Re: [patch] mm: mlock: document scary-looking stack expansion mlock chain

From: Michel Lespinasse
Date: Wed Feb 20 2013 - 09:24:11 EST

On Fri, Feb 1, 2013 at 2:10 PM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> The fact that mlock calls get_user_pages, and get_user_pages might
> call mlock when expanding a stack looks like a potential recursion.
> However, mlock makes sure the requested range is already contained
> within a vma, so no stack expansion will actually happen from mlock.
> Should this ever change: the stack expansion mlocks only the newly
> expanded range and so will not result in recursive expansion.
> Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Acked-by: Michel Lespinasse <walken@xxxxxxxxxx>

Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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