Subscribing to Address Sanitizer Events (ArkTS)

Available APIs

For details about how to use the APIs (such as parameter usage constraints and value ranges), see Application Event Logging.

API	Description
addWatcher(watcher: Watcher): AppEventPackageHolder	Adds a watcher to subscribe to application events.
removeWatcher(watcher: Watcher): void	Removes a watcher to unsubscribe from application events.

How to Develop

The following describes how to subscribe to an address sanitizer event for an array bounds write.

Create a native C++ project. The directory structure is as follows:

entry:
  src:
    main:
      cpp:
        - types:
            libentry:
              - index.d.ts
        - CMakeLists.txt
        - napi_init.cpp
      ets:
        - entryability:
            - EntryAbility.ets
        - pages:
            - Index.ets

In the entry/src/main/ets/entryability/EntryAbility.ets file of the project, import the dependent modules.
```
import { hiAppEvent, hilog } from '@kit.PerformanceAnalysisKit';
```

In the entry/src/main/ets/entryability/EntryAbility.ets file of the project, add a watcher in onCreate() to subscribe to system events. The sample code is as follows:

hiAppEvent.addWatcher({
  // Set the watcher name. The system identifies different watchers based on their names.
  name: "watcher",
  // Add the system events to watch, for example, the address sanitizer event.
  appEventFilters: [
    {
      domain: hiAppEvent.domain.OS,
      names: [hiAppEvent.event.ADDRESS_SANITIZER]
    }
  ],
  // Implement a callback for the registered system event so that you can apply custom processing to the event data obtained.
  onReceive: (domain: string, appEventGroups: Array<hiAppEvent.AppEventGroup>) => {
    hilog.info(0x0000, 'testTag', `HiAppEvent onReceive: domain=${domain}`);
    for (const eventGroup of appEventGroups) {
      // The event name uniquely identifies a system event.
      hilog.info(0x0000, 'testTag', `HiAppEvent eventName=${eventGroup.name}`);
      for (const eventInfo of eventGroup.appEventInfos) {
        // Customize how to process the event data obtained, for example, print the event data in the log.
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.domain=${eventInfo.domain}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.name=${eventInfo.name}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.eventType=${eventInfo.eventType}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.time=${eventInfo.params['time']}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.bundle_version=${eventInfo.params['bundle_version']}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.bundle_name=${eventInfo.params['bundle_name']}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.pid=${eventInfo.params['pid']}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.uid=${eventInfo.params['uid']}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.type=${eventInfo.params['type']}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.external_log=${JSON.stringify(eventInfo.params['external_log'])}`);
        hilog.info(0x0000, 'testTag', `HiAppEvent eventInfo.log_over_limit=${eventInfo.params['log_over_limit']}`);
      }
    }
  }
});

Edit the entry/src/main/cpp/types/libentry/index.d.ets file. The sample code is as follows:
```
export const test: () => void;
```

In the entry/src/main/cpp/napi_init.cpp file, implement the array bounds write scenario and provide Node-API for the application layer code to call. The sample code is as follows:

#include "napi/native_api.h"

static napi_value Test(napi_env env, napi_callback_info info)
{
    int a[10];
    // Construct the array bounds write.
    a[10] = 1;
    return {};
}

EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports)
{
    napi_property_descriptor desc[] = {
        { "test", nullptr, Test, nullptr, nullptr, nullptr, napi_default, nullptr }
    };
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}
EXTERN_C_END

static napi_module demoModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = ((void*)0),
    .reserved = { 0 },
};

extern "C" __attribute__((constructor)) void RegisterEntryModule(void)
{
    napi_module_register(&demoModule);
}

In the entry/src/main/ets/pages/Index.ets file, add a button to trigger the address sanitizer event.

import testNapi from 'libentry.so'

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button("address-sanitizer").onClick(() => {
          testNapi.test();
        })
      }
      .width('100%')
    }
    .height('100%')
  }
}

In DevEco Studio, choose entry, click Edit Configurations, click Diagnostics, select Address Sanitizer, and click OK. Click the Run button to run the project. Then, click the address-sanitizer button to trigger an address sanitizer event. The application crashes. After restarting the application, you can view the following event information in the Log window.

HiAppEvent onReceive: domain=OS
HiAppEvent eventName=ADDRESS_SANITIZER
HiAppEvent eventInfo.domain=OS
HiAppEvent eventInfo.name=ADDRESS_SANITIZER
HiAppEvent eventInfo.eventType=1
HiAppEvent eventInfo.time=1713161197957
HiAppEvent eventInfo.bundle_version=1.0.0
HiAppEvent eventInfo.bundle_name=com.example.myapplication
HiAppEvent eventInfo.pid=12889
HiAppEvent eventInfo.uid=20020140
HiAppEvent eventInfo.type=stack-buffer-overflow
HiAppEvent eventInfo.external_log=["/data/storage/el2/log/hiappevent/ADDRESS_SANITIZER_1713161197960_12889.log"]
HiAppEvent eventInfo.log_over_limit=false