In common setups ptrace rights aren't highly privileged, the normal situation is that users can ptrace their own processes. To be clear, I'm just adding a bit

In common setups ptrace rights aren't highly privileged, the normal situation is that users can ptrace their own processes. To be clear, I'm just adding a bit of context around why a page in a read-only mapping is COWed when these debugging interfaces are used to write to it, rather than failing with an exception. The bug existed in the handling of this edge-case.