Reading ActivityManager-logs on a Jelly Bean devic

问题:

Jelly Bean has removed the ability to read the logs of other apps (according to this I/O talk), which is a sensible security improvement. However, I need to read ActivityManager-logs for my app to work (to see which app is currently starting). To do this, I was using

private static final String clearLogcat = "logcat -c";
private static final String logcatCommand = "logcat ActivityManager:I *:S";
//...

which no longer works, as I can only read my own application's logs in Jelly Bean. Is there an alternative solution to finding out when another app is starting (apart from root)? I understand why we shouldn't be able to read other applications' logs (kind of - it should be the other developers' resposibility to make sure that no personal information is logged, not mine by being prevented from reading the log), but I don't understand why the ActivityManager, a framework class, is included in that policy...

Thanks,
Nick

回答1:

There is an extensive discussion of this issue going on here. Unfortunately, it's "expected behavior" and as such won't be fixed. The only current solution (for reading the logs from within an application on JB and above) is to manually grant the permission to the app through adb:

adb shell pm grant <pkg> android.permission.READ_LOGS

A such-granted permission:

• survives reboots
• survives application updates (i.e. "adb install -r")
• does not survive if the application was uninstalled and then installed again

It's obvious that this isn't something that a normal user can be expected to do. A GUI-solution (where users can grant this permission from the Settingsmenu of their device) is promised by the Android team, but unfortunately the functionality was removed before the "fix" was implemented.

回答2:

First of all, ActivityManager isn't an application... it's a class that makes up part of the Android application framework.

Second of all, if the Android team deliberately went out of their way to prevent this from working, then I doubt there is a security loophole around it. The fact is that third party applications should not have to rely on logcat logs in order to work properly. If you give some details about your reason for needing to read these logs, maybe we can help point you to a better solution.