On Thu, 10 Aug 2023 at 05:42, Schimpe, Christina <christina.schimpe@xxxxxxxxx> wrote: > > 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. Ahh. That would explain why nobody noticed. I do wonder if perhaps /proc/<pid>/mem should just match the real addresses (ie the ones you would see in /proc/<pid>/maps). The main reason GUP does the untagging is that obviously people will pass in their own virtual addresses when doing direct-IO etc. So /proc/<pid>/mem is a bit different. That said, untagging does make some things easier, so I think it's probably the right thing to do. Linus