RE: [PATCH] mm: Fix access_remote_vm() regression on tagged addresses

[Schimpe, Christina]

> Interesting that it took this long to notice.
> 
> Not surprising considering that LAM isn't actually available, but I'd have
> expected the arm people to notice more. Yes, I have (and test) my
> arm64 laptop, but I obviously don't do user space debugging on it.
> Apparently others don't either.
> 
> Or maybe TBI is used a lot less than I thought.

Just for the record:

We don't have any LAM support in GDB yet, we are just working on it.
We currently rely on that feature, but could still change it. We don't 
necessarily require /proc/PID/mem to support tagged addresses.

ARM's TBI support in GDB does not rely on /proc/PID/mem to support tagged
addresses AFAIK.
I also thought that the kernel does not support tagged addresses for
/proc/PID/mem in case of ARM. This is at least reflected by their patches
for TBI and the kernel docs
https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt.

Christina
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