Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760260AbYFQWWH (ORCPT ); Tue, 17 Jun 2008 18:22:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759588AbYFQWVx (ORCPT ); Tue, 17 Jun 2008 18:21:53 -0400 Received: from one.firstfloor.org ([213.235.205.2]:34480 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758002AbYFQWVw (ORCPT ); Tue, 17 Jun 2008 18:21:52 -0400 Message-ID: <485838F9.8010001@firstfloor.org> Date: Wed, 18 Jun 2008 00:21:45 +0200 From: Andi Kleen User-Agent: Thunderbird 1.5.0.12 (X11/20060911) MIME-Version: 1.0 To: Al Viro CC: Linus Torvalds , Bron Gondwana , Linux Kernel Mailing List , Nick Piggin , Andrew Morton , Rob Mueller , Ingo Molnar Subject: Re: BUG: mmapfile/writev spurious zero bytes (x86_64/not i386, bisected, reproducable) References: <1213682570.13708.1258839317@webmail.messagingengine.com> <485829A1.4020705@firstfloor.org> <20080617213618.GL28946@ZenIV.linux.org.uk> <48582FAB.1020402@firstfloor.org> <20080617221118.GM28946@ZenIV.linux.org.uk> In-Reply-To: <20080617221118.GM28946@ZenIV.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 907 Lines: 21 > AFAICS, what happened is that b0rken copy_*FROM*_user() had been discussed > with references to copy_*TO*_user(). With proposed patch indeed not affecting > any legitimate calls of the latter. Does affect the former and that, from > my reading of the code in question, correctly. > > IOW, s/copy_to_user/copy_from_user/ in Linus' postings upthread and they > make sense. Yes, it makes some more sense, but I'm not completely happy with the fix because it makes the fault point reporting very unreliable (maximum error will be 63 instead of 7 now). iirc especially mount was sensitive to that. Unfortunately fixing the accuracy is a little tricky. -Andi -- 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/