From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754183AbcBBJVj (ORCPT ); Tue, 2 Feb 2016 04:21:39 -0500 Received: from mail-wm0-f44.google.com ([74.125.82.44]:34506 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753861AbcBBJVh (ORCPT ); Tue, 2 Feb 2016 04:21:37 -0500 Date: Tue, 2 Feb 2016 11:21:33 +0200 From: "Kirill A. Shutemov" To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Andrew Morton , Andrea Arcangeli , linux-kernel@vger.kernel.org, Dmitry Vyukov , Oleg Nesterov Subject: Re: [PATCH] mm: replace vma_lock_anon_vma with anon_vma_lock_read/write Message-ID: <20160202092133.GA817@node.shutemov.name> References: <145440421918.17103.16454803336779455616.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <145440421918.17103.16454803336779455616.stgit@zurg> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 02, 2016 at 12:10:19PM +0300, Konstantin Khlebnikov wrote: > Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if > anon_vma appeared between lock and unlock. We have to check anon_vma > first or call anon_vma_prepare() to be sure that it's here. There are > only few users of these legacy helpers. Let's get rid of them. > > This patch fixes anon_vma lock imbalance in validate_mm(). > Write lock isn't required here, read lock is enough. > > And reorders expand_downwards/expand_upwards: security_mmap_addr() and > wrapping-around check don't have to be under anon vma lock. > > Signed-off-by: Konstantin Khlebnikov > Reported-by: Dmitry Vyukov > Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.com Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov