Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1431806

Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG: unable to handle kernel paging request at ffffc90000997f18)

Show all headers | View raw

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.

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

Thread

kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG: unable to  handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@kernel.org> - 2016-06-27 07:30 +0200
  Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Peter Zijlstra <peterz@infradead.org> - 2016-06-27 10:30 +0200
  Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Oleg Nesterov <oleg@redhat.com> - 2016-06-27 17:00 +0200
    Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@amacapital.net> - 2016-06-27 17:50 +0200
      Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Oleg Nesterov <oleg@redhat.com> - 2016-06-27 19:00 +0200
        Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Oleg Nesterov <oleg@redhat.com> - 2016-06-28 21:00 +0200
          Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@amacapital.net> - 2016-06-28 21:20 +0200
            Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Oleg Nesterov <oleg@redhat.com> - 2016-06-28 22:20 +0200
              Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@amacapital.net> - 2016-06-28 23:00 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Linus Torvalds <torvalds@linux-foundation.org> - 2016-06-28 23:20 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Linus Torvalds <torvalds@linux-foundation.org> - 2016-06-28 23:20 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@amacapital.net> - 2016-06-28 23:30 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Linus Torvalds <torvalds@linux-foundation.org> - 2016-06-28 23:40 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Linus Torvalds <torvalds@linux-foundation.org> - 2016-06-28 23:50 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Oleg Nesterov <oleg@redhat.com> - 2016-06-29 01:00 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Oleg Nesterov <oleg@redhat.com> - 2016-06-29 01:10 +0200
                Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@amacapital.net> - 2016-06-29 17:40 +0200
                [PATCH] kthread: to_live_kthread() needs try_get_task_stack() Oleg Nesterov <oleg@redhat.com> - 2016-06-29 20:10 +0200
                Re: [PATCH] kthread: to_live_kthread() needs try_get_task_stack() kbuild test robot <lkp@intel.com> - 2016-06-29 20:40 +0200
                Re: [PATCH] kthread: to_live_kthread() needs try_get_task_stack() Oleg Nesterov <oleg@redhat.com> - 2016-06-29 20:50 +0200
                Re: [PATCH] kthread: to_live_kthread() needs try_get_task_stack() kbuild test robot <lkp@intel.com> - 2016-06-29 21:00 +0200
                Re: [PATCH] kthread: to_live_kthread() needs try_get_task_stack() Andy Lutomirski <luto@amacapital.net> - 2016-06-30 01:10 +0200
          Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Andy Lutomirski <luto@amacapital.net> - 2016-06-30 01:40 +0200
  Re: kthread_stop insanity (Re: [[DEBUG] force] 2642458962: BUG:  unable to handle kernel paging request at ffffc90000997f18) Linus Torvalds <torvalds@linux-foundation.org> - 2016-06-27 19:20 +0200

csiph-web