Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756267Ab0DGVxu (ORCPT ); Wed, 7 Apr 2010 17:53:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1824 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756321Ab0DGVxq (ORCPT ); Wed, 7 Apr 2010 17:53:46 -0400 Message-ID: <4BBCFE8A.1030602@redhat.com> Date: Wed, 07 Apr 2010 17:52:10 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.1 MIME-Version: 1.0 To: Linus Torvalds CC: KOSAKI Motohiro , Borislav Petkov , Andrew Morton , Minchan Kim , Linux Kernel Mailing List , Lee Schermerhorn , Nick Piggin , Andrea Arcangeli , Hugh Dickins , sgunderson@bigfoot.com, hannes@cmpxchg.org Subject: Re: [PATCH -v2] rmap: make anon_vma_prepare link in all the anon_vmas of a mergeable VMA References: <20100406195459.554265e7@annuminas.surriel.com> <20100407151357.FB7E.A69D9226@jp.fujitsu.com> <20100407105454.2e7ab9bf@annuminas.surriel.com> <4BBCAA5B.7080603@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 966 Lines: 27 On 04/07/2010 05:19 PM, Linus Torvalds wrote: > Comments? I remember there being an "unfixable" spot with this approach when I originally wrote the new anon_vma linking code. However, I can't for the life of me find that spot. I am starting to believe I made it fixable as a side effect of one of the changes I made :) One of the issues with your patch is that anon_vma_prepare can fail and this patch ignores its return value. Having anon_vma-prepare fail after an mremap or mprotect might result in messing up the VMAs of a process, or having to undo the VMA changes that were made. In fact, this may be the problem I was running into - not wanting to add even more complex error paths to the vma shuffling code. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/