zircon/system/ulib/kernel-debug/kernel-debug.cc

// Copyright 2019 The Fuchsia 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 <lib/kernel-debug/kernel-debug.h>

#include <fuchsia/kernel/c/fidl.h>
#include <lib/fidl-async/bind.h>
#include <lib/zircon-internal/ktrace.h>
#include <string.h>
#include <zircon/assert.h>
#include <zircon/syscalls.h>

namespace {

zx_status_t HandleSendDebugCommand(void* ctx, const char* command, size_t command_size,
                                   fidl_txn_t* txn) {
  const zx_handle_t root_resource = static_cast<zx_handle_t>(reinterpret_cast<uintptr_t>(ctx));
  const auto status = zx_debug_send_command(root_resource, command, command_size);
  return fuchsia_kernel_DebugBrokerSendDebugCommand_reply(txn, status);
}

zx_status_t HandleSetTracingEnabled(void* ctx, bool enabled, fidl_txn_t* txn) {
  const zx_handle_t root_resource = static_cast<zx_handle_t>(reinterpret_cast<uintptr_t>(ctx));
  zx_status_t status;
  if (enabled) {
    status = zx_ktrace_control(root_resource, KTRACE_ACTION_START, KTRACE_GRP_ALL, nullptr);
  } else {
    status = zx_ktrace_control(root_resource, KTRACE_ACTION_STOP, 0, nullptr);
    if (status == ZX_OK) {
      status = zx_ktrace_control(root_resource, KTRACE_ACTION_REWIND, 0, nullptr);
    }
  }
  return fuchsia_kernel_DebugBrokerSendDebugCommand_reply(txn, status);
}

constexpr const fuchsia_kernel_DebugBroker_ops_t kInterfaceOps = {
    .SendDebugCommand = HandleSendDebugCommand,
    .SetTracingEnabled = HandleSetTracingEnabled,
};

zx_status_t Connect(void* ctx, async_dispatcher_t* dispatcher, const char* service_name,
                    zx_handle_t request) {
  if (!strcmp(service_name, fuchsia_kernel_DebugBroker_Name)) {
    return fidl_bind(dispatcher, request, (fidl_dispatch_t*)fuchsia_kernel_DebugBroker_dispatch,
                     ctx, &kInterfaceOps);
  }

  zx_handle_close(request);
  return ZX_ERR_NOT_SUPPORTED;
}

constexpr const char* kServices[] = {
    fuchsia_kernel_DebugBroker_Name,
    nullptr,
};

constexpr zx_service_ops_t kServiceOps = {
    .init = nullptr,
    .connect = Connect,
    .release = nullptr,
};

constexpr zx_service_provider_t kDebugBrokerServiceProvider = {
    .version = SERVICE_PROVIDER_VERSION,
    .services = kServices,
    .ops = &kServiceOps,
};

}  // namespace

const zx_service_provider_t* kernel_debug_get_service_provider() {
  return &kDebugBrokerServiceProvider;
}