Re: WARNING: at mm/mremap.c:211 move_page_tables in i386

[Linus Torvalds]

On Tue, Jul 14, 2020 at 11:12 AM Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> I think you misunderstood me. I was not advocating breaking the stack
> movement code or breaking stack randomization, I was going to try to
> see if I could keep that working while not having to do an overlapping
> move.

I'm not really seeing how you'd do that with a big stack that gets
close to the stack ulimit.

Except by avoiding randomization.

But the existing randomization may be so bad that it doesn't much
matter. And I do think we limit the execve stack to a reasonably small
fraction of the whole ulimit. So worth exploring, I guess.

The current code with "align_stack" doing randomization could also do
with a lot of clarifications. The code is odd.

            Linus