Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758205AbXKLIqS (ORCPT ); Mon, 12 Nov 2007 03:46:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755599AbXKLIp7 (ORCPT ); Mon, 12 Nov 2007 03:45:59 -0500 Received: from mtagate3.de.ibm.com ([195.212.29.152]:43184 "EHLO mtagate3.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754886AbXKLIp6 (ORCPT ); Mon, 12 Nov 2007 03:45:58 -0500 Subject: Re: dio_get_page() lockdep complaints From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Peter Zijlstra Cc: Trond Myklebust , Zach Brown , Jens Axboe , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-aio@kvack.org, Chris Mason , linux-mm , Hugh Dickins , Linus Torvalds In-Reply-To: <1194810546.6098.6.camel@lappy> References: <20070419073828.GB20928@kernel.dk> <1194627742.6289.175.camel@twins> <4734992C.7000408@oracle.com> <1194630300.7459.65.camel@heimdal.trondhjem.org> <1194810546.6098.6.camel@lappy> Content-Type: text/plain Organization: IBM Corporation Date: Mon, 12 Nov 2007 09:45:52 +0100 Message-Id: <1194857152.972.5.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 868 Lines: 23 On Sun, 2007-11-11 at 20:49 +0100, Peter Zijlstra wrote: > Right, which gets us into all kinds of trouble because some sites need > mmap_sem to resolve some races, notably s390 31-bit and shm. You are refering to the mmap_sem use in compat_linux.c:do_mmap2, aren't you? That check for adresses > 2GB after the call to do_mmap_pgoff can be removed since arch_get_unmapped_area already checks against TASK_SIZE. The result of the do_mmap_pgoff call will never be out of range. This check is a left-over from the early days of the s390 compat code. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. - 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/