Re: [PATCH 0/2] fix the traced mt-exec deadlock

From	Oleg Nesterov <oleg@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/2] fix the traced mt-exec deadlock
Date	2017-03-04 18:10 +0100
Message-ID	<thllT-3Un-1@gated-at.bofh.it> (permalink)
References	<tapDY-4My-5@gated-at.bofh.it> <teqL8-2Ds-29@gated-at.bofh.it> <tgK2Z-26x-3@gated-at.bofh.it> <tgZlo-4ue-31@gated-at.bofh.it> <th13Q-5HD-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 03/03, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@redhat.com> writes:
>
> >> @@ -699,8 +701,6 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
> >>  	}
> >>
> >>  	tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE;
> >> -	if (tsk->exit_state == EXIT_DEAD)
> >> -		list_add(&tsk->ptrace_entry, &dead);
> >>
> >>  	/* mt-exec, de_thread() is waiting for group leader */
> >>  	if (unlikely(tsk->signal->notify_count < 0))
> >> @@ -711,6 +711,8 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
> >>  		list_del_init(&p->ptrace_entry);
> >>  		release_task(p);
> >>  	}
> >> +	if (autoreap)
> >> +		release_task(tsk);
> >
> > These 2 changes are not needed. release_task(tsk) will be called by
> > list_for_each_entry_safe() above if autoreap == T.
>
> Except for the practical case that for threads that are ptraced
> tsk->ptrace_entry is already in use.  Which means we can't use
> list_add(&tsk->ptrace_entry, &dead).

Yes, I was wrong here, thanks for correcting me.

Oleg.

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [PATCH 0/2] fix the traced mt-exec deadlock ebiederm@xmission.com (Eric W. Biederman) - 2017-03-03 02:20 +0100
  Re: [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov <oleg@redhat.com> - 2017-03-03 18:40 +0100
    Re: [PATCH 0/2] fix the traced mt-exec deadlock ebiederm@xmission.com (Eric W. Biederman) - 2017-03-03 20:30 +0100
      [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped. ebiederm@xmission.com (Eric W. Biederman) - 2017-03-03 21:20 +0100
        Re: [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped. Oleg Nesterov <oleg@redhat.com> - 2017-03-04 18:10 +0100
      Re: [PATCH 0/2] fix the traced mt-exec deadlock ebiederm@xmission.com (Eric W. Biederman) - 2017-03-03 22:40 +0100
      Re: [PATCH 0/2] fix the traced mt-exec deadlock ebiederm@xmission.com (Eric W. Biederman) - 2017-03-04 01:10 +0100
      Re: [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov <oleg@redhat.com> - 2017-03-04 18:10 +0100

csiph-web