[PATCH 3] utrace-ptrace-mini: ptrace_stop: make it utrace-friendly

[Roland McGrath]

> Introduce xxx_utrace_stop() which notifies engine we are going to stop.
> It calls report_quiesce(0), but report.action = UTRACE_STOP instead of
> UTRACE_RESUME.

I don't think this is necessary to go along with the ptrace cooperation
hacks.  For any engine, there could always be a later engine that returns
UTRACE_STOP and causes a stop after you thought the task was going to keep
running.  If an engine is concerned about that, it uses UTRACE_REPORT and
all it knows for sure is that it will get another report after resumption
if indeed there was a stop.  So all the ptrace hacks need to do is meet
that guarantee: set utrace->report when ptrace stops "after" or "between"
utrace event points.


Thanks,
Roland