On 09/25, Oleg Nesterov wrote: > > On 09/25, Roland McGrath wrote: > > > > > > it being after the syscall insn, but (in vanilla ptrace, and at the > > > > time of report_clone callbacks at utrace level) without the return > > > > value register having been written yet. > > > > > > And how we can implement this? > > > > > > regs->ax is updated right after "call *sys_call_table[]", and we > > > report PTRACE_EVENT_FORK or PTRACE_EVENT_EXEC much later. > > > > I didn't intend to. This is a change I think is more desireable than the > > bug-compatibility. In today's ptrace these extra stops are the sole > > exceptions where the register state you fiddle with ptrace gets clobbered > > later. I've never thought that was useful. > > Ah, good! I misunderstood you. > > Let's ignore this minor incompatibility then.
OK, but I'd like to clarify one thing, just to be absolutely sure I understand what do you think. > It's a further oddity that you can single-step (or not) "into" the > system call and then get a ptrace stop "inside" it, that being for > PTRACE_EVENT_FORK et al. And utrace-ptrace should be compatible here, yes? Oleg.