From: Michel Lespinasse <walken@google.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Hugh Dickins <hughd@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [patch] mm: mlock: document scary-looking stack expansion mlock chain
Date: Wed, 20 Feb 2013 22:24:02 +0800 [thread overview]
Message-ID: <CANN689Hwp-fm-SUzAXAqLKGkGHxjw2X+pkQRr01=Fjq=BaSoDQ@mail.gmail.com> (raw)
In-Reply-To: <1359699013-7160-1-git-send-email-hannes@cmpxchg.org>
On Fri, Feb 1, 2013 at 2:10 PM, Johannes Weiner <hannes@cmpxchg.org> 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@ZenIV.linux.org.uk>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michel Lespinasse <walken@google.com>
--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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prev parent reply other threads:[~2013-02-20 14:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-01 6:10 Johannes Weiner
2013-02-20 12:51 ` Ric Mason
2013-02-20 14:22 ` Michel Lespinasse
2013-02-20 14:24 ` Michel Lespinasse [this message]
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