Magisk Zygisk breaks NDK C++ native breakpoints and stacktraces

[twisted89]

Please actually test this before closing the issue without explanation!
The NDK issue was created before I realised Magisk was the real cause, I've left them open to cover all bases.

Device: Tested multiple - Samsung S20 FE, LG G6, HTC One M7
Android version: 11 &12
Magisk version name: 25.2
Magisk version code: 25203

With the latest Magisk installed and the Zygisk option enabled NDK C++ breakpoints cease to function, LLDB reports the error

warning: failed to set breakpoint side 0xa3d741c for breakpoint -5.1: error: 9 sending the breakpoint request.

Upon uninstalling Magisk or disabling Zygisk breakpoints then work again.

android/ndk#1754

[twisted89]

Guessing this is just getting ignored then.

[twisted89]

Response from Google bug report

https://issuetracker.google.com/issues/243471116#comment10

I verified that native debugging works with Magisk, but it does not work with Magisk+Zygisk.

This is outside our scope of Android Studio support. I suggest reaching out to Magisk owner.

If you file a bug against Magisk, you may add this information:

LLDB has a mechanism for detecting when an .so is loaded.
This is implemented by inserting a breakpoint, called a rendezvous breakpoint, into a specific location in the dynamic linker.
Enabling Zygisk seems to break this mechanism.
This can be observed as follows:

Create a simple C++ native activity app using Android Studio.
Start debugging the app in Android Studio. Let the app load the activity.
Pause the app using the Native debugger.
Open the LLDB console tab and type image list.
Expected:
The native-lib.so is in the list.
Actual:
The native-lib.so is missing in the list.
The list has a bunch of other .so files, but those are the system .so files that have already been loaded at the time LLDB attached.
Possible Workaround (other than disabling Zygisk):

Start your app.
Wait until it loads your .so file(s).
Use Android Studio's Attach Debugger to Android Process.
Your breakpoints should now work.
Note that you cannot debug the startup part of your app using this technique as the app won't wait until the debugger is attached and continue running.

Since this doesn't seem to be an Android Studio issue, I'll close this as intended-behavior.

[ys1231]

I have the same problem, At present, you can only turn off the zygisk mode.
This problem bothered me for two days. At first, I had all kinds of guesses.
The problem was found only after repeated tests.

[canyie]

Try this module instead of official zygisk?
https://github.com/Dr-TSNG/ZygiskOnKernelSU

[5ec1cff]

Try executing umount -l /system/bin/app_process64 in global namespace (e.g. adb shell ) before debugging.

[canyie]

Fixed in 9fbd079