Re: [PATCH v3 00/13] Virtually mapped stacks with guard pages (x86, core)

Andy Lutomirski
2016-06-24T21:35:20Z

On Fri, Jun 24, 2016 at 2:32 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Fri, Jun 24, 2016 at 2:25 PM, Andy Lutomirski <luto@amacapital.net> wrote:
>>
>> What's the prognosis for this patch? Should I queue up all the pieces
>> and send them out after the vmap-stack thing?
>
> I'm going to split this thing up and apply the "semantically null"
> cleanup parts.
>
> For example, this patch makes it clear that our current
> "alloc_thread_info_node()" this is entirely insane.
>
> We literally do:
>
> ti = alloc_thread_info_node(tsk, node);
> ...
> tsk->stack = ti;
>
> and
>
> arch_release_thread_info(tsk->stack);
> free_thread_info(tsk->stack);
>
> and the pure *confusion* there is just crazy. We're talking
> "tsk->stack", but then we talk about freeing and allocating
> "thread_info"
>
> So I'll apply the whole "rename 'free_thread_info()' into
> 'free_thread_stack()'" part independently of anything else. It will
> not change any semantics at all, since we currently have "tsk->stack
> == thread_info", but it's too ugly to live, and it will then make the
> patches that *do* change semantics much clearer and easier to see.
>
> So let me get the pure semantic patches done, and then for 4.8 when we
> do the things that actually change real meaning we'll have a sane
> base. Ok?
>

Works for me. I'll see whether my vmap patches still apply and, if
needed, rebase and send a v5.

--Andy