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

From: Linus Torvalds
Date: Tue Jun 28 2016 - 17:14:51 EST


On Tue, Jun 28, 2016 at 1:54 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
> But I might need to that anyway for procfs to read the the stack,
> right? Do you see another way to handle that case?

I think the other way to handle the kernel stack reading would be to
simply make the stack freeing be RCU-delayed, and use the RCU list
itself as the stack cache.

That way reading the stack is ok in a RCU context, although you might
end up reading a stack that has been re-used.

Would that work for people?

Linus