Re: [RFC][PATCH 2/2] exec: If possible don't wait for ptraced threads to be reaped

From: Oleg Nesterov
Date: Wed Apr 05 2017 - 12:47:09 EST


On 04/03, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@xxxxxxxxxx> writes:
>
> > I meant that may_hang == 0 implies zap_other_threads(do_count => -1) which should
> > return the number of threads which didn't pass exit_notify(). The returned value
> > can be wrong unless you change exit_notify() to set exit_state under
> > siglock.

but I forgot to add that, of course, this problem is very minor because
we can only miss a thread which is already at the end of exit_notify()
so nothing bad can happen.

But imo should be fixed anyway, simply because this looks wrong/racy.
Your recent 4/5 has the same problem.

> Interesting an existing bug.

Hmm... what do you mean? The current code looks fine.

Oleg.