src/traced/probes/ftrace/vendor_tracepoints.cc

/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * 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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "src/traced/probes/ftrace/vendor_tracepoints.h"

#include <errno.h>
#include <string.h>

#include <map>
#include <string>
#include <vector>

#include "perfetto/ext/base/file_utils.h"
#include "protos/perfetto/android_vendor/atrace_categories.gen.h"
#include "src/traced/probes/ftrace/atrace_hal_wrapper.h"
#include "src/traced/probes/ftrace/ftrace_procfs.h"
#include "src/traced/probes/ftrace/proto_translation_table.h"

namespace perfetto {
namespace vendor_tracepoints {
namespace {

std::vector<GroupAndName> DiscoverTracepoints(AtraceHalWrapper* hal,
                                              FtraceProcfs* ftrace,
                                              const std::string& category) {
  ftrace->DisableAllEvents();
  hal->EnableCategories({category});

  std::vector<GroupAndName> events;
  for (const std::string& group_name : ftrace->ReadEnabledEvents()) {
    size_t pos = group_name.find('/');
    PERFETTO_CHECK(pos != std::string::npos);
    events.push_back(
        GroupAndName(group_name.substr(0, pos), group_name.substr(pos + 1)));
  }

  hal->DisableAllCategories();
  ftrace->DisableAllEvents();
  return events;
}

}  // namespace

std::map<std::string, std::vector<GroupAndName>>
DiscoverVendorTracepointsWithHal(AtraceHalWrapper* hal, FtraceProcfs* ftrace) {
  std::map<std::string, std::vector<GroupAndName>> results;
  for (const auto& category : hal->ListCategories()) {
    results.emplace(category, DiscoverTracepoints(hal, ftrace, category));
  }
  return results;
}

base::Status DiscoverVendorTracepointsWithFile(
    const std::string& vendor_atrace_categories_path,
    std::map<std::string, std::vector<GroupAndName>>* categories_map) {
  std::string contents;
  bool res = base::ReadFile(vendor_atrace_categories_path, &contents);
  if (!res) {
    return base::ErrStatus("Cannot read vendor atrace file: %s (errno: %d, %s)",
                           vendor_atrace_categories_path.c_str(), errno,
                           strerror(errno));
  }
  protos::atrace::gen::Categories categories;
  res = categories.ParseFromString(contents);
  if (!res) {
    return base::Status("Cannot parse vendor atrace file");
  }
  for (const protos::atrace::gen::Category& cat : categories.categories()) {
    std::vector<GroupAndName> events;
    for (const protos::atrace::gen::FtraceGroup& group : cat.groups()) {
      for (const std::string& event : group.events()) {
        events.push_back(GroupAndName(group.name(), event));
      }
    }
    (*categories_map)[cat.name()] = std::move(events);
  }
  return base::OkStatus();
}

}  // namespace vendor_tracepoints
}  // namespace perfetto