From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>, Tejun Heo <tj@kernel.org>,
LKP <lkp@01.org>, LKML <linux-kernel@vger.kernel.org>,
kernel test robot <xiaolong.ye@intel.com>
Subject: Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG: unable to handle kernel paging request at ffffc90000997f18)
Date: Mon, 27 Jun 2016 10:28:23 +0200 [thread overview]
Message-ID: <20160627082823.GW30154@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CALCETrVZUJdVNdt3W9_o6EO_BjeO1V8JtQ+aig=zkR5xukeZhg@mail.gmail.com>
On Sun, Jun 26, 2016 at 10:22:32PM -0700, Andy Lutomirski wrote:
> kthread_stop is *sick*.
>
> struct kthread self;
>
> ...
>
> current->vfork_done = &self.exited;
>
> ...
>
> do_exit(ret);
>
> And then some other thread goes and waits for the completion, which is
> *on the stack*, which, in any sane world (e.g. with my series
> applied), is long gone by then.
cute
> Is there seriously no way to directly wait for a struct task_struct to
> exit? Could we, say, kmalloc the completion (or maybe even the whole
> struct kthread)
I suppose the easiest is to merge struct kthread into struct
kthread_create_info, and maybe union some bits if we're really worried
about size.
> and (ick!) hang it off ->vfork_done?
This... cleanup is going to be somewhat icky.
next prev parent reply other threads:[~2016-06-27 8:28 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-27 5:22 Andy Lutomirski
2016-06-27 8:28 ` Peter Zijlstra [this message]
2016-06-27 14:54 ` Oleg Nesterov
2016-06-27 15:44 ` Andy Lutomirski
2016-06-27 17:00 ` Oleg Nesterov
2016-06-28 18:58 ` Oleg Nesterov
2016-06-28 19:12 ` Andy Lutomirski
2016-06-28 20:12 ` Oleg Nesterov
2016-06-28 20:54 ` Andy Lutomirski
2016-06-28 21:14 ` Linus Torvalds
2016-06-28 21:18 ` Linus Torvalds
2016-06-28 21:21 ` Andy Lutomirski
2016-06-28 21:35 ` Linus Torvalds
2016-06-28 21:40 ` Linus Torvalds
2016-06-28 22:47 ` Oleg Nesterov
2016-06-28 22:59 ` Oleg Nesterov
2016-06-29 15:34 ` Andy Lutomirski
2016-06-29 18:03 ` [PATCH] kthread: to_live_kthread() needs try_get_task_stack() Oleg Nesterov
2016-06-29 18:28 ` kbuild test robot
2016-06-29 18:44 ` Oleg Nesterov
2016-06-29 18:51 ` kbuild test robot
2016-06-29 23:01 ` Andy Lutomirski
2016-06-29 23:33 ` kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG: unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski
2016-06-27 17:16 ` Linus Torvalds
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