On Mon, Jan 10, 2022 at 04:20:03PM +0000, Al Viro wrote: > Geert, do you see any problems with that? The only difference is that > current->ptrace_message would be set to 1 for ptrace stop on entry and > 2 - on leave. Currently m68k just has it 0 all along. > > It is user-visible (the whole point is to let the tracer see which > stop it is - entry or exit one), so somebody using PTRACE_GETEVENTMSG > on syscall stops would start seeing 1 or 2 instead of "0 all along". > That's how it works on all other architectures (including m68k-nommu), > and I doubt that anything in userland will get broken. > > Behaviour of PTRACE_GETEVENTMSG for other stops (fork, etc.) remains > as-is, of course. Actually, the current behaviour is "report what the last PTRACE_GETEVENTMSG has reported, whatever kind of stop that used to be for". So I very much doubt that anything could break there.