Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754512AbZLIPNQ (ORCPT ); Wed, 9 Dec 2009 10:13:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754053AbZLIPNO (ORCPT ); Wed, 9 Dec 2009 10:13:14 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:43837 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752869AbZLIPNN (ORCPT ); Wed, 9 Dec 2009 10:13:13 -0500 Date: Wed, 9 Dec 2009 07:12:16 -0800 (PST) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Hugh Dickins cc: Al Viro , David Miller , Ollie Wild , Peter Zijlstra , Rik van Riel , viro@ftp.linux.org.uk, linux-arch@vger.kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCHSET] mremap/mmap mess In-Reply-To: Message-ID: References: <20091208060701.GM14381@ZenIV.linux.org.uk> <20091208.130802.25121122.davem@davemloft.net> <20091208220638.GN14381@ZenIV.linux.org.uk> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1157 Lines: 28 On Wed, 9 Dec 2009, Hugh Dickins wrote: > > David: Yes, that's one of my fears too - I don't think > rlimits would pose any new problem, but building up the argv+env below > sp on the execer's userstack would be in danger of colliding with the > vma below if the space allowed to that userstack is too small. For threads, the stack is usually pretty small, so yeah, it would severely limit threads doing execve. That's supposed to be unusual and is frowned upon, but we've spent a fair amount of effort on making sure it works, so I think it would be unacceptable. And I really don't see what the problem with our current approach is. We have a nice source array - the originating VM, and a nice destination array - the resulting VM, and trying to exchange that nice conceptual setup with another setup with _different_ problems that isn't even as clean sounds like a major mistake to me. Linus -- 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/