AppendValueAsJSON(arg_types_[i], arg_values_[i], out);
+      }
+    } else {
+      *out += "\"stripped\":1";
+    }
   }
+
   *out += "}";
 
   if (phase_ == TRACE_EVENT_PHASE_COMPLETE) {
     int64 duration = duration_.ToInternalValue();
     if (duration != -1)
       StringAppendF(out, ",\"dur\":%" PRId64, duration);
     if (!thread_timestamp_.is_null()) {
       int64 thread_duration = thread_duration_.ToInternalValue();
       if (thread_duration != -1)
         StringAppendF(out, ",\"tdur\":%" PRId64, thread_duration);
@@ skipping 255 matching lines @@
     } else if (*iter == kRecordContinuously) {
       record_mode = RECORD_CONTINUOUSLY;
     } else if (*iter == kTraceToConsole) {
       record_mode = ECHO_TO_CONSOLE;
     } else if (*iter == kRecordAsMuchAsPossible) {
       record_mode = RECORD_AS_MUCH_AS_POSSIBLE;
     } else if (*iter == kEnableSampling) {
       enable_sampling = true;
     } else if (*iter == kEnableSystrace) {
       enable_systrace = true;
+    } else if (*iter == kEnableArgsWhitelist) {
+      enable_args_whitelist = true;
     } else {
       return false;
     }
   }
   return true;
 }
 
 std::string TraceOptions::ToString() const {
   std::string ret;
   switch (record_mode) {
     case RECORD_UNTIL_FULL:
       ret = kRecordUntilFull;
       break;
     case RECORD_CONTINUOUSLY:
       ret = kRecordContinuously;
       break;
     case ECHO_TO_CONSOLE:
       ret = kTraceToConsole;
       break;
     case RECORD_AS_MUCH_AS_POSSIBLE:
       ret = kRecordAsMuchAsPossible;
       break;
     default:
       NOTREACHED();
   }
   if (enable_sampling)
     ret = ret + "," + kEnableSampling;
   if (enable_systrace)
     ret = ret + "," + kEnableSystrace;
+  if (enable_args_whitelist)
+    ret = ret + "," + kEnableArgsWhitelist;
   return ret;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // TraceLog
 //
 ////////////////////////////////////////////////////////////////////////////////
 
 class TraceLog::ThreadLocalEventBuffer
@@ skipping 433 matching lines @@
   {
     AutoLock lock(lock_);
     dispatching_to_observer_list_ = false;
   }
 }
 
 TraceLog::InternalTraceOptions TraceLog::GetInternalOptionsFromTraceOptions(
     const TraceOptions& options) {
   InternalTraceOptions ret =
       options.enable_sampling ? kInternalEnableSampling : kInternalNone;
+  if (options.enable_args_whitelist)
+    ret |= kInternalEnableArgsWhitelist;
   switch (options.record_mode) {
     case RECORD_UNTIL_FULL:
       return ret | kInternalRecordUntilFull;
     case RECORD_CONTINUOUSLY:
       return ret | kInternalRecordContinuously;
     case ECHO_TO_CONSOLE:
       return ret | kInternalEchoToConsole;
     case RECORD_AS_MUCH_AS_POSSIBLE:
       return ret | kInternalRecordAsMuchAsPossible;
   }
   NOTREACHED();
   return kInternalNone;
 }
 
 CategoryFilter TraceLog::GetCurrentCategoryFilter() {
   AutoLock lock(lock_);
   return category_filter_;
 }
 
 TraceOptions TraceLog::GetCurrentTraceOptions() const {
   TraceOptions ret;
   InternalTraceOptions option = trace_options();
   ret.enable_sampling = (option & kInternalEnableSampling) != 0;
+  ret.enable_args_whitelist = (option & kInternalEnableArgsWhitelist) != 0;
   if (option & kInternalRecordUntilFull)
     ret.record_mode = RECORD_UNTIL_FULL;
   else if (option & kInternalRecordContinuously)
     ret.record_mode = RECORD_CONTINUOUSLY;
   else if (option & kInternalEchoToConsole)
     ret.record_mode = ECHO_TO_CONSOLE;
   else if (option & kInternalRecordAsMuchAsPossible)
     ret.record_mode = RECORD_AS_MUCH_AS_POSSIBLE;
   else
     NOTREACHED();
@@ skipping 226 matching lines @@
 }
 
 // Usually it runs on a different thread.
 void TraceLog::ConvertTraceEventsToTraceFormat(
     scoped_ptr<TraceBuffer> logged_events,
     const TraceLog::OutputCallback& flush_output_callback) {
 
   if (flush_output_callback.is_null())
     return;
 
+  InternalTraceOptions options = trace_options();
+  bool enable_args_whitelist = (options & kInternalEnableArgsWhitelist) != 0;
   // The callback need to be called at least once even if there is no events
   // to let the caller know the completion of flush.
   bool has_more_events = true;
   do {
     scoped_refptr<RefCountedString> json_events_str_ptr =
         new RefCountedString();
 
     while (json_events_str_ptr->size() < kTraceEventBufferSizeInBytes) {
       const TraceBufferChunk* chunk = logged_events->NextChunk();
       has_more_events = chunk != NULL;
       if (!chunk)
         break;
       for (size_t j = 0; j < chunk->size(); ++j) {
         if (json_events_str_ptr->size())
           json_events_str_ptr->data().append(",\n");
-        chunk->GetEventAt(j)->AppendAsJSON(&(json_events_str_ptr->data()));
+        chunk->GetEventAt(j)->AppendAsJSON(&(json_events_str_ptr->data()),
+                                           enable_args_whitelist);
       }
     }
     flush_output_callback.Run(json_events_str_ptr, has_more_events);
   } while (has_more_events);
 }
 
 void TraceLog::FinishFlush(int generation) {
   scoped_ptr<TraceBuffer> previous_logged_events;
   OutputCallback flush_output_callback;
 
   if (!CheckGeneration(generation))
     return;
 
   {
     AutoLock lock(lock_);
 
     previous_logged_events.swap(logged_events_);
     UseNextTraceBuffer();
     thread_message_loops_.clear();
 
     flush_message_loop_proxy_ = NULL;
     flush_output_callback = flush_output_callback_;
     flush_output_callback_.Reset();
   }
 
   if (use_worker_thread_ &&
       WorkerPool::PostTask(
           FROM_HERE,
-          Bind(&TraceLog::ConvertTraceEventsToTraceFormat,
-               Passed(&previous_logged_events),
-               flush_output_callback),
+          Bind(&TraceLog::ConvertTraceEventsToTraceFormat, Unretained(this),
+               Passed(&previous_logged_events), flush_output_callback),
           true)) {
     return;
   }
 
   ConvertTraceEventsToTraceFormat(previous_logged_events.Pass(),
                                   flush_output_callback);
 }
 
 // Run in each thread holding a local event buffer.
 void TraceLog::FlushCurrentThread(int generation) {
@@ skipping 808 matching lines @@
 }
 
 ScopedTraceBinaryEfficient::~ScopedTraceBinaryEfficient() {
   if (*category_group_enabled_) {
     TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_group_enabled_,
                                                 name_, event_handle_);
   }
 }
 
 }  // namespace trace_event_internal