In the below the line comments of the lwn.net article:
[https://lwn.net/Articles/1011366/]
there's a lot of discussion about the way Android Banking Apps behave and what they are trying to achieve.
There's a lot to wade through and perhaps off topic but at the same time it is interesting to read how increased security measures in a future kernel might trip up banking apps.
I thought some here might find it interesting.

A short extract:

In the field, I've found that many applications read the ranges from /proc/self/[s]maps to determine what they can access (usually related to obfuscation techniques).

followed by:

It seems that banking apps running on Android are known for this sort of behavior and could run into trouble if guard pages are installed — which is something that the Android runtime might well want to do as a general hardening measure.

but there is fairly substantial discussion following in the lwn.net comments to that article.

Use your browser search function with keyword banking if you want to quickly grep through the comments.