enable memory tagging for android app? #10934

We could explicitly opt-in to MTE by setting android:memtagMode="async" inside the <application> tag in our AndroidManifest.xml.

Why? Well, why not.

• allegedly not many apps opt-in, so by opting it we could "signal" that we are interested in MTE: it would show up as a tiny blip in the play store statistics looked at by google overlords xD
• cpython itself is of course in C, and e.g. the json parser from the stdlib is partially implemented in C. We communicate with electrum servers using json: would be scary/devastating if an electrum server could RCE due to a bug in the json-parser: MTE might perhaps catch that
  • well, that one is just my classic nightmare example, but now after typing that, I want MTE on my x86 laptop
• some of us already have it force-enabled on GrapheneOS since Memory tagging error on Android #8783 was fixed, so it is not untested, so there should not be widespread common crashes

nice blog post: https://thore.io/posts/2025/09/introduction-to-arm-memory-tagging-extensions/