[Q] ActivityManager.forceStopPackage() from Task Manager
This is my first time posting here. I'm not sure if this is the right place to ask this question, but I don't seem to find other more appropriate places. Here's my question anyways.
I understand that the API ActivityManager.forceStopPackage() is an internal one and can be called only from system process. However, it puzzles me that the built-in Task Manager app (with package name "com.motorola.PerformanceManager") on my motorola atrix phone can directly call it without being a system process. There are two things that I verified.
First, it is non-system process from "ps" command:
app_64 13681 1379 170788 29820 ffffffff 00000000 S com.motorola.PerformanceManager
Second, it indeed calls the ActivityManager.forceStopPackage() API from its odex file (decompiled into smali, then into dex, and then into java). From the smali code, it is already clear that it calls this API.
I also checked its AndroidManifest.xml file which seems nothing special to me (the forum mistakenly recognizes the content as URLs and prevents me from posting them).
The manifest file does include the "android.permission.FORCE_STOP_PACKAGES" permission which is supposed to be a system one. A non-system app will still get permission denial error even with this permission. I tried using reflection to access this API with "android.permission.FORCE_STOP_PACKAGES" permission but still get the runtime error.
Now, how can the built-in Task Manager app call the internal API without being a system process.
One possibility is that the app is signed with the same platform private key. However, I'm not sure how I can verify that. Further, it is still supposed to be a system process with additional descriptions in the manifest file.
Hope someone can answer my question. Thanks.